We have a 2 foot space between our main level and finished basement where all our ductwork is ran between the engineered joists. We have 4 rooms with large windows framed with stone and block walls beneath. This space is getting mold near exterior walls. The ductwork is sweating. I believe the stone and block walls are transferring heat into this space and causing the dew point.

I’m not sure the correct way to keep this from happening. Insulate the block walls? Add hidden dehumidifiers? Foam insulation on these exterior walls? Any advice is greatly appreciated.

Hi everyone. After experience with CO2 sensors for a long time - ended up building desktop app for it. Reasons - if monitor it to close - my breathing affects it, if its to far - i ignore the data. And most important part - i don’t want or need to see numbers - just want to get desktop notification when to open a window, when air is back to normal, etc. No servers, everything is local and native with nice UI. Let me know if someone is interested as well - if yes - i will clean it up, post screenshots and share link to test flight ( or windows package)