First off, is the temperature remaining at the thermostat setpoint? When the outdoor temperature is high it is not unusual for your air conditioner to run a lot. In fact, the longer the air conditioner runs the more humidity it will remove from the air in your home. This will make you more comfortable. However, if you think that your air conditioner is running excessively, check your air vents. The return air vents should be clear and unobstructed. The supply air vents should be open to allow for full airflow. The air filter should be clean.

You should also make sure that there are no obstructions around the outdoor unit. Keep shrubs cut back at least a foot away from the air conditioner and at least 5 feet above the unit to allow for proper airflow.

If you can access it, you can also inspect your ductwork to ensure that no ducts have come apart allowing for air leakage into or out of the duct system. This can not only affect the performance of the system but can also drastically reduce the air quality in your home.

If you have checked all of these measures and still believe that your air conditioner is running too long or if it is not maintaining the temperature set on the thermostat then it is probably time to call a professional to come service or repair the system.

Some of the more common problems found are dirty evaporator coils, condenser coils, or blower wheels. Refrigerant leaks can be a mirror repair or sometimes may require removing the refrigerant to solder a leaking line or joint. This can run up the cost substantially. Indoor or outdoor fan motors can fail and can be fairly expensive to repair. The most expensive repair is replacing a compressor. If you are facing a compressor replacement you should evaluate the age of the system as it may make more sense to replace the air conditioner than to put a new compressor in an old unit.

Some of the less common problems may include an undersized air conditioner or duct system. When designing an air conditioning system for a home there are many items that must be taken into consideration. The first step is to do a Manual J load calculation on the home that will tell what size of an air conditioner is required to properly cool the home. A Manual J room by room load calculation along with a Manual D duct design will ensure that the right size ductwork is in place to deliver the right amount of air into and out of each room so that comfort is achieved. It is unfortunate but there are companies that use the rule of thumb instead of scientific calculations to design and install air conditioning systems. These are rarely comfortable homes and sometimes are completely inadequate.

An undersized system will not keep up with the air condition or heating load on the house and therefore may run nonstop.

An oversized system will run short cycles which can lead to uneven temperatures, excessive humidity in the home, and higher utility costs.

Please consider this!

The heating and air conditioning system in your home is the most complex and important part of the home. It keeps you comfortable in all weather. It cleans the air that you breathe. It controls a tremendous amount of energy that can be dangerous if not installed or maintained properly. This is the one thing in your home that should never be touched by a “handyman” or “fly by night” type of person.

A professional heating and cooling company will have invested a tremendous amount of time and capital into research, development, training, tools, employees, etc. They will have a physical place of business with office staff, sheet metal shop, warehouse, labeled vehicles, and be open to inspection. They will do professional work and warranty anything that they do. They will also provide 24-hour service because if your heat quits working at 9:00 p.m. on Friday night when it’s 10 degrees outside you don’t want to have to wait until Monday to get service.

I hope this information has been helpful and I wish you and your air conditioner a long comfortable life.