An evaporator coil drain pan is a highly specialized appliance that is located in a furnace and is responsible for the evaporation of water from the furnace air. It is also responsible for the flow of air out of the house. It is important to use a drain pan to keep this delicate system in good working order. A loose drain pan can cause the faulty drain discharge connection on the evaporator coil to cause an overheating condition. In fact, improperly installed drains can also affect the efficiency of the condensing unit and cause condensation.
Usually, a single unit controls both the heating and cooling of the house with the help of two tanks containing the engine coolant and the reservoir tank containing the heater coolant. A leak in the drain pan causes loss of water to the evaporator coil. The water used to keep the coolant circulating in the furnace is drained away causing the coolant temperature to rise causing a build up of water in the coil. The air used by the furnace to move from the exhaust of the furnace is also lost when the water in the evaporator coil is lost. If the leak continues, the furnace becomes inefficient and cannot sustain the operating temperatures required by the furnace.
Proper installation of a drain pan is one of the most important steps for the efficient operation of the evaporator coil. Drain pans are usually designed to contain a liner made of a material that will resist water intrusion. The drain pan should have a drain line that will provide a stop where it can be pumped out. The most common material used for the liner is galvanized pipe. Installation of a drain pan is very easy and is a must for any high-efficiency furnace.