Where are filters for cleaning the supplied air typically installed?

The filters for cleaning supplied air are typically installed in the mixed air plenum. This location is crucial because the mixed air plenum is where fresh outdoor air is combined with return air from the conditioned space. By placing filters in the mixed air plenum, it ensures that the air being distributed throughout the building is clean and free of particulates before it is sent into the living or working areas.

This positioning helps maintain indoor air quality while protecting the system's components from pollutants that could cause damage or reduce efficiency. Filters in this location can effectively capture dust, pollen, and other contaminants before the air is conditioned and circulated.

While other ducts like the supply air duct deal with the air that is already conditioned or being sent back into the system, they do not provide the same level of protection and filtration as placing filters in the mixed air plenum. The goal is to ensure that the initial batch of air entering the system is properly filtered, thus enhancing overall air quality and system performance.