Most people feel that air conditioners should be turned off to save energy when you leave the house. However, this is not always the case. Leaving an air conditioner on can save energy if you keep it in the right mode.
In general, air conditioners should be set to 78 degrees or higher when you are home. According to Energy Star, for every degree you lower the thermostat; you’ll increase your energy usage by about 6 percent. So if your summertime utility bill is $100 a month and you turn your thermostat down from 78 degrees to 74 degrees, your bill will rise to about $120 a month for those four hours a day that you are out of the house.
This is especially true if your air conditioner doesn’t have an automatic shut-off feature activated by your central thermostat. If you don’t have this feature, leaving the A/C on while you’re out may cost less instead of having it repeatedly cool down and heat back up while you are away.
If you take advantage of smart technology like Wi-Fi thermostats and smart plugs, turning off your A/C or leaving it on when you leave the house is simple and convenient.
There are some good arguments for keeping your air conditioner (or at least some part of it) running while you’re away. Here are some of them:
It will make your home more comfortable when you come back
One of the most important aspects of a well-designed HVAC system is its ability to recover quickly after a period of non-use. As long as you are outside your home for less than two hours, you won’t be wasting energy by keeping your air conditioner on while you’re out of the house. What have you saved if you keep the system running while you’re away to save money on electricity but then come back to an overheated home? Leaving it would be the best option if your system can keep up with the load without too much trouble and too much energy.
Prevents Mold Growth
When a house is left to heat up too much, condensation will form on the walls, windows, and floor. This water can significantly increase the chances of mold growth because of the humidity created inside the home and the coolness outside.
Keeps Pets Cool
While it is essential to let your pet get some fresh air and exercise, leaving them in a hot house for hours is inhumane and illegal in many states. It is best to adjust the temperature or leave them somewhere with friends or family members at home during the day.
Turning off your air conditioning will not save money
Turning off the A/C when you head out for work will not save you much money. Turning it back on requires more energy than running it at a steady temperature all day. In addition, returning to a hot home means your A/C has to work overtime to cool down each room again, which uses even more energy.