Many people in the Valley wonder if the amount of time their unit runs is right. There are a few factors that affect this. Typically we size a unit to keep the home 75° when its 108 outside. What this means for run time is that when we start our season – or the days when it's in the 80-90's – the unit will cycle more frequently. As the temperature increases, the unit will run more and when we have our extreme temps – 110° plus – the unit may not cycle off. As long as the set point is kept, the unit should be operating properly.
The type of thermostat also affects run time. Older stats used a temperature differential of 2°, meaning that if the stat is set on 78°, it will turn on at 80 and off at 76. New stats use a .5° differential, so they will cycle more than the old ones.
It's a myth that leaving the heat pump off while you're away and then turning it back on once you return home uses less energy than leaving the system on when you are gone. Turning the unit off when you are not there allows the house to get too hot, so the unit will continue to run once you return home and turn it back on, which negates any savings and can strain your HVAC unit. A set point of 3-5 degrees higher than normal is sufficient when leaving the house for the day.
If you aren't sure if your air conditioning unit is running correctly, Just Call John's.