The air coming from my vents smell as if something may be wet. I know that sounds crazy, but could the air be passing through some moisture source? We have the heat on at the current time. Last week we had the air on, I smelled this same smell. The air filter had this particular smell on it, like it had gotten wet some how, but it was bone dry when removed. The air filter was replaced( a different brand), the smell went away for a few days, it has returned today. We have a heat pump system, its almost 2 yrs old, it pulls air from the hallway. The dust is heavy also around the house. Any ideas?

The air coming from my vents smell as if something may be wet. I know that sounds crazy, but could the air be passing through some moisture source? We have the heat on at the current time. Last week we had the air on, I smelled this same smell. The air filter had this particular smell on it, like it had gotten wet some how, but it was bone dry when removed. The air filter was replaced( a different brand), the smell went away for a few days, it has returned today. We have a heat pump system, its almost 2 yrs old, it pulls air from the hallway. The dust is heavy also around the house. Any ideas?
Hmmmm....pretty odd!

Usually, at the beginning of the heat season, you'll get the smell of the dust burning off the heat strip coils on the first activation or two, but smells of "wet"? Sorry...this is a new one on me.

You can open up the filter slot look in with a flashlight and see if some old filters may have dropped down into the return box. It's common for me to have to remove 4 or 5 old filters because the incorrect size was used and it fell down into the return box. Of course, the homeowners either don't know it, or can't manage to get them out.

Sorry...that's about it.