Clean the evaporator and condenser coils the same time you clean the filter; before the start of the cooling season and once a month during the season. If your area is particularly dusty, this may need to be done more frequently. The coils can be cleaned with a vacuum cleaner hose. If the fins on the coils become bent, use a fin comb from your local hardware store to straighten them. The evaporator coil condenses water vapor from the air and funnels it through a drain port. At this point, the water is blown against the condenser coil, where it is dissipated.