Mitigating high indoor humidity
I’ve been battling indoor humidity issues for some time now and need more advice.
Here are some quick stats:
–Location: Western Washington
–1600 sq ft one story rambler built in 1987
–Two adult occupants and two indoor cats
–Main heating is supplied by a free standing propane stove that vents to the outside. Supplemental cadet wall heaters
I have an average of 65% humidity inside the house and have great difficulty getting it down. I contracted a green energy auditor in January and his solution was to replace my current loud, 80cfm bathroom fan (which vents outside) with a 100cfm quiet fan tied to a humidity switch. He posited that this would be sufficient to vent the excess moisture from the whole house. However, from what I’ve been researching about house ventilation, the air that is exiting the structure has to be replaced with incoming air (coming in through air leaks). The air outside in western WA is very high humidity (most of the winter it is high. Today it was in the 80s %). So from what I understand, running the bathroom fan is simply going to draw in moist air from outside. I’ve tested his theory to some degree by running the 80cfm fan that is already installed for hours and it makes a negligible difference in the RH in the bathroom.
As it stands, I’m stumped as to what I should do. I can see mold growing in parts of the bathroom. I’m thinking of buying a dehumdifier for the the whole house, but I want to do that as a last-ditch option.
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