In HVAC, what is the purpose of an auxiliary drain pan?

The purpose of an auxiliary drain pan is to collect excess water from HVAC systems, particularly from air conditioning units or high-efficiency furnaces. In situations where the primary drain line becomes clogged or fails, water can accumulate and potentially lead to overflow, which could cause significant water damage to the surrounding area.

The auxiliary drain pan is positioned beneath the primary unit and is equipped with a drain line that directs any collected water away safely when the primary system is not functioning properly. This preventative measure safeguards property and helps maintain the integrity of the HVAC system by ensuring that excess water does not lead to leaks or damage.

The other options relate to functions that are not typically associated with an auxiliary drain pan. For instance, regulating airflow, enhancing cooling efficiency, and lowering operating noise are all aspects that pertain to other components of HVAC systems, such as ductwork, coil design, and unit design, respectively. Thus, the primary role of the auxiliary drain pan is primarily focused on water collection to prevent damage rather than impacting airflow, efficiency, or noise levels.