If you're noticing that your air conditioner is running for longer than usual, or not running for as long as usual, it's important to consider all the factors that determine the length of a cooling cycle. The air temperature outside, the size and condition of air ducts, the amount of insulation, and the quality of the weather stripping around windows and doors, are just a few of the factors that will determine the length of the cooling cycle.
The cooling cycle lasts until the temperature on the thermostat is reached. It shuts off at that point and starts again when the house begins to warm up again. If it is just a few degrees warmer outside, it may run for a few minutes. If it is very hot and humid, with a 30 degree difference between the thermostat setting and outside temperature, it may need to run much longer to reach the desired temperature.
Air Ducts and Circulation
Because a central air conditioner performs best when cooling the entire house, it's best to keep all vents and doors open when possible. Closing off rooms will not save energy, it will only make the AC work harder. Keeping your AC properly maintained, including changing the filter regularly, will also ensure that it's performing at peak efficiency.
Air conditioners perform best when they are properly sized for the space they are cooling. The size of an air conditioner is measured in BTUs. One BTU is equal to the amount of energy needed to raise the temperature of one pound of water by one degree Fahrenheit. If your air conditioner has more BTUs than necessary, it will cycle more frequently. If it has too few BTUs, it will run much longer per cycle.
Assuming your central air conditioner is properly sized for your home, it should be able to cool and remove moisture from the air in 7 to 10-minute cycles. If not there could be a problem.
Have questions about your central air conditioner? Call ABC Southwest Plumbing and Air Conditioning, we're here to help.