In the winter my house's humidity naturally drops to 20%. We had a whole house humidifier installed and raised the humidity to 35%. The air is much more comfortable but we get condensation on the windows due to blinds trapping cold air.

One window gets constant condensation and drips it onto the wooden window sill. As the sill is constantly wet, it has gotten moldy. I started leaving the blind partly open but the wetness and mold persist.moldy wooden sill

How can I keep the window sill dry without reducing the house's humidity?

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You are correct, the higher moisture is more comfortable. For us it also eliminated some problems we had with glued wood furniture. I use fans 24/7. I try to keep my house is from 37% - 40%. The fans move the air minimizing temperature variations, drafts, and keep things dry eliminating mold problems. If you have central heat turn the blower on, eliminating the mold will more then save you the const of the energy to run the blower. The fans can run on low speed, you just need some air movement. We also have ceiling fans which run 24/7/365, no more mold problems. If your blinds seal tight crack them a little so air can pass to the window. I also installed uv lamps in the ducts a few years back, that is another reason to keep the fan on.


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