There are a few warning signs you need house ventilation, starting with:
1. Lingering odors
If you have issues getting strong smells out of your space, you could have a ventilation issue.
2. Musty air
The air in your space should be fresh, but stuffy sectors mean you could have inadequate ventilation.
3. Disproportionate dust
Dust can get stuck more frequently in areas with insufficient ventilation.