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Community and Q&A

ERV in a Leaky House

Jamie_Givens | Posted in Mechanicals on

I am adding a two-story addition off the back of my 1940s full brick ranch. The existing house has been remodeled but only cosmetically so I imagine it isn’t very air tight. The addition we are building, however, should be fairly tight although we aren’t going crazy with it. My question is:

Would it still be beneficial to do an ERV in the new addition even though it will be open to the main house which is very likely constantly exchanging air with the outside?

Thank you for any input.


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  1. Trevor_Lambert | | #1

    A leaky house leaks different amounts under different conditions. Even a very leaky house will have poor air exchange at certain times. Because of this, an ERV or HRV is a legitimate upgrade in just about any house. Whether it's worthwhile is somewhat subjective, since obviously people have been living in houses with terrible air quality for decades. The thing about fresh air is you can't bank it and use it later, you need it all of the time. In your situation, I would at least put an ERV in the new section. If it's better air sealed, the bulk of your air ingress and egress will be in the old section of the house, and mixing with the new section is going to be limited. In an ideal situation, you'd want a whole house ventilation system.

    1. Jamie_Givens | | #2

      Got it that makes a lot of sense. Thanks!

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