Indoor Coil -- The indoor coil is a heat transfer device. It absorbs the heat from the inside of the house and passes it on to the refrigerant and is pumped outside. Dust that builds up on the coil can hamper its ability to absorb heat. High heat transference coils use very thin metal. Airborne chemicals can cause corrosion which leads to leaks. The constant vibration of the compressor can also cause solder joints to weaken and leak. An indoor coil may operate for weeks with a tiny leak, and you may not notice the loss in performance right away. As soon as a leak is made known, it should be replaced or repaired immediately.
Seasonal checks. Once a year have a licensed professional change all filters, clean and flush the coils, drain the pan and drainage system, and vacuum the blower compartments. The contractor should also check to make sure that the system is properly charged with refrigerant, that there are no leaks, and that all mechanical components are working properly.
Beware these aluminum clad wood doors. The wood is particle board. Why would anyone make a storm door out of particle board? They don't seal it in any way, it gets wet between the aluminum cladding and boils and blisters the aluminum and looks terrible in just a few years. I have two Larson's and they were horrible doors almost from the start. I've seen reviews and EMCO is the exact same way. When your storm door needs a storm door, you bought the wrong door.