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Community and Q&A

Ventilation in large condo buildings

jkonst | Posted in General Questions on

Hi all,

I’m currently shopping for a condo in Brooklyn, looking mostly at new construction. The buildings in my search so far range from 20-500 units, 8-65 floors. As context for my question, my partner has mild asthma. 

I’m finding that none of the buildings I’m looking at seem to have mechanical ventilation in-unit, other than bathroom fans and range hoods (some of which are recirculating). Almost all have gas cooktops, as well.

My question is – would you feel comfortable purchasing what is probably a pretty airtight apartment without an HRV/ERV? Or is there another way ventilation might be happening that should give me comfort? If so, is there a good way to ask this question in a way sales agents might understand, or a document I could request that would spell this kind of thing out?

I’m very much sold on the IAQ movement and would like to make sure my investment is a wise and comfortable one. I would welcome any opinions or considerations – thanks!

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  1. user-2310254 | | #1


    I would look for an all-electric unit since combustion appliances (especially gas stoves and cooktops) can really degrade indoor air quality. (See for more info.) I'd also query the building owner/hoa to see if you could install an ERV. Something like the Lunos E might be a good fit for a small unit or bedroom space.

    1. jkonst | | #3

      Totally makes sense! The main challenge is the lack of all-electric buildings here. A very few US cities have enforced/pushed that (San Francisco is one), but New York has not. Of the eight new construction buildings I've looked at, seven have gas stoves and one induction. The induction one is my favorite, but I'm unfortunately not the only party involved in this purchase :) I asked one building (still under construction) if they would consider swapping gas for induction if I purchased, and the answer was a pretty solid no (though I probably could retrofit for $10k or so). That said - I think this will start to shift, as I've seen at least one large all-electric build planned in the area.

      And very good point on the Lunos - I think I could pull that off at one of the smaller buildings. Probably not an option for the 60-story towers, but so it goes...

  2. JacobTig | | #2

    It is definitely possible that there are ‘common’, for lack of a better term, HRVs or ERVs that serve many units, which means each individual condo has no control over them, but they do supply fresh air and extract old air from each condo.
    I work for an affordable housing provider in Ontario. We have multiple passive house apartment buildings that utilize this approach.

    1. jkonst | | #4

      That makes sense (and it's great that you are doing that), thanks. I'll try inquiring further on my upcoming tours...

  3. Expert Member
    BILL WICHERS | | #5

    You might try asking using the commerical term. Ask what the building does for "makeup air" and where a "fresh air intake" is. There are typically code requirements for these things, so the HVAC people should be aware of them. I have never worked on a large multi-unit residential project though, so they might be different -- I'm much more familiar with large commercial properties, typically multitenant office buildings and specialized technical buildings. We are required to provide outside makeup air for these buildings since it's recognized that people need to breathe. I expect there are similar requirements for large residential buildings.

    I'm not sold on the "all electric" part. I do agree induction is a good option, I just don't think all electric for heating needs such as water heaters and furnaces/boilers is such a good idea. In many ways, the load shift makes things LESS efficient when running all electric, resulting in MORE natural gas being consumed to do the same work. This is because the majority of new electric power generation has been from natural gas (and that's unlikely to change any time soon), and the process of converting the gas to electricity and moving that electricity around to get to your home has a lot of unavoidable losses -- physics just won't let you convert or move energy around without loosing some of it in the process. Heat pumps alter the overall efficiency part of that a bit, but they have their issues too.

    I'm surprised they won't swap a gas cooktop for an induction unit. Costs to plumb a gas line or run a heavy electric circuit (usually 40 amps or more for a typical induction cooktop) should be similar, maybe even a bit less for the electric run. Induction cooktops cost more than lower-end gas cooktops, but they aren't a lot different on the higher end. You might just be running into the builder not wanting to change their process. If you can get them to at least run the electric circuit for you so that you can prep the kitchen for induction when it's built, that will make swapping out the cooktop at a later date MUCH easier.


    1. jkonst | | #6

      This is great, thanks. I have a feeling I'm not quite speaking the same language on my ventilation questions, so that is very helpful guidance. It probably doesn't help that I'm working with real estate agents as opposed to builders, as well. From what I've read, in the absence of an ERV, makeup air is pulled from the corridor through gaps in the front door - though it also seems this generally doesn't work all that well:

      Very fair points on the all-electric building concept, too. I do think it's a good goal, but needs to be paired with a more holistic renewable energy and storage plan.

      And thanks for the note on the electric circuit - if we go with that building, we'll see if we can swing that, at least...

      1. Expert Member
        BILL WICHERS | | #7

        Most realtors are familiar more with the "pretty stuff" (finish level, windows, parking, school district, etc.) than they are with the building itself. That's because the pretty stuff is what sells most properties to most buyers.

        Technical stuff is less well known to the realtor people. The people most likely to know this stuff will be the builders/contractors, and, after the building is built, the facilities and maintenance people. Ask the realtor if you can talk to one of the facilities guys, that might get you the answers you want.

        Makeup air usually needs some sort of system. In the commerical buildings, it's usually introduced into large air handlers that serve a big piece of an entire floor of a building, for example. If it comes in through the gap under the door, it needs to have a way to get out too. In the telecom facilities I usually work with, we run the building at a slight positive pressure. We do this so that we can control humidity and dust levels, but the result is that we bring in makeup air through a special filter/conditioner unit and the "out" for the "old" air is through ALL of the leaks in the entire building. Some sites monitor static pressure too, so they actually can tell when leaks get worse.

        Your realtor MIGHT have someone they can call to help you get the answers you want. Tell your realtor these are important concerns for you that will help you make your decision on a property. I have been a consultant to realtors before when they have a technical customer, since the relator wants to help their customer and knows they don't know the technical stuff. I don't normally charge for this service (I get new customers this way, actually), but I don't know if there would be anyone doing something like that on the residential side. A home inspector is probably an option for a detached home, and might be able to help you in a condo development so that might be an option -- but it will cost you some money to pay for their time.


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