16 years installing only ervs in Maine. Though the finer screen seems like a good idea and I've seen a number of people do this over the years it makes for cleaning the intake much more frequently. And if not done, reduces ventilation and throws the system negative in relation to pressure. The engineers figured it made more sense to progressively filter larger particles first on the outside and the have the finer filter in the unit and clean at least every 3 months. The silicon was a mistake because your going to find that proper cleaning of that fine mesh will be way easier if you can remove it. As to the bees nest, I've never seen one in an intake that had air always flowing. Seems they don't want to be in a wind tunnel. Only ones that have the unit off for extended times. You won't need mesh in the exhaust side as the exhaust air has already gone through the filter in the unit and does not get dirty .
I've had similar issues and what was recommended and has worked well is as follows. Instead of a vent terminal, a long turn 90 elbow pointing down with an open end cap holding the bug screen. Elbow is push fitted so it can be easily removed to inspect and clean, inside the duct too. For the exhaust the pipe points straight out horizontally to eject the exhaust air away from the house, no screen, and the ERV is always on so bugs don't enter. PVC painted to protect from UV.
I bought an in-line duct filter box for my ERV intake. It has a full size air handler filter. Better flow, lasts longer, cheaper than the little manufacturer specific ERV filters.
I had this similar problem so I built my own filter box out of tin and a 12 x 12 washable air filter. This way you can easily remove it from the outside and wash it then replace. as a general rule I prefer to keep the dirt out of my ductwork and home. filter I used was Air-Care 12-in W x 12-in L x 1-in Washable Electrostatic Air Filter. good luck.
I once removed 1” of insects from an outdoor air intake for an industrial make up air unit. The intake was about 3’x6’ and it was completely caked. With. Bugs. Stuff of nightmares
😅 … this morning, I woke up thinking about how I want to plumb the fresh air intake on my home design. So started researching, which led me to think about the fresh air intake vent itself. As usual, Google led me here again! Thanks again Corbett!
Great video. I am seeing ERV's mentioned in so many videos and very few people talk or even mention the design and maintenance implications of the system. Many thanks!
A little, probably. The ERV duct system was upsized to 8” rounds even though the collars on the machine itself are 6”, so I’m not concerned at all about it. The bugs are a much bigger deal.
The finer mesh screens greatly reduce airflow, you should look at a flow chart and see if it meets the specs of the system. Having done some airflow projects over the years the restrictions of the smaller screens is pretty amazing.
Would you mind going over how you covered your exterior foundation Rockwool? This is the first time I've seen it covered, and I'm very curious regarding your thoughts & decision making journey for above/below-grade insulation continuity... Unless I missed a video covering that detail? Thanks!
This video could not have come at a better time! I've been wrestling with the decision of where to place the grilles of my HRV and simply couldn't find many even opinions much less stated reasons for preferring high vs low placement. Low = more insects, so it shall be high placement!
Thank you Corbett for the smart points all around. Any reason the new screen could be installed on the bottom output/input of the vent? This would be easier to clean in future and less creatures building nests up inside no?
Love the setup. Right now we’re in a townhome in Vegas that we’ve been maintaining based on your videos for our mold sensitivity but pretty soon we’re hoping on building a house out in New Mexico. We’re excited to implement a lot of this technology into our build
Have you considered putting the insect screen at the intake portion of the vent? This would be the bottom of the intake so insects and grass cannot enter the vent at all and make cleaning this screen easier because you only have to dust the bottom.
@@tweake7175 I would think he is going to have this problem anyway since he has both screens installed. In fact I think the video makes that point too.
Would it be just as effective if you installed the insect screen filter on the whole entry opening of the vent? So not with the original screen but for a screen on the vent hood, that way it’ll be easier to reach for cleaning and it’ll be more obvious that it needs cleaning. I hate wasps and definitely do not want surprises like that.
I use a the existing screen you have, but use bailing wire to tie a washable blue air filter material behind the mesh to stop bugs and capture some dust. You can wash it once a month or so, all you’ll need to do is remove the bailing wire. My intake is on a 45 deg and the mesh snaps in.
@@HomePerformance That’s not bad, well worth it. Never thought to wash them, guess you can considering that outside air isn’t going straight into the AHU.
You mention that ERVs may not be the best choice for a "not super airtight house". Why is this? And what do you consider "not super airtight"? Would you say that a code-built 3.0 ACH 50 house would benefit from an ERV?
That small screen will restrict airflow and needs maintenance, I found better solution, I attached paint straining bag, they come in different sizes. Benefits includes insects cant get thought, easy to install, easy to clean & wash, you may have it hanging outside and rain will wash dirt off and main benefit is that it has way more sqin. of net and does not affect air flow. I just use 1gl straining bag attached to 6" round duct with rubber ring. There is way more requirements for air intake; away from dryer vents, away from sewage vents especially those on the roof as wind blows from top to the bottom, also with no wind some sewage gasses are heavier than air and tend to flow towards ground level so solution is to use the side of the house with no sewage vents on the roof. Away from idling cars in the morning, at least 40' away from gas water tank & furnace exhausts as they produce very high peak of carbon monoxide at start and after that it stinks and you dont want it into the house. Away from neighbor's with RoundUp spray :), under the vent should be gravel that polls water away, not muddy soil that will stink when wet, also no concrete on the floor as it also smells when in contact with water (must be sealed). On the sunny side of the house so that there is no Fungai growing close by... this is all from experience and not available in instructional books, some instruction guides calls minimum 3 or 10' away from gas exhaust vents which is insane.. The thing is that most of these thing wont affect VOC readings in the house, however, it would bring variety of smell into the house and what ERV can pool in in about 5 minutes it would take hours to later replace... That 1/4 net that came with vent tells you that manufacturers dont have field experience, if they ever did any kind of test they would find handful of stinkbugs inside... cant believe that ashree people did not warn about it...
If finer screen is a problem because it reduces airflow, cant you just use a much larger opening so there is effectively the same open space for air to pass?
Thanks for the great practical advice. As I plan my home with the ERV in the conditioned attic, do I need to plan for easier access to the vent from the inside out or is it just better to use a ladder and keep the air sealing to a minimum.
I watched your show on PBS and we are just beginning to start a new home from the ground up. In just looking for the best way to get the builder, us, and the best practices aligned. In your show your wife mentioned demanding what you want. What if you don't know what to want or demand that's measurable or proved by some instrument? Do you do consulting with builders and homeowners so we can get the most efficient house we can afford?
I’ve really been enjoying binging these videos on this build. I’ve had a difficult time trying to find a good liquid flashing for the ForceField WRB. Any suggestions? Hoping to use that over wood bucks and for the transition from lumber to poured concrete stem wall.
Start with lifting up insulation in the attic and sealing up all gaps with can spray foam in the areas where drywall meets walls as well all electrical cans to prevent warm air to escape through holes in them . If the insulation is not molded and let air easily to pass through you can reuse it and add some more of same kinde
Not necessarily bad, but certainly doesn’t do all it’s marketed to, AND has all kinds of side effects for chemistry that have not been studied yet. Why be a willing guinea pig when we’re already unwilling guinea pigs in so many cases?
@@HomePerformance what do you think about prefiltration UV in the outdoor returns make up air and erv ? and the indoor returns Prefiltration that way any negatives will end up in your filters that's what I'm thinking what do you think ?
16 years installing only ervs in Maine. Though the finer screen seems like a good idea and I've seen a number of people do this over the years it makes for cleaning the intake much more frequently. And if not done, reduces ventilation and throws the system negative in relation to pressure. The engineers figured it made more sense to progressively filter larger particles first on the outside and the have the finer filter in the unit and clean at least every 3 months. The silicon was a mistake because your going to find that proper cleaning of that fine mesh will be way easier if you can remove it. As to the bees nest, I've never seen one in an intake that had air always flowing. Seems they don't want to be in a wind tunnel. Only ones that have the unit off for extended times. You won't need mesh in the exhaust side as the exhaust air has already gone through the filter in the unit and does not get dirty .
I was going to write exactly the same thing. I have seen many ERV experts against those finer screens because of the huge reduction on air flow.
@NaturebyGus maintenance is life, life is maintenance. Pick your battles.
I've had similar issues and what was recommended and has worked well is as follows. Instead of a vent terminal, a long turn 90 elbow pointing down with an open end cap holding the bug screen. Elbow is push fitted so it can be easily removed to inspect and clean, inside the duct too. For the exhaust the pipe points straight out horizontally to eject the exhaust air away from the house, no screen, and the ERV is always on so bugs don't enter. PVC painted to protect from UV.
Great to see these updates even when things haven’t gone perfectly with high end equipment.
I bought an in-line duct filter box for my ERV intake. It has a full size air handler filter. Better flow, lasts longer, cheaper than the little manufacturer specific ERV filters.
Which one did you buy? And where exactly did you mount it? All I can find are in insulated boxes, and I live where it freezes half the year.
I had this similar problem so I built my own filter box out of tin and a 12 x 12 washable air filter. This way you can easily remove it from the outside and wash it then replace. as a general rule I prefer to keep the dirt out of my ductwork and home. filter I used was Air-Care 12-in W x 12-in L x 1-in Washable Electrostatic Air Filter. good luck.
I once removed 1” of insects from an outdoor air intake for an industrial make up air unit. The intake was about 3’x6’ and it was completely caked. With. Bugs. Stuff of nightmares
😅 … this morning, I woke up thinking about how I want to plumb the fresh air intake on my home design. So started researching, which led me to think about the fresh air intake vent itself. As usual, Google led me here again! Thanks again Corbett!
Here for you buddy
Great video. I am seeing ERV's mentioned in so many videos and very few people talk or even mention the design and maintenance implications of the system. Many thanks!
Excellent, Travis, great to hear
Does the smaller size screen reduce the amount of air intake thereby affecting the ERV?
A little, probably. The ERV duct system was upsized to 8” rounds even though the collars on the machine itself are 6”, so I’m not concerned at all about it. The bugs are a much bigger deal.
The finer mesh screens greatly reduce airflow, you should look at a flow chart and see if it meets the specs of the system. Having done some airflow projects over the years the restrictions of the smaller screens is pretty amazing.
Would you mind going over how you covered your exterior foundation Rockwool? This is the first time I've seen it covered, and I'm very curious regarding your thoughts & decision making journey for above/below-grade insulation continuity... Unless I missed a video covering that detail? Thanks!
Mine is inside my house 3rd floor main intake. I didn't even realize what it was until I started watching these home builder videos.
"Every Tool's A Hammer" by Adam Savage... A good read!
This video could not have come at a better time! I've been wrestling with the decision of where to place the grilles of my HRV and simply couldn't find many even opinions much less stated reasons for preferring high vs low placement. Low = more insects, so it shall be high placement!
Thank you Corbett for the smart points all around. Any reason the new screen could be installed on the bottom output/input of the vent? This would be easier to clean in future and less creatures building nests up inside no?
Yes, great idea, maybe next time
Love the setup. Right now we’re in a townhome in Vegas that we’ve been maintaining based on your videos for our mold sensitivity but pretty soon we’re hoping on building a house out in New Mexico. We’re excited to implement a lot of this technology into our build
Hell yes Abe
Have you considered putting the insect screen at the intake portion of the vent? This would be the bottom of the intake so insects and grass cannot enter the vent at all and make cleaning this screen easier because you only have to dust the bottom.
That’s a good idea, Mark, but in this case since there are two screens I feel more comfy with one access to both.
Trouble is it would be smaller, restrict air flow and clog up quicker.
@@tweake7175 I would think he is going to have this problem anyway since he has both screens installed. In fact I think the video makes that point too.
Would it be just as effective if you installed the insect screen filter on the whole entry opening of the vent? So not with the original screen but for a screen on the vent hood, that way it’ll be easier to reach for cleaning and it’ll be more obvious that it needs cleaning. I hate wasps and definitely do not want surprises like that.
I use a the existing screen you have, but use bailing wire to tie a washable blue air filter material behind the mesh to stop bugs and capture some dust. You can wash it once a month or so, all you’ll need to do is remove the bailing wire. My intake is on a 45 deg and the mesh snaps in.
How much do you spend a year on ERV filters? Thanks for the vid!
You’re welcome, Pete. The 2 packs are $25, so maybe $50-100 per year, depending on use and whether you wash them or not.
@@HomePerformance That’s not bad, well worth it. Never thought to wash them, guess you can considering that outside air isn’t going straight into the AHU.
Our intake and exhaust is about 10 feet off the ground. Surprisingly the filters have had almost no dirt on them in the first year of operation.
That’s the stuff man
Is it a good idea to place the outdoor supply and exhaust little higher rather than this low to get he ground?
It’s a tradeoff, but yes would be my advice
You mention that ERVs may not be the best choice for a "not super airtight house". Why is this? And what do you consider "not super airtight"? Would you say that a code-built 3.0 ACH 50 house would benefit from an ERV?
Not necessarily. Factors vary, of course, but I advise under 2 ACH50 is ERV-necessary territory.
That small screen will restrict airflow and needs maintenance, I found better solution, I attached paint straining bag, they come in different sizes. Benefits includes insects cant get thought, easy to install, easy to clean & wash, you may have it hanging outside and rain will wash dirt off and main benefit is that it has way more sqin. of net and does not affect air flow. I just use 1gl straining bag attached to 6" round duct with rubber ring.
There is way more requirements for air intake; away from dryer vents, away from sewage vents especially those on the roof as wind blows from top to the bottom, also with no wind some sewage gasses are heavier than air and tend to flow towards ground level so solution is to use the side of the house with no sewage vents on the roof. Away from idling cars in the morning, at least 40' away from gas water tank & furnace exhausts as they produce very high peak of carbon monoxide at start and after that it stinks and you dont want it into the house. Away from neighbor's with RoundUp spray :), under the vent should be gravel that polls water away, not muddy soil that will stink when wet, also no concrete on the floor as it also smells when in contact with water (must be sealed). On the sunny side of the house so that there is no Fungai growing close by... this is all from experience and not available in instructional books, some instruction guides calls minimum 3 or 10' away from gas exhaust vents which is insane.. The thing is that most of these thing wont affect VOC readings in the house, however, it would bring variety of smell into the house and what ERV can pool in in about 5 minutes it would take hours to later replace... That 1/4 net that came with vent tells you that manufacturers dont have field experience, if they ever did any kind of test they would find handful of stinkbugs inside... cant believe that ashree people did not warn about it...
GREAT ADVICE SEPERTUDE! I think this might warrant a video of its own…
@@HomePerformance make it, also include downside of bringing in attic odors when intake is mounted in soffits
Wanna be in it?
@@HomePerformance You would make it way better :) I can collaborate if you want, I texted you on FB, there is even more things to add...
If finer screen is a problem because it reduces airflow, cant you just use a much larger opening so there is effectively the same open space for air to pass?
How about putting the finer screen across the bottom of the vent hood -easier to clean?
How do you prevent or bug proof your air intake???
Hey corbett, what do you think of air scrubber's that attach to a duct system? For example the "Air Scrubber by Aerus"
Thanks for the great practical advice. As I plan my home with the ERV in the conditioned attic, do I need to plan for easier access to the vent from the inside out or is it just better to use a ladder and keep the air sealing to a minimum.
Nah, Matt, just make it obvious from outside so you can keep an eye on it regularly.
Why wasn't the screen adapted to the rectangular opening? In that way, it would be more obvious when it needs to be cleaned and preclude wasp nests?
Addressed in several other comment replies, Joseph-
Love the siding what kind is it beautiful
Thanks Tracy, it’s Thermory solid wood:
ua-cam.com/video/YrLMaHOCzUs/v-deo.html
Even my intake gets lawn clippings caught in it and its 20ft off the ground.
I watched your show on PBS and we are just beginning to start a new home from the ground up. In just looking for the best way to get the builder, us, and the best practices aligned. In your show your wife mentioned demanding what you want.
What if you don't know what to want or demand that's measurable or proved by some instrument?
Do you do consulting with builders and homeowners so we can get the most efficient house we can afford?
Yes I do, C- book a session at:
buildingperformanceworkshop.com/video-consulting
@@HomePerformance t tried, it said the form was no longer taking submissions
Please try again, C, I’ve received several bookings this morning alone, so it’s definitely still active.
Now bend up another screen to fill in the bottom of the opening to keep them from getting into the wall cover and building a home.
I’ve really been enjoying binging these videos on this build. I’ve had a difficult time trying to find a good liquid flashing for the ForceField WRB. Any suggestions? Hoping to use that over wood bucks and for the transition from lumber to poured concrete stem wall.
We used Dymonic 100 I think. Proseco R Guard is also great, lots more out there.
Thanks.
I was wondering where is the first place to start with a 70s home? ERV ,air tightness, insulation?
Start with lifting up insulation in the attic and sealing up all gaps with can spray foam in the areas where drywall meets walls as well all electrical cans to prevent warm air to escape through holes in them . If the insulation is not molded and let air easily to pass through you can reuse it and add some more of same kinde
Andrey is exactly right- always airseal first. Then add insulation. Then better machines.
@@andreycham4797 Thank you
Not in this video but are you saying uv Lights in your Hvac equipment is bad?
Not necessarily bad, but certainly doesn’t do all it’s marketed to, AND has all kinds of side effects for chemistry that have not been studied yet. Why be a willing guinea pig when we’re already unwilling guinea pigs in so many cases?
@@HomePerformance what do you think about prefiltration UV in the outdoor returns make up air and erv ? and the indoor returns Prefiltration that way any negatives will end up in your filters that's what I'm thinking what do you think ?
I always have to ask: why? Why do we need something better than filters? What exactly are we worried about?
I would never even has though to do this
Kick ass
Thanks Dave-o
And by using a finer mesh screen you will make your erv work harder because you’ve reduced air flow.
But we upsized the duct from 6” to 8”. Basically twice the size. So don’t worry about it.
Hey Corbett, check your IG messages. I'll be in Atlanta this weekend.
Why not put a screen on the bottom that can be removed to help stop the other screens from getting clogged?
Wolf spider
Scott True / DimoraHomes, via Matt Risinger sent me here :)
Good!