Inspecting Air Cooled Air Conditioners

During the inspection of the air conditioning system, the home inspector should identify the type of system and document all of the relevant information from the data plate, including the age, and should make a determination as to whether or not to operate the system. The inspection should include examining the outdoor cabinet, refrigerant lines, the indoor unit, and ductwork.

These procedures should be followed when inspecting the cooling system.  Additionally, make sure state standards of practice or an association’s standard of practice are being followed.

1. Examine the compressor/condenser unit. Note the presence of an electrical disconnect, clearances around the unit, the condition of the cabinet and fan blade, whether the cabinet is level, whether the refrigerant lines are kinked or damaged, and the insulation on the lines.
2. Determine if you will turn the unit on. It is always a good idea to know what the temperature was the night before the inspection. Also note what the current temperature is at the inspection. The current temperature ideally will have been 60-65 degrees or warmer for the last 12-24 hours. When examining the outdoor unit, note if the disconnect is turned off, indicating the system is shut down. The unit power should be on for roughly 24 hours before the inspection to prevent damage to the compressor.
3. If you have decided to turn the equipment on, lower the thermostat while inspecting the interior of the home. Listen for any problems with the unit as the system starts up.  Be sure to shut off the equipment if the compressor and condenser fan don’t start up immediately, if you hear problem noises, or if any parts aren’t functioning.
4. Continue with other aspects of the interior inspection and let the air conditioning operate for at least 15 minutes. As the cooling system comes up to speed, check supply registers and return grills for air flow, and check visible ductwork.
5. Go outside once more to check the outdoor unit. Check fan operation and feel for warm air blowing out of the unit. Also, feel the refrigerant lines for an indication of any problems. The larger line should feel cold and be insulated and the smaller line warm.
6. Allow the cooling system to continue operating while you listen to the indoor evaporator unit. Check the temperature of air before and after the coil for appropriate differential (14-22 degrees).  Keep in mind, doing a temperature differential is beyond the Standards of Practice. Note any excessive vibrations, fan motor problems, condensate leaking, and so on.
7. Finally, turn of the system by turning the thermostat back up to either whatever the seller had it set at, or if it was off, turn it back off. Then inspect the indoor unit more closely, checking the condition of the air handler for rusting and corrosion, the presence and condition of the air filter, mounting (if an attic unit), and the condition of the condensate tray and line(s).

Watch for the following conditions during the inspection of the air cooled air conditioning system:

• Obstructed or tilted unit
• Missing exterior disconnect switch
• Damaged, dirty, leaking, corroded, or rusted equipment
• Missing or dirty air filter
• Noisy, vibrating, or malfunctioning equipment or loose mountings
• Frost or icing
• Too high or too low temperature differential (Not required by Standards)
• Improper condensate drainage
• Leaking, damaged, loose, or corroded ducts
• Lack of cooling source in each room