What type of air does a return air system typically deal with?

A return air system primarily deals with stale air. This system is designed to gather air from inside a building after it has been circulated through the heating, ventilation, and air conditioning (HVAC) system. Stale air refers to air that has already been used, containing contaminants, odors, and varying humidity levels. By capturing and returning this air to the HVAC system, it can be properly filtered and treated, helping to maintain indoor air quality.

Using a return air system allows for improved efficiency in the HVAC operations, as the system re-circulates air to effectively manage temperature and humidity levels throughout the building. This process plays a critical role in ensuring a comfortable and healthy indoor environment for occupants.