What is typically the purpose of a return duct in an HVAC system?

The primary purpose of a return duct in an HVAC system is to recirculate air back to the system. Return ducts are designed to collect air from various spaces within a building and transport it back to the HVAC unit, where it can be conditioned (heated or cooled) before being distributed back into the living areas through supply ducts. This process ensures effective airflow and maintains consistent temperature and air quality throughout the space.

In addition to enhancing comfort, the return ducts play a crucial role in balancing pressure within the system. By recycling air, the HVAC system can maintain an optimal working environment and reduce energy consumption, as conditioned air can be reused rather than constantly introducing new outdoor air that may require additional energy for heating or cooling.