There are two main aspects to evaporator coil maintenance. The first is keeping the coolant-filled coils free of dirt and debris. Second is keeping the evaporator drain clean and clear so that the condensed moisture from the air can drain rather than pool. Doing both of these regularly will keep the air conditioner working efficiently and cleanly.
The heart of any air conditioning system is the evaporator coil. Inside the piping of the coils is a coolant that, when hot air is forced over, the heat is removed causing the coolant to evaporate. This excess heat is then dumped outside. Thus, rather than putting cool air into a house, the air conditioner actually pulls hot air out. This process of evaporation is why keeping the coils clean is so important. Over time, small amounts of dirt and debris will build on the coils. These add up and eventually create small areas of insulation which prevent the coolant from evaporating.
Dirty coils thus make the machine less efficient. Gently clean the coils with a brush. The coils can be very fragile though, so the best thing to do is have an experienced technician handle this cleaning. A professional HVAC company knows how to clean the coils without breaking them. Replacing or cleaning the air filter on a regular basis will also help prevent the coils from dirtying in the first place.
As the warm air is forced over the cool coils, the humidity from the air will condense on the coils in the same way as it condenses on the side of a cool drink. This water then drips into the collection pan and down into the evaporator drain. This drain can become clogged by the same dirt and grime that can cover the coils. To test for blockages, take a bottle of water and pour it down the drain, noting if the water drains freely. If it does not, an experienced technician should be called to help clear the block.
These simple steps are all you need to reduce expensive air conditioning repair service calls and keep your air conditioner running efficiently.