Short cycling is the term used when the cooling cycle on an air conditioning unit is shorter than it should be. On a hot day, this will typically last 10 minutes and then stop for 10 minutes, and so on. On cooler days, the breaks will be longer.
One of the most common air conditioning cycle issues is short cycling. This means the unit has a short cycle duration, usually 10 minutes or less. You might notice the air conditioner turns on, runs for a few minutes, and then turns off without cooling.
Cooling a house from 90 degrees to 72 degrees typically takes about 2 to 4 hours, depending on various factors.
Short cycling means that your air conditioner turns off and on too often, too rapidly, or at irregular intervals. That frequent on-off switching will ultimately damage the compressor motor, fan motor, controls, or other components, leading to system failure and costly repairs.
Should I turn my AC off if it is short cycling? No, this is not necessary unless the evaporator coils are frozen, in which case, turn off your air conditioner to let the coils thaw.
Central AC Short Cycling
Homeowners spend between $75 and $600 to deal with short cycling issues in their central AC systems.
Some of the basics include: turn your thermostat up a couple degrees and deal with 76 to 78 degree temperatures indoors for a few days. close off unused rooms. close doors and vents.
Typically, it takes about an hour for an average-sized air conditioning unit in typical conditions to lower room temperature by one degree Fahrenheit. But remember, 'average' doesn't mean 'always'. Like people, every AC has its personality – some are sprinters while others prefer marathons.
Energy Efficiency: Setting the thermostat to 78-80 degrees can help save energy and reduce utility bills. Raising the thermostat during extremely hot days can save you up to 10-15% on your cooling costs, depending on factors like your home's insulation and your AC's efficiency level.
Causes of Short Cycling
Lack of enough refrigerant in the AC can cause short cycling. Unfortunately, it can also cause other issues, such as ice buildup in the AC unit. Thermostat issues can also cause short cycling.
Replace your air filter: Keeping your air filter free of dust and debris can prevent your coils from freezing and reduce the risk of short-cycling. Check your thermostat placement: Be sure to have your thermostat far enough away from your air conditioner to get an accurate temperature reading.
When an air conditioner is short cycling, it will typically only run for a few minutes at a time before shutting off prematurely. As a result, it takes significantly longer for your home to reach your preferred temperature, which uses more electricity and puts extra wear and tear on the AC unit.
When things are working right, your central air conditioner should run for 15 to 20 minutes and then turn off for a few minutes. It will do this two or three times every hour. It may run longer when it's sweltering outside.
This means the compressor will run for 10 minutes, stop for 10 minutes, and repeat the cycle two more times during a single hour. You can tell a system that's short cycling when it turns on and off three times in five to ten minutes.
Simply put, it means you should never set your thermostat for a temperature more than 20 degrees cooler than the outside air. Why not? Most air conditioning systems can only handle a 20-degree difference between the outside and inside air temperatures.
Cooling a house from 80 to 72 degrees is a common goal for many, especially during the peak of summer. On average, this process takes roughly two and a half to three and a half hours.
Temperatures Above 100 Degrees Fahrenheit
When temperatures outside become higher than 100 degrees Fahrenheit, the air conditioning system can consume more energy and begin to malfunction or fail. Most air conditioning systems are designed to function with outside temperatures of 100 degrees or less.
Just because the outdoor temperature is above 100, the Ideal temperature to set your AC unit to doesn't change — it's 78 degrees. Higher temperatures in the home are to be expected when the weather is hotter than usual, but your thermostat can still be set the same as if it were a lower temperature outside.
Your AC might not cool properly due to thermostat issues, an undersized unit, or extremely high outdoor temps—so check those first. Keep an eye on airflow—replace clogged filters every 3 months, and make sure vents and ducts aren't blocked for efficient cooling.
Air conditioners shouldn't generally work all the time unless the thermostat is set to “fan on” (inadvisable). A correctly sized and well-maintained AC system should run for 15 to 20 minutes, two or three times every hour—with longer cycles in the higher temperatures of summer.
If your air conditioner is too large, it is also too powerful for your home. It will put out far too much cool air, resulting in air conditioner short cycling. The only way to resolve this issue is to replace the oversized unit with one that better suits your home.
HVAC Pro Cost
You'll want to ensure a crucial task like this is done correctly. To avoid potential injuries or problems with unit sizing or installation, ask an experienced local AC installation pro for a quote for your system. Most people pay $500 to $2,500 in labor for AC replacement.
Several issues can cause short cycling, such as an oversized HVAC system, a clogged air filter, or a malfunctioning thermostat. Low refrigerant levels or a blocked evaporator coil can also force the system to shut down prematurely.