There are a a couple warning signs you should consider house ventilation, starting with:
1. Ever-present odors
If you have trouble getting powerful odors out of your home, you likely have a ventilation issue.
2. Stale air
The air in your space should be fresh, but stale sectors mean you may have insufficient ventilation.
3. Disproportionate dust
Dust can build up more quickly in areas with inadequate airflow.