Most likely the smell will be knock you out strong in one particular area and that should be able to help you identify the source whether it s in the attic basement or some specific wall.
House smells like hot attic.
Such odors may even make the items or clothing you re storing in your attic smell as well.
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.
Chimney smells can be drawn into the house when these are left open.
I would say eliminate the smell through ventilation.
The musty mold odor can creep down from your attic and take up residence in other areas of your home.
Sniffed the walls the floor outlets ac vents no moldy window sills and it s mostly in the doorway.
This is a combination of lumber insulation shingles all getting cooked in this hot attic air.
Little ventilation high humidity and darkness says bill carroll jr an adjunct professor of chemistry.
It might be you have a gap or air leak in the returrn air duct that is allowing this smell to get into ductwork.
What causes that old house smell three things that musty old houses have in common.
Rodent droppings urine.
However attics can also have problems such as a musty mold odor that are normally associated with basements and cellars.
If you notice this type of odor coming from your attic avoid entering it unless you are wearing a proper respirator.
There are other holes as well like where the wire from your light switch travels up into the attic.
If the smell persists after the firebox has dried following this cleaning call in a chimney sweep to clean and inspect your chimney.
And infiltrate the airr in the duct even though it s not running.
If that s not the problem vacuum and then scrub the firebox the area that contains the fire at the base of the chimney.
The unpleasant odor can also attach itself to items stored in the attic.