Home Inspectors are required to inspect central and through wall air conditioning systems.  Most central air conditioning systems are split systems which, consists of two sections: The condenser (compressor) as seen in the first photo below and the evaporator unit that is typically unseen as being built into an air handler or the furnace.  A through wall air conditioner is not referring to window air conditioner that have been installed in a sleeve in a wall.  Though wall air conditioners are not portable units.  One type is shown in the second photo below.

One of the most neglected systems a home inspector has to evaluate is the central air conditioning system. Typically, one half of this system (the condensing unit) is found outside, and all to often, out of mind. In addition, the interior coil of the system is considered by many homeowners to be part of the heating system or is in an attic and receives even less attention.

To get the best service and longest life from your central air conditioning system it should be serviced on an annual basis by a qualified air conditioning technician. They will check it to make sure it is operating properly, and often repair problems before they become costly. If you’re selling a home, having this service performed before your house is placed on the market, can often reveal a problem so it can be rectified. You then will not have to worry about it being an issue to hold up the sale process. If you are purchasing a home, and your home inspector points out that the system has not been serviced in a reasonable time, it is to your benefit to have this type of service performed during the inspection period.

As a homeowner there are certain things that you can do yourself to help ensure that your system will function at its best. Don’t begin using the system until there has been consistent temperatures above 60 to 65 degrees for at least five to six days. The area around the condensing unit (the outside unit) should be kept clear of leaves, debris and shrubs at least one foot in all directions. With a restricted airflow the system will not function properly. Check your filter once a month, clean or change it as needed. Periodically you can check the two copper lines that extend from the condenser to the inside coil. One of them is supposed to be totally wrapped with insulation. It is important to maintain this insulation in good condition at all times. If your air handler is in the attic, make sure the condensate pan is not collecting water that could be stagnant because it could become the source of Legionnaire’s Disease.

The information contained on this page is not exhaustive and is meant to be only an overview.  For complete documentation on this subject please contact local or State heath officials.