HRV or ERV, that is the question!

Question submitted to Aprilaire:

HRV or ERV and  why?

Aprilaires’ Response:

Aprilaire believes that ERV’s are a better choice than HRV’s.

HRV’s only transfer heat energy so in the winter the moisture in the air that is exiting your house will all go outside. This can dry out your house too much. In the summer the moisture in the air that is entering your house can over humidify house. Too much humidity can cause mold and other problems.

ERV’s transfer heat energy and moisture. In the winter 77% of the heat energy and 50% of the moisture from the air that is exiting the house will be transferred back into the house. In the summer 77% of the heat energy and 50% of the moisture from the air that is entering the house will be transferred back outside. This allows the ERV to run year around with out drying it out or over humidifying.

0 thoughts on “HRV or ERV, that is the question!

  1. scott

    We just moved into our newly built home on Dec. 9. By Jan 3, I noticed in the storage area of our basement that there was condensation on the osb board behind the insulation. (whole backside of basement is exposed and framed 2×6 with r 13 insulation) Long story short…after cutting holes in some closets etc. we noticed that all of the exterior walls on the inside have condensation between the insulation and osb. The osb has a moisture content ranging from 18-28%. We also have mold growing in some areas on the osb. In our area it was the wetest year on record and the house was wrapped the day after a lot of rain and about 3 months after it had been framed up, insullated and dry walled. Between the actual rain fall, new house moisture and the possiblitly that we made the house to air tight we are looking at an air exchanger. Do you believe this will take care of the condensation problems? From what I guys prefer ERV over HRV. I am not sure if I should go with ERV as it returns some of the moisture back into the house. RH readings in the house range from 52-60% depending what part of the house you are in. Hope this gives you an idea of what we are dealing with. Federal heating and cooling in Dresden OH. suggested your system. Any iformation suggesting what to do would be greatly appriciated.


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