I am currently finishing 75 % of my basement area. The remainder of the
area will remain unifinished (all the mechanicals and some storage). The
foundation is block and I do have a sump pump so things are dry. As a last
step in the project I plan to install carpet. I do have a decent size
dehumidifier to keep the moisture level down. Is there a humidity threshold
that I should stay at or below to avoid the musty smell that could develop
over time? My house is 7 years old and I do have Central Air. However,
there are no cold air return vents in the basement.

Thanks,
-a12vman