Only once: it was a MERV 13 filter and I installed just at the beginning of winter. It did filter the air more effectively, but it wasn't worth the cost of the filter or the higher gas bill.
Your gas bill will not be higher if you install an air filter. Electricity use might be if it gets very plugged. Even If you don’t mind dust and pet hair or dander, you at least need a filter to keep your AC A-frame heat exchanger clean. If you do not keep it clean, your AC will run constantly and it’s very expensive to get them cleaned. I’ve seen AC A-frames they have so much lint and pet hair on their surfaces that no air at all was going through. It looked like grey fabric was on the surface. The homeowner forgot to replace the filter for a year.
I built a corsi rosenthal box with a $20 walmart box fan and 4 MERV 13 filters I had laying around. Yeah people talk about how HEPA is so much more efficient, but when my system is moving like 10x more air through its filters it doesnt matter if mine is filtering out 60% vs 99% of particles, mine will filter the air faster and better regardless through pure volume. You need to spend like $800 for a HEPA system that can actually compete with a Corsi box at a fraction of the cost.
@@Inbal_Feuchtwanger yeah but it literally does not matter how much air it's moving if MERV 13 isn't high enough to get some of the most harmful stuff out of the air. MERV 16 with that solution would be even better because less of the smaller stuff gets kicked back up and continually recirculated as is currently happening with yours.
@@thomasolson8417 Im not sure what your comment is implying. MERV 13 gets the most harmful stuff out of the air. During wildfire season it does wonders, its also great for allergens and cat dander. Being able to remove the particles quicker means you will be breathing less of them, it doesnt matter if it needs to circulate the same air. If you come home from work and the room youre in measures 300PPM from wildfire smoke, being able to reduce it down to 50PPM in 30 minutes rather than it taking 4hrs to do the same is whats important. There are actually a good deal of research on this and you can them recommended straight from the EPA.
When our HVAC guy did our house he sized the system for 20”x25”x5” MERV 11. Our house doesn’t get dusty and it has helped with mild seasonal allergies. We also installed an air sanitizing UV system. No regrets.
My AC Contractor who installed a new TRANE Furnace and AC system in our house suggested no higher than MERV 9 for the filters. If you watch other Air conditioning vidoes, they point out if the MERV is too high, blocking the intended air flow form the Blower, you can create harmful Air Pressure which can damage your unit and shortedn the life.
@@Chiroman527 I change filters in a ton of houses, and tell the home owners to get the Merv 3-5 and change them every 30 days. No need to buy any expensive filters, since in reality, they all work the same. You'd be surprised at how many systems are actually ruined because they use the high end, high Merve rating filters. Not to mention that the reduced air flow allows the condensation to build up on the interior of the ducts, which attracts/holds the dust particles/debris to the walls and actually makes the air quality get worse, faster than just using a lower costing, medium Merv level filter and changing it every 30 days.
Working HVAC I replaced a filter that was so plugged it almost was sucked into the return air vent. I could hear it whistling upon entering the front door. I pulled it then checked the system to verify it was the only filter. Told the homeowner that it was the filter and I could find nothing else wrong. It was less than a month and I had the same call, same problem. Had to explain that when a filter was plugged no matter the time in place it needed to be replaced. They had just moved in. I think it was the sprinkle carpet deodorant that was popular at the time that put a lot of powder in the air when vacuumed. I think it was a heat pump unit.
When we had our new furnace installed, the HVAC contractor put in a 2 inch filter holder, and increased the furnace intake area. Made a big difference in home comfort and the furnace handles a MERV 8 no problem.
I would argue that HVAC designers need to stop designing return air ducts and grilles to the minimum size for a given airflow. A modest increase in duct and grille size would allow enough airflow with a premium filter to avoid this issue. When I did my own system many years ago, the pro I brought in to charge the A/C was impressed and pointed out the oversized return. I told him I did it on purpose to allow for better filters. The total extra cost of the oversized grille and short duct run? Around $50.
Static pressure is a big player in HVAC design. Im not an expert in ductwork or static pressure but i do know that tampering with it can cause problems with its ability to cool and heat. Plus, bigger coils have show a significant issue with dehumidification as well as short cycling. Another big thing you need to know. While hvac companies have people who design the ductwork, often times the BUILDER has the final say. Alot of bad filter slots and designs are attributed to the builder saying what happens at the end
told that same duct size goes in and out or bigger return . like 12" round in and 12" round out. something 'about energy efficiency return too small a system must work harder. that's why they have damper in return airi it re-approve by the engineer
The issue is not just the return system, the issue is that the entire system is designed for a desired flow rate. If you reduce the flow through the system beyond design parameters, you will alter cycle times which can negatively affect both heating and cooling. Yes, it would be nice if the manufacturers of the equipment and the designers of the overall duct systems would base their designs on a better filter. Until they do, I strongly suggest you don't exceed a MERV 11 filter. If you want the air in your rooms to be cleaner than what a MERV 11 can do, get a properly sized whole house electrostatic air cleaner added to your system.
My local HVAC company educates customers just as you have in this video. I've been using the 3M Dust Reduction Level 300. MERV rating not on package as you stated. It is located on the filter itself. Back side on the bottom reads MERV level 5. Thanks for all you do for us!
I had the furnace and the AC serviced last year and I asked about the filters I should use. The answer was to avoid both the cheapest filters and anything higher than MERV 8. So, pretty much in line with what you're recommending.
@@Slick1020 out of curiosity, who are you asking that question of? I don’t know, as you cannot tell from YT’s comment system. Do you actually think the average home HVAC system was designed by an degreed engineer? The one in my home, was field installed and like most custom homes was a one-off job following general rules of thumb. They follow the Furnace and AC manufacturers guidelines, if they even took the time to read them. And as a professional degreed engineer myself that talks to many engineers a day, I don’t offer recommendations outside my field of disciplinary expertise.
@davidsamsonite5791 you are saying things I did not say, taking things out of context, and twisting what was said and clearly meant. I’m not going to get into a big back and forth with you on my intent and what I actually said when it’s very clear and what you are saying is not what I said or a twisted version of it.
Filtrete filters are electrostatically charged depth filters. Unlike a conventional pleated filter that catches particulate on the surface and blocks air flow paths, the Filtrete is a woven web of charged material that grabs particulate. Air continues to move through a low pressure path through the depth of the filter material. That's why it can catch more particulate and still retain an acceptable pressure drop. I've worked with 3M on these in the past in commercial air handlers with continuous pressure drop monitoring. They cost more, but they catch more particulate and last longer.
23 years doing HVAC installer, tin knocker, service tech, service manager, and instructor working in residential, light commercial, and commercial work. I pretty much agree with this whole video. The only thing that makes it hard to say this is the filter that you should go with or not because everybody’s duct system is different, and also depending on equipment, registers, and zoning it makes it really difficult just to say this is what you need to go with and you’ll be good. So my recommendation is if someone only had a 1” filter slot they could get a couple different filters and have a reputable company come out and check total static pressure while changing of each and then make your determination after you actually measure instead of guess. It is always better to have a media cabinet 4”+ filter you will be able to have much more surface area and be able to have a higher efficiency filter at a lower total static pressure. FYI MERV 16 is equivalent HEPA efficiency. Hope this helps!
@@kirkdarling4120 I was just referring to more the 1” filter more so due to that’s what the video was referring, I just threw in my two cents about the 4” filter.
@@jonesjones7057 that’s what I was thinking that too especially today’s blower motors that are mostly constant torque or ECM. And most of your indoor coil have TXV and outdoor coils are big enough to hold a good bit of liquid takes a lot of things going wrong to get liquid back to compressors these days. And even if that happens scroll compressors will float the scroll and not try to compress liquid.
We had to call the pro because our central heater was stopping before the set temperature. He recommended us to use a thinner filter than what we were using. Thank you for sharing this info with the community.
Mine too! He told me max Merv rating of 8 and change every 30days. I change it every time I write the monthly check to the electric company…makes it easy to remember
never had a problem with my systems and as an asthmatic wholeheartedly will say there is nothing better than a high end 3M to ease your breathing and deal with allergens. Happy user since the mid 80’s. 1500 minimum, which captures cooking odors and smoke as well. if you want to keep the large particles from clogging the better filters, sandwich one of their basic (blue mesh washable) filters ahead of it to catch those and change that one out or wash it when you see it load up, the carpet of dust that forms is what helps reduce service life of the better filter.
My daughter has really bad allergies, and is an asthmatic. I’ve used good quality filters for years and it has helped her out a lot. We also have standalone HEPA filters in the bedrooms. Without all of this, we end up making several trips to the emergency room every year. I will take the chance of wearing out parts on my HVAC system as a side effect of keeping my daughter healthy.
I'm an Engineer with extensive filtering experience in industry. I totally disagree with you. I have bern running the 3M Filtrete filters for several years, with zero problems. I live in Phoenix, and the air here is totally polluted. These filters work great for removing all types of contaminates. I also add a carbon filter on top of the filtrete filter. The AC moves air with a fan, so these filters aren't going to affect the compressor, which is the main power consumer. The fan can handle a bit of airflow restriction. Like I said I have not had any problems witj my AC, and its hotter than hell here in Phoenix. You should see all the crap these filters pull out of the air. I also run HEPA air filters in our bedrooms, but they can't process the amount of air, that an AC can process.
I use a MERV13 Filtrete as well, which keeps the equipment exceptionally clean). This greatly prolongs the lifespan of all equipment in the house (AC, heat pump, refrigerator coils much cl eaner, computers, etc). I us 3 small HEPAs as well. My House is like a micrchip manufacruing facility ! lol...Micropartcles will coat surfaces over time and degrade equipment. Air is much healthier as well.
I’ll stick to my MERV 17 air purifier 3800sf right next to my AC air intake vent and stick a MERV 1 in the AC unit. Cools the house down faster without restriction and I’ve never had better air quality before. I sleep like a king now, air is so pure I literally forgot I was breathing.
Well there it is folks, the typical "I'm an engineer" and know better than everyone else. I'm an hvac tech for 25 years and can tell you for a fact that heavier filters will damage your equipment. Merv 8 at the most you want to go. Remember ppl, your hvac system is not an air purifier. They make equipment for that as well.
Have you or any of your readers noticed that lately (some) filter manufacturers are making their filters ¼ inch smaller than the posted size on the wrapper? This is causing extra air noise inside the house coming from the filter cage in the ceiling. What is causing this because I do not agree with selling us consumers short. The the way - great video and I absolutely love your channel as you have helped me maintain my home much better and have saved me considerable money.
I noticed that about the Home Depot HDX filters - instead of 1 inch thick filters, they give you a 0.8" thick filter. Multiply 0.2" x 2 x the number of pleats is much much material they saved. So now I just stick with Filtrete and buy them in bulk whenever they're on sale.
I’ve ran 4” thick MERV11 filters in my system for years with zero issues. I change them every 60 days even though they’re completely clean (what human eyes can see anyway). Yes, the air is dry and cold in my house but my German Shepherd greatly appreciates it.
From what I've seen, particulate filters for air "expire" by getting clogged, not by leaking. Use them until air stops moving through them quickly enough, they should actually clean the air that does go through at end of service life better than when they were new. Charcoal filters start leaking mostly high vapor pressure substances (and with mixtures this can actually result in the filter's output air having a higher concentration of one chemical than the inpur), experience migration when in storage, are difficult to check the saturation of without knowing what's in them or doing $100+ tests, and otherwise have issues that make conservative replacement common when it's really important.
Consider getting a manometer, it's just a differential pressure guage with tubes, sensitive enough to measure the pressure drop across a filter. They sell them as portable units and parts you can install on your system. When the pressure drop gets too high (depends on your system, ask an HVAC tech) the filter needs to be replaced.
@@reddragonflyxx657This is the only way to know when a filter really needs to be changed. I don’t know why makers don’t do it from the factory. Time based is just guessing. Although I look at mine to see how dirty it is. I was thinking about installing a gauge on my air handler. There are a couple ways of doing it. Problem that I would have is knowing what reading I would use to know when the filter needs to be changed.
I've been tech for 31 years. My home built 2008. I installed merv 8 in my two systems. My evap coils had to be replaced from coils leaking refrigerant after 7 years on one and 14 years with the other. Both coils were spotless and drain pans had no sludge. What this means. No air restrictions and optimum performance. The original merv 1 filters are nothing. If you can sprinkle salt through it. It's nat a filter. I have proven it with my own home. Trust me. I can tell you to never buy expensive washable filters. It is job security for techs when they freeze your unit up in the summer. Merv 8 is the perfect filter. Also. I have my fan selections to on not auto. This means I filter my home 24 hours a day 365 days a year. My blower motors have run since 2008 non stop. I hope I helped anyone who read this.
I ran Filtrete 1500 on my 20-year-old furnace, in a 2500 sq ft house, for 12 years and never had a problem. I did have to replace the blower motor once, a temperature sensor, and an exhaust fan motor. But it is a very old furnace. We replaced the filter every 3 to 6 months and kept the fan on continuous.
My AC guys (I’ve been using for 23 years) told me max merv rating of 8…no higher because it’s too much stress on my system. They’ve never steered me wrong yet. Thank you for saving us money AND our systems with your valuable info! *I change mine every 30days - the day I write the check to the electric company. Easy to remember that way. Thanks again! ♥
@@Soljarag5 Yes…every 30 days…makes it very easy to remember to change the filter: write the check to electric company - change the filter. Understand, I live in Florida…my AC runs nearly 24/7. During the winter months the filter isn’t in terrible shape, but I still change it. But in May thru October it gets filthy because it’s running nonstop. I buy a case of the filters at Home Depot - cheaper that way and my AC is happy for the clean filter 😃
Good point to not rely on the HVAC to clean your air. I buy the filter that the project farm guy recommends. His testing showed the higher pleat count didn’t restrict airflow as much as the low pleat count did, which is what we’re trying to avoid here.
One more thought about "higher pleat count is better": I think that comparison refers to filters that have the same (or similar) MERV rating. The same MERV rating can be achieved with fewer pleats (less surface area) but that requires greater thickness and/or greater density. Less surface area is more restrictive against flow, and so are greater thickness and/or greater density, so fewer pleats is a loser in two ways when comparing filters with the same MERV rating. If you're comparing filters with different MERV ratings, the effect on air flow of the thickness & density of the filter material may be more significant than the pleat count. For example, the MERV=1 filter shown in the video has zero pleats, yet it has better air flow than high-MERV pleated filters because its filter material is thinner and less dense. The effect of _deeper_ pleats ought to be like having _more_ pleats, because that too would increase total surface area. But there's a practical limit on depth since the filter must fit in a narrow slot in the HVAC intake duct. (The narrowness of the slot is also what limits the thickness of the filter, of course.) A DIYer who isn't concerned with aesthetics might consider constructing a large filter-holding frame at the inlet of the HVAC's return air duct, and either leave the original slot empty or put a MERV=1 filter in the original slot. The custom frame could be very large so a filter with much more surface area (and thickness) could be used. An array of high-MERV filters, taped together side-by-side, would have a huge total surface area to maximize air flow. A large filter (or a large array of filters) will also last longer than a smaller filter because the captured particles would be distributed over its larger surface & larger volume. A clever DIYer could also add a one-way "valve" -- a gate on a hinge -- to the frame, which opens only when the HVAC fan is moving air, to eliminate backdraft. (Gravity could close the gate. If the gate is lightweight and the hinge has little friction, the HVAC suction would be stronger than the effect of gravity and would open the gate.) The anti-backdraft valve would help when the HVAC unit is located outside or in an unconditioned room/closet, and the unconditioned air around the intake duct makes the duct cold in winter or hot in summer. (Wrapping the duct with thermal insulation is a good idea too.)
@@brothermine2292 that is partially true. It is correct, the same material, same pleat counts but higher MERV would create more restriction, but project farm showed that higher pleats with higher MERV can reduce air flow. Possible due to changes in materials, maybe the fuzziness 3M has to their higher end filters.
I understand the concern about a filter restricting the flow. But the filtering efficiency is not the only factor to consider when trying to determine how much the airflow is restricted. It also depends on the material, how thick the filter is, how large the filter is, and the amount of area created by folding. First there needs to be some measurements taken of the airflow restriction caused by these filters. Second, we need some determination of how airflow restriction affects the unit's efficiency and reduces it's life span. The problem is more complex than just picking a MERV number.
If you make the intake oversized, it should compensate a bit for the restricted air flow. I don't know anything about the industry, but I would imagine that modern HVAC systems would take into account that people want them to double as air filters and know they're going to use these restrictive clean room filters. Unless early failure and selling more units is what they're hoping for. There's a sweet spot between more sales and poor reputation there.
I only use Camfil/Farr aeroplete filters.They are the best,no question! Been an HVAC tech for 30 years,and I have used them all and there is no comparison,Merv 8!
Didn't scroll through all the comments but every quality filter should have its airflow ratings printed on it or the packaging somewhere. Your HVAC system has ratings that it was designed for. You should be able to match them up. Issues arise when the entire system (furnace, AC, ducts & filter) is not in harmony. Our old house was an example of this. Not enough intake air in original ducts and the AC was running too a high a fan speed that made for short runs and the humidity remained high. This also stressed the filter. Corrected these issues and was able to maintain correct air flow with MERV 11 filter. It is always a sum of all the parts in play.
That is exactly what I've learned and discussed with one of our local HVAC companies. New(er) systems can handle the higher-rated MERV filters just fine. Putting a MERV 13 on an old furnace/system might seem helpful, but it would likely be doing more harm than good.
@@Dbb27 They are in the paperwork that comes with your system. In the homes I have lived in, it was in a envelope attached to the furnace. The units have ranges that are dependent on the duct work, etc.
I watched another video "Furnace filter-which furnace filter is best". The tested a wide range of filters using a manometer. He found that the 3M filters were quite impressive for the low pressure drop across the filter. We have been getting a lot of fire smoke here in Alberta. I installed a thicker filter box to use 25X20X5 filters. I installed a Merv 11 and use it with 2 Honeywell extra large room Hepa Air Purifiers with good results. Keep in mind that a lot of house hold dust will settle out before it makes it into your return air to be filtered so don't think you can throw away your Swiffer any time soon!
What does he say at the end of the video though? That one controlled test he did is not the gospel truth. Which is why I believe he says what he does at the end of his video. Also I have nothing against Filtrete fillers. They are some of the most popular for a reason. My issue is the MERV rating regardless of brand.
Now have them do one when the filters have been in the unit a week. Because they catch more things, they fill quicker and efficiency is not going to be nearly as good. I will trust the guys that have all told me the same thing that work on and replace parts on numerous acs due to the higher efficiency filters.
@@HowToHomeDIYProject Farm also did a video on this I believe. While what you’re saying used to be true of higher MERV filters, I’ve yet to see any tests that actually show this to be true with the modern Filtrete filters. All tests I’ve seen show better airflow even when clogged with fine particles. My understanding is that the idea that higher MERV ratings reduce airflow is a common myth that feels logical but isn’t true due to the complexities of airflow.
i think the high number of pleats on the Filtrete 1500 and up increase the surface area substantially to make up for the restriction they would otherwise have. In most cases the Filtrete 1900 filters flow more than many Merv 8 filters from other brands. I don't believe the Filtrete filters suffer from restrictive flow issues. However, they do clog up faster and should be replaced every 30 days. On the other hand, there are other companies that make Merv 10 through 13 filters that DO NOT increase the pleat count, and thus are terrible for the air handler from the beginning.... Filterete is the only company I know of that increases the pleats on their 1 inch thick filters.
At work, our units have to circulate a lot of air and the pleats are four inches deep. The air filters are sort of intimidating to look at. One thing I notice is that all the good air filters have metal mesh to resist filter collapse from overpressure if it gets clogged up from not being changed often enough.
My HVAC tech designed the intake for MERV 14, and that's what they provided and said I could use, but the intake is a huge. 20x30 for a 1300 sqft home. It didn't really add significant cost to the system, and I appreciate the ability to clean the air a bit better.
My father had a excellent solution. Instead of putting the filter at the HVAC unit, he put smaller filters at all the intake points. More filters equals greater filter surface area, and the ductwork is kept clean since the air is filtered before it enters the ducts. He did this when he built their house back in 1986.
Uhm, the filter goes at the beginning of the system, before the ducts. Adding more filters will slow down the air flow, reducing the efficiency and longevity of the HVAC system, not to mention allow more debris to contact and collect on the inside of the duct walls.
I custom built a pre-filter box for my whole house air filtration system. The box has a series of six slots with six inches between each slot and twelve inches between the opening and first slot as well as the sixth slot and the exhaust which goes into the actual system for a total of ~65". I also use a UVC lights at the beginning and end. I use 24x24" filters in the following order: Electrostatic metal washable MPR (MERV) 300 (5) MPR (MERV) 600 (7) MPR (MERV) 800 (10) MPR (MERV) 1200 (11) carbon MPR (MERV) 1500 (12) System filter: MPR (MERV) 1900 (13) I clean the metal electrostatic weekly or better. The rest get replaced 1-12 months. My system has an airflow monitor and has only gone off twice after wildfires. Note that it cost me about $75 to make the pre-filter box and has saved me dozens of times more in expensive filter costs and maintenance as the system and downflow ducts remain very clean. Yes, I did go overboard but enjoyed the process and final results.
You and my youngest son think alike. He redesigned his HVAC system and runs a schedule for spring allergies and autumn dust. He also added an ion machine to precipitate dust.
Man, that's a lot of money and impo, a lot of wasted money. I'm not dogging you, but hear me out. Even the A/C companies say that, unless you have an extreme allergy or a serious medical issue, you don't need a lot of "high tech" filters or systems in the HVAC system, and to literally use the lowest costing paper filter 3 to 5 Merv Rating and change them out every 30 days. They recommend this for the exact reasons that were stated in the video. Once they are dirty, they restrict air flow and cause excessive strain on the equipment, not only with the blower motor, but also in the condenser side. This also slows down the amount of air that is passing through the ducts which allows more condensation to build up on the interior walls, which then attracts/holds more debris which then will build up on the inside of the ducts, creating a bad situation. As a GC as well as a RE Investor, I have seen a lot of units that need to be replaced way too soon due to these issues that can easily be remedied by using a simple filter and changing it every 30 days.
@@jmackinjersey1 I don't consider 75 US dollars a lot of money, and it definitely isn't wasted. My allergies were minor but are near non-existent now as I am allergic to indoor mold/mildew. Also, considering that most indoor dust is exfoliated human skin cells and I have nothing noticeable in my home, I consider it money well spent. My outer box uses filters bigger than the unit requires and the unit has an airflow monitor which is always in the green, never yellow or red. It passed inspection by the government, and several exerts in the field all liked it including an instructor liked it. Again, money well spent.
Just got new AC, used FPR 10 for my first filter=Merv 13. 2 weeks later the Air Handler starts squealing and squeaking when running full speed. Just figured out it was the AC filter clogged with cat hair and dust and the filter even bent letting air around it. Point is there is a sweet spot between rock stoppers and those very restrictive filters. Merv 8 or less is ideal. or FPR 4-5
@@MundiTaurus How can I be offended when I don't even know what you are talking about? Learn proper grammar and English and try again. Nobody is dictating what you need to do on here guy. You do you.
@@NoNORADon911 LOL! Hilarious. Specifically point out my improper, "grammar and English". You're projecting. Learn comprehension. Show one place I even implied you were or would be offended. I said: "No insult intended...". That means exactly what it says, I was not even implying or trying to insult you. Where did I even imply that you are dictating what I need do _"on here"?_ Write clearly. "Merv 8 or less is ideal. or FPR 4-5" For who? Everyone? Again: "...you cannot tell everyone what is idea. You can only dictate that for your own home/system." FYI: YT is not a university English final essay! LOL! Get over yourself.
a very timely video! I live in New Mexico. In the desert! it doesn't matter what filter i buy i can't seem to knock the dust down that gets in the house. This has pointed me in a better direction!
@@biz4twobiz463 i ordered some merv 8 last week after seeing your video. they are all cheap enough that i can try different ones. the ones i had been buying were merv 13 and i did notice that when changing them every month they were so full of dust and lint that it would be surprising it the heat-a/c unit was breathing at all.
During wilfire smoke season, my family runs a box fan pulling air through one of those 20"x25" HVAC filters to clean our indoor air. It works great, since you can run the fan 24/7. The same box fan has been working for years. We also have an air purifier similar to the one from your links, I like having the air quality display.
Have you experimented on dirty air days to see how much sooner the air is clean as indicated by your unit with the display? That is, on a dirty air day, after allowing dirty air to enter the residence, for Test #1, run just the clean air unit and see how long it takes for the display to show a certain "clean air" level has been reached. For Test #2, run both the clean air unit AND the box fan plus its MERV 12 to 14 filter and see how long it takes for the display to show the same "clean air" level as in Test #1. For Test #3, you'd run the MERV 12 to 14 filter with the box fan by itself. Every now and then you'd turn on the unit with the display indicator to measure the "clean air" level. When the same "clean air" level has been reached of Test #1, then you can get an idea of how effective box fan plus filter works based upon the time difference.
@@animejanai4657 that sounds like a good way to quantify the exact difference. When the air was smoky outside, I was less interested in precise measurements and more interested in getting the indoor air as clean as I could get it. The box fan got turned on and left on. I may try to do some testing like you've mentioned the next time the air is smoky.
Project Farm basically showed that MERV 11 was the beginning of the quality filtering of the tiny particles. The MERV 8 was basically for dust particles and large floating things and let a lot of the small particles through. As for when to swap out your central air filter, it depends on how dirty your household air is. If it is full of greasy air and tiny dust, then you'll need to swap filters out. I run both HEPA and MERV14 air purifiers inside the house, so the central air filter lasts much longer as the amount of dust and pollen in the air is already greatly reduced. I have quality exterior exhaust for the kitchen air plus I never deep fry, so I don't particularly have greasy air mixed with dust that clogs up the central air filter.
@@animejanai4657 yes, airborne grease kills filters very fast. If you have a gas stove and do not have a powerful exhaust hood, you will find sticky oily crap collects on every surface within 3 meters. Exhaust hoods should go directly outside and should have a washable metal filter in them.
My AC guy installed an Aprilaire media filter on my system -- its a MERV13 but designed for a much longer life due to how much area it uses to filter. They run about $50 a filter, but only need to be changed annually.
I too once installed a higher rating filter which was restricting air flow, and when the unit shut-off, I was able to hear the metal pop as it deflated. I now use an FPR #5 rating, works well and there is no decompression sound after it shuts-off.
I've been using these filters for years. I write the "Change On" date on the filter which usually coincides when my Nest says "Time to replace your filter". I recommended this filter to a friend for her allergies, she can now sleep at night. Just make sure you change them accordingly, if you've been "renovating" or doing anything that produces a lot of dust / air borne debris, change your filter. I've changed a one month old filter once they finished putting in our windows.
I often get told by HVAC experts to to use use EZ flow type filters, and to just change them more frequently. I do use them, and I run free standing air cleaners in the house. The part I don't understand is why you would need to change a coarser furnace filter more frequently than one that traps a lot more dust and debris. If you change them once a month you are throwing away a filter that is still clear. Seems to me you should change the higher MERV filters more frequently, not the lower MERV.
The high MERV Filtrete filters have a lot more capacity for holding small particles or dust and lint and hair *without* having a high pressure drop. I run my furnace recirculation fan 24 hours a day on the low speed to ensure uniform temperature and to pick up any dust that is generated. Those see through filters might pick up some pet hair but there is no benefit to changing them when they have nothing on them. The higher MERV rated filters are fantastic and you will notice that all the horizontal services in your house are cleaner with those in place
@@crazydoglady5 I but them online and always keep a spare or two. I have to set a reminder on my phone to change them as I don’t notice any and performance over time
@@davidsamsonite5791 I set mine on the fan running constantly and AC man that installed it said not to do that. It feels like dead air without it running so that's why i did it. But havent since. the higher the rating..the less air that can go through them. While i do buy the higher rated ones..i have heard not to do that. I been using merv 11. guess i should drop back. I also have the same air purifier as this fella doing the video. I would like to add another..but dang..the filters are expensive. I found my honeywell 200 has alot cheaper filters....and you change charcoal filter more often.
We have a 2000sqft house. I have 3 return vents to the AC/Heater (two 20x20x1" and one 12x12x1). I use MERV8 1" thick on all the return vents and change them every 4 months. They do such a great job that when I change them the filters are obviously dirty. I also lined the return vert housing's so the filters seat with an air-tight seal around their edges - otherwise the dirty air will get pulled into the system around the gaps on the edges of the filter. With a total of 1000sqin of airflow into the blower, it is more than enough airflow to keep the blower from burning out. I built a simple air purifier using a 20" box fan and five 24"x24"x4" MERV13 filters taped together to form a cube that is taped to the back of the box fan. The MERV13 filters are rated to remove crap down to the bacteria level. Five MERV13 4" thick filters allow for almost unrestricted airflow through the box fan and can recycle a bedroom's worth of air in a few minutes. I built it during the COVID lockdown, but I keep using them. It's about $10 per filter on Amazon.
Those DIY air filters are far better performing than the most expensive air purifier you can buy, HEPA purifiers just don't move much air or they're a jet turbine. Using a merv 13 filter and a fan and your moving so much more air to actually get filtered, and you're actually able to filter the rooms air volume constantly.
I have been using 20x30x1 Merv 12-14 filters (my partner has major allergies) for more than 23 years (when we bought our new house - first owner). Our A/C and heater units are still working with a perfect bill of health, so to speak. I think we had to replace a compressor once (~$200-$300) in our A/C during that time period. Many technicians are very surprised to see how clean our A/C unit is. We change our filters every 450 to 550 hours (it runs on auto). For the last 12 years or so, we have our A/C maintained/checked every spring and the heater, every two years.
I use a regular box fan for white noise when I sleep in which I got a MERV 8 taped to it... I got another box fan I run through the day at the other end of my apartment- that's got a merv 8 taped to the back of it also. The filters get changed every 3 months or when I notice them getting visibly dirty. My lung feels great :)
I bought a 20-in box fan made by Lasko off of Amazon that has a filter holder in it so you don't have to tape it. I think it's called a dual Flex or maybe an Air Flex.
If you look on the end of that filter you will read the MERV number. That 1500 is a MERV 12. I was told by the guy who just installed my new furnace to use filters between 6-8 MERV. He also said to change the filter every month.
You got good advice. Almost every AC tech I’ve talked to has advised against using anything above 8. I think I talked to one out of all of them that said 10 at the highest but he was in the minority. Appreciate the feedback!
After doing much research, i wont go higher than a merv 7 with charcoal. My furnace is from the 80's. When we had the Canadian smoke hovering over us in michigan the pop up tents went from white to yellow in a week. Inside i think the filter did its job. Great vid!! Dont kill your system trying to be as clean as a surgical room!! Merv 8 or lower, charcoal is an option ppl.
I learned this one the hard way. I always replaced the merv1 filters my apartment would install and put in my own (typically MERV 14). One day I got a call from my wife who told me the AC wasn't working and I asked her to check the filter and she sent a photo of our evap coils behind the filter completely covered in ice. Luckily the ice melted and the unit started working again. Since then I've only used the super low rated filters and have an air purifier.
I tried one of these out. I replaced a cheaper one with it in mid-September once. 3 weeks later I turned the heat on. The furnace kept shutting down. I figured the furnace was older and just needed to be replaced. Had a tech come in and he explained why he did not recommend the filter for my furnace. I explained I had tried this filter for the first time. I still had one of the type of filters I had always used. I placed the new, "previous type" filter in. The furnace started up and ran normally.
Good info as always! I always wondered if the "better" filter put a strain on your unit so I always stuck to mid tier. Also I bought 2 Levoit air purifiers (Core 300M i believe) for my home because I suffer from allergies about 6 months ago, and I would say by far the best investment Ive made. Im no longer sneezing constantly and my eyes dont itch near as much. Good content, even better to know I picked a good brand lol
Yes it will if not sized for opening you can tell when you turn it on by how much noise you here form the air going pass the filter. It shuld not whistle?
Problems with these filters occur when people don't change them often enough when the furnace is used to heat not cool. The heat exchanger has insufficient air flow, over heats and kicks off on safety. The filters are however ideal to have on hand when smoke or pollutants are an issue. They can also be placed across the output of a fan in rooms where smoke is an issue and no central hvac in building. Did this for my daughter's apartment when local forest fires created tremendous smoke. Worked great. Again monitor fan for over heating as you are restricting airflow with filter.
I have several AC guys in my family. They say use the cheap filters on the AC intake to keep big gunk out of the main system, the Electric bill down, and keep the load off the system. Buy an air purifier with a HEPA filter to clean the air.
With all due respect, you have the right to your opinion. Most everything you stated isn't based off of real data from distinguished HVAC research authorities who have the data from extensive research on this and many topics in the industry. I've worked with three different HVAC companies in my career over 18 years. I have seen and heard it all. I have experience from the residential, commercial, and industrial areas of the industry. Without going into a long drawn out explanation which I don't have time for, if a contractor knows how to properly size equipment for a home, building etc.. and knows how to properly size the duct system for using high efficiency filters, then there is nothing wrong with using them. Yes there are alternatives to catch particulates and better ways to help purifier the air we breathe. The issue is a lot of contractors do not have a clue. They are not trained properly, use old methods or made up methods to size both. That is where the bigger problem comes from because the equipment life will be shorter, the equipment will have more frequent breakdowns, comfort will be sacrificed, performance as well and on and on. All costing the consumer more on top of the cost of the original install.
They aren’t designing them to use 1” high MERV filters. Most people’s systems just aren’t made for them. Nothing I stated is false and there is plenty of data for it.
You are very welcome! I remember when it was pointed out to me years ago by an AC tech and it was like my eyes were opened to what I was doing haha. Thanks for the feedback!
I work for an air filter company in NC. We make residential and industrial filters all between MERV 8 and MERV 15. Merv 8s and 10s are for smaller units and spaces. MERV 11 and higher are our industrial filters we make. Top of the line material and company. Filters are made to last about 2 months
Lived in Asia for a short time and had two air filter machines in our apartment. Was a shock each month to see how bad our air tuned the filters black every 30-days
I have a large Veloit air filter in my bedroom. I've had it for 3 years and haven't had one problem. The filter is expensive but it lasts a year. Thanks for the furnace air filter info. Now I know what to buy!
I find that I only like those type of Filtrete filters that have the very many pleats or very high surface area. I used cheap filters and found they would clog up and really block airflow and sometimes even bend out of shape to allow air in. The high end Filtrerte seem to stay cleaner for much longer, which still providing adequate airflow. I don't care about the number, but want the high number of pleats.
My daughter is very allergic to just about everything. These have been a game changer for her. Her comfort and health is all I care about, otherwise I'd get the cheap ones. But, with someone incredibly sensitive to air particles, they do work.
I use a merv 16 filter in my HVAC. 20x20x5 size. The actual pressure drop measured is lower than the merv 8 filters i was given and hasn't changed more than 0.01 wc at 650cfm after 8 months. The rated pressure drop is just 0.10 wc at 650cfm at 0.25 wc at 1400 cfm. By far the biggest factor to filter restriction is the quality of it. Buy yourself a cheap merv 6 from filterbuy and you'll have more restriction than a well known brand like Honeywell or 3M merv 13. Do some testing yourself or look up some independent testing to confirm.
I have one that i keep in my room. It tells me when to replace it and after having for about 2 years i have only replaced the filter once. the price of the filter is dependent on which purifier you get tho.
I have been using electrostatic filters for 30 years. Take them out hose them off every 90 days. They have carbon in them as well which removes odors etc.
NO. Use MERV 8 and call it a day. Merv 8 keeps your household air clean and your AC clean as well without undue airflow restrictions. Replace it when it's dirty (2 to 6 months; most common is 3 months) - it will depend on your particular house (pets, location, cooling/heating use, etc.). Also consider an air purifier for your bedroom and other rooms, especially if you don't use your AC or Heat year-round and/or have allergies.
I'm local to a supplier Airstar in Boca Raton and he ships. I have his filter frames. He sells the filter material that goes in the frames. I change both filters (2 units) every month. I buy a years worth of filters at a time. It comes out to a good cost savings once you have the frames. I had an ECM blower motor go out after 1.5 years. These don't like static pressure (restriction) This is a 4 year old house now. This is also before I started using these filters. I was using those high merv ones previously. I have since cut panels in my A/C closet doors and installed custom louvers for more return air. The builders A/C company wanted $700 labor to install the warranty blower motor. I bought an ECM rescue motor for $300 and installed it myself. I also installed UV lights in both units.
I have been using merv 13 filters for the past 10 years and they never caused any issues with my system. My electric bill is increased less than 5% and I have excellent air quality.
Curious how frequently you change filters. Wife and I have no kids, but a few pets - I currently use MERV 8 filters that change color as they deplete and they last 3-4 weeks at most. It’s a 2T heat pump system with 1 return and 8 registers.
The thing is, it MIGHT not be effecting him as much as it could others depending on his unit and setup. It could also be effecting things more than he thinks. But there are HVAC techs in the comments and most of them that you will talk to will almost never recommend a MERV 9+. Some may go to 10. The good air quality can be achieved in other ways that won’t be possibly detrimental to the system or electric bill.
Ac expert here. If the unit can't breathe, it runs inefficient. When people say no problems with unit, I say how do you know. They don't. Some people wait until the unit fails before they admit damage. It's called denial.
When I put a higher MERV filter in my furnace it would collapse because of the force of the air flow. I solved the problem by replacing the 1 inch filter with a 2 inch filter. By doubling the thickness of a pleated filter it doubles the surface area and allows double the air flow. So happy with the outcome.
You've pretty much confirmed half of my strategy here - my furnace/AC is running a fairly low-MERV filter to maximize airflow. However, HEPA filters often don't move enough air to get things purified. They're great at removing things from the air that they do move, but they don't move much. A filter that moves enough is going to cost you a LOT of money. I have a high-MERV 20x20x1 furnace filter attached to the back of a box fan running on Low instead. It filters far more air for the dollar. I don't have the space for a Corsi-Rosenthal setup (4 filters in parallel making a cube with the fan), but those can move significantly more air than a single-filter setup.
Yeah I can attest to this. My 1 year-old ac shut itself down one day I thought it was blown. The technician came in and said the AC was fine but the switch box that the AC was hardwired into was blown. Turns out that the AC has a little bit of intelligence and it understood that filter was restricting airflow so it worked harder to achieve the same performance, thus drawing more power. Sometimes it's not the AC that can't handle the airflow, it's the wiring and whatnot in your house. After that I used 1/3 of a sheet of filter to let more air through. In the end I just got an air purifier unit. Just get a dedicated thing. You are in the space all day. The air you breathe is worth it.
Great video. I had the same filter but mine is a MERV 13. It trapped a lot of dust and debris but made my unit run harder in the summer and froze my coils. Now I'm having to defrost the ac unit. I did call a local HVAC company and that was the first thing he asked me is what MERV rating I have. He did tell me to go with anything between 5 and 8.
Project Farm tested and found higher pleats with better material and higher MERV can have better air flow than low MERV with bad material and few pleats.
Yep. The Filtrete 1500 has really high pleats and good flow, better than their 1200 filter. Found a website that tested Filtrete and other filters that they sold I switched from the 1200 to the 1500. Been using the 1500 filters for nearly 20 years, never have called AC guy. I get annoyed by people just yacking about filters with zero evidence to back up the claims. Filter material and higher pleats make a big difference in performance.
@markmalyn3861 3M Filtrete is a brand and model. I never said anything about the two as a product. 3M makes some of the best filters on the market. That’s not what the video is about though or what I was referring to. It’s all about the MERV rating regardless of brand.
Restricted air flow will affect your air handler. I realized this when I had to replace the fan motor due to bearing failure, however a lot of people don't know that if you "completely" restrict the air flow to the air handler the fan will free wheel and draw very little current and there will be very little to no air flow. I personally use a MERV rating of 13 because I have a high level of allergy to dust mites and it does make a difference. I replace the filter every month or so based on time of use. In addition to this, when vacuuming carpet I also use a 20" box fan in conjunction with a 20" x 20" x 2" MERV 13 filter or higher. This option is less costly than the very expensive single room air purifiers and will exchange the air in an average size room in about 20 minutes. People don't realize how much dust vacuums put in the air. One thing I found out about filters is that if you notice your return making noises related to air leakeage around the filter or if the air filter is deformed and appears concave (which means the air handler fan motor is drawing lots of current) its time to change the filter to a different design or rating that solves the issue. I have maintenance experience in HVAC, Electrial, Mechanical and predictive technologies since 1976 and have held level 3 certifications in IR thermography, Oil analysis, motor analysis, ultrasonic analysis, Power Quality analysis and have 10 years experience in vibration anaylsis.
Wait! Did I just watch a 12 minute advertisement? You never addressed the fact that in many new homes there are multiple air returns, each with an air filter, and not just one at the furnace. For example, my home has 4 returns. This dramatically increases the total number of square feet available for air to pass through which reduces the load on the HVAC system. Also, that 3M filter has roughly 2-3 times as many pleats as the cheaper filter you showed. That represents 2-3 times the surface area for air to pass through and is another way the load on the HVAC system is reduced. Having said that, I too wouldn't use the 1500 series filters. I do use MERV 11 filters in my system as I believe they provide an good compromise between air flow and air filtration. My HVAC system is 27 years old and the fan, etc. is doing just fine. Project Farm has done actual data driven testing of HVAC filters. I would recommend your viewers check out his videos.
No you watched a 12 minute video on what has been passed on to me by actual HVAC techs (every single one of them) and what I have personally been using for years that I paid for myself. I am giving the info I have and providing what I use as people ALWAYS want to know. Your house is different than many. Mine is newer and there is one. Either way I wouldn't use the higher MERV filters. But do as you please!
Agree with both of you. We really need someone to test these various filters out after putting gunk them. Can measure draw from the fan, filtered air quality effectiveness after said gunking, and/or measure airflow to determine if this is just knowledge passed along in which we don't know the original idea behind it.
@@HowToHomeDIY Fair enough and I sincerely apologize for accusing you of something you did not intend to do regarding advertising on your channel. Having said that, after 45 years working in a data driven profession (physics), I stand by my comments regarding air filters. As offensive as it may be, the “opinion” of HVAC technicians doesn’t do much for me and that’s why I advocated your viewers consult actual testing results of various filters on sites like Project Farm. History is replete with examples of “facts” that were eventually debunked when someone actually bothered to collect the data. I believe your viewers would be better off if you did that here.
@@HowToHomeDIY I would have hoped for a more reasoned and reasonable response to a request for actual experimentally determined data to support the argument you made in the video. Aristotle would have loved you. Galileo, not so much.
I use both. The same name, brand, and size. The round levit ones clog way too fast. Cost much more. Now, I only use the 3m hvac filters on a box fan. 4 of them to 1 box fan. They last months vs a week, and the air is definitely cleaner with the 3m by far. You can see it work. The round ones that are over 100 bucks and then 30 buck filters are good for already clean homes in a room. I have 2 dogs, the box fan, with 3m, do the best hands down, and no comparison.
HVAC tech here,Never use anything above Merv 8 we get calls all the time for failures caused by the filter. Especially with newer units the added restriction to the airflow presented by the filter causes high limit switch on the heat exchanger to trip over and over until it fails..
We can remote monitor the performance of "certain" systems we install and can see if the high Limit trips using Merv-11 thru Merv-16 Filters. This has not been the case after our installations as the set up is very specific. These type of systems always use Variable Speed DC Current Blowers. So, it's not the case every time. I do agree that bad filtration can cause hi-limit actuation.
@@pedrojorge3221 We Monitor the Variable Capacity Systems and others that have Communicating Equipment with WIFI Capability from Lennox & Trane Systems. This info is privileged and in our Mgr. office. Can't wait for the newer systems that come out witch we can diagnose with our phones!
@@VisionStance we are a Comfortmaker Dealer. All ICP brands new lineup are programmed on site by the technician using a phone or a tablet and an app called Mobile Tech. We can also diagnose the unit remotely. Pretty soon will be out of a job. lol
Bro you're a tech. You're not an engineer. I've never had this brand of filter crash an HVAC system and I've lived in practically every state and used them all the time.
Please note that the MERV 12 has more folds than the MERV 6. Therefore, the MERV 12 has a larger area for air to pass and thereby counteracting the effects of the thicker material.
The more surface area the better. Automotive filters too. Deeper and more numerous pleats are needed. If you can hear your filter popping inward when the air turns in it’s probably impeding too much flow.
Every hvac person I've talked to told me to use the cheapest filter to extend the life of your unit. I stay with merv 5. Had my home built in 1999 and i still have the original ac and furnace.
We have been using a MERV 11 for many years and was ok'd by our heating and air people, they also said don't go any higher. haven't noticed any diminished air flow. We just had our duct worked cleaned which has cut down on the amount of dust.
The facts are that the pressure drop curves vs face velocity (or air flow for a given size) are published for all of these filters. So, you can look up the information and what you find is that there are high merv filters that don't have a particularly high - or excessive - pressure drop. So, those can be used in an HVAC system. As long as you keep your system static pressure drop within the limits of your air handler manufacturer, your system should work just fine. You can't simply make blanket statements and say a high Merv filter is bad and restrictive. It might be, it might not be any more restrictive and might actually be better than a lower Merv filter. It depends of the surface area of filter media and the specific filter technology (electrostatic tweaks to the media). Why don't you get a digital monometer and do the actual measurements for the filters instead of creating a advertisement for room air filters.
Blah blah blah. Yeah that helps but it’s still restricting the air more than a MERV 5 or 6 but quite a bit more and when it starts getting dirty it’s way worse.
Someone who gets it! The real issue is with the HVAC industry. They use too many rules of thumb. There needs to be a gauge that measures the pressure drop and signals when the filter is too restrictive for the air handler. Why aren't skilled HVAC techs recommending an actual solution? Is it because they weren't trained or didn't investigate? Imagine if vehicles didn't come with a gas gauge. Mechanic "just put in 20 gallons every 3 days". That statement is meant to make the reader think a little. Yes, on a long trip you'll run out, other days you will overflow the tank (waste). FYI. Dwyer sells a differential pressure gauge for ~ $100. Every house is different, the frequency of filter changes will vary seasonally. An HVAC system can be designed to clean the air. Regarding the proposed solution of separate air cleaners: it increases user maintenance. Check the air cleaners' web site. 3 different filters, 3 different change intervals. Average homeowners don't change 1 filter regularly. P.S. This is meant to help educate. The video is helpful for those who don't want to go deeper.
Amazing how many people have no idea they are suppose to replace their furnace filter. I saw one house where it was so clogged it actually tore the center out and it was flapping with the air flowing causing an annoying airflow up down noise in the registers. Just crazy.
Had a system with a five inch thick pleated filter in the attic, right before the air handler.But we kept dogs, and those hugely expensive filters clogged with dog hair. I put cheap cheap cheap glass filters in the downstairs return grill and replaced them every other month. They collected a huge mat of hair and other crap, and the big filter upstairs lasted much longer.
I use these.. and have suspected they are not good for the handler.. and my installer said. Had to replace both AC units 18months ago. Ugh. Thanks for the video. I swap these out every 60 days.. and they cost a fortune. They are merv 11. Need merv 6-8.
You replaced the outside AC unit or you had to replace the heat exchanger inside the house? The only reason to replace those is if they are so dirty they cannot be cleaned!
Thank you for this video!! I see below a fellow engineer tried to school you. Though I am an engineer i have to point out experience counts for a lot. I am sure you've seen your share of systems destroyed by restricted airflow. Basic fluid mechanics and air flow compensation built into most systems at work.
I use a MERV 16 and replace the filter every 2 to 3 months depending on seasons.. My airflow is good and after removal the filter is stained brown to black in a non-smoking home.. I would never use a MERV one and will take my chances on lower flow and replacing the fan motor to achieve cleaner air.. I also have a separate air purifier that I cut and place a Merv 16 with a carbon oversheet and I Have found that I seldom have to dust the house... Lol..
Haha, it's the pressure difference between the air going into and out of your heating/air-conditioning system. Mine is 5 inches of water column, recommended. So the total resistance of return ductwork, supply ductwork, wet air-conditioning coil, heat exchanger, and filters should add up to no more than 5" W.C. Pick the best filter you can get that doesn't push your system over the "W.C." limit!😢
Air filters are not intended to remove `normal household dust`- everything that makes up dust is heavy enough to fall out of the air long before it can hit an air filter. Neither will running an air filter make you have to dust less.
When I replaced / upgraded my HVAC, I arranged for my intake air to be filtered twice. The first filtering happens as the air enters the air return duct. Here I placed a rinsable, relatively coarse filter. This filter catches large dust, pet fur, and the like. When dirty I simply remove, rinse off, and return to use. At the furnace I place the best / finest filter I can find. This filter catches everything else. With my pre-filtering, this filter typically does last three months of peak use. Filter expense? Often you can save as much as 50% simply by buying the filters three or four (a case) at a time. Spare filters are stored in the furnace closet.
I can highly recommend removing 1" filters from the system and installing a 4" or even 5" filter housing on the intake side of the air handler. The increased air flow for the same given MERV rating is super easy to prove with a manometer and a simple inspection of the filter media. When you destructively remove the 1" filter media from the cardboard it is in, you can measure the square footage of it. Then compare that to the square footage of the media removed from a 4 or 5" filter's cardboard frame. The difference is night and day. If you want the single most cheapest and effective whole home filtration solution you should start with a MERV 10 or MERV 11 5" filter in a 5" filter housing on the intake side. Then if you want to add HEPA filtration for bedrooms or living spaces where you spend a lot of time, you can run those longer between cleanings because they don't get dirty as fast The 4" filter housing that was easy to add 2 my two 5-ton air handlers have kept my coils clean for 7 years. They were inspected in the last year and the HVAC Tech confirmed for me that the coils were like new. I 100% agree that high MERV 1" filters decrease the airflow across the coil too much. I've seen it first hand. Slow airflow leads to icing over more quickly which leads to even less airlfow and higher humidity in the house. As the tech in the video already knows, low airflow across the coil will also increase the pressure inside the refrigerant lines. Higher head pressure means a lot more work / more wear and tear on your compressor. The more efficiently you get the heat to transfer across the coils both inside and outside, the less stress there is on the compressor.. this is also why it is important to clean your heat pump coils outside carefully. I know with first hand experience it is possible to have better air flow and better air filtration. There is absolutely room for high filtration units in rooms, but that doesn't mean you can't filter the air more efficiently before those filters finish the job.
Tried all kinds of filters. In the end I settled for a lower merv filter, replaced it more often, and set a fan-only % cycle to keep the air moving now and then when it didn't need to run heating/cooling for a while.
This video could not be more spot on. Another tip is don't waste money on brand name filters for your air handler, like Honeywell. There are aftermarket filters that are every bit as good, and they are MUCH less expensive, especially if you buy them by the case.
Not all filters are the same. One brands merv 8 filter can be significantly lower restriction than another, it's not a restriction rating as material quality makes a huge difference. If they don't have testing data for initial airflow resistance you should not buy it! Generally the cheap filters are noticably restrictive, like filterbuy, compared to something like 3M or Honeywell Merv 13. I can give an example as well, the merv 8 filters that were white label branded by the HVAC company I used tested about the same to slightly worse than Honeywell branded merv 13 filters I bought, both the same dimensions. A merv 16 filter from Lennox that was 1 inch thicker tested lower than all of them and after 8 months of 24/7 blower circulation it's not really increased much.
When I used these charcoal filter type air purifiers, I had problems with thick mucus that would wake me up in the middle of the night to hack- brownish and causes coughing. The charcoal filter is the culprit. When I stopped using the purifiers I stopped getting the mucus
You are conveniently overlooking the cost of the filters for those air purifiers. I had a Levoit air purifier and the cost for replacement filters ranged from C$50 to $80 !! It was also only rated for a single room. I threw it out and use only Merv11 filters in my furnace - replaced every 60 days. My furnace fan has run 7/24 for 9 years without a problem.
I said they take filters in the video. Mine aren’t nearly that expensive so not sure where you were buying them from and I have had the same filters in mine for around a year now, just keep cleaning the outside. Will probably finally need to replace them later this year. Your furnace doesn’t run 24/7. If it does it’s probably because you’re starving it with your MERV 11 filters 😂
@@HowToHomeDIY My furnace does, repeat does, run 24/7. It is a 3 speed. Low speed when no a/c or heat. Medium speed when a/c or heat is called for. High speed after 15 minutes if thermostat temperatures not achieved. It was installed in 2015 and, except for occasional power outages, has not stopped since. Filters for the Levoit were genuine OEM from Amazon. Remember these are Canadian $. Edit - the current cost of filters for my unit (on Amazon) ranges from C$107 to C$148. It’s cheaper to buy Merv11 filters.
Can you quantify how much more electricity is needed when using a high-MERV filter, and how much more quickly the added strain will cause the HVAC blower to need service?
>petersmart1999 : I'm very skeptical of your claim, because even if less air is moved, there's more friction that the motor needs to overcome. You need to also count the energy that heats the motor (hotter than if there's easier air flow).
I'm curious, have you been using these filters or used them in the past?
Yes. Depending on whatever is cheaper but 2500or 2800.
Filtrete = Concrete, saw this on an HVAC forum.
Pros all recommend the plain cheap ones.
Yes I get them at Home Depot and they seem to work well.
Only once: it was a MERV 13 filter and I installed just at the beginning of winter. It did filter the air more effectively, but it wasn't worth the cost of the filter or the higher gas bill.
Your gas bill will not be higher if you install an air filter. Electricity use might be if it gets very plugged. Even If you don’t mind dust and pet hair or dander, you at least need a filter to keep your AC A-frame heat exchanger clean. If you do not keep it clean, your AC will run constantly and it’s very expensive to get them cleaned. I’ve seen AC A-frames they have so much lint and pet hair on their surfaces that no air at all was going through. It looked like grey fabric was on the surface. The homeowner forgot to replace the filter for a year.
Moved here 2 years ago, air system filter is MERV 11 , 15" X 25" X 5" . It worked well cleaning smoke when forest fires were in full fury.
I built a corsi rosenthal box with a $20 walmart box fan and 4 MERV 13 filters I had laying around. Yeah people talk about how HEPA is so much more efficient, but when my system is moving like 10x more air through its filters it doesnt matter if mine is filtering out 60% vs 99% of particles, mine will filter the air faster and better regardless through pure volume. You need to spend like $800 for a HEPA system that can actually compete with a Corsi box at a fraction of the cost.
@@Inbal_Feuchtwanger yeah but it literally does not matter how much air it's moving if MERV 13 isn't high enough to get some of the most harmful stuff out of the air. MERV 16 with that solution would be even better because less of the smaller stuff gets kicked back up and continually recirculated as is currently happening with yours.
@@thomasolson8417 Im not sure what your comment is implying. MERV 13 gets the most harmful stuff out of the air. During wildfire season it does wonders, its also great for allergens and cat dander. Being able to remove the particles quicker means you will be breathing less of them, it doesnt matter if it needs to circulate the same air. If you come home from work and the room youre in measures 300PPM from wildfire smoke, being able to reduce it down to 50PPM in 30 minutes rather than it taking 4hrs to do the same is whats important. There are actually a good deal of research on this and you can them recommended straight from the EPA.
When our HVAC guy did our house he sized the system for 20”x25”x5” MERV 11. Our house doesn’t get dusty and it has helped with mild seasonal allergies. We also installed an air sanitizing UV system. No regrets.
Which system did you purchase? 1:23
@@moniqueheubel8970 I’m not sure what you mean by system. Our filter box is Air Bear, the UV device is a BioShield72.
@@joeyoungs8426that’s a good system.
My AC Contractor who installed a new TRANE Furnace and AC system in our house suggested no higher than MERV 9 for the filters. If you watch other Air conditioning vidoes, they point out if the MERV is too high, blocking the intended air flow form the Blower, you can create harmful Air Pressure which can damage your unit and shortedn the life.
@@Chiroman527 I change filters in a ton of houses, and tell the home owners to get the Merv 3-5 and change them every 30 days. No need to buy any expensive filters, since in reality, they all work the same. You'd be surprised at how many systems are actually ruined because they use the high end, high Merve rating filters. Not to mention that the reduced air flow allows the condensation to build up on the interior of the ducts, which attracts/holds the dust particles/debris to the walls and actually makes the air quality get worse, faster than just using a lower costing, medium Merv level filter and changing it every 30 days.
Working HVAC I replaced a filter that was so plugged it almost was sucked into the return air vent. I could hear it whistling upon entering the front door. I pulled it then checked the system to verify it was the only filter. Told the homeowner that it was the filter and I could find nothing else wrong. It was less than a month and I had the same call, same problem. Had to explain that when a filter was plugged no matter the time in place it needed to be replaced. They had just moved in. I think it was the sprinkle carpet deodorant that was popular at the time that put a lot of powder in the air when vacuumed. I think it was a heat pump unit.
When we had our new furnace installed, the HVAC contractor put in a 2 inch filter holder, and increased the furnace intake area. Made a big difference in home comfort and the furnace handles a MERV 8 no problem.
I would argue that HVAC designers need to stop designing return air ducts and grilles to the minimum size for a given airflow. A modest increase in duct and grille size would allow enough airflow with a premium filter to avoid this issue. When I did my own system many years ago, the pro I brought in to charge the A/C was impressed and pointed out the oversized return. I told him I did it on purpose to allow for better filters. The total extra cost of the oversized grille and short duct run? Around $50.
Static pressure is a big player in HVAC design. Im not an expert in ductwork or static pressure but i do know that tampering with it can cause problems with its ability to cool and heat. Plus, bigger coils have show a significant issue with dehumidification as well as short cycling.
Another big thing you need to know. While hvac companies have people who design the ductwork, often times the BUILDER has the final say. Alot of bad filter slots and designs are attributed to the builder saying what happens at the end
told that same duct size goes in and out or bigger return . like 12" round in and 12" round out. something 'about energy efficiency
return too small a system must work harder. that's why they have damper in return airi
it re-approve by the engineer
The issue is not just the return system, the issue is that the entire system is designed for a desired flow rate. If you reduce the flow through the system beyond design parameters, you will alter cycle times which can negatively affect both heating and cooling. Yes, it would be nice if the manufacturers of the equipment and the designers of the overall duct systems would base their designs on a better filter. Until they do, I strongly suggest you don't exceed a MERV 11 filter. If you want the air in your rooms to be cleaner than what a MERV 11 can do, get a properly sized whole house electrostatic air cleaner added to your system.
define oversized return?? I'm curious... Thanks!
@@biz4twobiz463 If you need me to define it, then you obvoiusly don't know how to properly size ductwork.
My local HVAC company educates customers just as you have in this video. I've been using the 3M Dust Reduction Level 300. MERV rating not on package as you stated. It is located on the filter itself. Back side on the bottom reads MERV level 5. Thanks for all you do for us!
I had the furnace and the AC serviced last year and I asked about the filters I should use. The answer was to avoid both the cheapest filters and anything higher than MERV 8. So, pretty much in line with what you're recommending.
I was using a MERV 12 and our HVAC guy stated not to go over an 8 as well.
Good to hear many people parrot the same thing from their HVAC guy.
I said MERV 5-8 is recommended. I use a 6.
Did you actually talk to an engineer who designed your system? No.
@@Slick1020 out of curiosity, who are you asking that question of? I don’t know, as you cannot tell from YT’s comment system. Do you actually think the average home HVAC system was designed by an degreed engineer? The one in my home, was field installed and like most custom homes was a one-off job following general rules of thumb. They follow the Furnace and AC manufacturers guidelines, if they even took the time to read them. And as a professional degreed engineer myself that talks to many engineers a day, I don’t offer recommendations outside my field of disciplinary expertise.
@davidsamsonite5791 you are saying things I did not say, taking things out of context, and twisting what was said and clearly meant. I’m not going to get into a big back and forth with you on my intent and what I actually said when it’s very clear and what you are saying is not what I said or a twisted version of it.
Filtrete filters are electrostatically charged depth filters. Unlike a conventional pleated filter that catches particulate on the surface and blocks air flow paths, the Filtrete is a woven web of charged material that grabs particulate. Air continues to move through a low pressure path through the depth of the filter material. That's why it can catch more particulate and still retain an acceptable pressure drop. I've worked with 3M on these in the past in commercial air handlers with continuous pressure drop monitoring. They cost more, but they catch more particulate and last longer.
thank you. i have always used filtrete and this is nice to know.
23 years doing HVAC installer, tin knocker, service tech, service manager, and instructor working in residential, light commercial, and commercial work. I pretty much agree with this whole video. The only thing that makes it hard to say this is the filter that you should go with or not because everybody’s duct system is different, and also depending on equipment, registers, and zoning it makes it really difficult just to say this is what you need to go with and you’ll be good. So my recommendation is if someone only had a 1” filter slot they could get a couple different filters and have a reputable company come out and check total static pressure while changing of each and then make your determination after you actually measure instead of guess. It is always better to have a media cabinet 4”+ filter you will be able to have much more surface area and be able to have a higher efficiency filter at a lower total static pressure. FYI MERV 16 is equivalent HEPA efficiency. Hope this helps!
So is this discussion only about 1-inch filters and not about 4-inch filters?
@@kirkdarling4120 I was just referring to more the 1” filter more so due to that’s what the video was referring, I just threw in my two cents about the 4” filter.
@mikeschmid5133 Why burn the compressor out? Just curious.
@@DevonWildZillaTeschJrnot sure either. The compressor is outside the house. Maybe he meant the air handler motor?
@@jonesjones7057 that’s what I was thinking that too especially today’s blower motors that are mostly constant torque or ECM. And most of your indoor coil have TXV and outdoor coils are big enough to hold a good bit of liquid takes a lot of things going wrong to get liquid back to compressors these days. And even if that happens scroll compressors will float the scroll and not try to compress liquid.
We had to call the pro because our central heater was stopping before the set temperature. He recommended us to use a thinner filter than what we were using. Thank you for sharing this info with the community.
A pro who didn't design the system. Right...
Mine too! He told me max Merv rating of 8 and change every 30days. I change it every time I write the monthly check to the electric company…makes it easy to remember
I was told to buy in bulk cheaper filters because you can change monthly and it's cheaper!
@@NYtalk60 Yes it’s true…mine net out to about 5.60 per filter when I buy them by the case…every 30 days I change them and my AC is happier for it 😉
never had a problem with my systems and as an asthmatic wholeheartedly will say there is nothing better than a high end 3M to ease your breathing and deal with allergens. Happy user since the mid 80’s. 1500 minimum, which captures cooking odors and smoke as well.
if you want to keep the large particles from clogging the better filters, sandwich one of their basic (blue mesh washable) filters ahead of it to catch those and change that one out or wash it when you see it load up, the carpet of dust that forms is what helps reduce service life of the better filter.
My daughter has really bad allergies, and is an asthmatic. I’ve used good quality filters for years and it has helped her out a lot. We also have standalone HEPA filters in the bedrooms. Without all of this, we end up making several trips to the emergency room every year.
I will take the chance of wearing out parts on my HVAC system as a side effect of keeping my daughter healthy.
@@91CavGT5 the 3m 1900 has the lowest pressure drop of the higher Merv 3m's and better even than most low merv ones.
I'm an Engineer with extensive filtering experience in industry. I totally disagree with you. I have bern running the 3M Filtrete filters for several years, with zero problems. I live in Phoenix, and the air here is totally polluted. These filters work great for removing all types of contaminates. I also add a carbon filter on top of the filtrete filter. The AC moves air with a fan, so these filters aren't going to affect the compressor, which is the main power consumer. The fan can handle a bit of airflow restriction. Like I said I have not had any problems witj my AC, and its hotter than hell here in Phoenix. You should see all the crap these filters pull out of the air. I also run HEPA air filters in our bedrooms, but they can't process the amount of air, that an AC can process.
I use a MERV13 Filtrete as well, which keeps the equipment exceptionally clean). This greatly prolongs the lifespan of all equipment in the house (AC, heat pump, refrigerator coils much cl eaner, computers, etc). I us 3 small HEPAs as well. My House is like a micrchip manufacruing facility ! lol...Micropartcles will coat surfaces over time and degrade equipment. Air is much healthier as well.
Can you provide examples of overworked blower motors due to high Merv rating filters? No?
@@bert1450 I burnt up my fan motor by installing MERV13. The fan also uses more energy.
I’ll stick to my MERV 17 air purifier 3800sf right next to my AC air intake vent and stick a MERV 1 in the AC unit. Cools the house down faster without restriction and I’ve never had better air quality before. I sleep like a king now, air is so pure I literally forgot I was breathing.
Well there it is folks, the typical "I'm an engineer" and know better than everyone else. I'm an hvac tech for 25 years and can tell you for a fact that heavier filters will damage your equipment. Merv 8 at the most you want to go. Remember ppl, your hvac system is not an air purifier. They make equipment for that as well.
Have you or any of your readers noticed that lately (some) filter manufacturers are making their filters ¼ inch smaller than the posted size on the wrapper? This is causing extra air noise inside the house coming from the filter cage in the ceiling. What is causing this because I do not agree with selling us consumers short. The the way - great video and I absolutely love your channel as you have helped me maintain my home much better and have saved me considerable money.
I noticed that about the Home Depot HDX filters - instead of 1 inch thick filters, they give you a 0.8" thick filter. Multiply 0.2" x 2 x the number of pleats is much much material they saved. So now I just stick with Filtrete and buy them in bulk whenever they're on sale.
Yeah, they are taking a page from the lumber industry. I use Honeywell, they are true to size.
I’ve ran 4” thick MERV11 filters in my system for years with zero issues. I change them every 60 days even though they’re completely clean (what human eyes can see anyway). Yes, the air is dry and cold in my house but my German Shepherd greatly appreciates it.
From what I've seen, particulate filters for air "expire" by getting clogged, not by leaking. Use them until air stops moving through them quickly enough, they should actually clean the air that does go through at end of service life better than when they were new.
Charcoal filters start leaking mostly high vapor pressure substances (and with mixtures this can actually result in the filter's output air having a higher concentration of one chemical than the inpur), experience migration when in storage, are difficult to check the saturation of without knowing what's in them or doing $100+ tests, and otherwise have issues that make conservative replacement common when it's really important.
Consider getting a manometer, it's just a differential pressure guage with tubes, sensitive enough to measure the pressure drop across a filter. They sell them as portable units and parts you can install on your system. When the pressure drop gets too high (depends on your system, ask an HVAC tech) the filter needs to be replaced.
@@reddragonflyxx657This is the only way to know when a filter really needs to be changed. I don’t know why makers don’t do it from the factory. Time based is just guessing. Although I look at mine to see how dirty it is.
I was thinking about installing a gauge on my air handler. There are a couple ways of doing it. Problem that I would have is knowing what reading I would use to know when the filter needs to be changed.
I've been tech for 31 years. My home built 2008. I installed merv 8 in my two systems. My evap coils had to be replaced from coils leaking refrigerant after 7 years on one and 14 years with the other. Both coils were spotless and drain pans had no sludge. What this means. No air restrictions and optimum performance. The original merv 1 filters are nothing. If you can sprinkle salt through it. It's nat a filter. I have proven it with my own home. Trust me. I can tell you to never buy expensive washable filters. It is job security for techs when they freeze your unit up in the summer. Merv 8 is the perfect filter. Also. I have my fan selections to on not auto. This means I filter my home 24 hours a day 365 days a year. My blower motors have run since 2008 non stop. I hope I helped anyone who read this.
I ran Filtrete 1500 on my 20-year-old furnace, in a 2500 sq ft house, for 12 years and never had a problem. I did have to replace the blower motor once, a temperature sensor, and an exhaust fan motor. But it is a very old furnace. We replaced the filter every 3 to 6 months and kept the fan on continuous.
Glad that you found a working solution. Just wondering how old is your furnace? Hoping to get 30+ from my hvac unit lol.
I used a 3m for years no problem with my furnace
My AC guys (I’ve been using for 23 years) told me max merv rating of 8…no higher because it’s too much stress on my system. They’ve never steered me wrong yet. Thank you for saving us money AND our systems with your valuable info!
*I change mine every 30days - the day I write the check to the electric company. Easy to remember that way. Thanks again! ♥
Every 30 days????
@@Soljarag5 Yes…every 30 days…makes it very easy to remember to change the filter: write the check to electric company - change the filter. Understand, I live in Florida…my AC runs nearly 24/7. During the winter months the filter isn’t in terrible shape, but I still change it. But in May thru October it gets filthy because it’s running nonstop. I buy a case of the filters at Home Depot - cheaper that way and my AC is happy for the clean filter 😃
@lizzieb6311 absolutely same thing. I also live in florida. Every 30 days, I also clear my drain lines every 90 days.
@@gogators5762 Yes! The drain lines….so important here with our ac running non stop…what a slimy mess! Haha…hey, Gator fan here too! Chomp Chomp!! 🐊
@@lizzieb6311Maybe get a manometer and test if it's still in tolerance for your system every 30 days.
Good point to not rely on the HVAC to clean your air.
I buy the filter that the project farm guy recommends. His testing showed the higher pleat count didn’t restrict airflow as much as the low pleat count did, which is what we’re trying to avoid here.
Higher pleat count implies more surface area, yes?
I would rather use air purifiers.
Project farm is awesome
One more thought about "higher pleat count is better": I think that comparison refers to filters that have the same (or similar) MERV rating. The same MERV rating can be achieved with fewer pleats (less surface area) but that requires greater thickness and/or greater density. Less surface area is more restrictive against flow, and so are greater thickness and/or greater density, so fewer pleats is a loser in two ways when comparing filters with the same MERV rating.
If you're comparing filters with different MERV ratings, the effect on air flow of the thickness & density of the filter material may be more significant than the pleat count. For example, the MERV=1 filter shown in the video has zero pleats, yet it has better air flow than high-MERV pleated filters because its filter material is thinner and less dense.
The effect of _deeper_ pleats ought to be like having _more_ pleats, because that too would increase total surface area. But there's a practical limit on depth since the filter must fit in a narrow slot in the HVAC intake duct. (The narrowness of the slot is also what limits the thickness of the filter, of course.)
A DIYer who isn't concerned with aesthetics might consider constructing a large filter-holding frame at the inlet of the HVAC's return air duct, and either leave the original slot empty or put a MERV=1 filter in the original slot. The custom frame could be very large so a filter with much more surface area (and thickness) could be used. An array of high-MERV filters, taped together side-by-side, would have a huge total surface area to maximize air flow. A large filter (or a large array of filters) will also last longer than a smaller filter because the captured particles would be distributed over its larger surface & larger volume.
A clever DIYer could also add a one-way "valve" -- a gate on a hinge -- to the frame, which opens only when the HVAC fan is moving air, to eliminate backdraft. (Gravity could close the gate. If the gate is lightweight and the hinge has little friction, the HVAC suction would be stronger than the effect of gravity and would open the gate.) The anti-backdraft valve would help when the HVAC unit is located outside or in an unconditioned room/closet, and the unconditioned air around the intake duct makes the duct cold in winter or hot in summer. (Wrapping the duct with thermal insulation is a good idea too.)
@@brothermine2292 that is partially true. It is correct, the same material, same pleat counts but higher MERV would create more restriction, but project farm showed that higher pleats with higher MERV can reduce air flow. Possible due to changes in materials, maybe the fuzziness 3M has to their higher end filters.
I understand the concern about a filter restricting the flow. But the filtering efficiency is not the only factor to consider when trying to determine how much the airflow is restricted. It also depends on the material, how thick the filter is, how large the filter is, and the amount of area created by folding. First there needs to be some measurements taken of the airflow restriction caused by these filters. Second, we need some determination of how airflow restriction affects the unit's efficiency and reduces it's life span. The problem is more complex than just picking a MERV number.
Project Farm did just this.
If you make the intake oversized, it should compensate a bit for the restricted air flow. I don't know anything about the industry, but I would imagine that modern HVAC systems would take into account that people want them to double as air filters and know they're going to use these restrictive clean room filters. Unless early failure and selling more units is what they're hoping for. There's a sweet spot between more sales and poor reputation there.
I only use Camfil/Farr aeroplete filters.They are the best,no question! Been an HVAC tech for 30 years,and I have used them all and there is no comparison,Merv 8!
Where do you buy them at?
From Camfil USA local branch,
Smart man. Good advice.
Didn't scroll through all the comments but every quality filter should have its airflow ratings printed on it or the packaging somewhere. Your HVAC system has ratings that it was designed for. You should be able to match them up. Issues arise when the entire system (furnace, AC, ducts & filter) is not in harmony. Our old house was an example of this. Not enough intake air in original ducts and the AC was running too a high a fan speed that made for short runs and the humidity remained high. This also stressed the filter. Corrected these issues and was able to maintain correct air flow with MERV 11 filter. It is always a sum of all the parts in play.
That is exactly what I've learned and discussed with one of our local HVAC companies. New(er) systems can handle the higher-rated MERV filters just fine. Putting a MERV 13 on an old furnace/system might seem helpful, but it would likely be doing more harm than good.
Where are the ratings? I have a split system.
@@Dbb27 They are in the paperwork that comes with your system. In the homes I have lived in, it was in a envelope attached to the furnace. The units have ranges that are dependent on the duct work, etc.
I watched another video "Furnace filter-which furnace filter is best". The tested a wide range of filters using a manometer. He found that the 3M filters were quite impressive for the low pressure drop across the filter. We have been getting a lot of fire smoke here in Alberta. I installed a thicker filter box to use 25X20X5 filters. I installed a Merv 11 and use it with 2 Honeywell extra large room Hepa Air Purifiers with good results. Keep in mind that a lot of house hold dust will settle out before it makes it into your return air to be filtered so don't think you can throw away your Swiffer any time soon!
What does he say at the end of the video though? That one controlled test he did is not the gospel truth. Which is why I believe he says what he does at the end of his video. Also I have nothing against Filtrete fillers. They are some of the most popular for a reason. My issue is the MERV rating regardless of brand.
@@HowToHomeDIY 3M filter myth busting Video. Video is from 3M so many would call it fake news. I personally believe in filter media R&D
Now have them do one when the filters have been in the unit a week. Because they catch more things, they fill quicker and efficiency is not going to be nearly as good. I will trust the guys that have all told me the same thing that work on and replace parts on numerous acs due to the higher efficiency filters.
@@HowToHomeDIYProject Farm also did a video on this I believe. While what you’re saying used to be true of higher MERV filters, I’ve yet to see any tests that actually show this to be true with the modern Filtrete filters. All tests I’ve seen show better airflow even when clogged with fine particles. My understanding is that the idea that higher MERV ratings reduce airflow is a common myth that feels logical but isn’t true due to the complexities of airflow.
@TheHeadincharge again why at the end of that video does he still recommend a lower MERV rating if it’s so great to just use high MERV filters?
i think the high number of pleats on the Filtrete 1500 and up increase the surface area substantially to make up for the restriction they would otherwise have. In most cases the Filtrete 1900 filters flow more than many Merv 8 filters from other brands. I don't believe the Filtrete filters suffer from restrictive flow issues. However, they do clog up faster and should be replaced every 30 days. On the other hand, there are other companies that make Merv 10 through 13 filters that DO NOT increase the pleat count, and thus are terrible for the air handler from the beginning.... Filterete is the only company I know of that increases the pleats on their 1 inch thick filters.
At work, our units have to circulate a lot of air and the pleats are four inches deep. The air filters are sort of intimidating to look at. One thing I notice is that all the good air filters have metal mesh to resist filter collapse from overpressure if it gets clogged up from not being changed often enough.
My HVAC tech designed the intake for MERV 14, and that's what they provided and said I could use, but the intake is a huge. 20x30 for a 1300 sqft home. It didn't really add significant cost to the system, and I appreciate the ability to clean the air a bit better.
My father had a excellent solution. Instead of putting the filter at the HVAC unit, he put smaller filters at all the intake points. More filters equals greater filter surface area, and the ductwork is kept clean since the air is filtered before it enters the ducts. He did this when he built their house back in 1986.
Smart dad
Sadly, not many things are designed with maintenance or longevity in mind anymore.
Uhm, the filter goes at the beginning of the system, before the ducts. Adding more filters will slow down the air flow, reducing the efficiency and longevity of the HVAC system, not to mention allow more debris to contact and collect on the inside of the duct walls.
there's a reason no one really does this
@@MattYoumans what is the reason
I custom built a pre-filter box for my whole house air filtration system. The box has a series of six slots with six inches between each slot and twelve inches between the opening and first slot as well as the sixth slot and the exhaust which goes into the actual system for a total of ~65". I also use a UVC lights at the beginning and end.
I use 24x24" filters in the following order:
Electrostatic metal washable
MPR (MERV) 300 (5)
MPR (MERV) 600 (7)
MPR (MERV) 800 (10)
MPR (MERV) 1200 (11) carbon
MPR (MERV) 1500 (12)
System filter:
MPR (MERV) 1900 (13)
I clean the metal electrostatic weekly or better. The rest get replaced 1-12 months. My system has an airflow monitor and has only gone off twice after wildfires. Note that it cost me about $75 to make the pre-filter box and has saved me dozens of times more in expensive filter costs and maintenance as the system and downflow ducts remain very clean.
Yes, I did go overboard but enjoyed the process and final results.
You and my youngest son think alike. He redesigned his HVAC system and runs a schedule for spring allergies and autumn dust. He also added an ion machine to precipitate dust.
Man, that's a lot of money and impo, a lot of wasted money. I'm not dogging you, but hear me out. Even the A/C companies say that, unless you have an extreme allergy or a serious medical issue, you don't need a lot of "high tech" filters or systems in the HVAC system, and to literally use the lowest costing paper filter 3 to 5 Merv Rating and change them out every 30 days.
They recommend this for the exact reasons that were stated in the video. Once they are dirty, they restrict air flow and cause excessive strain on the equipment, not only with the blower motor, but also in the condenser side. This also slows down the amount of air that is passing through the ducts which allows more condensation to build up on the interior walls, which then attracts/holds more debris which then will build up on the inside of the ducts, creating a bad situation.
As a GC as well as a RE Investor, I have seen a lot of units that need to be replaced way too soon due to these issues that can easily be remedied by using a simple filter and changing it every 30 days.
@@jmackinjersey1 I don't consider 75 US dollars a lot of money, and it definitely isn't wasted. My allergies were minor but are near non-existent now as I am allergic to indoor mold/mildew. Also, considering that most indoor dust is exfoliated human skin cells and I have nothing noticeable in my home, I consider it money well spent. My outer box uses filters bigger than the unit requires and the unit has an airflow monitor which is always in the green, never yellow or red. It passed inspection by the government, and several exerts in the field all liked it including an instructor liked it.
Again, money well spent.
That’s some really crazy DYI
@@mrbillinsf Retirement boredom can result in crazy projects. I started designing on a Friday and it was completed Sunday evening.
I've had many a AC tech call the low MERV rating "rock stoppers", because that's all they will stop!
Just got new AC, used FPR 10 for my first filter=Merv 13. 2 weeks later the Air Handler starts squealing and squeaking when running full speed. Just figured out it was the AC filter clogged with cat hair and dust and the filter even bent letting air around it. Point is there is a sweet spot between rock stoppers and those very restrictive filters.
Merv 8 or less is ideal. or FPR 4-5
Exactly
@@NoNORADon911 No insult intended, but you cannot tell everyone what is idea. You can only dictate that for your own home/system.
@@MundiTaurus How can I be offended when I don't even know what you are talking about? Learn proper grammar and English and try again. Nobody is dictating what you need to do on here guy.
You do you.
@@NoNORADon911 LOL! Hilarious. Specifically point out my improper, "grammar and English". You're projecting. Learn comprehension. Show one place I even implied you were or would be offended. I said: "No insult intended...". That means exactly what it says, I was not even implying or trying to insult you. Where did I even imply that you are dictating what I need do _"on here"?_ Write clearly.
"Merv 8 or less is ideal. or FPR 4-5"
For who? Everyone? Again: "...you cannot tell everyone what is idea. You can only dictate that for your own home/system."
FYI: YT is not a university English final essay! LOL! Get over yourself.
a very timely video! I live in New Mexico. In the desert! it doesn't matter what filter i buy i can't seem to knock the dust down that gets in the house. This has pointed me in a better direction!
sounds like a MERV5 or MERV7 is best for NM, based on this video.
@@biz4twobiz463 i ordered some merv 8 last week after seeing your video. they are all cheap enough that i can try different ones. the ones i had been buying were merv 13 and i did notice that when changing them every month they were so full of dust and lint that it would be surprising it the heat-a/c unit was breathing at all.
Your home may not be seald and your are pulling in dirt from other places. A smoke test will show you if you have leaks.
During wilfire smoke season, my family runs a box fan pulling air through one of those 20"x25" HVAC filters to clean our indoor air. It works great, since you can run the fan 24/7. The same box fan has been working for years. We also have an air purifier similar to the one from your links, I like having the air quality display.
Have you experimented on dirty air days to see how much sooner the air is clean as indicated by your unit with the display? That is, on a dirty air day, after allowing dirty air to enter the residence, for Test #1, run just the clean air unit and see how long it takes for the display to show a certain "clean air" level has been reached. For Test #2, run both the clean air unit AND the box fan plus its MERV 12 to 14 filter and see how long it takes for the display to show the same "clean air" level as in Test #1. For Test #3, you'd run the MERV 12 to 14 filter with the box fan by itself. Every now and then you'd turn on the unit with the display indicator to measure the "clean air" level. When the same "clean air" level has been reached of Test #1, then you can get an idea of how effective box fan plus filter works based upon the time difference.
@@animejanai4657 that sounds like a good way to quantify the exact difference. When the air was smoky outside, I was less interested in precise measurements and more interested in getting the indoor air as clean as I could get it. The box fan got turned on and left on. I may try to do some testing like you've mentioned the next time the air is smoky.
Project Farm did a pretty comprehensive test of these types of filters. I ended out changing the one I use because of it.
PF…the best!
Project Farm basically showed that MERV 11 was the beginning of the quality filtering of the tiny particles. The MERV 8 was basically for dust particles and large floating things and let a lot of the small particles through.
As for when to swap out your central air filter, it depends on how dirty your household air is. If it is full of greasy air and tiny dust, then you'll need to swap filters out. I run both HEPA and MERV14 air purifiers inside the house, so the central air filter lasts much longer as the amount of dust and pollen in the air is already greatly reduced. I have quality exterior exhaust for the kitchen air plus I never deep fry, so I don't particularly have greasy air mixed with dust that clogs up the central air filter.
@@animejanai4657 yes, airborne grease kills filters very fast. If you have a gas stove and do not have a powerful exhaust hood, you will find sticky oily crap collects on every surface within 3 meters. Exhaust hoods should go directly outside and should have a washable metal filter in them.
Oh it must be the gospel truth then 😂
Thanks heading over to see his video now! Love that guy.
My AC guy installed an Aprilaire media filter on my system -- its a MERV13 but designed for a much longer life due to how much area it uses to filter. They run about $50 a filter, but only need to be changed annually.
I too once installed a higher rating filter which was restricting air flow, and when the unit shut-off, I was able to hear the metal pop as it deflated. I now use an FPR #5 rating, works well and there is no decompression sound after it shuts-off.
I've been using these filters for years. I write the "Change On" date on the filter which usually coincides when my Nest says "Time to replace your filter". I recommended this filter to a friend for her allergies, she can now sleep at night. Just make sure you change them accordingly, if you've been "renovating" or doing anything that produces a lot of dust / air borne debris, change your filter. I've changed a one month old filter once they finished putting in our windows.
I often get told by HVAC experts to to use use EZ flow type filters, and to just change them more frequently. I do use them, and I run free standing air cleaners in the house. The part I don't understand is why you would need to change a coarser furnace filter more frequently than one that traps a lot more dust and debris. If you change them once a month you are throwing away a filter that is still clear. Seems to me you should change the higher MERV filters more frequently, not the lower MERV.
@@crazydoglady5 Furnace filters? Wherever I can find my sizes. Sometimes Walmart, sometimes Amazon, etc.
@@gort8203 I looked on amazon but couldnt find THAT brand.
The high MERV Filtrete filters have a lot more capacity for holding small particles or dust and lint and hair *without* having a high pressure drop. I run my furnace recirculation fan 24 hours a day on the low speed to ensure uniform temperature and to pick up any dust that is generated. Those see through filters might pick up some pet hair but there is no benefit to changing them when they have nothing on them. The higher MERV rated filters are fantastic and you will notice that all the horizontal services in your house are cleaner with those in place
@@crazydoglady5 I but them online and always keep a spare or two. I have to set a reminder on my phone to change them as I don’t notice any and performance over time
@@davidsamsonite5791 I set mine on the fan running constantly and AC man that installed it said not to do that. It feels like dead air without it running so that's why i did it. But havent since. the higher the rating..the less air that can go through them. While i do buy the higher rated ones..i have heard not to do that. I been using merv 11. guess i should drop back. I also have the same air purifier as this fella doing the video. I would like to add another..but dang..the filters are expensive. I found my honeywell 200 has alot cheaper filters....and you change charcoal filter more often.
I agree with your video , stop restricting your ac , IF you have a big problem with your air purity buy an air purifier,
We have a 2000sqft house. I have 3 return vents to the AC/Heater (two 20x20x1" and one 12x12x1). I use MERV8 1" thick on all the return vents and change them every 4 months. They do such a great job that when I change them the filters are obviously dirty. I also lined the return vert housing's so the filters seat with an air-tight seal around their edges - otherwise the dirty air will get pulled into the system around the gaps on the edges of the filter. With a total of 1000sqin of airflow into the blower, it is more than enough airflow to keep the blower from burning out.
I built a simple air purifier using a 20" box fan and five 24"x24"x4" MERV13 filters taped together to form a cube that is taped to the back of the box fan. The MERV13 filters are rated to remove crap down to the bacteria level. Five MERV13 4" thick filters allow for almost unrestricted airflow through the box fan and can recycle a bedroom's worth of air in a few minutes. I built it during the COVID lockdown, but I keep using them. It's about $10 per filter on Amazon.
Neat idea
Those DIY air filters are far better performing than the most expensive air purifier you can buy, HEPA purifiers just don't move much air or they're a jet turbine. Using a merv 13 filter and a fan and your moving so much more air to actually get filtered, and you're actually able to filter the rooms air volume constantly.
Yes I have the same stuff. I stock-up on the filters whenever Costco/samsclub has it on sale. Gets rid of bacon smell too when cooking.
I have been using 20x30x1 Merv 12-14 filters (my partner has major allergies) for more than 23 years (when we bought our new house - first owner). Our A/C and heater units are still working with a perfect bill of health, so to speak. I think we had to replace a compressor once (~$200-$300) in our A/C during that time period. Many technicians are very surprised to see how clean our A/C unit is. We change our filters every 450 to 550 hours (it runs on auto). For the last 12 years or so, we have our A/C maintained/checked every spring and the heater, every two years.
MERV between 8 and 10 are great for winter and 6 through 10 great for summer.
Appreciate the feedback!
I use a regular box fan for white noise when I sleep in which I got a MERV 8 taped to it... I got another box fan I run through the day at the other end of my apartment- that's got a merv 8 taped to the back of it also. The filters get changed every 3 months or when I notice them getting visibly dirty. My lung feels great :)
Do much the same!
Box fan in bedroom with 3x carbon layers
It will work better if the air has a chance to expand use a card bord box betwbetween the filter and the fan. It will be quieter as well.
Just one lung?
I bought a 20-in box fan made by Lasko off of Amazon that has a filter holder in it so you don't have to tape it. I think it's called a dual Flex or maybe an Air Flex.
Look up corthi box, works a lot better than a single filter taped to it
If you look on the end of that filter you will read the MERV number. That 1500 is a MERV 12. I was told by the guy who just installed my new furnace to use filters between 6-8 MERV. He also said to change the filter every month.
You got good advice. Almost every AC tech I’ve talked to has advised against using anything above 8. I think I talked to one out of all of them that said 10 at the highest but he was in the minority. Appreciate the feedback!
@@HowToHomeDIYYou're talking to techs not engineers. Bro please.
@@Slick1020so when the techs agree with the engineers we should then take the information provided by the engineers and throw it in the trash?
After doing much research, i wont go higher than a merv 7 with charcoal. My furnace is from the 80's. When we had the Canadian smoke hovering over us in michigan the pop up tents went from white to yellow in a week. Inside i think the filter did its job. Great vid!! Dont kill your system trying to be as clean as a surgical room!! Merv 8 or lower, charcoal is an option ppl.
I learned this one the hard way. I always replaced the merv1 filters my apartment would install and put in my own (typically MERV 14).
One day I got a call from my wife who told me the AC wasn't working and I asked her to check the filter and she sent a photo of our evap coils behind the filter completely covered in ice. Luckily the ice melted and the unit started working again. Since then I've only used the super low rated filters and have an air purifier.
I tried one of these out. I replaced a cheaper one with it in mid-September once. 3 weeks later I turned the heat on. The furnace kept shutting down. I figured the furnace was older and just needed to be replaced. Had a tech come in and he explained why he did not recommend the filter for my furnace. I explained I had tried this filter for the first time. I still had one of the type of filters I had always used. I placed the new, "previous type" filter in. The furnace started up and ran normally.
Good info as always! I always wondered if the "better" filter put a strain on your unit so I always stuck to mid tier. Also I bought 2 Levoit air purifiers (Core 300M i believe) for my home because I suffer from allergies about 6 months ago, and I would say by far the best investment Ive made. Im no longer sneezing constantly and my eyes dont itch near as much. Good content, even better to know I picked a good brand lol
Yes it will if not sized for opening you can tell when you turn it on by how much noise you here form the air going pass the filter. It shuld not whistle?
@@mathewoliveira9028 thanks for the info!
Problems with these filters occur when people don't change them often enough when the furnace is used to heat not cool. The heat exchanger has insufficient air flow, over heats and kicks off on safety. The filters are however ideal to have on hand when smoke or pollutants are an issue. They can also be placed across the output of a fan in rooms where smoke is an issue and no central hvac in building. Did this for my daughter's apartment when local forest fires created tremendous smoke. Worked great. Again monitor fan for over heating as you are restricting airflow with filter.
I have several AC guys in my family. They say use the cheap filters on the AC intake to keep big gunk out of the main system, the Electric bill down, and keep the load off the system. Buy an air purifier with a HEPA filter to clean the air.
With all due respect, you have the right to your opinion. Most everything you stated isn't based off of real data from distinguished HVAC research authorities who have the data from extensive research on this and many topics in the industry. I've worked with three different HVAC companies in my career over 18 years. I have seen and heard it all. I have experience from the residential, commercial, and industrial areas of the industry. Without going into a long drawn out explanation which I don't have time for, if a contractor knows how to properly size equipment for a home, building etc.. and knows how to properly size the duct system for using high efficiency filters, then there is nothing wrong with using them. Yes there are alternatives to catch particulates and better ways to help purifier the air we breathe. The issue is a lot of contractors do not have a clue. They are not trained properly, use old methods or made up methods to size both. That is where the bigger problem comes from because the equipment life will be shorter, the equipment will have more frequent breakdowns, comfort will be sacrificed, performance as well and on and on. All costing the consumer more on top of the cost of the original install.
They aren’t designing them to use 1” high MERV filters. Most people’s systems just aren’t made for them. Nothing I stated is false and there is plenty of data for it.
@HowToHomeDIY Who isn't designing what for high efficiency filters? And where are your resources for the data you're referring to?
this is good information cause I have used these in the past. I will be switching next season thanks so much 😊
You are very welcome! I remember when it was pointed out to me years ago by an AC tech and it was like my eyes were opened to what I was doing haha. Thanks for the feedback!
I work for an air filter company in NC. We make residential and industrial filters all between MERV 8 and MERV 15. Merv 8s and 10s are for smaller units and spaces. MERV 11 and higher are our industrial filters we make. Top of the line material and company. Filters are made to last about 2 months
Lived in Asia for a short time and had two air filter machines in our apartment. Was a shock each month to see how bad our air tuned the filters black every 30-days
I have a large Veloit air filter in my bedroom. I've had it for 3 years and haven't had one problem. The filter is expensive but it lasts a year. Thanks for the furnace air filter info. Now I know what to buy!
I find that I only like those type of Filtrete filters that have the very many pleats or very high surface area. I used cheap filters and found they would clog up and really block airflow and sometimes even bend out of shape to allow air in. The high end Filtrerte seem to stay cleaner for much longer, which still providing adequate airflow. I don't care about the number, but want the high number of pleats.
My daughter is very allergic to just about everything. These have been a game changer for her. Her comfort and health is all I care about, otherwise I'd get the cheap ones. But, with someone incredibly sensitive to air particles, they do work.
I use a merv 16 filter in my HVAC. 20x20x5 size. The actual pressure drop measured is lower than the merv 8 filters i was given and hasn't changed more than 0.01 wc at 650cfm after 8 months. The rated pressure drop is just 0.10 wc at 650cfm at 0.25 wc at 1400 cfm.
By far the biggest factor to filter restriction is the quality of it. Buy yourself a cheap merv 6 from filterbuy and you'll have more restriction than a well known brand like Honeywell or 3M merv 13. Do some testing yourself or look up some independent testing to confirm.
Merv 13 3m 1900 has one of the lowest pressure drops out there.
Yes, I agree. I also vacuum mine every month or so even tho' it seems clean.
8 months?? Your air must be clean!!
I've been using those green EZ flow filters in my house since it was new 9 years ago in both units. Never had a single issue with the AC.
QUESTION: Do you have to keep buying hepa filters for that air purifier if so how often and how much? 🤔
I have one that i keep in my room. It tells me when to replace it and after having for about 2 years i have only replaced the filter once. the price of the filter is dependent on which purifier you get tho.
I have been using electrostatic filters for 30 years. Take them out hose them off every 90 days. They have carbon in them as well which removes odors etc.
NO. Use MERV 8 and call it a day. Merv 8 keeps your household air clean and your AC clean as well without undue airflow restrictions. Replace it when it's dirty (2 to 6 months; most common is 3 months) - it will depend on your particular house (pets, location, cooling/heating use, etc.). Also consider an air purifier for your bedroom and other rooms, especially if you don't use your AC or Heat year-round and/or have allergies.
I'm local to a supplier Airstar in Boca Raton and he ships. I have his filter frames. He sells the filter material that goes in the frames. I change both filters (2 units) every month. I buy a years worth of filters at a time. It comes out to a good cost savings once you have the frames. I had an ECM blower motor go out after 1.5 years. These don't like static pressure (restriction) This is a 4 year old house now. This is also before I started using these filters. I was using those high merv ones previously. I have since cut panels in my A/C closet doors and installed custom louvers for more return air. The builders A/C company wanted $700 labor to install the warranty blower motor. I bought an ECM rescue motor for $300 and installed it myself. I also installed UV lights in both units.
I have been using merv 13 filters for the past 10 years and they never caused any issues with my system. My electric bill is increased less than 5% and I have excellent air quality.
Curious how frequently you change filters. Wife and I have no kids, but a few pets - I currently use MERV 8 filters that change color as they deplete and they last 3-4 weeks at most. It’s a 2T heat pump system with 1 return and 8 registers.
The thing is, it MIGHT not be effecting him as much as it could others depending on his unit and setup. It could also be effecting things more than he thinks. But there are HVAC techs in the comments and most of them that you will talk to will almost never recommend a MERV 9+. Some may go to 10. The good air quality can be achieved in other ways that won’t be possibly detrimental to the system or electric bill.
Ac expert here. If the unit can't breathe, it runs inefficient. When people say no problems with unit, I say how do you know. They don't. Some people wait until the unit fails before they admit damage. It's called denial.
When I put a higher MERV filter in my furnace it would collapse because of the force of the air flow. I solved the problem by replacing the 1 inch filter with a 2 inch filter. By doubling the thickness of a pleated filter it doubles the surface area and allows double the air flow. So happy with the outcome.
You've pretty much confirmed half of my strategy here - my furnace/AC is running a fairly low-MERV filter to maximize airflow.
However, HEPA filters often don't move enough air to get things purified. They're great at removing things from the air that they do move, but they don't move much. A filter that moves enough is going to cost you a LOT of money.
I have a high-MERV 20x20x1 furnace filter attached to the back of a box fan running on Low instead. It filters far more air for the dollar. I don't have the space for a Corsi-Rosenthal setup (4 filters in parallel making a cube with the fan), but those can move significantly more air than a single-filter setup.
Apparently putting it on the front with some enclosed space between the fan and the filter can further increase airflow and so efficiency
Yeah I can attest to this. My 1 year-old ac shut itself down one day I thought it was blown. The technician came in and said the AC was fine but the switch box that the AC was hardwired into was blown. Turns out that the AC has a little bit of intelligence and it understood that filter was restricting airflow so it worked harder to achieve the same performance, thus drawing more power. Sometimes it's not the AC that can't handle the airflow, it's the wiring and whatnot in your house. After that I used 1/3 of a sheet of filter to let more air through. In the end I just got an air purifier unit. Just get a dedicated thing. You are in the space all day. The air you breathe is worth it.
How often do you have to replace the stand alone filters and what is the yearly cost?
Great video. I had the same filter but mine is a MERV 13. It trapped a lot of dust and debris but made my unit run harder in the summer and froze my coils. Now I'm having to defrost the ac unit. I did call a local HVAC company and that was the first thing he asked me is what MERV rating I have. He did tell me to go with anything between 5 and 8.
Yup. Very common. You got some good advice from him! Thanks for leaving that feedback.
Project Farm tested and found higher pleats with better material and higher MERV can have better air flow than low MERV with bad material and few pleats.
Thank you! I watched this video a long time back and it changed how I purchased my filters.
Yep. The Filtrete 1500 has really high pleats and good flow, better than their 1200 filter. Found a website that tested Filtrete and other filters that they sold I switched from the 1200 to the 1500. Been using the 1500 filters for nearly 20 years, never have called AC guy. I get annoyed by people just yacking about filters with zero evidence to back up the claims. Filter material and higher pleats make a big difference in performance.
@@Taluvian I agree with you. I have been using the 3M filtrate and never had a problem.
@markmalyn3861 3M Filtrete is a brand and model. I never said anything about the two as a product. 3M makes some of the best filters on the market. That’s not what the video is about though or what I was referring to. It’s all about the MERV rating regardless of brand.
@@HowToHomeDIY I've been using the 4 inch 1550 3M filter without any problems.
Restricted air flow will affect your air handler. I realized this when I had to replace the fan motor due to bearing failure, however a lot of people don't know that if you "completely" restrict the air flow to the air handler the fan will free wheel and draw very little current and there will be very little to no air flow. I personally use a MERV rating of 13 because I have a high level of allergy to dust mites and it does make a difference. I replace the filter every month or so based on time of use. In addition to this, when vacuuming carpet I also use a 20" box fan in conjunction with a 20" x 20" x 2" MERV 13 filter or higher. This option is less costly than the very expensive single room air purifiers and will exchange the air in an average size room in about 20 minutes. People don't realize how much dust vacuums put in the air. One thing I found out about filters is that if you notice your return making noises related to air leakeage around the filter or if the air filter is deformed and appears concave (which means the air handler fan motor is drawing lots of current) its time to change the filter to a different design or rating that solves the issue. I have maintenance experience in HVAC, Electrial, Mechanical and predictive technologies since 1976 and have held level 3 certifications in IR thermography, Oil analysis, motor analysis, ultrasonic analysis, Power Quality analysis and have 10 years experience in vibration anaylsis.
Wait! Did I just watch a 12 minute advertisement? You never addressed the fact that in many new homes there are multiple air returns, each with an air filter, and not just one at the furnace. For example, my home has 4 returns. This dramatically increases the total number of square feet available for air to pass through which reduces the load on the HVAC system. Also, that 3M filter has roughly 2-3 times as many pleats as the cheaper filter you showed. That represents 2-3 times the surface area for air to pass through and is another way the load on the HVAC system is reduced. Having said that, I too wouldn't use the 1500 series filters. I do use MERV 11 filters in my system as I believe they provide an good compromise between air flow and air filtration. My HVAC system is 27 years old and the fan, etc. is doing just fine. Project Farm has done actual data driven testing of HVAC filters. I would recommend your viewers check out his videos.
No you watched a 12 minute video on what has been passed on to me by actual HVAC techs (every single one of them) and what I have personally been using for years that I paid for myself. I am giving the info I have and providing what I use as people ALWAYS want to know. Your house is different than many. Mine is newer and there is one. Either way I wouldn't use the higher MERV filters. But do as you please!
Agree with both of you. We really need someone to test these various filters out after putting gunk them. Can measure draw from the fan, filtered air quality effectiveness after said gunking, and/or measure airflow to determine if this is just knowledge passed along in which we don't know the original idea behind it.
@@HowToHomeDIY Fair enough and I sincerely apologize for accusing you of something you did not intend to do regarding advertising on your channel. Having said that, after 45 years working in a data driven profession (physics), I stand by my comments regarding air filters. As offensive as it may be, the “opinion” of HVAC technicians doesn’t do much for me and that’s why I advocated your viewers consult actual testing results of various filters on sites like Project Farm. History is replete with examples of “facts” that were eventually debunked when someone actually bothered to collect the data. I believe your viewers would be better off if you did that here.
@@SignorLuigi And that is YOUR opinion. Which you are entitled to.
@@HowToHomeDIY I would have hoped for a more reasoned and reasonable response to a request for actual experimentally determined data to support the argument you made in the video. Aristotle would have loved you. Galileo, not so much.
I use both. The same name, brand, and size. The round levit ones clog way too fast. Cost much more. Now, I only use the 3m hvac filters on a box fan. 4 of them to 1 box fan. They last months vs a week, and the air is definitely cleaner with the 3m by far. You can see it work. The round ones that are over 100 bucks and then 30 buck filters are good for already clean homes in a room. I have 2 dogs, the box fan, with 3m, do the best hands down, and no comparison.
HVAC tech here,Never use anything above Merv 8 we get calls all the time for failures caused by the filter. Especially with newer units the added restriction to the airflow presented by the filter causes high limit switch on the heat exchanger to trip over and over until it fails..
We can remote monitor the performance of "certain" systems we install and can see if the high Limit trips using Merv-11 thru Merv-16 Filters. This has not been the case after our installations as the set up is very specific. These type of systems always use Variable Speed DC Current Blowers. So, it's not the case every time. I do agree that bad filtration can cause hi-limit actuation.
@@VisionStance do you monitor your systems using Mobile Tech?
@@pedrojorge3221 We Monitor the Variable Capacity Systems and others that have Communicating Equipment with WIFI Capability from Lennox & Trane Systems. This info is privileged and in our Mgr. office. Can't wait for the newer systems that come out witch we can diagnose with our phones!
@@VisionStance we are a Comfortmaker Dealer. All ICP brands new lineup are programmed on site by the technician using a phone or a tablet and an app called Mobile Tech. We can also diagnose the unit remotely. Pretty soon will be out of a job. lol
Bro you're a tech. You're not an engineer. I've never had this brand of filter crash an HVAC system and I've lived in practically every state and used them all the time.
Would have liked to see how you clean the air purifier filters, or do they get replaced.
How do you clean the air purifier filters?
Charcoal? How much does it cost to be replaced?
He showed cleaning the outside screen in the video.
@@johnpicard4909 as you said that is the screen, not the filter itself.
I use a Merv 4 pleated filter in my system and I change them every 4-6 weeks depending on how much the unit is having to run.
Can you tell us where you find MERV 4 filters? I find that the stores mainly stock the really high numbers.
@@marct9587 Home Depot house brand.
Please note that the MERV 12 has more folds than the MERV 6. Therefore, the MERV 12 has a larger area for air to pass and thereby counteracting the effects of the thicker material.
Great note!
Questions is how much the diffrence will be.
The more surface area the better. Automotive filters too. Deeper and more numerous pleats are needed. If you can hear your filter popping inward when the air turns in it’s probably impeding too much flow.
Every hvac person I've talked to told me to use the cheapest filter to extend the life of your unit. I stay with merv 5. Had my home built in 1999 and i still have the original ac and furnace.
Great video. With 4 cats and a dog, we would benefit from a stand alone air purifier. The Levoit brand seems to have excellent reviews.
I have two Levoit air purifiers and a humidifer, and I love them all.
I use a washable filter that has a static draw to capture the dust. It was amazing the 1st month that I used it.
They don't last very long!
We have been using a MERV 11 for many years and was ok'd by our heating and air people, they also said don't go any higher. haven't noticed any diminished air flow. We just had our duct worked cleaned which has cut down on the amount of dust.
You won’t notice the reduced airflow. The issue is the strain on your unit from the increased pressure.
@@johnpicard4909 Thanks for the info! We might invest in an air purifier and then buy some MERV 6 or 8.
Last couple of times I went down to Lowes, the lowest Filtrete type filter in 20x30x1 I could find was 1800. Literally, it was the ONLY choice.
The facts are that the pressure drop curves vs face velocity (or air flow for a given size) are published for all of these filters. So, you can look up the information and what you find is that there are high merv filters that don't have a particularly high - or excessive - pressure drop. So, those can be used in an HVAC system. As long as you keep your system static pressure drop within the limits of your air handler manufacturer, your system should work just fine.
You can't simply make blanket statements and say a high Merv filter is bad and restrictive. It might be, it might not be any more restrictive and might actually be better than a lower Merv filter. It depends of the surface area of filter media and the specific filter technology (electrostatic tweaks to the media). Why don't you get a digital monometer and do the actual measurements for the filters instead of creating a advertisement for room air filters.
Blah blah blah. Yeah that helps but it’s still restricting the air more than a MERV 5 or 6 but quite a bit more and when it starts getting dirty it’s way worse.
Someone who gets it! The real issue is with the HVAC industry. They use too many rules of thumb. There needs to be a gauge that measures the pressure drop and signals when the filter is too restrictive for the air handler. Why aren't skilled HVAC techs recommending an actual solution? Is it because they weren't trained or didn't investigate? Imagine if vehicles didn't come with a gas gauge. Mechanic "just put in 20 gallons every 3 days". That statement is meant to make the reader think a little. Yes, on a long trip you'll run out, other days you will overflow the tank (waste). FYI. Dwyer sells a differential pressure gauge for ~ $100. Every house is different, the frequency of filter changes will vary seasonally. An HVAC system can be designed to clean the air. Regarding the proposed solution of separate air cleaners: it increases user maintenance. Check the air cleaners' web site. 3 different filters, 3 different change intervals. Average homeowners don't change 1 filter regularly. P.S. This is meant to help educate. The video is helpful for those who don't want to go deeper.
Amazing how many people have no idea they are suppose to replace their furnace filter. I saw one house where it was so clogged it actually tore the center out and it was flapping with the air flowing causing an annoying airflow up down noise in the registers. Just crazy.
Very, very... very-very-very; very useful.
Thank you sir.
I’ve been running these filters for 19yrs on my same unit. Zero issues… and believe it of not my ducts are clean as hell.
Very helpful. Thank you.
You are very welcome! Really glad to hear you liked it. Thanks a lot for the feedback!
Had a system with a five inch thick pleated filter in the attic, right before the air handler.But we kept dogs, and those hugely expensive filters clogged with dog hair. I put cheap cheap cheap glass filters in the downstairs return grill and replaced them every other month. They collected a huge mat of hair and other crap, and the big filter upstairs lasted much longer.
I use these.. and have suspected they are not good for the handler.. and my installer said. Had to replace both AC units 18months ago. Ugh. Thanks for the video. I swap these out every 60 days.. and they cost a fortune. They are merv 11. Need merv 6-8.
You replaced the outside AC unit or you had to replace the heat exchanger inside the house? The only reason to replace those is if they are so dirty they cannot be cleaned!
@@davidsamsonite5791 replace both units, both sides.. 1 month apart. 100 new now.
Thank you for this video!! I see below a fellow engineer tried to school you. Though I am an engineer i have to point out experience counts for a lot. I am sure you've seen your share of systems destroyed by restricted airflow. Basic fluid mechanics and air flow compensation built into most systems at work.
I use merv7 , and a fiberglass filter(roll) at the air intake vent to remove pet hair/bigger particles
I use a MERV 16 and replace the filter every 2 to 3 months
depending on seasons.. My airflow is good and after removal the filter is stained brown to black in a non-smoking home.. I would never use a MERV one and will take my chances on lower flow and replacing the fan motor to achieve cleaner air.. I also have a separate air purifier that I cut and place a Merv 16 with a carbon oversheet and I Have found that I seldom have to dust the house... Lol..
I’d advice changing it monthly. That’s a lot of dust it’s capturing.
Haha, it's the pressure difference between the air going into and out of your heating/air-conditioning system.
Mine is 5 inches of water column, recommended. So the total resistance of return ductwork, supply ductwork, wet air-conditioning coil, heat exchanger, and filters should add up to no more than 5" W.C.
Pick the best filter you can get that doesn't push your system over the "W.C." limit!😢
Air filters are not intended to remove `normal household dust`- everything that makes up dust is heavy enough to fall out of the air long before it can hit an air filter. Neither will running an air filter make you have to dust less.
When I replaced / upgraded my HVAC, I arranged for my intake air to be filtered twice.
The first filtering happens as the air enters the air return duct. Here I placed a rinsable, relatively coarse filter. This filter catches large dust, pet fur, and the like. When dirty I simply remove, rinse off, and return to use.
At the furnace I place the best / finest filter I can find. This filter catches everything else. With my pre-filtering, this filter typically does last three months of peak use.
Filter expense? Often you can save as much as 50% simply by buying the filters three or four (a case) at a time. Spare filters are stored in the furnace closet.
I can highly recommend removing 1" filters from the system and installing a 4" or even 5" filter housing on the intake side of the air handler.
The increased air flow for the same given MERV rating is super easy to prove with a manometer and a simple inspection of the filter media. When you destructively remove the 1" filter media from the cardboard it is in, you can measure the square footage of it. Then compare that to the square footage of the media removed from a 4 or 5" filter's cardboard frame. The difference is night and day.
If you want the single most cheapest and effective whole home filtration solution you should start with a MERV 10 or MERV 11 5" filter in a 5" filter housing on the intake side.
Then if you want to add HEPA filtration for bedrooms or living spaces where you spend a lot of time, you can run those longer between cleanings because they don't get dirty as fast
The 4" filter housing that was easy to add 2 my two 5-ton air handlers have kept my coils clean for 7 years. They were inspected in the last year and the HVAC Tech confirmed for me that the coils were like new.
I 100% agree that high MERV 1" filters decrease the airflow across the coil too much. I've seen it first hand. Slow airflow leads to icing over more quickly which leads to even less airlfow and higher humidity in the house.
As the tech in the video already knows, low airflow across the coil will also increase the pressure inside the refrigerant lines. Higher head pressure means a lot more work / more wear and tear on your compressor. The more efficiently you get the heat to transfer across the coils both inside and outside, the less stress there is on the compressor.. this is also why it is important to clean your heat pump coils outside carefully.
I know with first hand experience it is possible to have better air flow and better air filtration. There is absolutely room for high filtration units in rooms, but that doesn't mean you can't filter the air more efficiently before those filters finish the job.
Tried all kinds of filters. In the end I settled for a lower merv filter, replaced it more often, and set a fan-only % cycle to keep the air moving now and then when it didn't need to run heating/cooling for a while.
Yup I settled for an inexpensive MERV 8 filter with good air flow and changing it every 30-60 days.
This video could not be more spot on. Another tip is don't waste money on brand name filters for your air handler, like Honeywell. There are aftermarket filters that are every bit as good, and they are MUCH less expensive, especially if you buy them by the case.
Not all filters are the same. One brands merv 8 filter can be significantly lower restriction than another, it's not a restriction rating as material quality makes a huge difference. If they don't have testing data for initial airflow resistance you should not buy it!
Generally the cheap filters are noticably restrictive, like filterbuy, compared to something like 3M or Honeywell Merv 13. I can give an example as well, the merv 8 filters that were white label branded by the HVAC company I used tested about the same to slightly worse than Honeywell branded merv 13 filters I bought, both the same dimensions. A merv 16 filter from Lennox that was 1 inch thicker tested lower than all of them and after 8 months of 24/7 blower circulation it's not really increased much.
When I used these charcoal filter type air purifiers, I had problems with thick mucus that would wake me up in the middle of the night to hack- brownish and causes coughing. The charcoal filter is the culprit. When I stopped using the purifiers I stopped getting the mucus
You are conveniently overlooking the cost of the filters for those air purifiers. I had a Levoit air purifier and the cost for replacement filters ranged from C$50 to $80 !! It was also only rated for a single room. I threw it out and use only Merv11 filters in my furnace - replaced every 60 days. My furnace fan has run 7/24 for 9 years without a problem.
I said they take filters in the video. Mine aren’t nearly that expensive so not sure where you were buying them from and I have had the same filters in mine for around a year now, just keep cleaning the outside. Will probably finally need to replace them later this year. Your furnace doesn’t run 24/7. If it does it’s probably because you’re starving it with your MERV 11 filters 😂
@@HowToHomeDIY My furnace does, repeat does, run 24/7. It is a 3 speed. Low speed when no a/c or heat. Medium speed when a/c or heat is called for. High speed after 15 minutes if thermostat temperatures not achieved. It was installed in 2015 and, except for occasional power outages, has not stopped since. Filters for the Levoit were genuine OEM from Amazon. Remember these are Canadian $. Edit - the current cost of filters for my unit (on Amazon) ranges from C$107 to C$148. It’s cheaper to buy Merv11 filters.
I use a merv 5 3M pleated. 18 bucks for a 4 pack. Change usually once a month unless usage is less. Unit is now 26 years old.
Can you quantify how much more electricity is needed when using a high-MERV filter, and how much more quickly the added strain will cause the HVAC blower to need service?
You actually use less electricity! But thats because your unit is doing less work(not moving as much air!
>petersmart1999 : I'm very skeptical of your claim, because even if less air is moved, there's more friction that the motor needs to overcome. You need to also count the energy that heats the motor (hotter than if there's easier air flow).
You can look it up,itd a fact
No worries,It played my brain when I was proven wrong a long time ago.Just didnt make sense,but it does now!
>petersmart1999 : I just googled it, and all the results say you're wrong. Cite a source that says you're right.