September 25, 2023
Is It Bad If Your AC Runs All Day?

Many people believe that leaving your air conditioning running all day long is a bad thing, but the truth is a bit more complicated. Leaving your AC turned on all day is definitely a good idea. If you ever shut the system off for more than an hour or two, the temperature and humidity level inside your home can quickly increase. This forces the system to work harder once you turn it back on, leading to greater wear and tear and greater energy usage. While it’s always a good idea to leave your AC switched on all day, the system shouldn’t actually run constantly and instead should only come on a few times an hour. If your AC does run constantly throughout the day, it’s a definite sign that you need to have it inspected.

Understanding Typical AC Cooling Cycles

A cooling cycle is the time it takes from when the AC system turns on until it cools the building down to the temperature the thermostat is set at and shuts off again. Your AC should always turn on when the temperature inside your home is somewhere between 1 and 3 degrees warmer than what you have your thermostat set to, depending on how the thermostat is calibrated and programmed. As long as the temperature in your home is no more than 3 degrees above the thermostat setting, each cooling cycle should last no more than 15 or maybe 20 minutes at the most.

When an AC system is functioning effectively, it will normally perform two or three full cycles every hour. This means that it will run for around 15 to 20 minutes and then shut off for around 10 minutes so the system can cool off before turning on again and starting another cycle. An AC that shuts off in less than 10 minutes is said to be short cycling, whereas a system that frequently runs for up to an hour or more is long cycling. Both long and short cycles are a sign that the system isn’t functioning properly and may need to be serviced or repaired.

What Causes Short Cycling?

If your AC compressor frequently turns on and off in less than 10 minutes, you should always check the condition of the air filter before doing anything else. A clogged air filter prevents the system from getting sufficient airflow and can lead to either the blower or the motors in the AC compressor overheating causing the system to prematurely shut off.

Short cycling can also occur because the system doesn’t have enough refrigerant to work properly, which typically indicates that there is a leak in the system. Issues with your thermostat can also lead to short cycling. In this case, the cycles may last for the normal amount of time but the system will only stay off for five minutes or so before turning back on. When this happens, it usually means that the thermostat isn’t calibrated properly or is poorly located. If the thermostat is in a warmer location or in a place where it receives direct sunlight, it can get tricked into thinking the home is warmer than it is leading to it signaling the system to turn on again almost immediately after it shuts off.

Short cycling can also occur if the AC compressor is worn out or too large for the home. Unfortunately, your only real option in either of these situations is to have the unit replaced.

Issues That Can Lead to Long AC Cycles

If your AC cycles are often much longer than normal, you should again check your air filter and replace it if necessary. Any time the filter is overly dirty, less air will flow through the system so it will cool much more slowly. Long cycling can also occur because the evaporator coil or condenser coil is too dirty for the system to work properly or because the blower is malfunctioning or worn out and not able to move air through the system effectively. In truth, there are a wide variety of issues that can lead to longer than normal AC cycles, and the only real way to determine the problem is with a professional inspection.

If you’re experiencing issues with short cycling or your AC constantly runs throughout the day, Heatwave Heating & Cooling is here to help. We offer professional AC maintenance and AC repair services, and our team can work on any make or model. We are proud to be the best HVAC company in Amherst, so contact us today for all of your air conditioning and heating needs.

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