ERV vs. HRV Mythbusting: Which Ventilation is Safer for Moisture and Humidity? 

Thank you so much for keeping this clear. For the last few years it's been a mess of misinformation or flat out using the wrong terms as people have tried to explain the differences between what these two do.

Thanks for clearing the misconceptions

A peak performance video! Thanks, mate.

I erroneously assumed that an ERV would be better than a dehu. In a spray foam house, I ended up installing a dehu on my dime. Lessened learned, ERVs do not dehumidify. In a super humid climate like the south, it cannot transfer enough moisture from fresh air to exhaust to break even, you will always net more moisture. Love the video.

Well done as always!

Thanks for the video Corbett! Question: I know some ERVs have a self balancing option to correct for pressure imbalances in the home, so would an alternate solution to solve for humidity be to use a regular exhaust only fan in the showers to eject the steam straight out, and then use an ERV that can increase the CFM going to the bathroom to makeup the lost air. Almost like a bath fan makeup air system. Or would that make it hard to then also ventilate the rest of the house?

This is a great video. One, it takes complex information and tries to simplify it in a way that's conversational, and not talking down to the audience. It also shows, like in science, when new information comes up that supercedes old information, the new information is accepted. I caught that comment about needing a dehumidifier AND POSSIBLY a humidifier. Humidifiers used to be a four letter word for you lol But I still have to admit ignorance about what exactly, besides water, humid air carries that can be so bad for indoor air quality.

Thank you clarifying the use of ERV's in the south, particularly Florida. I know that it is designed to mitigate humidity, but this is Florida. In this state, you learn that not all "stainless steel" products are created equal for a reason. Our atmosphere is brutal on machinery of any kind.

Thank you!

Canada has cold climate ERV (see fantech) dry winters(20-30%) and humid summers(50-100%)

Thank you. Conundrum resolved 😁

I just swapped out my HRV to an Venmar N series ERV. I’m in Victoria B.C. Which is the most mild climate in Canada. My install is challenging in that it’s an attic with some decent runs of of flex. I’m going to rearrange it a bit and replace some of the flex with metal. But the auto balancing feature seems to work well, and as an added bonus, the supply from the ERV is going straight into the 8” line that runs to my Bypass HEPA system. 👌

This is great info! I’ve been touting ERV>HRV for about 90% of North American climates. Regarding freezing, I’m not an expert in all models, but apparently newer ERV cores are as good or better than HRVs in colder climates. In really cold climates it’s probably worth installing a ground loop pre-heat system for incoming air.

Thank you for your video. I live in MD and want to have an ERV installed. I'm worried about the air intake side of the core building mold due to humidity air coming into the unit. Did you see this type of issue for ERV? I saw someone complained about it online.

Fantastic video mate. Much appreciated :-) I live in Hamburg where its cold (goes to minus 5 at the most) and very humid inside and outside. What do I buy? Please let me know. Many thanks

Great info. Thanks. What if you live in west Michigan where it's -5 to 32 degrees F. In the winter for 2 to 5 months and it's 75 to 100 degrees with high humidity in the summer for 2 to 4 months?

What about Ohio/PA for ERV vs HRV? Temps get down to -10 F outside, or do you only mean if the HOUSE freezes ? (lived in houses shouldn't ever freeze)

Furnace(propane) and air handler installed in attic due as it is a “pole building”. Central air with compressor outside. Vey tight. Whole house humidifier not an option due furnace location … possible freeze issues occasionally in attic. We live in mid Atlantic. Hot , humid in summer and as I write this it’s 23F outside. My HVAC person suggested an ERV as possible solution to dry air in house in winter. Room humidifiers are a pain and don’t seem to be all that effective. Even with cold dry air outside the OUTDOOR humidity generally stays in the 50+%. It seems most issues discussed are about dehumidification and adding whole house humidifiers. Is this a viable option in our case? Btw… due to allergy issues of my wife, windows remain closed year round… I like the idea of fresh filtered air. Thanks for your video!

I live in climate zone 3B, hot and dry, but I'm coastal with little to no real humidity and a more of a mild climate because of the location to the coast. I got a quote from Zender, and they called for an HRV. What do you think in this scenario, ERV or HRV?

Another great video! Quick Question: How do we properly let in 'supply' for what the clothes dryer pushes out of the house?

Question would an ERV be of any value in ventilating a non conditioned crawl space vs simple screened vent holes. Would UVC LAMP be good enhancements to maintain a better environment within them. I never enjoyed entering dusty insect ridden crawl areas

Towards the end of the video you mentioned you would comment on one marketing myth, “self-balancing” in a couple of months in another video. Did you make that video?

I live in Northern Canada which means it's colder during winter the temp is around -9 to -40. Is ERV still advisable? Having problem with high condensation on my windows. What is your recommendations?

Does ERV connect to an existing central air duct system on a finished house? Or is this the kind of thing that needs a whole second duct system alongside the central air?

What about the argument that the dew point created by the crossing of air leads to mold issues and HVR/ERVs?

When you say you swapped out the core of a HRV for an ERV, where does one get an ERV core? I've got a Venmar HRV that I'd love to turn into an ERV, but I can't figure out where to buy a paper core to swap into the unit...

How load is it? I need to put one in my condo so it will be in a bedroom. Will it be comfortable?

I think you glossed over that you need the mechanicals to set the humidty in the first place. The erv just makes it easier by trying to maintain the status quo. Erv is only part of the system and you need the rest of the system to work with it. Like in the tiny lab where you had the dehumidifier .

Great video on the subject. Can you do a video on how to safely humidify a home - tolerances, new air tight homes vs older homes, etc.

I live in the greater Seattle area and despite the common belief we rarely get below freezing for a sustained period of time (1-2 days typically, but rarely more than 1-2 week at a time over the winter) and the humidity swings greatly. At this very moment it's 61 degrees F and 85% humidity outside and inside my home it's 70 degrees F with 56% humidity. While I have a new 15 Seer central a/c, inside humidity varies greatly. I'm in the middle of air sealing and using aero barrier and bring the attic insulation to a R-49 level and crawl to R-30. I'm considering ventilation options and was recommended a HRV by a national high-end brand. What should my target humidity level be and what range should I maintain and what specific tools / equipment should I use to maintain these targets? Is it simply add a dehumidifier and a ERV tied into the HVAC system or seperate? Advice and reasoning would be greatly appreciated because I want to filter through the noise and make fact based decisions using science.

I am confused what to do for our house. We had some mold issues in the past and want and air exchanger to get fresh clean air inside and get rid of stale/unclean air outside. We live in southern ontario in canada. Very humid here, but air gets pretty dry in the house when its cold outside, so i don't want to remove even more humidity from the house with the air exchanger. The air conditionner and furnace does a good job at keeping the house dry I would say. My main goal is to get rid of pollutants in the house. Filtration isn't enough really. I need to get rid of VOCs from the pollutants, since there is a bit of smell as well. Any tips would be great. What our tech recommended was an HRV from venmar, i think its one of those self-balancing, which sounds great, but as a telecoms tech, can be skeptical of anything auto. Sometimes its great, sometimes awful.

There IS a more extreme example. A Jamaican family lived in Michigan and preferred (endeavored to maintain) hot, humid air, as in their home country. This created huge moisture issues in their home - up north, in the cold, in the winter. A bit worse than some showers. How do you handle this?

+1 Can you comment on your plan for bath exhaust with the ERV.

Great video, do you happen to know a product better than the Panasonic WhisperComfort ERV, looking for an spot ERV, and this is the only one i found but i'd like to have more CFM capacity. Thanks!

I want fresh air in my NJ basement, my plan was to install an ERV and run a dehumidifier. I was hoping the ERV would help dehumidify the basement by pulling out the stale moist air, but now i realize i was wrong. Is an ERV still my best option or something all together different? I just want my basement to have nice fresh air and keep it from getting stale/moist, it has no windows that open.

I have two ervs in nh My large primary shower overwhelms the bathroom with humidity... thoughts on how to remedy without just getting a high cfm exhaust fan? Thanks

Anyone clued in to what ERV/HRV unit on the market has the best low temperature behaviour (i.e. continues to ventilate without freezing up down to the lowest outside air temp… as opposed to plain shutting down or going into recirc only mode to prevent freezing)? Thanks from colder-than-Minneapolis, Canada.

I was thinking of an erv with braided plastic cores increased durability for cleaning. Think its a good idea ?

Wow so ideally my tiny house would need an hrv, minisplit, bathroom dehumidifier, and air filter?

Living in New York in a ICF home, which would you recommend?

I am in Maine with a tight house with humidity problems in the winter- it becomes TOO humid and the windows condensate. I am about to purchase an ERV to get some fresh air in and stale moist air out- is this not the solution in this case? Thanks

For Florida what is the best erv de humidifier in the market which does both and connects with hvac

Thank you, can I used in birds room? I’m not very good in English. Thanks.

Hi it is true that it is not recommended to use ERVs to extract air from the bathrooms? Thanks

Is there an affordable option for a 700sqft house that wont set me back $6k? I live in the upper Midwest on lake Superior. Id lije humidity control ans fresh air exchange.

Are you saying that because most of the day you aren't using the shower, it doesn't matter that you are recycling the humidity from the shower back into the house? And that you could have a humidifier or dehumidifier hooked up to the ERV in order to control for that? I'm unclear about what your main point is.

I have a Broan hrv100h ... what should I be running it on low ? high ? I have no clue on this machine... thanks!

This is a good video, but I think you gloss over some key points with basic comparisons to make points that might confuse people. IF you have a typical environment of 60% unaided you don't need to focus on dehumidifying if you have a spike due to showers, cooking or a sudden increase of people. The only thing this requires is extraction. A shower can easily add 200ml of water into the air. Only when fighting with high outside humidity does the ERV benefit. Many climates don't have that high humidity and could skip over this very key point. IF your outside humidity isn't high, your humidity source is due to breathing, showers, cooking and condensation from heating / cooling (day/night) cycles then HRV's work great. Any good one has a humidity sensor and switches to extraction. If your fighting condensation this is fine. However like the video says IF your in a high humidity climate a ERV will help your house from climate spikes. But some people need to fix the shower issue. Simply installing a hrv with humidity extraction sensors is the answer. A simple ductless hrv in your bathroom and ideally another room will quickly get you back to where you need to be and are highly effective to reduce moisture without loosing all your heat.

I have an ERV in the Midwest… fight air being too dry in the winter and way too humid in the summer

I haven't seen you talk about VOC transfer through ERV cores. In addition to transfer from exhaust to supply side because of air leakage around the core, the core itself allows an amount of VOCs to pass through. And from the studies I've seen, it's not a trivial amount. There are ways to minimize it by increasing the exhaust cfm relative to the intake but that makes the system unbalanced. I don't believe HRVs have this problem. For those whose primary issue is VOC ventilation, what are your thoughts ?

10 kids !! 🫡

So…. Don’t use an ERV “if it’s gonna freeze” -? 😳 😕 I’m so confused. Every time I think I understand it and have decided which one I need…. 😒 So how cold are we talking, then? How cold would it need to get in the winter’s, in order for someone to need an HRV instead of an ERV? And why would you ever need an HRV over an ERV, if an ERV does •both• preserving humidity AND heat, within the home-? 😶

Hi I live in Montreal Quebec our summers are hot and winters are really cold sometimes -15 or so do you recommend HRV or ERV. My heating is also baseboard electric

Hi what do i need if my bedroom is really dry and not much air?? due too a very small window,,even plants die a slow death in the bedroom..Thanks

Wasn't Brian ultimately not happy with an ERV in his home and moved to a ventilating dehumidifier?

Ever since I had this installed in my house I’ve been getting an odd smell coming from my fence. Has anybody had these issues?

Does that ERV thingy crackled your voice so terribly ?

I mean, buy a cerv2 and it’ll do it all and far more efficient. These units came as building since was evolving but it is about 1/5 the solution. There are evolutions to this.

I cut allot of sodium (soda drinks, and chips ) out of my diet.. I belive it helped my nose bleeds allot.

Erv for life baby. Hrv can kiss my ass. Great vid.

Unfortunately ERV is so noisy

You are talking rubbish. I have a small single room MVHR in a drying room where I hang wetsuits and damp clothing and it drys them extremely quickly. It has a huge effect on humidity.

Like Chinese finger traps

Honestly, you must be scared to go outside in case you get a humidity spike....really...a shower should kill you on contact I assume...this whole ERV HRV crap seems like a money making thing.

Biggest waste of money in my new house. Noisy. Expensive. Energy hungry. Basically a very over priced fan. Its a scam. Its just a Greenwashing Scam. Some one is getting rich and ERVs are a bunch of green hyped BS