What is the purpose of a primary and secondary drain in an HVAC system?

The purpose of primary and secondary drains in an HVAC system is primarily to manage condensate and prevent water damage. In HVAC systems, especially air conditioning units, moisture is often generated as a byproduct of cooling. The primary drain is responsible for removing the majority of this condensate by directing it away from the unit. However, in the event that the primary drain becomes clogged and can't effectively carry away the water, the secondary drain acts as a backup. It is designed to catch any overflow, thereby preventing water from leaking into areas where it could cause damage, such as ceilings, walls, or floors.

This dual-drain system ensures that moisture is efficiently removed and that the system operates safely and efficiently. By having both primary and secondary drains, the risk of water damage is significantly reduced, protecting both the HVAC unit and the surrounding structure. Other options do not align with the primary role of these drains, as their functions are not focused on airflow adjustment, energy efficiency, or filtering water.