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Short-Cycling: Why It’s Bad News for an Air Conditioner

air-conditioning-condensers-near-plantsOne of the most common and harmful troubles an air conditioner can encounter is a condition called short-cycling. It’s both a symptom of a problem and a problem itself. Although sometimes a few simple adjustments may fix short-cycling, if the root cause is serious it requires a professional HVAC technician to do the repairs. Unless short-cycling is stopped, it will eventually lead to an early replacement for an air conditioner and waste enormous amounts of power until then.

The Brutal Facts of Short-Cycling

The phrase short-cycling is HVAC-speak for when an air conditioner (or heat pump) becomes caught in the start-up cycle and turns on and off repeatedly without completing the cooling cycle. Under normal conditions, an AC powers up the compressor and runs until the thermostat registers it has met the temperature request. The AC then powers down the compressor. A short-cycling AC will prematurely stop the compressor before the end of the cooling cycle, and then start up again a short time later. When the compressor is turning on and off multiple times an hour and the compressor runs for less than 15 minutes at a time, the AC is short-cycling.

Why Short-Cycling Happens to Good (and Bad) Air Conditioners

Short-cycling indicates the AC has a malfunction somewhere—and there are many possibilities:

  • A clogged air filter
  • An oversized or undersized air conditioner
  • Low refrigerant charge due to leaks
  • Air escaping through a leaky ventilation system
  • Miscalibrated thermostats reading incorrect temperatures

A clogged air filter is easy to remedy. An oversized/undersized system must be replaced. The other troubles require professional repairs. Please don’t attempt to diagnose the cause of short-cycling on your own: you want HVAC professionals to identify the correct source of the problem so it can be fixed fast and accurately.

Why You Must Stop an AC From Short-Cycling

Not only does short-cycling warn of a problem somewhere in the air conditioner, such as leaking refrigerant, the strain of the constant start-stop on the compressor will shorten the AC’s service life, increase repair needs, and waste electricity. It also leads to a drop in comfort.

Some details about these negative short-cycling effects:

  • An air conditioner drains the most power when the compressor starts. When the system becomes trapped in a continual start-up process it draws on far greater amounts of power.
  • The compressor picks up more wear and tear while this goes on, and this can cause the unit to overheat and burn-out. The cost to replace a burnt-out compressor is high enough to make it more cost-effective for most homeowners to replace the entire air conditioner.
  • If an AC stops the compressor before completing the full cooling cycle, it will not have sufficient time to spread cooling to all parts of a home, leading to uneven comfort.

When you need Durham, NC air conditioning repair to save an AC from the terror demon of short-cycling, make a call to Comfort Master, any time of the day or night. We offer comfort from our family to yours!

Make Comfort Master Heating & Air Conditioning, Inc. your choice for all your AC repairs. Service throughout the Triangle Area of North Carolina.

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