Activity Overview: The U.S. Department of Energy estimates that individual homes can achieve a 10% reduction in heating and cooling costs by leveraging the power of the programmable thermostat to change the set temperature by 7°F to 10°F for 8 hours a day.¹ Working as a group or a class, use students' preferences on comfort and what they know about weather and temperature trends to create a schedule for a programmable thermostat.
Use your classroom or a representative example of a family home as the setting for your model programmable thermostat. First, project a spreadsheet labeled with the hours of the day or write an hour-by-hour schedule on the board in your classroom. Determine during what hours of the day people will be using the space. You may use your classroom between the hours of 8 a.m. and 3 p.m. Mark those hours in some way on your chart. Alternatively, a private home has the opposite use pattern. Your family may leave the house at 7 a.m. and return again after 5 p.m. after a day at work or school and sports. Explain to students that you can change the set temperature from desired temperature when people are not using the space to save energy.
Second, identify the warmest and coldest hours of the day. Your students will know that by 9 a.m. in August, you know it's already a hot day. On the converse, by 10 p.m. on a summer night, the temperature is starting to drop (finally). Mark those hot hours in some way on your chart. Explain to students that you can change the set temperature from desired temperature when people are sleeping or when the temperature outside is more comfortable.
Then, discuss a comfortable set temperature. Do you students tend to prefer a colder room? What is your classroom set to? Is it too cold or too warm? Decide on an optimal set temperature. Then, determine which hours of the day you should set your thermostat to this desired temperature. This depends on whether people are in the space and whether the indoor and outdoor temperatures are close enough to be comfortable. Per the findings from the Department of Energy, consider a more efficient set temperature when cooling is less needed that is 7°F to 10°F away from desired temperature.
You and your students should work together to determine a model schedule for whatever space you choose. Does your schedule for a programmable thermostat include 8 hours of settings 10°F warmer than desired temperature? Is it possible with the scheduled usage pattern in your model?