What level of Humidity forms mold, Exhaust fan Setup level?

Often I see mold is formed at bath (no windows) that is fixed with exhaust fans. It cost me lot to remove mold by replacing the entire sheet rocks on the wall.

Now, I bought a humidity sensor exhaust fan that I can setup to start above certain humidity level, say 60% to 80%.

When I see outside humidity, it is like 60% to 75% range. When is the best range I can setup (only during installation, not possible after installation as it needs attic access) so that humidity is gone and mold does not form at the same time fan should not run 24x7 (low humidity setting runs forever)?

Here is the info.

I found answer

1 Like

https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1133&context=mengin_fac

Cool. Had never considered having a humidity sensor automated fan. Can we get a fart-sensor too?

1 Like

These days code requires one to use humidity sensors with bathroom fans. You can even leave the old fan in place and change out the switch to a humidity sensing switch.

1 Like