What are the optimal temperature settings for my air conditioning?

Learn the secrets to staying cool while lowering your energy bills.

Utility bills soar when the summer heat arrives and air conditioners get turned on. High energy costs cause people with tight budgets to skimp on their AC. Many people turn off their AC units while they are away thinking that this will save them money. Family squabbles flare up when the penny-pincher and overheated family members butt heads. Hillside wants you to know there is a way for you to be cool, comfortable, and save money at the same time while keeping peace in the household.

Program Your Thermostat to these Optimal Temperature Settings

There is no one perfect temperature for both comfort and energy savings. Rather, there are three distinct temperatures and times of day that will maximize your comfort levels and energy bills.

Use a programmable thermostat to match your cooling needs to your schedule. A programmable thermostat is ideal for people who are away from home during set periods of time throughout the week. Through proper use of pre-programmed settings, a programmable thermostat can save you about $180 every year in energy costs. You can make the adjustments manually if you don’t have one for your central air system. If you upgrade to a smart thermostat, you can use a mobile app on your phone. Use the  following settings as a guide:

• 78° F when you’re home*.
• 85° F when you’re at work or away.
• 82° F when you’re sleeping.

*A study by Energy Star, a joint federal program run by the DOE and the Environmental Protection Agency, discovered that 78° F is the optimal temperature for both cooling and energy efficiency. Keep your thermostat set is 78° F when you’re at home and awake.


Thermostats were rather ugly rectangular boxes until smart thermostats burst on the scene in 2011. Smart thermostats use your mobile phone to make programming a programmable thermostat much simpler. It has become super easy to change settings and schedule via an app. Enjoy smart-home features, automation of heating and cooling, and wireless setup:

  •  manage temperature settings and schedules from both the thermostat itself and a smartphone app
  • make temperature adjustments with your voice using a digital assistant on your phone or a smart speaker. (For example, you could say, “Alexa, set the temperature to 74 degrees.”)
  • geofencing (the ability to track when you come and go via the presence of your smartphone) to make temperature adjustments

Thinking about swapping out your old thermostat? Call us today at 302-738-4144 or 410-398-2146 and schedule appointment.

Don’t Turn Off Your AC

Air conditioners in DE, PA, or MD should be kept ON in the summer instead of turning them completely off. Leaving your central air conditioner off can raise your home’s indoor humidity levels. Your AC not only cools your air, but it also dehumidifies it. When humidity levels reach 60%, mold growth and bug infestations occur. While the mold and bugs will love the humidity,  you’ll hate it.

Myth Busters: It’s more efficient to leave it on all day than to raise and lower the temperature

According to the U.S. Department of Energy, you will save more money on your cooling bills by programming your thermostat while you are asleep or away from home. You can save as much as 10% a year on heating and cooling by simply turning your thermostat back 7°-10°F for 8 hours a day from its normal setting.

3 BONUS Cooling Tips

1. Change Your AC Filters:

A clogged air filter could add 5% to 15% to your summer’s energy costs, shorten the lifespan of your whole system, and may even be undercutting your health. Change the filter on your central AC system regularly—check your filter every month, especially during heavy use months (winter and summer). If the filter looks dirty after a month, change it. At a minimum, change the filter every 3 months.

Don’t neglect this chore. A dirty filter can lead to poor air flow or freezing up of your unit’s evaporator coil, says James Braun, a professor of engineering and director of the Center for High-Performance Buildings at Purdue University.

“If you have a badly maintained system, it can become contaminated with microorganisms that may be harmful if inhaled,” says Mark Mendell, a staff scientist with the Lawrence Berkeley National Laboratory’s Indoor Environment Group. Mendell mentions asthma problems and allergies as some of those possible harms.

2. Tune-Up Your AC unit

A recent study showed that over half of existing air conditioning units are improperly charged with refrigerant (commonly called Freon®). Improperly charged means too much or not enough refrigerant, not that the unit will not run. Even though improperly charged units seem to work fine and cool your home, the fact is these units are not performing optimally. Optimal performance increases efficiency, which is what we are all looking for these days…savings on our energy bills. A tuned-up air conditioning system is less likely to break down when the unit is needed most. Regular maintenance increases the lifespan and can give you an idea of how much longer your system may have before considering a replacement.

3. Taking Full Advantage of Fans

  • Use ceiling fans to help keep cool air circulating throughout your home. This lifts of the burden from your AC system, Braun says. Turn ceiling fans counterclockwise during the summer, which promotes greater air flow.
  • At night, use window fans to pull in the cooler air from outside to cool your rooms.
  • During the hot summer days, place a fan in a position so that it’s blowing on the people in the room, but with the window shut.

“Fans don’t cool the room; they cool the body because there’s more air movement,” says Persily. And specifically, because they’re not cooling the room, it’s useless to leave them on when no one is occupying the space. In that case, the fan motor may actually just be adding to the heat in the room.

In the absence of an AC, fans can help keep us cool when we are hot and sweaty. Turn on the ceiling fans, oscillating fans, and boxed fans and let them all blow directly on you. “The sensation of [air speed]”—that is to say, air blowing over you—” improves thermal comfort in a cooling situation,” says Andrew Persily, an engineer focused on indoor-air quality at the National Institutes of Standards and Technology in Gaithersburg, Maryland. Fans create a wind-chill effect when air that moves over our bodies and sweat evaporates into the air, taking away the heat. That evaporation process, making us feel cooler.

Summer beating your AC up? Hillside will be in your corner so you can beat the heat.


Need a New Air Conditioning System? Take advantage of our Summer Air Conditioning Specials.

  • 0% Financing,
  • $250 Instant Rebate, and
  • FREE wireless Wi-Fi thermostat upgrade with the purchase of a new installation or replacement.

Call 302-738-4144 (DE & PA) or 410-398-2146 (MD) or fill out the form on this page to schedule a FREE estimate with Jerry. 🙂

the perfect programmable thermostat settings in the summer