Residential AC: Perfect Indoor Temperature Settings

Are There Perfect Indoor Temperature Settings?

Most households discuss indoor temperature settings at least twice annually—at the beginning of the cooling season and the beginning of the heating season. The struggle is, . . . well, people. No two of us are alike and that extends to our comfort level when it comes to indoor temperatures.

While some will call themselves “warm-blooded,” and others consider themselves “cold-blooded,” these names declare a preference for indoor temperature settings.

Are there perfect settings? Can you find a compromise that will make every occupant happy? Let’s give it a try.

In most locations, both in Spring and Fall, there are periods of almost idyllic weather—the perfect temperature and humidity, with plenty of sunlight. The windows are opened because inside and outside temperatures are about the same. Ah . . . if only the weather could stay that way year-round!

After a relatively short period, the changing season brings more extreme temperatures and we rely upon our heating/cooling system to keep us comfortable. Two major considerations govern how hot or cool we keep our homes during summer or winter.

Residential AC:  Energy Costs

The energy efficiency of heating, ventilation, and air conditioning (HVAC) systems has improved tremendously over the years. New construction techniques also seal and insulate homes better, keeping conditioned air inside better than drafty, older homes.

Even with improved efficiency, wise energy consumers will consider both the financial and environmental cost of energy and make wise choices concerning temperature settings.

For the cooling season, the U.S. Department of Energy (DOE)recommends¹:

• a temperature setting of 78⁰F during waking hours while the home is occupied
• raising the setting to 88⁰F while occupants are away or sleeping.

For the heating season, the DOE recommends setting the heat at:

• a temperature setting of 68⁰during waking hours while the home is occupied
• lowering the temperature 10⁰ to 58⁰ while occupants are away or sleeping.

Before you ignore the rest of the information, understand that energy costs are only one consideration. New HVAC systems are designed to minimize energy use at the stated settings. If you raise the AC setting and/or lower the heat setting by 10⁰ for 8 hours per day, you should see an energy use reduction of up to 15%. The DOE is focused on energy efficiency, not comfort. Let’s consider comfort as well.

Residential AC:  Personal Comfort

For most people, 78⁰ F in the summer is too warm and 68⁰ F in the winter is too cold. However, our comfort level can be expanded a little bit. Often, the difference between “too much” and “just right” is only a degree or two. Here are some suggestions for expanding your temperature comfort level;

• Begin with the seasonal temperature change in the Fall. Open some windows to bring the indoor temp close to the outdoor temp. How cool is too cool? Perhaps 68⁰F is too cool, but 70⁰ F is tolerable, compared with a 76⁰ setting from last Fall
• Do the same with AC in the Spring. Open some windows and let the Spring air inside and consider “how warm is too warm?” Perhaps 78⁰F is too warm, but perhaps 75 or 76⁰ F is okay.
• Experiment with sleeping comfort. Can everyone tolerate sleeping in a cooler home during winter nights, sleeping under warm blankets? Is there tolerance for sleeping in a warmer home during the summer with lighter bedding?
• The best setting should include at least one cycle per hour to help maintain proper humidity and to keep the air filter.

Residential AC: Applying What You’ve Learned

If you understand the “ideals” of energy efficiency and have explored comfort tolerances with family members, you can develop a schedule of temperature setting that comes close to “perfect.”

However, it is not practical to stay home all day in order to change the temperature setting on the thermostat. The best method for implementing your schedule is with a programmable thermostat.

Programmable thermostats are relatively simple improvements with remarkable flexibility. Temperature settings are inputted according to the desired schedule, keeping your family comfortable while saving as much energy as possible. Your schedule can change at least six times per day. Let’s consider a potential cooling schedule at an average home:

• A family has determined that 75⁰F is a tolerable comfort level during normal activities, but with summer-weight bedding, everyone can tolerate 84⁰ F overnight. At 10 pm, the thermostat makes the adjustment.
• Family members begin to stir and get ready for the day at 6:30 am most days. The thermostat setting changes back to 75⁰F at 6 am, to ensure the home is back at the desired temperature as the family wakes.
• Everyone is generally out the door by 8:30 am, accomplishing great things while away from home. The thermostat is scheduled to raise the temperature again to 84⁰F while the home is empty.
• Family members begin filtering in between 4:30 and 5:00 pm, so the thermostat makes the change at 4 pm, bringing the temperature back to 75⁰ 
• Weekends are a little different, with more downtime spent at home. Each day can be scheduled differently to account for schedule variations.

After extensive study, the DOE has determined that an average home that schedules a thermostat setting change of 5 to 10 degrees for 8 or more hours, will save 5 to 15% on their total energy bill.

Northwind AC has a variety of programmable and smart thermostats. Our technicians have considerable experience with installation and with educating homeowners on proper programming. Once you have determined your “perfect” temperature schedule, let us help you achieve your savings and comfort goals.

Have Questions About Residential AC Temperature Settings?

Northwind Air Conditioning and Heat can help with Residential AC Maintenance and repair. Contact us and get the answers you need.

^{1 https://www.energy.gov/energysaver/thermostats}