There are a a couple signals you should have house ventilation, such as:
1. Stubborn odors
If you have trouble getting powerful aromas out of your house, you may have a ventilation concern.
2. Musty air
The air in your rooms should seem fresh, but stale sectors mean you may have insufficient ventilation.
3. Disproportionate dust
Dust can develop more frequently in areas with inadequate air movement.