What they don’t tell you about before home dehumidifiers: Home humidity needs to be looked at like home heat energy, meaning what things are in you home that can be causing the high moisture? Do you have a very leaky house? Do you have a very tight house? Is your AC pulling away the humidity from your home as it should? When your HVAC blower is running does it create a negative pressure in your home? Do you have a water leak in your home that you are unaware of? Do you have an excessive amount of plants in your home? Do you run your AC too low or too high? Do you have a crawl space and if so does it have a vapor barrier? I’ve found that if you can address these issues first, it could lesson your need for a whole home humidifier. Don’t obsess over getting your home to 50 or below relative humidity, when 60RH to 50RH are fine numbers to have as well. If you wanna know what 35 RH feels like, I can tell you, because I’ve had my Aprilaire unit for 2 years now. 35 RH at 72 degrees feels like a dream when coming in from hot outdoors weather, and getting out of a hot shower. The feeling of water evaporating from your skin so rapidly is an amazing feeling, absolutely so, but there’s a catch 22! Your skin, eyes, nasal pathways, and throat suffers from the lack of moisture in the air. It’s something you don’t notice right away, but when you wake up in the mornings with dry eyes, dry mouth and throat you soon realize how some moisture in the air isn’t such a bad thing. Another thing that happens with a wood construction home is the wood will sometimes shrink. We all experience this sometimes when some doors closes well in the winter but not so well in the summers or vise versa. It can literally cause your wooden boarders (crown moldings) to shrink enough that it cracks. The bottom line is purchasing a whole home dehumidifier can be a life changing event in a good way, or it can leave a sour taste in your mouth. They are not for everybody who can afford one. Mine averages about 750w when in use, and it does have a noticeable compressor hum like all heat pumps have.
I’m on the fence with whole house dehumidifiers. The amount of water I pick up from my 5 conventional units on wheels (set at 45), using fans to aggravate air, with my thermostat set at 75, when it’s a hundred degrees out , is insane amounts of water. But damn, it feels good… I just don’t see how using a new random return cut out in 1 hallway ceiling, or using my existing air returns could do what I am already doing in my 3,000 sq ft home. Pulling up that much water!? All that vapor in my ductwork!? Part of my job is understanding microbial growth and I see a problem with inviting that much water vapor through ductwork. Not to mention, not keeping the RH equal in all areas of my home, like I have now, I can testify from using my hygrometer.
@@sp1200M3D the single whole home until is the way to go if you’re using 5 units. It’s overall more efficient and you don’t have to worry about it because it takes care of it’s. If you do by one get the biggest unit you can afford and install a dedicated return. Humid air is lighter the dry air so put the return in the highest conditioned space of your home and you’ll be fine.
@@twosawyers Thanks for your input man! Have you tested each room to see if they are all adequately dehumidified? I just can’t see how 1 return can dehumidify a whole 3,000 sq ft house. I get what you’re saying, but damn, that’s a lot of water, and my biggest concern is having moisture all over the inside of the flex connected to that 1 return.
@@sp1200M3D the indoor humidity will typically equalize throughout the house. You can run a stand alone unit in one room and the rooms at the other end of the house will still see a drop. It’s not like temperature where you can have hot rooms and cold rooms.
*We liked it **Fastly.Cool** so much in the basement, we bought a second one for the main level. The amount of moisture it pulls out of the air is astonishing.*
I have had a very checkered experience with the whole house, dehu. I have had more ultra-stars (a pair of April-Air's, too) than I can remember, and all have failed. The company was great and shipped many new units even outside their warranty period, but none have lived long. I have given up and lived with what the air handler can squeeze out of the air and a plain jane crawl space big box dehu. If I could find an HVAC tech that offers the skill sets you demonstrate, I might be inclined to try again, but not sure they exist around here.
Wow! Great teacher! And very interesting. I have some family with a beach house on a slope where the first story is again set a hill and often can see 70% humidity. I love the step by step formula breakdown!
I like the explanation you provided in your video. There is one thing that is of concern is bringing into the living area any air from the crawlspace. Viewing it from an indoor air quality (IAQ) standpoint, the crawl space is often a source of rodant droppings, mold spores, the possibility of Radeon, and odors of different types. Yes, a HEPA filter can remove most of the bad stuff but won't do anything for Radeon or other odors. It would be best to bring in fresh outside air for the fresh air intake port on the dehu. The crawlspace should have its own dehu without a fresh air makeup.
Micah, in a typical crawlspace I may agree, but mine is far from typical. Perhaps the cleanest air in the whole house down there, since there’s no people, cooking, or cleaning products at work. Also, radon is mitigated with a fan-driven system, very important I agree.
@@HomePerformance it's hard to think of, and cover every situation that could be involved with IAQ and all the factors involved in a relatively short video. You still did pretty good in addressing the subject. I would like to see the HVAC industry embrace IAQ training as a standard. The two industries go hand-in-hand. To often I've seen HVAC companies think that they are helping their customers but because of not being throughly trained in IAQ they have created an undesirable situation for their customers. Some HVAC engineers and companies have independently seen this need and embraced this training. It would be nice to see it across the board.
Well we’d be happy to have you join our members, since we’ve created the first ever TV show about all of what you’re wanting to become mainstream knowledge! If you want to participate: patreon.com/homediagnosistv
I actually watched this a second time and came up with a new question. When the Utra-Aire dehumidifier runs, is there some control line from the Ultra-Aire back to the HVAC system to run the main fan to distribute the dehumidified air throughout the house?
I'm a custom builder, and chose to run the Ultra Aire SD-12 in my own home here in SW Florida. It is a split unit, so the compressor is outside, and we are pulling in fresh air from outdoors. I figured the heat load we're introducing from bringing in outside air is being (at least partially) offset by not having the one piece unit introducing additional heat load inside the house. Or at least that was the theory. :-) We've got two dogs and a cat, so a lot of fresh air was important for indoor air quality. (Update, UA is now Santa Fe and they disco'd the SD-12...)
Very informative video! I got a little bit confused on the calculations at 12 minutes 30 seconds. I think you meant to say density of air is 0.075 lb/cu ft instead of 0.75. Thanks again for the information.
I live in a cheaply built 1986 1600 sq ft colonial foot home in central MA with 2x4 construction with only a boiler. Basement is about 400 square feet and I just spray foamed 2-part closed cell spray foamed all the exposed 2x4s four inches thick which made a huge improvement but the 50% that of spaces is concrete walls are left as is. In the hot humid summer my cold basement pipes sweat. I have a Poured concrete floor mostly above grade and a 400 square foot garage which I assume is a lost cause due to leakage of two medium priced contractor grade garage doors. Upstairs is a door seperating the two levels that leads to a 400 square foot living room which leads into 200 square foot dining room and 150 foot kitchen and then 3rd floor is 260 square foor master bedroom, 160 foot bedroom and 110 square foot bedroom each with doors for privacy. The attic is sealed off unconditioned space. The 260 square foot bedroom has a 9500 btu LG dual inverter AC and the 160 footer has the U-Shaped 8000 BTU Midea. Should i just place a 6k humidifier in the basement and another 6k on the 1st floor? I dont care about house temperatures or humidity except in two larger bedrooms that have oversized variable units. Should i just put a 6000 btu stand alone 1990s dehumidifier in the basement and a 50 gal AO Smith Hybrid H20 heater in the basement and one in the 1st floor and call it a day? I dont care about comfort, I just dont want my house to rot, warp or get moldy and Im cheap. We work and sleep in the two larger bedrooms. Am i being paranoid beliving that my house will rot if I dont do more than what i just listed. I have modern vinyl two pane argon filled widows and even installed insulated glass storm doors myself on the front and rear enterances.any advice is appreciated. Its all a cost/benefit calculation to me. Am i slowly destroying my home by not doing more or doing a full expensive Mini-split install complete with manual-J and blower door tests?
Hello I just buy a aprilare e 130 and i was asking my self if i need an air conditioner system to run my aprilaire of it can work stand alone only de humidifing Thanks great video!!
@@HomePerformance Ha- Regarding caulking the windows shut- We just emerged from a brutal wave of humidity in upstate NY which has prompted me to re-evaluate my pretty tight house's exhaust only ventilation setup. Our old AC window units need replacing and I'm planning a larger ventilation upgrade to include an ERV, and I'm exploring AC and dehumid options. Today, the weather is cool, dry and beautiful. September is generally a month where we start opening the windows again. Do you open the windows on beautiful days, or have you "caulked the windows shut" to maintain air control? The shoulder months here can be quite nice and I'd like to be able to open the windows without sending whatever "system" I install into overdrive if the outside humidity is slightly higher than the equipment set point. Thankfully, my family does not suffer seasonal allergies; we're pretty tolerant of humidity and temperature swings and enjoy being outside. In other words, I don't seek the absolute control you have, I just want to control the extremes. How can one incorporate open windows into the system or is that a pipe dream? Thanks, I love your channel.
6 pts / kwh @ 120 pts / day = 20 kwh / day. @ 20 c/kwh = $4 / day or $120 / mo. when operating at full nameplate capacity. That's a real expense! I live in an old leaky house in a humid mid-Atlantic climate and I can keep my indoor RH at 45-50% just by running a reasonably sized a/c set to 73 deg F. What are doing and where do you live?!?
Great video, you are an amazing teacher. I see the outlet of the dehumidifier goes to the outlet of the HVAC air handler. Wondering where the inlet to the dehumidifier comes from? I will install a dehumidifier and new HVAC soon. One vendor recommended taking the air off the inlet to the HVAC air handler, while another said it is important that the dehumidifier have an independent return from the house, which of course is more difficult. If you see this, I would appreciate your thoughts.
This seems to be the best place to pose a dehumidifier question, since viewers are not afraid of tech and numbers. I have a common Hisense portable unit of the 50 pint persuasion, which draws 600W when the compressor runs. This concerns me. Almost all the Wattage is exhausted through the top as hot air, which serves to noticeably warm the area, and has to be evacuated by the central AC. I propose to enable the pump and send the condensate to a radiator mounted above the unit, and then let it drain as before, to a floor drain or laundry tub drain. The goal would be to capture some of the heat before it could warm my home. This seems so obvious that I wondered why no manufacturer builds in such a feature. Could it be that doing so would not improve the efficiency rating as it is measured; even though it would benefit the consumer? It would be hard to explain why the consumer should pay an extra hundred dollars, and very few customers would be savvy enough to understand it. I'd buy it though. I'd even buy an add-on unit, IF the idea even works. Any thoughts? Keep in mind that I'm envisioning capturing perhaps half of the 600 Watts of heat, and that condensation is not a concern.
Very cool thank you. I have a 1840’s house in MA that has like 80% RH in the basement since I started monitoring it in January. There’s rot damage down there in structural members which I’ll be repairing but I also wonder if and at what point in the process I should get something like this. Just opening the door (walk in basement) drops the RH like 15%. So maybe I just need to ventilate more for now. Half of the basement is still dirt floor. So. You know. Lol
Thanks for your replies! I will get poly and put it on the dirt part. How much does sealing it off matter though? I wonder if I should go up the walls with it too. Part of the 2 brick walls that are the above grade walls of the walk in basement are on 2 sides of the dirt. I intend to add a concrete slab that’s insulated and has a water control layer but I feel like getting the moisture content down ASAP would be a good idea.
Since you are ducting into the HVAC supply, will you need to ensure the central air handler runs whenever the dehumidifier runs? Won't this be more costly to run the central blower instead of keeping the dehumidifier supply seperated?
Couple of years late, but I did watch this a while ago, the first time. Great information and it helps me with a humidity problem I am tackling in, of all places, Arizona. During monsoon season, the humidity in the house is unreasonable and the flooring is buckling. Anyway, question about your crawl space and your system. You are intentionally pulling air from your crawl space and directing it into the living space. Radon is a concern in homes and it starts in the crawl space. We try to keep it from entering the home by pulling the soil air and directing it outside. What you have is doing the opposite. Do you have thoughts on this/have you tested for radon? Thank you.
Hi! Great program, thank you. I have a question re mold and humidity, how do you deal with this issue and also can you do deep clean the dehumidifier. I thank you in advance for your response.
Great video good sir. Here in hot humid Southeast Louisiana, will will be installing this into a totally encapsulate unvented attic. I was contemplating zoning my dehumidifier to do the attic as well as the house. Also bringing in my fresh air from outside the home/attic space. Just curious what's your crawlspace psychometrics look like? I'm assuming all your ductwork is uninsulated in down there? How are you controlling the humidity levels down in the crawlspace to prevent condensation on your duct and equipment?
Thanks Supercool- and the crawl temp and RH is exactly the same as the living space above. In an attic, that is a little harder to do because the sun beats down so hard.
Great video. I'm in Louisiana. What settings would you suggest on venting and fan on a new 2600 square foot home with only my wife and I? I did spray foam the roof deck with open cell, so the house is pretty tight. We are both retired so at home most of the day.
You didn't really talk about how the dehumidified air (from either dehumidifier) gets into the living space other than to say it is piped into the supply side (duct) of the main heat/AC unit. Is the main heat/AC air handler running constantly (maybe at variable or stepped speeds) to carry the dehumidified air or is there a 1-way damper to ensure the dehumidified air doesn't travel backwards as well as forwards in the main ductwork? I suspect the air handler is running constantly to (also) provide constant filtration and de-stratification regardless if there is a "call for heat" or "call for AC".
@@HomePerformance Is there a way to prevent backflow of air if you don't wish to run the fan 24/7? My two story with 2 systems, fresh air intake plus two returns for the first floor, and media filters just in front of the evaporator coils, is a challenge for my A/C guy. Since I have a huge volume of space that is common to up and down spaces--2 story ceiling in family room, adjacent stairway and 2 story space with chandelier, I was thinking of making the dehumidifier a standalone system with return and supply both upstairs near the open space. Since dry air is heavier, it will "fall" down anyway. It would also eliminate tapping to the existing ductwork. Conceivably, I might or might not connect the fresh air duct to the dehumidifier or leave it connected to the downstairs unit. Sound feasible?
Caesarean-if you have a basement lots of walls doors, it’s not that simple. I. An open barn without a basement the air at ceiling will be more musket. In most north American houses with full basement though and anything less than the most obsessive mositure proofing (and air tightness)of foundation, most humidity will be berated through concrete wall. So basement is almost always the most humid area of house. In two zone system, I would just pull air from the bottom systems return and return the dry air into the that HVAC systems output BUT with caveat well downstream from your a coil ! At least ten feet imo-if can’t do that just install, a separate return into largest in basement. I would, avoid what most dehumidifier manufacturers suggest , ie ducting HVAC return to dehumidifier return, than that air returning dehumidifier output to HVAC return-the potential for ‘short circuiting’ is real.
I've been watching several of your videos and I am aware that ductless mini splits do not dehumidify well but you made a comment that utilizing a ducted air handler "mini split" was better and that you would discuss this in another video. Can you point me to this video or where I can learn more about the differences in latent heat removal between the two systems. I understand I can read some of the published data but want to understand the control strategy and science behind this.
Love your videos! Quick question, what kind of flexible duct did you use or recommend to use to decouple dehumidification or even HVAC equipment from metal duct? I have looked into vibration isolation devices, but they are terribly expensive. Just trying to accomplish better acoustics affordably. Thanks.
Can/should you put one of these in a crawlspace if the crawlspace doesn’t extend to the whole home and is more adjacent to the basement? I’ve been looking at ventilating dehumidifiers as I’m trying to remediate moisture issues in the basement as well as average 60% humidity in a dual zone system. One zone sits over the basement (and a portion over a crawlspace) the second zone sits over the garage. Looking for options.
GREAT VIDEO! quick question, i understand you are pumping the air out of the dehumidifier into the whole house supply plenum (after the ac) now what about the return duct? Where are you pulling your air from? did you build independent returns in extreme points of the house? Would love more detail on That! Thanks again!
Thanks- you can go way deep on our duct system here: ua-cam.com/video/MCKTOAyN9kM/v-deo.html Central return, no extreme returns at all, since the ventilation system pushes/pulls as well.
Thanks for the video! We live in Alberta, Canada where we have major swings in humidity. I’ve installed a new VARIABLE-CAPACITY GAS FURNACE with a MERV 16 filter and HRV system in a 1960s home we’ve been slowly renovating. We’ve been working on sealing the house up, and have gotten it to a point where the HRV is required. We don’t have any cooling in our system yet (we plan on putting a heat pump into the system in the future, which our furnace can accommodate). My question is, with our HRV dumping fresh humid air into our return duct, should we hook up the dehumidifier to pull from below the HRV supply and dump it back into the supply before the MERV 16 filter so it can still filter the air coming in from the HRV? Thank you for all the great information you two are putting out!
Thanks for following, Bryan- no, I don’t think the amount of humidity you have in Alberta is anything to worry about on the incoming HRV side. Such a small amount of humid air (maybe 150 cfm) mixing with a huge amount in the return (maybe 1000 cfm) should be no problem, as long as you have that dehumidifier anywhere in thr chain it should do its job fine.
Thanks for this, Corbet. My home has a concrete block foundation so it's not sealed - would this still be my solution for my humidity problems or am I supposed to be looking more for ventilation solutions? Thanks!
Yes, seal first to remove the sources- cheaper, easier, only one time if you do it right. Then machines that are expensive, use energy, and must be maintained and replaced.
greetings. thanks for sharing. we have a home on the beach in central california where the humidity is always too high. If we were to install a dehumidifier in this home, would the water that is produced be ok to water the outdoor landscaping? we live in an area where water is scarce and very expensive, so if we could use the water from the dehumidifier we could solve two problems. Do you think the water would have too much salt to be helpful?
Hi! I have a heat recovery system in my house in the UK, it's a very old house with some mud and straw (cob walls) the humidity outside is 80-95% and inside we manage to get 60% am looking into a inline dehumidifier into the system have you got any experience with how it affects a heat recovery system
Should be fairly straightforward, though depending on incoming temps you may want to use a dessicant dehum, like the brand ECOR Pro. Video forthcoming.
How can i verify that my unit (same as the one here) is actually working properly? My production builder's contractor installed it and they did a bad job on the HVAC so I don't have much confidence this was done right either. We have a long return duct (about 20ft or more) to the unit. They originally had the return installed in a tight kitchen/mud area corner next to the garage entry door and a side exit door. It was a bad spot so we had them move it which created a longer duct but not much choice.
I’m desperately trying to figure out how to dehumidify with a split system in place. I am in Austin, TX, and it’s essential. I was thinking of putting a couple feeding into the medium static boxes on each side of the house. the supply coming out are very small and there are multiple in these boxes sold by like Mitsubishi and Daikin. Do I have to decouple my dehumidification? I’m going to be on Solar off-grid and trying to optimize.
Hey corbet How long does your dehum run on average in a day. I was curious in real life experience as i have a dedicated dehum for 3 yrs like you but i dont have as air sealed house, house size, etc. As i tighten up my house, im always looking how it affects my dehum run time, so i assume you might have the target dehum run time. I expected the dehum to catchup faster after a shower than 1 to 2 hrs on a 90pint 1,000sqft in birmingham. Your info has gotten me into home performance, thanks Shelby
Great video! Question about the ventilation part. So I would think you would want separate control of ventilation air and recirculation through the dehumidifier. The April Aire E100V with 8190FF provides control of either recirc or ventilation that it auto electronically controls based on settings. The SanteFe you show appears to just bring a mixture of recirc and ventilation air dependent on a manual damper on the ventilation input. Is this true and what are your thoughts on this. I like all features of the SanteFe except not having separate control. Thanks!
Hi Corbett, could you explain the math for pints/hr please? You are multiplying by 1/8 then multiplying by 8 a little later in the equation, it would seem they cancel? Is the pounds per hour the same as pints per hour as 1 pint is one pound? Forgive me for being nit picky, your tuition is fantastic I just got mentally stuck at this equation
The 8s are for different things, the first 8 is part of the equation for delta, his delta just happens to be 8. The 2nd is just a conversion from pounds to gallons, so his resulted in pounds per hr and to convert to gallons per hour then water weighs 8 pounds per gallon, so 1/8 is 0.125
@@HomePerformance I will reach out to Santa Fe direct to see if they have any... Additionally - I am curious about your install...from your previous videos, it seems that you probably handled this install yourself. However, I understand that Santa Fe will not honor their product warranty unless it is installed by licensed installers? How did you handle this side of the project? Many thanks for all you do.
You’re right- it intimidated me less than the Mitsu heat pumps, but I had our HVAC superstar duo Kaleb Saleeby and Brent Ridley start this up. I ducted and hung the whole thing though.
By slightly opening the fresh air input duct, you are satisfying one objective I have for some dehumidification for the basement/crawlspace. What about the attic? Do you supply dehumidified air to the attic or use the method to create a slight negative pressure for a conditioned attic to help manage the humidity in the attic?
Great video, you mentioned florida. What’s your take on a ventilating dehumidifier vs having an ERV system for balanced ventilation and a separate dehumidifier (not ventilating)
I don’t know that anybody’s building very airtight in FL- an ERV only becomes necessary once you’re down around 1 ACH50. I’d go ventilating dehum any day.
You just briefly mentioned the MD33...how is this working for you? Would this be a viable whole house dehumidifier for a tiny house or small home? It seems that being able to wall mount it would be a huge space savings plus the drain line is a perk.
Can you take the fresh air from an ERV fresh air discharge side, (not the stale air exhaust to outside vent), and put it inline or on the intake side of a dehumidifier unit? I live on Texas gulf coast, it’s pretty much high humidity year round, 360 out of 365 days. We are building a recording studio with open cell insulation on the outer wall of the double walls, so it’s air tight.
Best Video I've seen on this topic. Thanks so much. I'm building a new home in central FL and was thinking this might be a more affordable upgrade with a better ROI than stepping up to top of the line Variable Speed systems since the main attraction to me is making the house more comfortable. I also absolutely love my Ecobee Thermostat which I believe will control a dehumidifier. Am I correct that the Ecobee's work well with this type of setup? Also does the Air Handler have to be on while the dehumidifier is running or does it push enough air by itself?
Thanks Jack! Not sure about an Ecobee here, but I keep our air handler running on low continuously for filtration and mixing. As long as it can’t make a feedback loop, you shouldn’t have to do that if you don’t want to. Return and supply far enough apart would do the trick.
I believe they don’t need to communicate. They would set the controlling sensor(inside grate) to whatever value produces a desired result as measured by the sensor outside the grate. Clear as mud?
How do you like the MD33? I have a 2 story home in Central FL. Upstairs is normally around 60%-65%. One of the bigger units like you have in the crawl space isn't really an option for my home.
Try it- it works well. BUT, 33 pints/day is not very big, you can get standalone dehums at 50 pints/day, and if you need to experiment a little it’s easier if you can move the unit around or buy multiple.
If the dehumidifier supply is ducted to supply of air handler is there a damper to keep the ac from blowing back through dehumidifier? If so if both are running at the same time can the dehumidifier over come the blower from the AC ?
Hello Corbet, I've been watching you for some time and first- thank you for all these videos. So much to learn.. Question(s) for adding the dehumidifier to the supply; 1: does the positive static pressure from the HVAC cause (meaningful) backflow in the humidifier? 2: does it the dehumidifier meaningfully increase the static pressure putting extra strain on the air handler?
It does not- you can see how this 250 CFM fan deals with static pressure in the specifications: www.santa-fe-products.com/wp-content/uploads/sites/4/2021/05/Santa-Fe-Ultra120-Data-Sheet.pdf And the air handler is set up to deal with up to 0.8 iwc, the highest pressure capability available. The pressure in the supply plenum should be 0.2 iwc max with both of these fans running.
When Exhausting/Supplying from/to more than One Area/Room/Locations, How do you maintain Suction/Supply Air? I notice a Significant drop in Air Suction from Exhaust and Decrease in Supply Air when I "Tee" in to more than One Area. The 6in Ducts drastically drops the air movement after I "Tee" Off into Any Location. How do You Overcome this?
Questions. A) do you run the Mitsubishi fan while the dehumidifier is on or is the fan in the unit able to circulate the air? B) 40 percent humidity in Georgia is fantastic how do we determine what’s appropriate for us? I’m in Illinois at 50% with a 69 degree home I would like to get to 40% and raise the set point to 72 degrees. Does the heat from the dehumidifier condenser cancel out the cold evaporator coil that’s doing the work?
Hey Adam- yes, the heat pump fan runs on low speed continuously. And the air is still cool with the added dehum heat, as shown in the testing portion near the end of the vid.
Great video as always, been a long time viewer and fan of the channel. I recently purchased an aprilaire e100 and was trying to determine the best course of routing the dehumidfied air into my ductwork. Can someone with ductwork experience help me out? I am tryning to figure out how to duct my dehumidfier into my supply side but am concerned about back flow. I have a supply plenum that I can duct into but I was concerned that just pumping the air into the plenum would push air back to the AC return which my Dehumidifier return will be near. Alternativly I can maintin the seperate return idea but wye the dehumidifier into the return side and maintain a better flow.... Am I over thinking the flow?
Put a butterfly damper at the supply plenum connection to prevent backflow- everything will be fine, the e100 only pushes 300ish chm and it will not want to send it back thru the heat exchangers and coils and filter to start a feedback loop.
@@HomePerformance will the built in damper of the e100 serve this propose or should I add an additional one? Thank you again for the advice, explanation of the principals behind the advice, and making it accessible to a homeowner who is just trying to do things the right way!
Thank you so much. Very informative. I have a question for you. For homes in the north Georgia area, would you recommend in ERV with a whole home dehumidifier or just a dehumidifier with a fresh air intake similar to what you have in this video? The equipment will be going into an unconditioned attic.
First I’d recommend putting your HVAC into a conditioned space, but as far as ERV vs Ventilating Dehu goes, watch this: Borderline of Balanced Ventilation: When Bath Fans Won't Work, and an ERV Becomes Necessary at Home ua-cam.com/video/lnOCAPPVT5g/v-deo.html
@@HomePerformance it’s an existing home so that’s not really an option. I had already watched that video and was planning to route all the bath exhausts to the ERV and then I started to watch Dehu videos and saw many people recommended using them with a fresh air intake in lieu of an ERV which confused me. It sounds like you would recommend removing the bathroom fans and ducting their exhaust out of the house through an ERV while also adding a dehu in a completely different duct system without a separate fresh air intake?
Multiplying by 0.125 is the same as dividing by 8, and then the next step was multiplying by 8, which cancels out the previous step. So it looks like one pound can be treated as the same as one pint.
Can you link the drill bit and sized plugs. I have had challenges finding matching plugs for access points made in ducts. I’m in Florida and we primarily have fiberglass duct boxes and flex hose ducts.
Do you still need bathroom exhaust fans with this setup? I'm in FL and the home I purchased doesn't have exhaust fans in the bathrooms. I was going to just have them installed but I'm considering a whole house dehumidifier instead.
Thanks for the show and topic. I'm building in a tropical location in Australia. I'll build in a dehumidifier however am wondering if one intake point and one exit would be adequate to dehumidify to whole house. Thinking humidity would equalize throughout the house.
One exit is ok as long as you keep you duct as short as possible to allow adequate air flow. I would suggest to have adequate return Grill size for a pre-filter before it gets to the dehumidifier. You can never go to big to supply the dehumidifier.
Ok can you tell me exactly how you have this running, is it running in the ductwork for the ac system without the ac being on and if so where are you pulling in coming air from is it in the house or outside only?
Since you've added a whole-house demudifier, do you still think the ERV was the better call over the HRV? It makes the systems a little more redundant, which the engineer in me loves, but it also adds a bit more cost, where I've found HRVs are cheaper than ERVs. It also seems that HRVs are more widely recommended for bathroom exhaust, whereas ERVs are just slightly more questionable.
@@HomePerformance Either an ERV takes some of the load off the demudifier while also supplying pre-tempered fresh air, or the demudifier does all the work, but either way the same amount of work has to be done. So I'm not entirely sure an ERV with dedicated dehumidification beats an HRV with dedicated demudificarion. Oh wait, Matt Risinger agrees with you. You're a genius, Corbett! ERV all the way. Maybe I just really want the Fantech Hero series and I'm sad it's only an HRV.
I’m sad about that too, fellow nerd, trust me. Try Broan if you want an EC motor. Also, remember that as much as you can cut down on contaminants (like humidity), the better- the dehum only grabs air from one return location, probably central- meanwhile, your ventilator delivers air into all bedrooms. Bedrooms have LOTS of soft stuff, which will soak up the moisture before the dehum gets to do its job. Therefore, ERV.
@@HomePerformance Ya, I have a Fantech VER150 modeled out in my house 3D model for that same reason. HRV vs ERV was more a thought exercise. Honestly a $400 difference between ERV and HRV isn't much when compared to to total cost of a home. Get hardwood or countertops, tile that are a little cheaper per square ft and make it up there. As someone and married to someone with Ehlers-Danlos Syndrome and the wonky effects contaminates especially have on our bodies, I'm very much following your lead on the IAQ of the home.
You shouldn't have been moving the sensor used in the duct. Reason being the wind are vectors or forces in a direction. As physics would dictate moving the sensor tip towards or away the direction of the wind flow can minus/divide or adds/multiply respectively force wind. But then again air tightness is critical and helps in out air flow
I am a Hvacr tech and I just now came across my first customer requesting a dehumidifier. Your input helped educate me on the subject. P.s. My son (6yrs old) was also captured by your vid. When you started the math portion, he ran to grab his Etch-a-Sketch and wrote your formula on his board! 🤣🤣🤣
What's the point of running AC at the same time? The whole point of the dehumidifier is to save energy by not running AC during warm/cool "shoulder" seasons.
@@HomePerformance how can it get out of control if AC is running just by itself? Unless the house is sitting on a swamp, AC does a great job by itself. But those shoulder seasons is a different story. Running AC when your home temp is already at 67F makes it uncomfortable. That's when a dehumidifier is a great addition. I'm in Massachusetts so maybe it's different here
Why would you not want to pipe it directly into the return of the a/c? I understand its not ideal (say if the fan of the a/c is off or something, but will it actually hurt anything? I have a situation where I can only really access two spaces of the return ducting, the supply isn't wide enough and there are trunks going upstairs and one going to the main floor, and above the a/c unit the trunk isn't wide enough to fit 8 or 10 inch collar.
Gotta do what you gotta do, Chad. But it degrades the efficiency of your A/C and removes the drying power from it as well. Oversize the dehum if that’s the case.
The way this is explained does not make physical sense to me. How at time stamp 8:49 does a "heated" output of the dehumidifier cause a 90 plus degree environment to decrease to 76.7 degrees??? I have a floor-standing unit in my basement and am researching to install this type of ducted system. However, even the floor unit directions indicate that where you run this 70-pint-per-hour floor unit will have an ambient temperature increased by about five degrees. I have observed this effect while running the unit at max output. So how are you saying that your unit is sending heated and dehumidified air into what is evidently the duct with the supply or post-conditioned area, and having it magically be decreased to below 90 degrees?. (Are the "supply" and "return" terms being swapped here???)
Haha, it could, I suppose, be filtered, but it wouldn’t be worth the trouble and expense for most people. We used to put our condensate thru a Berkey when we lived in our offgrid tiny house.
@@HomePerformance Thanks. My unit has a dry mode which keeps the humidity in the 40's even on hot days here in Northern California. I'm not sue what the humidity will be like in the winter yet. Hopefully the system can control the humidity then also.
@HomePerformance how much heat is acceptable? I have one of those portable dehumidifiers and its adding 15F to the outgoing air. It defeats the porpose because the AC is kicking on more often and dehumidifying the house
I'm sure your explanations are good, but some people are better with a written/drawn explanation. Consider adding some white board time or animations to put your videos over the top and reach more folks. Some of what you were saying about the temperature before and after the ducts and which ones were connected where was just too much without some sort of diagram. ***Edit*** Kept watching, and voila, visual aids. Would still like to see a diagram of the ductwork and airflow you're talking about.
@@HomePerformance I'm in the humid part of paradise. I think its officially called oceanic sub tropical. Go south a bit and its a lot drier and a bit cooler. I think its that humidity that causes more housing issues than people like to admit which is why full house dehumidifier is worth looking at.
This exact piece of equipment will be going in my home in about 2 months in the Atlanta area. Your timing is perfect!!!!
Good work Neil!
Great video! Love the tip about using the outside air intake of the dehumidifier to slightly pressurize the house to prevent air infiltration!
What they don’t tell you about before home dehumidifiers:
Home humidity needs to be looked at like home heat energy, meaning what things are in you home that can be causing the high moisture? Do you have a very leaky house? Do you have a very tight house? Is your AC pulling away the humidity from your home as it should? When your HVAC blower is running does it create a negative pressure in your home? Do you have a water leak in your home that you are unaware of? Do you have an excessive amount of plants in your home? Do you run your AC too low or too high? Do you have a crawl space and if so does it have a vapor barrier?
I’ve found that if you can address these issues first, it could lesson your need for a whole home humidifier. Don’t obsess over getting your home to 50 or below relative humidity, when 60RH to 50RH are fine numbers to have as well. If you wanna know what 35 RH feels like, I can tell you, because I’ve had my Aprilaire unit for 2 years now. 35 RH at 72 degrees feels like a dream when coming in from hot outdoors weather, and getting out of a hot shower. The feeling of water evaporating from your skin so rapidly is an amazing feeling, absolutely so, but there’s a catch 22! Your skin, eyes, nasal pathways, and throat suffers from the lack of moisture in the air. It’s something you don’t notice right away, but when you wake up in the mornings with dry eyes, dry mouth and throat you soon realize how some moisture in the air isn’t such a bad thing. Another thing that happens with a wood construction home is the wood will sometimes shrink. We all experience this sometimes when some doors closes well in the winter but not so well in the summers or vise versa. It can literally cause your wooden boarders (crown moldings) to shrink enough that it cracks.
The bottom line is purchasing a whole home dehumidifier can be a life changing event in a good way, or it can leave a sour taste in your mouth. They are not for everybody who can afford one. Mine averages about 750w when in use, and it does have a noticeable compressor hum like all heat pumps have.
I’m on the fence with whole house dehumidifiers. The amount of water I pick up from my 5 conventional units on wheels (set at 45), using fans to aggravate air, with my thermostat set at 75, when it’s a hundred degrees out , is insane amounts of water. But damn, it feels good… I just don’t see how using a new random return cut out in 1 hallway ceiling, or using my existing air returns could do what I am already doing in my 3,000 sq ft home. Pulling up that much water!? All that vapor in my ductwork!? Part of my job is understanding microbial growth and I see a problem with inviting that much water vapor through ductwork. Not to mention, not keeping the RH equal in all areas of my home, like I have now, I can testify from using my hygrometer.
@@sp1200M3D the single whole home until is the way to go if you’re using 5 units. It’s overall more efficient and you don’t have to worry about it because it takes care of it’s. If you do by one get the biggest unit you can afford and install a dedicated return. Humid air is lighter the dry air so put the return in the highest conditioned space of your home and you’ll be fine.
@@twosawyers Thanks for your input man! Have you tested each room to see if they are all adequately dehumidified? I just can’t see how 1 return can dehumidify a whole 3,000 sq ft house. I get what you’re saying, but damn, that’s a lot of water, and my biggest concern is having moisture all over the inside of the flex connected to that 1 return.
@@sp1200M3D the indoor humidity will typically equalize throughout the house. You can run a stand alone unit in one room and the rooms at the other end of the house will still see a drop. It’s not like temperature where you can have hot rooms and cold rooms.
@sp1200M3D you can add more returns in other rooms if you want more peace of mind, but you don't need too.
*We liked it **Fastly.Cool** so much in the basement, we bought a second one for the main level. The amount of moisture it pulls out of the air is astonishing.*
I have had a very checkered experience with the whole house, dehu. I have had more ultra-stars (a pair of April-Air's, too) than I can remember, and all have failed. The company was great and shipped many new units even outside their warranty period, but none have lived long. I have given up and lived with what the air handler can squeeze out of the air and a plain jane crawl space big box dehu. If I could find an HVAC tech that offers the skill sets you demonstrate, I might be inclined to try again, but not sure they exist around here.
Just replaced this one too, Richard. I hear you.
Wow! Great teacher! And very interesting. I have some family with a beach house on a slope where the first story is again set a hill and often can see 70% humidity. I love the step by step formula breakdown!
Hey, thanks Doug!
Best video I've seen ever on ventilation in florida.
Thx man
I wish the guy from Crawford Services, who had sold me my HVAC unit ,was AS knowledgeable as this guy. Subscribed.
I like the explanation you provided in your video. There is one thing that is of concern is bringing into the living area any air from the crawlspace. Viewing it from an indoor air quality (IAQ) standpoint, the crawl space is often a source of rodant droppings, mold spores, the possibility of Radeon, and odors of different types. Yes, a HEPA filter can remove most of the bad stuff but won't do anything for Radeon or other odors.
It would be best to bring in fresh outside air for the fresh air intake port on the dehu. The crawlspace should have its own dehu without a fresh air makeup.
Micah, in a typical crawlspace I may agree, but mine is far from typical. Perhaps the cleanest air in the whole house down there, since there’s no people, cooking, or cleaning products at work. Also, radon is mitigated with a fan-driven system, very important I agree.
@@HomePerformance it's hard to think of, and cover every situation that could be involved with IAQ and all the factors involved in a relatively short video. You still did pretty good in addressing the subject.
I would like to see the HVAC industry embrace IAQ training as a standard. The two industries go hand-in-hand. To often I've seen HVAC companies think that they are helping their customers but because of not being throughly trained in IAQ they have created an undesirable situation for their customers. Some HVAC engineers and companies have independently seen this need and embraced this training. It would be nice to see it across the board.
Well we’d be happy to have you join our members, since we’ve created the first ever TV show about all of what you’re wanting to become mainstream knowledge! If you want to participate: patreon.com/homediagnosistv
I actually watched this a second time and came up with a new question. When the Utra-Aire dehumidifier runs, is there some control line from the Ultra-Aire back to the HVAC system to run the main fan to distribute the dehumidified air throughout the house?
Yes, but we don’t use a feature like that because our air handler runs on circulate mode (low speed) 24/7.
I'm a custom builder, and chose to run the Ultra Aire SD-12 in my own home here in SW Florida. It is a split unit, so the compressor is outside, and we are pulling in fresh air from outdoors. I figured the heat load we're introducing from bringing in outside air is being (at least partially) offset by not having the one piece unit introducing additional heat load inside the house. Or at least that was the theory. :-) We've got two dogs and a cat, so a lot of fresh air was important for indoor air quality. (Update, UA is now Santa Fe and they disco'd the SD-12...)
Nice, Paul- no avoiding extra heat in FLA
Paul, can you recommend an installer in central Florida. We need this in our home
Mo, try Kalos Services. Good reputation in our circle.
Very informative video! I got a little bit confused on the calculations at 12 minutes 30 seconds. I think you meant to say density of air is 0.075 lb/cu ft instead of 0.75. Thanks again for the information.
Thanks Bill- and I think there’s a coefficient in there that’s hidden, I might not have explained it fully.
Sitting in climate zone 5, looking forward to your future discussion on humidification! But still a useful video.
Right on Andrew
Easy to setup and powerful 👌.Connects easy to Google home assistant, voice commands work well.
I'm in Houston, and really really enjoyed this. Think I know what I'm about to purchase.
Lol you're right. I am so lost
I live in a cheaply built 1986 1600 sq ft colonial foot home in central MA with 2x4 construction with only a boiler. Basement is about 400 square feet and I just spray foamed 2-part closed cell spray foamed all the exposed 2x4s four inches thick which made a huge improvement but the 50% that of spaces is concrete walls are left as is. In the hot humid summer my cold basement pipes sweat. I have a Poured concrete floor mostly above grade and a 400 square foot garage which I assume is a lost cause due to leakage of two medium priced contractor grade garage doors. Upstairs is a door seperating the two levels that leads to a 400 square foot living room which leads into 200 square foot dining room and 150 foot kitchen and then 3rd floor is 260 square foor master bedroom, 160 foot bedroom and 110 square foot bedroom each with doors for privacy. The attic is sealed off unconditioned space. The 260 square foot bedroom has a 9500 btu LG dual inverter AC and the 160 footer has the U-Shaped 8000 BTU Midea. Should i just place a 6k humidifier in the basement and another 6k on the 1st floor? I dont care about house temperatures or humidity except in two larger bedrooms that have oversized variable units. Should i just put a 6000 btu stand alone 1990s dehumidifier in the basement and a 50 gal AO Smith Hybrid H20 heater in the basement and one in the 1st floor and call it a day? I dont care about comfort, I just dont want my house to rot, warp or get moldy and Im cheap. We work and sleep in the two larger bedrooms. Am i being paranoid beliving that my house will rot if I dont do more than what i just listed. I have modern vinyl two pane argon filled widows and even installed insulated glass storm doors myself on the front and rear enterances.any advice is appreciated. Its all a cost/benefit calculation to me.
Am i slowly destroying my home by not doing more or doing a full expensive Mini-split install complete with manual-J and blower door tests?
Hello I just buy a aprilare e 130 and i was asking my self if i need an air conditioner system to run my aprilaire of it can work stand alone only de humidifing Thanks great video!!
Looking at this exact unit for my home in the near future. Now if we could just stop opening the windows when it's raining outside!
Haha that’s maybe the only good reason to caulk windows shut. Living with other people IS good for us in the long run tho
@@HomePerformance Ha- Regarding caulking the windows shut- We just emerged from a brutal wave of humidity in upstate NY which has prompted me to re-evaluate my pretty tight house's exhaust only ventilation setup. Our old AC window units need replacing and I'm planning a larger ventilation upgrade to include an ERV, and I'm exploring AC and dehumid options. Today, the weather is cool, dry and beautiful. September is generally a month where we start opening the windows again. Do you open the windows on beautiful days, or have you "caulked the windows shut" to maintain air control? The shoulder months here can be quite nice and I'd like to be able to open the windows without sending whatever "system" I install into overdrive if the outside humidity is slightly higher than the equipment set point. Thankfully, my family does not suffer seasonal allergies; we're pretty tolerant of humidity and temperature swings and enjoy being outside. In other words, I don't seek the absolute control you have, I just want to control the extremes. How can one incorporate open windows into the system or is that a pipe dream? Thanks, I love your channel.
6 pts / kwh @ 120 pts / day = 20 kwh / day. @ 20 c/kwh = $4 / day or $120 / mo. when operating at full nameplate capacity.
That's a real expense!
I live in an old leaky house in a humid mid-Atlantic climate and I can keep my indoor RH at 45-50% just by running a reasonably sized a/c set to 73 deg F.
What are doing and where do you live?!?
Great video, you are an amazing teacher. I see the outlet of the dehumidifier goes to the outlet of the HVAC air handler. Wondering where the inlet to the dehumidifier comes from? I will install a dehumidifier and new HVAC soon. One vendor recommended taking the air off the inlet to the HVAC air handler, while another said it is important that the dehumidifier have an independent return from the house, which of course is more difficult. If you see this, I would appreciate your thoughts.
Aw thanks David- best case is a dedicated return (mine is essentially that) but better to have the dehu than not at all. Perfect is the enemy of Good.
This seems to be the best place to pose a dehumidifier question, since viewers are not afraid of tech and numbers. I have a common Hisense portable unit of the 50 pint persuasion, which draws 600W when the compressor runs. This concerns me. Almost all the Wattage is exhausted through the top as hot air, which serves to noticeably warm the area, and has to be evacuated by the central AC. I propose to enable the pump and send the condensate to a radiator mounted above the unit, and then let it drain as before, to a floor drain or laundry tub drain. The goal would be to capture some of the heat before it could warm my home. This seems so obvious that I wondered why no manufacturer builds in such a feature. Could it be that doing so would not improve the efficiency rating as it is measured; even though it would benefit the consumer? It would be hard to explain why the consumer should pay an extra hundred dollars, and very few customers would be savvy enough to understand it. I'd buy it though. I'd even buy an add-on unit, IF the idea even works. Any thoughts? Keep in mind that I'm envisioning capturing perhaps half of the 600 Watts of heat, and that condensation is not a concern.
Very cool thank you. I have a 1840’s house in MA that has like 80% RH in the basement since I started monitoring it in January. There’s rot damage down there in structural members which I’ll be repairing but I also wonder if and at what point in the process I should get something like this. Just opening the door (walk in basement) drops the RH like 15%. So maybe I just need to ventilate more for now. Half of the basement is still dirt floor. So. You know. Lol
I would do a vapor barrier on the open floor at a minimum. Even something like cheap plastic would be a big improvement
Yes, stop the incoming moisture as much as you can, and get a Santa Fe standalone to just sit in your basement- your body will thank you too.
Single biggest reduction in moisture in my place was from putting poly down on the dirt under the floor. Its a must have for any home.
Thanks for your replies! I will get poly and put it on the dirt part. How much does sealing it off matter though? I wonder if I should go up the walls with it too. Part of the 2 brick walls that are the above grade walls of the walk in basement are on 2 sides of the dirt.
I intend to add a concrete slab that’s insulated and has a water control layer but I feel like getting the moisture content down ASAP would be a good idea.
@@kenmarcou if you get 90% coverage you get 90% reduction in moisture coming out. Below grade walls i do not know.
Since you are ducting into the HVAC supply, will you need to ensure the central air handler runs whenever the dehumidifier runs? Won't this be more costly to run the central blower instead of keeping the dehumidifier supply seperated?
Couple of years late, but I did watch this a while ago, the first time. Great information and it helps me with a humidity problem I am tackling in, of all places, Arizona. During monsoon season, the humidity in the house is unreasonable and the flooring is buckling.
Anyway, question about your crawl space and your system. You are intentionally pulling air from your crawl space and directing it into the living space. Radon is a concern in homes and it starts in the crawl space. We try to keep it from entering the home by pulling the soil air and directing it outside. What you have is doing the opposite. Do you have thoughts on this/have you tested for radon? Thank you.
Hi! Great program, thank you. I have a question re mold and humidity, how do you deal with this issue and also can you do deep clean the dehumidifier. I thank you in advance for your response.
Hello Mr. Corbett, Great videos! thank you. Please tell us what pipe insulation that you've added over the line set? Thank you!
Thanks for following- that lineset came pre-insulated from Mueller-Streamline.
Great video good sir. Here in hot humid Southeast Louisiana, will will be installing this into a totally encapsulate unvented attic. I was contemplating zoning my dehumidifier to do the attic as well as the house. Also bringing in my fresh air from outside the home/attic space. Just curious what's your crawlspace psychometrics look like? I'm assuming all your ductwork is uninsulated in down there? How are you controlling the humidity levels down in the crawlspace to prevent condensation on your duct and equipment?
Thanks Supercool- and the crawl temp and RH is exactly the same as the living space above. In an attic, that is a little harder to do because the sun beats down so hard.
"Thanks for comming to my crawlspace" subscribed
Haha thx
Great video. I'm in Louisiana. What settings would you suggest on venting and fan on a new 2600 square foot home with only my wife and I? I did spray foam the roof deck with open cell, so the house is pretty tight. We are both retired so at home most of the day.
You didn't really talk about how the dehumidified air (from either dehumidifier) gets into the living space other than to say it is piped into the supply side (duct) of the main heat/AC unit. Is the main heat/AC air handler running constantly (maybe at variable or stepped speeds) to carry the dehumidified air or is there a 1-way damper to ensure the dehumidified air doesn't travel backwards as well as forwards in the main ductwork? I suspect the air handler is running constantly to (also) provide constant filtration and de-stratification regardless if there is a "call for heat" or "call for AC".
Yes to all, David- good questions. There’s a fantech butterfly damper in the dehum output duct, and the fan runs on low 24/7.
@@HomePerformance Is there a way to prevent backflow of air if you don't wish to run the fan 24/7? My two story with 2 systems, fresh air intake plus two returns for the first floor, and media filters just in front of the evaporator coils, is a challenge for my A/C guy. Since I have a huge volume of space that is common to up and down spaces--2 story ceiling in family room, adjacent stairway and 2 story space with chandelier, I was thinking of making the dehumidifier a standalone system with return and supply both upstairs near the open space. Since dry air is heavier, it will "fall" down anyway. It would also eliminate tapping to the existing ductwork. Conceivably, I might or might not connect the fresh air duct to the dehumidifier or leave it connected to the downstairs unit. Sound feasible?
Caesarean-if you have a basement lots of walls doors, it’s not that simple. I. An open barn without a basement the air at ceiling will be more musket. In most north American houses with full basement though and anything less than the most obsessive mositure proofing (and air tightness)of foundation, most humidity will be berated through concrete wall. So basement is almost always the most humid area of house. In two zone system, I would just pull air from the bottom systems return and return the dry air into the that HVAC systems output BUT with caveat well downstream from your a coil ! At least ten feet imo-if can’t do that just install, a separate return into largest in basement. I would, avoid what most dehumidifier manufacturers suggest , ie ducting HVAC return to dehumidifier return, than that air returning dehumidifier output to HVAC return-the potential for ‘short circuiting’ is real.
I've been watching several of your videos and I am aware that ductless mini splits do not dehumidify well but you made a comment that utilizing a ducted air handler "mini split" was better and that you would discuss this in another video. Can you point me to this video or where I can learn more about the differences in latent heat removal between the two systems. I understand I can read some of the published data but want to understand the control strategy and science behind this.
Don’t have that vid yet, Dave, but I’ll work on it!
Love your videos! Quick question, what kind of flexible duct did you use or recommend to use to decouple dehumidification or even HVAC equipment from metal duct? I have looked into vibration isolation devices, but they are terribly expensive. Just trying to accomplish better acoustics affordably. Thanks.
Can/should you put one of these in a crawlspace if the crawlspace doesn’t extend to the whole home and is more adjacent to the basement? I’ve been looking at ventilating dehumidifiers as I’m trying to remediate moisture issues in the basement as well as average 60% humidity in a dual zone system. One zone sits over the basement (and a portion over a crawlspace) the second zone sits over the garage. Looking for options.
GREAT VIDEO! quick question, i understand you are pumping the air out of the dehumidifier into the whole house supply plenum (after the ac) now what about the return duct? Where are you pulling your air from? did you build independent returns in extreme points of the house? Would love more detail on That! Thanks again!
Thanks- you can go way deep on our duct system here:
ua-cam.com/video/MCKTOAyN9kM/v-deo.html
Central return, no extreme returns at all, since the ventilation system pushes/pulls as well.
Thanks for the video! We live in Alberta, Canada where we have major swings in humidity. I’ve installed a new VARIABLE-CAPACITY GAS FURNACE with a MERV 16 filter and HRV system in a 1960s home we’ve been slowly renovating. We’ve been working on sealing the house up, and have gotten it to a point where the HRV is required. We don’t have any cooling in our system yet (we plan on putting a heat pump into the system in the future, which our furnace can accommodate). My question is, with our HRV dumping fresh humid air into our return duct, should we hook up the dehumidifier to pull from below the HRV supply and dump it back into the supply before the MERV 16 filter so it can still filter the air coming in from the HRV? Thank you for all the great information you two are putting out!
Thanks for following, Bryan- no, I don’t think the amount of humidity you have in Alberta is anything to worry about on the incoming HRV side. Such a small amount of humid air (maybe 150 cfm) mixing with a huge amount in the return (maybe 1000 cfm) should be no problem, as long as you have that dehumidifier anywhere in thr chain it should do its job fine.
Thanks for this, Corbet. My home has a concrete block foundation so it's not sealed - would this still be my solution for my humidity problems or am I supposed to be looking more for ventilation solutions? Thanks!
Yes, seal first to remove the sources- cheaper, easier, only one time if you do it right. Then machines that are expensive, use energy, and must be maintained and replaced.
Fantastic explanation as always. Loved the numbers. How does ERVs perform instead of having a dedicated dehumidifier system as you have
I’ll show you that too, Squeek, stay tuned
Whats more interesting is the difference in humidity between erv and hrv especially with a run counter on the dehumidifier.
Looking forward
greetings. thanks for sharing. we have a home on the beach in central california where the humidity is always too high. If we were to install a dehumidifier in this home, would the water that is produced be ok to water the outdoor landscaping? we live in an area where water is scarce and very expensive, so if we could use the water from the dehumidifier we could solve two problems. Do you think the water would have too much salt to be helpful?
Hi! I have a heat recovery system in my house in the UK, it's a very old house with some mud and straw (cob walls) the humidity outside is 80-95% and inside we manage to get 60% am looking into a inline dehumidifier into the system have you got any experience with how it affects a heat recovery system
Should be fairly straightforward, though depending on incoming temps you may want to use a dessicant dehum, like the brand ECOR Pro. Video forthcoming.
@@HomePerformance thanks for the speedy response! Look forward to the video!
How can i verify that my unit (same as the one here) is actually working properly? My production builder's contractor installed it and they did a bad job on the HVAC so I don't have much confidence this was done right either. We have a long return duct (about 20ft or more) to the unit. They originally had the return installed in a tight kitchen/mud area corner next to the garage entry door and a side exit door. It was a bad spot so we had them move it which created a longer duct but not much choice.
It’s in the installation manual, Kelly, but I’ll also add it to my list of videos to make.
Super great presentation and content.
I’m desperately trying to figure out how to dehumidify with a split system in place. I am in Austin, TX, and it’s essential. I was thinking of putting a couple feeding into the medium static boxes on each side of the house. the supply coming out are very small and there are multiple in these boxes sold by like Mitsubishi and Daikin. Do I have to decouple my dehumidification? I’m going to be on Solar off-grid and trying to optimize.
Thanks for this great video. Highly informative !
Hey corbet
How long does your dehum run on average in a day. I was curious in real life experience as i have a dedicated dehum for 3 yrs like you but i dont have as air sealed house, house size, etc. As i tighten up my house, im always looking how it affects my dehum run time, so i assume you might have the target dehum run time. I expected the dehum to catchup faster after a shower than 1 to 2 hrs on a 90pint 1,000sqft in birmingham. Your info has gotten me into home performance, thanks
Shelby
Super cool, Shelby! Don’t have a scientific answer for you on that, but I’d say 25-50% in spring. In July it’ll be different I expect.
Great video! Question about the ventilation part. So I would think you would want separate control of ventilation air and recirculation through the dehumidifier. The April Aire E100V with 8190FF provides control of either recirc or ventilation that it auto electronically controls based on settings. The SanteFe you show appears to just bring a mixture of recirc and ventilation air dependent on a manual damper on the ventilation input. Is this true and what are your thoughts on this. I like all features of the SanteFe except not having separate control. Thanks!
Yes, you would use their ventilation control (or Aprilaire’s) to control a mechanical damper on the outside intake.
Excellent stuff dude
Thx Clarence
Hi Corbett, could you explain the math for pints/hr please? You are multiplying by 1/8 then multiplying by 8 a little later in the equation, it would seem they cancel? Is the pounds per hour the same as pints per hour as 1 pint is one pound? Forgive me for being nit picky, your tuition is fantastic I just got mentally stuck at this equation
The 8s are for different things, the first 8 is part of the equation for delta, his delta just happens to be 8. The 2nd is just a conversion from pounds to gallons, so his resulted in pounds per hr and to convert to gallons per hour then water weighs 8 pounds per gallon, so 1/8 is 0.125
...But that is interesting, a pint of water does seem to weigh 1 pound.
@@HomePerformance "A pints a pound the world around" is how I remember it." (Water that is)
Nice explanation - can you share where you got your Santa Fe humidity wheel?
Honestly I don’t remember! It’s been with me for 12 years.
@@HomePerformance I will reach out to Santa Fe direct to see if they have any...
Additionally - I am curious about your install...from your previous videos, it seems that you probably handled this install yourself. However, I understand that Santa Fe will not honor their product warranty unless it is installed by licensed installers? How did you handle this side of the project? Many thanks for all you do.
You’re right- it intimidated me less than the Mitsu heat pumps, but I had our HVAC superstar duo Kaleb Saleeby and Brent Ridley start this up. I ducted and hung the whole thing though.
By slightly opening the fresh air input duct, you are satisfying one objective I have for some dehumidification for the basement/crawlspace. What about the attic? Do you supply dehumidified air to the attic or use the method to create a slight negative pressure for a conditioned attic to help manage the humidity in the attic?
We don’t have an attic, but if you do, it should be a room in the Man J and it needs a supply register and a return pathway.
Great video, you mentioned florida. What’s your take on a ventilating dehumidifier vs having an ERV system for balanced ventilation and a separate dehumidifier (not ventilating)
I don’t know that anybody’s building very airtight in FL- an ERV only becomes necessary once you’re down around 1 ACH50. I’d go ventilating dehum any day.
How do you like the Airthings system?
It’s my go-to out of all of my monitors.
If you have a variable speed air-conditioning system in your house would you still need a dehumidifier?
You just briefly mentioned the MD33...how is this working for you? Would this be a viable whole house dehumidifier for a tiny house or small home? It seems that being able to wall mount it would be a huge space savings plus the drain line is a perk.
The MD33 is good, but I would not recommend in a tiny home due to the hum it creates- I prefer dessicant dehums for tiny spaces.
Can you take the fresh air from an ERV fresh air discharge side, (not the stale air exhaust to outside vent), and put it inline or on the intake side of a dehumidifier unit? I live on Texas gulf coast, it’s pretty much high humidity year round, 360 out of 365 days.
We are building a recording studio with open cell insulation on the outer wall of the double walls, so it’s air tight.
Best Video I've seen on this topic. Thanks so much. I'm building a new home in central FL and was thinking this might be a more affordable upgrade with a better ROI than stepping up to top of the line Variable Speed systems since the main attraction to me is making the house more comfortable. I also absolutely love my Ecobee Thermostat which I believe will control a dehumidifier. Am I correct that the Ecobee's work well with this type of setup? Also does the Air Handler have to be on while the dehumidifier is running or does it push enough air by itself?
Thanks Jack! Not sure about an Ecobee here, but I keep our air handler running on low continuously for filtration and mixing. As long as it can’t make a feedback loop, you shouldn’t have to do that if you don’t want to. Return and supply far enough apart would do the trick.
Excellent video! How do you relay the home humidity levels outside the grate to communicate with your UA sensor in your grate?
I believe they don’t need to communicate. They would set the controlling sensor(inside grate) to whatever value produces a desired result as measured by the sensor outside the grate. Clear as mud?
What about hooking ERV output to outside air input on dehumidifier? Bad idea?
Why now put the dehumidifer exhaust back into hvac return and get additional dehumidification from the evaporator?
Because you get much less dehumidification that way.
@HomePerformance o wow, thank you and for the quick reply!
But would this increase the cycle time or is the same?
How do you like the MD33? I have a 2 story home in Central FL. Upstairs is normally around 60%-65%. One of the bigger units like you have in the crawl space isn't really an option for my home.
Try it- it works well. BUT, 33 pints/day is not very big, you can get standalone dehums at 50 pints/day, and if you need to experiment a little it’s easier if you can move the unit around or buy multiple.
If the dehumidifier supply is ducted to supply of air handler is there a damper to keep the ac from blowing back through dehumidifier?
If so if both are running at the same time can the dehumidifier over come the blower from the AC ?
Yes and yes. Butterfly damper. Dehum is rated for 0.2 and 0.4 static pressure.
@@HomePerformance thank you! I love your channel .
Thanks Johnny my man
Hello Corbet,
I've been watching you for some time and first- thank you for all these videos. So much to learn..
Question(s) for adding the dehumidifier to the supply; 1: does the positive static pressure from the HVAC cause (meaningful) backflow in the humidifier? 2: does it the dehumidifier meaningfully increase the static pressure putting extra strain on the air handler?
It does not- you can see how this 250 CFM fan deals with static pressure in the specifications:
www.santa-fe-products.com/wp-content/uploads/sites/4/2021/05/Santa-Fe-Ultra120-Data-Sheet.pdf
And the air handler is set up to deal with up to 0.8 iwc, the highest pressure capability available. The pressure in the supply plenum should be 0.2 iwc max with both of these fans running.
When Exhausting/Supplying from/to more than One Area/Room/Locations, How do you maintain Suction/Supply Air? I notice a Significant drop in Air Suction from Exhaust and Decrease in Supply Air when I "Tee" in to more than One Area. The 6in Ducts drastically drops the air movement after I "Tee" Off into Any Location. How do You Overcome this?
Duct design calculations. ACCA Manual D.
Questions. A) do you run the Mitsubishi fan while the dehumidifier is on or is the fan in the unit able to circulate the air? B) 40 percent humidity in Georgia is fantastic how do we determine what’s appropriate for us? I’m in Illinois at 50% with a 69 degree home I would like to get to 40% and raise the set point to 72 degrees. Does the heat from the dehumidifier condenser cancel out the cold evaporator coil that’s doing the work?
Hey Adam- yes, the heat pump fan runs on low speed continuously. And the air is still cool with the added dehum heat, as shown in the testing portion near the end of the vid.
Great video as always, been a long time viewer and fan of the channel. I recently purchased an aprilaire e100 and was trying to determine the best course of routing the dehumidfied air into my ductwork. Can someone with ductwork experience help me out? I am tryning to figure out how to duct my dehumidfier into my supply side but am concerned about back flow. I have a supply plenum that I can duct into but I was concerned that just pumping the air into the plenum would push air back to the AC return which my Dehumidifier return will be near. Alternativly I can maintin the seperate return idea but wye the dehumidifier into the return side and maintain a better flow.... Am I over thinking the flow?
Put a butterfly damper at the supply plenum connection to prevent backflow- everything will be fine, the e100 only pushes 300ish chm and it will not want to send it back thru the heat exchangers and coils and filter to start a feedback loop.
@@HomePerformance will the built in damper of the e100 serve this propose or should I add an additional one? Thank you again for the advice, explanation of the principals behind the advice, and making it accessible to a homeowner who is just trying to do things the right way!
Thank you so much. Very informative. I have a question for you. For homes in the north Georgia area, would you recommend in ERV with a whole home dehumidifier or just a dehumidifier with a fresh air intake similar to what you have in this video? The equipment will be going into an unconditioned attic.
First I’d recommend putting your HVAC into a conditioned space, but as far as ERV vs Ventilating Dehu goes, watch this:
Borderline of Balanced Ventilation: When Bath Fans Won't Work, and an ERV Becomes Necessary at Home
ua-cam.com/video/lnOCAPPVT5g/v-deo.html
@@HomePerformance it’s an existing home so that’s not really an option. I had already watched that video and was planning to route all the bath exhausts to the ERV and then I started to watch Dehu videos and saw many people recommended using them with a fresh air intake in lieu of an ERV which confused me.
It sounds like you would recommend removing the bathroom fans and ducting their exhaust out of the house through an ERV while also adding a dehu in a completely different duct system without a separate fresh air intake?
ERV only if your home is tight enough to need it. I bet not in this case- dehu instead.
There are pros and cons in both scenarios. I would not use an ERV unless your home is 3ach50 or less.
@@HomePerformance thanks.
What happens in the winter when you need to add humidity to the air?
Stay tuned. Used to say air sealing would fix dry homes, but now there’s a whole new issue when you build THIS tight.
Multiplying by 0.125 is the same as dividing by 8, and then the next step was multiplying by 8, which cancels out the previous step.
So it looks like one pound can be treated as the same as one pint.
"A pint's a pound the world around" - quote from my old man.
Can you link the drill bit and sized plugs. I have had challenges finding matching plugs for access points made in ducts. I’m in Florida and we primarily have fiberglass duct boxes and flex hose ducts.
Hey Mo- sure, it’s a standard 3/4” max unibit, with 3/4” plugs (metal or plastic). You can get it all online or in most hardware stores.
Do you still need bathroom exhaust fans with this setup? I'm in FL and the home I purchased doesn't have exhaust fans in the bathrooms. I was going to just have them installed but I'm considering a whole house dehumidifier instead.
YES, you need bath fans- put them IN the showers. A dehum will struggle forever to try, but can’t do the job. Video forthcoming.
@@HomePerformance Wow, thank you for your response! Very helpful!
Thanks for the show and topic. I'm building in a tropical location in Australia. I'll build in a dehumidifier however am wondering if one intake point and one exit would be adequate to dehumidify to whole house. Thinking humidity would equalize throughout the house.
One intake in a CENTRAL location is fine, and one output into a central dust system is fine. That’s what’s shown here.
One exit is ok as long as you keep you duct as short as possible to allow adequate air flow. I would suggest to have adequate return Grill size for a pre-filter before it gets to the dehumidifier. You can never go to big to supply the dehumidifier.
To Paul’s point, Ken, returns can never be too big for any piece of equipment.
Would you always recommend installing a whole house de humidifier if replacing the hvac system in an existing home?
If you have the room and the ductwork, probably yes- there are always days when the temp is mild but it’s raining.
Ok can you tell me exactly how you have this running, is it running in the ductwork for the ac system without the ac being on and if so where are you pulling in coming air from is it in the house or outside only?
All from the house. Yes, it runs independently from the heat pump based on humidity levels. Heat pump’s central fan runs on low speed continuously.
Since you've added a whole-house demudifier, do you still think the ERV was the better call over the HRV? It makes the systems a little more redundant, which the engineer in me loves, but it also adds a bit more cost, where I've found HRVs are cheaper than ERVs. It also seems that HRVs are more widely recommended for bathroom exhaust, whereas ERVs are just slightly more questionable.
YES, ERV always imho, unless you’re in Alaska or southern FL (and an HRV is not the answer in FL either).
@@HomePerformance
Either an ERV takes some of the load off the demudifier while also supplying pre-tempered fresh air, or the demudifier does all the work, but either way the same amount of work has to be done. So I'm not entirely sure an ERV with dedicated dehumidification beats an HRV with dedicated demudificarion.
Oh wait, Matt Risinger agrees with you. You're a genius, Corbett! ERV all the way.
Maybe I just really want the Fantech Hero series and I'm sad it's only an HRV.
I’m sad about that too, fellow nerd, trust me. Try Broan if you want an EC motor. Also, remember that as much as you can cut down on contaminants (like humidity), the better- the dehum only grabs air from one return location, probably central- meanwhile, your ventilator delivers air into all bedrooms. Bedrooms have LOTS of soft stuff, which will soak up the moisture before the dehum gets to do its job. Therefore, ERV.
@@HomePerformance
Ya, I have a Fantech VER150 modeled out in my house 3D model for that same reason. HRV vs ERV was more a thought exercise.
Honestly a $400 difference between ERV and HRV isn't much when compared to to total cost of a home. Get hardwood or countertops, tile that are a little cheaper per square ft and make it up there.
As someone and married to someone with Ehlers-Danlos Syndrome and the wonky effects contaminates especially have on our bodies, I'm very much following your lead on the IAQ of the home.
You shouldn't have been moving the sensor used in the duct. Reason being the wind are vectors or forces in a direction. As physics would dictate moving the sensor tip towards or away the direction of the wind flow can minus/divide or adds/multiply respectively force wind. But then again air tightness is critical and helps in out air flow
For the humidifier to work do you need to leave your fan running consistently?
Mmm no, but it distributes the dry air more evenly when fan is on
Phenomenal Video!
Thanks!
👍🏽👍🏽
CFM is in minutes, but your computation is in hours. Did I miss where you are converting these quantities (or is it baked into the 4.5)?
Yes, it's inside the 4.5
Can dirty filter trip the breaker on these?
Thank you for sharing. Awesome content. 👍
Hey, thanks for saying so Paul
I am a Hvacr tech and I just now came across my first customer requesting a dehumidifier. Your input helped educate me on the subject.
P.s. My son (6yrs old) was also captured by your vid. When you started the math portion, he ran to grab his Etch-a-Sketch and wrote your formula on his board! 🤣🤣🤣
THAT IS THE BEST REVIEW IN THE UNIVERSE. THANKS PAUL!
is the fresh air inlet able to be filtered?
Great you have supplier in phils
What's the point of running AC at the same time? The whole point of the dehumidifier is to save energy by not running AC during warm/cool "shoulder" seasons.
Energy doesn’t enter into it for me at all- it’s about ensuring you don’t let moisture get out of control in all seasons.
@@HomePerformance how can it get out of control if AC is running just by itself? Unless the house is sitting on a swamp, AC does a great job by itself.
But those shoulder seasons is a different story. Running AC when your home temp is already at 67F makes it uncomfortable. That's when a dehumidifier is a great addition.
I'm in Massachusetts so maybe it's different here
A/C will not work to dehumidify if it’s not properly sized with a Manual J calc, or if the temp demand is too low. But it’s not about saving energy.
Can you set these dehumidifiers to run continuously instead of running based off of the humidity?
You can, yes
Why would you not want to pipe it directly into the return of the a/c? I understand its not ideal (say if the fan of the a/c is off or something, but will it actually hurt anything? I have a situation where I can only really access two spaces of the return ducting, the supply isn't wide enough and there are trunks going upstairs and one going to the main floor, and above the a/c unit the trunk isn't wide enough to fit 8 or 10 inch collar.
Gotta do what you gotta do, Chad. But it degrades the efficiency of your A/C and removes the drying power from it as well. Oversize the dehum if that’s the case.
I still find it all complicated but I’ll get it eventually...I hope
Happy to try to clarify, Lex
The way this is explained does not make physical sense to me. How at time stamp 8:49 does a "heated" output of the dehumidifier cause a 90 plus degree environment to decrease to 76.7 degrees??? I have a floor-standing unit in my basement and am researching to install this type of ducted system. However, even the floor unit directions indicate that where you run this 70-pint-per-hour floor unit will have an ambient temperature increased by about five degrees. I have observed this effect while running the unit at max output. So how are you saying that your unit is sending heated and dehumidified air into what is evidently the duct with the supply or post-conditioned area, and having it magically be decreased to below 90 degrees?. (Are the "supply" and "return" terms being swapped here???)
Could the water from the dehumidifier be further harvested/processed for culinary or emergency uses?
Haha, it could, I suppose, be filtered, but it wouldn’t be worth the trouble and expense for most people. We used to put our condensate thru a Berkey when we lived in our offgrid tiny house.
What should I set my humidity for my house at?
Summertime 40-55 is a good range
would you then connect an ERV on the ventilation side?
In our case, yes, that's how the home is ventilated. Only because it's so tight. Video forthcoming on the point of no return.
What rope suspension kit/parts did you use for that?
Comes with the Santa Fe system
@@HomePerformance oh that's what's it's called, rope ratchets! Amazon has these for like 10 bucks.
So duct the dehumifier supply into the AC supply?
That’s best practice, yes
Can I use a dehumidifier when I have a ductless mini split system?
It’s even more important in that case.
@@HomePerformance Thanks. My unit has a dry mode which keeps the humidity in the 40's even on hot days here in Northern California. I'm not sue what the humidity will be like in the winter yet. Hopefully the system can control the humidity then also.
Drier in the winter. But if you’re using Dry Mode, you should definitely clean the unit asap.
How can I find someone in the Pee Dee part of South Carolina who knows how to add this unit correctly?
Hope this helps, Tracy:
homediagnosis.tv/pro
Thank you!
Does the dehumidifier add heat to the air
Yes
@HomePerformance how much heat is acceptable? I have one of those portable dehumidifiers and its adding 15F to the outgoing air. It defeats the porpose because the AC is kicking on more often and dehumidifying the house
I'm sure your explanations are good, but some people are better with a written/drawn explanation. Consider adding some white board time or animations to put your videos over the top and reach more folks. Some of what you were saying about the temperature before and after the ducts and which ones were connected where was just too much without some sort of diagram. ***Edit*** Kept watching, and voila, visual aids. Would still like to see a diagram of the ductwork and airflow you're talking about.
Good feedback, thanks
"80f 60% ....... is a ridiculous number" lmao. just keeping the humidity down to that would be nice.
Whoa, Tweak, I thought you lived in paradise?!?!
@@HomePerformance I'm in the humid part of paradise. I think its officially called oceanic sub tropical. Go south a bit and its a lot drier and a bit cooler. I think its that humidity that causes more housing issues than people like to admit which is why full house dehumidifier is worth looking at.
@12:23: 0.75 * 60 = 4.5? I get 45.
Not following you buddy
@14:00: So you divided by 8, then multiplied by 8. Hmm. I think I can save you 2 steps.
Just trying to make it clear for the audience bud
Beautiful equipment sitting on a stack of concrete brick 😂😂 cmon
Who cares don’t be such a dweeb