Many folks mistakenly assume that the cold refrigerant that is circulating through their evaporator coil adds cool air to a home. Actually, it removes heat energy. After this heat energy is extracted from the air, coolness is what is left behind.
In these systems, refrigerant becomes a liquid as it is compressed and will evaporate as it is released from the pressure. The evaporator coil will release pressure from the refrigerant and allow it to evaporate. That’s when the gas that’s released gets cold and absorbs the warmth coming from the return ducts. After the gas grows hotter, it’ll get sent to the condenser coils in which it releases the heat to the outside air.
After you release the captured heat from the house outside, the cold liquid returns to the inside unit, in which the process starts again. Therefore, what really happens? The heat from the house is captured by the interior evaporator coils then becomes distributed outside.
As the evaporator coil is directly installed inside the system’s airstream, it is a magnet for dust accumulation or additional contaminants. Here is a basic primer on how you can clean AC evaporator coils.
Buy a can of no-rinse coil cleaner. Normally, it’s a foamy substance inside a spray can that’s directly applied to the surfaces of the coils.
Find the air handler unit, typically installed in an attic or closet.
Turn the power off to the air handler at the circuit breaker or main switch.
Take off the metal reflective tape sealing the seams that surround the coil access panel.
Take out the screws which secure the air handler’s coil access panel.
The evaporator coil is configured inside an A-frame design that has two sides. Assess the outside surfaces of the coil for dust or dirt residue.
On all exposed coil surfaces, spray the coil cleaner.
As the cleaner is soaking the coil, assess the drain pan. Search for evidence of algae or mold growth. Small contaminations may be treated using a 50/50 mixture of water and bleach. However, severe contaminations must be addressed by an HVAC contractor.
Pour water down the condensate drain tube which leads away from your drain pan to check that the tube drains properly and is open. If you notice that the condensate drain tube is being blocked, from standing water inside the drain pan, discontinue use of your air conditioner and contact an HVAC contractor to clear away the blockage.
After the coil cleaner drips off of the coils, assess the coil surfaces for areas which might need an additional cleaner application and re-apply as needed.
Put the coil access cover back on then tighten the screws. With metal tape, tape all seams that surround the access cover. Restore power to your air handler then turn the system on to produce condensation on the coils for extra rinsing.