Should You Really Set Your Thermostat to 78 in the Summer?
Key takeaways:
• A 78° thermostat setting for summer could save you money, as long as you’re still comfortable.
• Your air conditioning system needs to run often enough and long enough to remove humidity from the air.
• Using a smart thermostat to adjust the temperature can help you save the most on energy costs.
By Anne Fonda
Summer-like heat can strike parts of the South as early as February or March. Unless you live alone, when it’s hot enough to turn the AC on, a debate among family members inevitably ensues about what to set the thermostat to in summer.
Some people want it to be ice cold in the house, while others want the temperature set higher to save money and avoid wearing a sweater in the summer.
According to the U.S. Department of Energy (DOE), it turns out that the best indoor temperature for your home during the summer months is 78° F. If that temperature falls outside your comfort level, there are several ways to modify how your home feels without causing your energy bill to spike. Keep in mind, each degree set above 72° can save you up to 3% on your cooling costs.
Best temperature for a comfortable home
Saving on your energy bill is important, but you also want to enjoy your space comfortably. If a thermostat at 78°F during summer heat isn’t cool enough for you, make small adjustments. Move the temperature one to two degrees higher than normal to see if you can notice a difference. Continue to increase the setting until you reach your comfort limit.
Also, remember that humidity can make you feel hotter. If high humidity is a constant challenge in your home, explore how a powerful whole-house dehumidifier can adjust the moisture in the air even as the seasons change to create a cooler space.
What temperature to set the thermostat to when away in summer?
When you’re home, you want a temperature setting that maintains comfort. No need to be sweating if central AC is available! But while you’re away, however, your set temperature doesn’t need to be quite so low. This might be while you’re at work, out volunteering, running errands, or on vacation.
Program or adjust the thermostat while you’re away to a higher setting. Installing a smart thermostat will make adjusting the indoor temperature even easier because you can do it from your smartphone via the Home App.
Set the temperature to be higher by 7-10°F during those away periods. For summer, don’t set it for higher than 80-85° because you need the system to come on often enough to remove humidity to prevent mold growth. According to the DOE, you can save as much as 10% a year on your cooling and heating bills if you raise or lower the temperature by 7°-10°F for 8 hours a day from its normal setting. Your savings will vary based on your climate.
“Your HVAC system has an optimal design point where it runs efficiently. When you keep your thermostat set higher, both when you’re home and especially when you’re away, you’re asking less from the system. That reduced strain can help it last longer and keep more money in your pocket through lower energy and repair costs.”
- Kimberly Sexton, Senior Systems Engineer
There are several other things you can do to save money on your energy bills besides adjusting the temperature on your thermostat. Let’s take a look.
#1: Consider a home energy audit
If you can feel drafts near your windows and doors, you may be letting cool conditioned air out and hot and humid air in. Your attic, basement, or crawl space may also be causing your HVAC system to run harder than it needs to, increasing your energy bills.
Consider getting a home energy audit. Many utility companies offer them for free – check your energy provider’s website. You don’t have to hire anyone to make some of the recommended changes, such as sealing gaps and cracks and improving insulation.
Making your home more airtight can help increase your comfort and decrease your energy bills year-round.
#2: Make your home naturally cooler
In addition to bumping up the thermostat setting during summer months, there are simple ways to make your home feel cooler.
- Close shades, blinds, and curtains to keep the sun out during the day. Blackout shades and curtains work wonders.
- Open windows and turn off your air conditioner at night to let in cooler air, as long as the humidity isn’t too high. Then shut the windows and shades in the morning to trap the cool air in your house.
- Only use heat-generating appliances like your stove, oven, and dryer after 8 pm to avoid heating up an already hot house. Appliances can raise the temperature up to 10°F! Grill out, use an air fryer, or incorporate more salads into your summer dinner routine.
#3: Install new or use existing ceiling fans: Ceiling fan direction in summer
Ceiling fans won’t replace your air conditioner during the summer months, but they can certainly complement it. On most models, there’s a small switch near the bottom or side of the mounting base of the fan. This switch allows you to change the direction of the fan to match the season.
During the summer months, your ceiling fan blades should spin counterclockwise. By spinning in this direction, your fan creates a cool breeze by pushing air down. The wind chill effect can make you feel up to four degrees cooler. You may find that you can increase your thermostat temperature by two to three degrees thanks to the ceiling fans. Since the fan doesn’t actually cool the air temperature, turn it off when you’re not in the room.
#4: Perform regular AC maintenance
Just as you prepare your vehicle for a long trip to ensure everything is in optimal working order, the same should be done for your air conditioning.
DIY maintenance:
- Change your air filter every 30-90 days year-round.
- Keep indoor return air vents and supply registers clear. Don’t let furniture or drapes block them.
- Keep the area around the outdoor AC unit or heat pump clear by about 2 feet on all sides. Trim bushes, etc.
Professional HVAC maintenance:
Scheduling professional heat pump or AC maintenance before the summer heat hits will help ensure the unit is performing properly and the unit is cooling as efficiently as possible.
“Regular HVAC maintenance is one of the simplest ways to protect your investment. Having a technician service your system before winter and again before summer may help prevent downtime during the most extreme temperature periods. It can reduce strain on the equipment, significantly extend its lifespan, and save you money in the long term.”
- Kimberly Sexton, Senior Systems Engineer
Explore our smart thermostats
Smart thermostats can help conserve energy and reduce your energy costs.
#5: Invest in energy-efficient air conditioning
Even when you’re setting your thermostat temperature higher, you may not see your electric bill go down if your air conditioner or heat pump isn’t running efficiently. If your system is old, inefficient, and repair bills are getting higher and higher, it may be time to start planning for an energy-efficient upgrade.
A newer AC unit or heat pump that has high Seasonal Energy Efficiency Ratio (SEER2) and Energy Efficiency Ratio (EER2) ratings can be 15% more efficient than older models. So, replacing an older, less efficient system could provide an immediate impact on your comfort and energy bills.
Consider upgrading to a multi-speed or variable speed unit if you have long, hot and humid summers. These systems run longer at lower speeds to provide more precise temperature control and better humidity control.
"The number of speeds or stages typically translates to energy efficiency and better comfort… so the more variability or number of stages, the more efficient the equipment will operate and the better temperature and humidity control the system can deliver to your home.
Multi-speed systems are a rather new design and straddle the gap between traditional two-stage systems and variable speed. They offer better efficiency than single or two-stage systems but are simpler than variable speed systems and are available at a lower price.”
- Mark Woodruff, Senior Product Manager, Air Conditioners
Work with your local Trane dealer to increase your comfort
If your air conditioner or heat pump is struggling to cool your home or high humidity is creating problems, your local Trane dealer can help you find a fix. From HVAC repair to adding a dehumidifier to replacing an aging system, you have options.
Anne Fonda
Content Writer, Trane Technologies
A Content Writer with Trane Technologies, Anne Fonda researches topics and writes for Trane® and associated residential HVAC brands. She works in collaboration with Trane Technologies subject matter experts, offering easy-to-understand, informative content on complex topics. Her goal is to help consumers make informed decisions on the products and services they need.
She has written for HVAC and other service provider websites for over 16 years. Before transitioning to web content writing, Anne had a 14-year stint as an award-winning journalist. She graduated cum laude from the University of Missouri-Columbia School of Journalism.
When she’s not working, Anne enjoys playing word games, reading, gardening, spending time with family, and visiting gardens and museums.
Expert review by Kimberly Sexton, Senior Systems Engineer
