Should our HRV keep our humidity lower than 40%, even in the cold months?
We are sitting at about -30C and ice is builidng up on almost all the windows. The humidty is registering at 40% on all levels, even though the HRV is set to Max. Is it possible that it is not functioning properly? Thanks in advance!
The thing about condensation on windows, is that there can be a number of causes. 40% RH isn’t unusual, and at -30C its not a surprise you’re seeing condensation form. Your HRV is not likely the problem I don’t think, it’s bringing in whatever air is outside. What climate zone are you in? I some regions there can still be quite a bit of humidity even in cold air, that could be a factor. Here is a good page to start reading that may have your answers –
Condensation on windows and how to deal with it
Humidity in homes can be from drying building materials, and general human occupation of a home such as cooking, cleaning, bathing, etc, and whether or not you have sufficient source removal in the form of bathroom fans and range hoods.
The quality of your windows will also impact how much ice you see forming, because the glazing surface of lower quality windows will be cooler and that will lead to more condensation. Do you use bathroom fans when showering? And your stove fan, do you use that as well?
Other things that can help would be stuff like putting lids on pots when cooking, shaking snow off boots and jackets, not leaving clothes to dry inside etc. Do you also have a dehumidifier in your basement? That would be a smart addition too.
Thank you very much! We are in Edmonton, Alberta which is 7A. Perhaps we should just get a dehumidifier?
I Just looked at some Edmonton charts, it says December, January and February are the most humid months of the year with an outdoor air average of about 60%RH. So yes on the dehumifier, and maybe you're running your HRV too much. An HRV is to bring fresh air in for occupants and to remove humidity, so in your case it's not helping with the humidity, so as long as the air isn't seeming stale I'd cut it back a bit, maybe to whatever you would normally do if you weren't running it full time.
Thank you, that's a wonderful idea. I will turn it back to minimum and see how we do.
Hopefully that works Kim. If if does please let us know. Good luck!