According to regulations, the return air from a dwelling unit shall not be discharged through the cooling system to what?

The regulation regarding the return air from a dwelling unit emphasizes maintaining air quality and ensuring the efficiency of the cooling system. Discharging return air to another room can lead to several issues, such as poor air circulation and contamination of air quality. This air may carry dust, allergens, or other pollutants from one area to another, undermining the primary purpose of the cooling system, which is to provide clean, conditioned air to occupied spaces.

Additionally, proper airflow is vital for the system's operation; sending return air to another room could disrupt the intended airflow pattern and affect temperature control in both the source and destination rooms. Moreover, in well-designed HVAC systems, the return air should be collected from common areas to help balance temperature and air quality throughout the dwelling.

In this context, sending air to areas like an exterior vent, attic space, or basement is also problematic for different reasons, such as efficiency, building code compliance, and potential for moisture problems in unconditioned spaces.