You may have heard that indoor air is two to five times more polluted than outdoor air, but what exactly is causing the contamination? Many invisible particles and gases can impact your comfort, health, and HVAC system.

National Refrigeration takes a look at 5 warning signs that your HVAC system is wasting energy.

Depending on the Air Conditioner in your home, the filters will vary. Regardless, regular replacement of filters is important for unit longevity and the healthy air quality of your home.