ERV and High CO2 Levels
mtamta
| Posted in Mechanicals on
Hello, My house was built a year ago. It’s around 1800 sq ft with 9 to 10 ft ceilings, well insulated, all electric, and has a Renewaire EV90 ERV.
We are having an issue with high CO2 levels over 1000ppm in the bedroom when the door is closed but only during warmer weather.
The house is partially below ground and has a radiant concrete floor on the lower level. The bedroom is on the lower level as well.
I’m not sure what’s going on because it’s not a problem in the winter. If we move up a size in ERV will it be enough. Is something else going on?
Thanks!
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Replies
What do you mean when you say you "have a problem"? Is this an issue where an instrument, of unknown accuracy, you purchased is reading over 1,000 ppm or are you actually experiencing drowsiness?
https://www.kane.co.uk/knowledge-centre/what-are-safe-levels-of-co-and-co2-in-rooms
Does your ERV have a dedicated distribution system? IF so you may need to have someone come out to re-balance the amount of air reaching the bedroom.
CO2 levels will increase in rooms when the door is closed. I suspect in the winter you have less of a temp difference between warm/cool air so there's less convective looping allowing more air to escape under the door.
What climate are you in? That might help us understand the general scenario better.
Make sure your ERV is delivering 15+ CFM per person directly to the bedroom.
Another reader asked a similar question. I think you would benefit from reading the conversation that ensued: ERV Sizing and Interior CO2 Levels.