I live in northern virginia hot humid climate in the summer and use heat pumps to heat and cool my house throughout the year.
Hot attic smell.
Where those wires punch through to the attic are rarely sealed properly or at all and that is just one more path for hot air to travel down into your house bringing that lovely odor with it.
Sealing up your building envelope is the only way to go.
A little sealing up in the attic will do wonders.
The unpleasant odor can also attach itself to items stored in the attic.
I have a shop in my attic for some of my hobbies and it get s very hot in the summer.
It might be you have a gap or air leak in the returrn air duct that is allowing this smell to get into ductwork.
Microbial volatile organic compounds mvoc are stinky gasses produced by attic mold.
This is a combination of lumber insulation shingles all getting cooked in this hot attic air.
I have large attic with ridge vents and screened vents at either end of the attic to maintain air flow.
Depending on the particular type of mold its mvoc may exhibit a damp musky odor.
Musty dirty animal and moldy smells in an attic create an unpleasant surprise when you go up to this easily overlooked space in the house.
Step 1 wear a pair of rubber gloves safety goggles a long sleeved shirt and pants to protect yourself from mold and its spores.
And infiltrate the airr in the duct even though it s not running.
If you notice this type of odor coming from your attic avoid entering it unless you are wearing a proper respirator.
The musty mold odor can creep down from your attic and take up residence in other areas of your home.