In this video, This Old House plumbing and heating expert Richard Trethewey explains how adjusting the thermostat can reduce energy consumption and save you money.
1. Temperature setback is the act of adjusting the thermostat while you’re asleep or away from the house.
2. Lowering the thermostat in winter keeps the house colder, but the furnace doesn’t kick on as often, so you use—and pay for—less energy.
3. In summer, raising the thermostat makes the house warmer but prevents the air-conditioning system from running all day, which lowers your electrical bill.
4. There are several types of thermostats, including manual single thermostat, programmable clock thermostat, and smart thermostat with motion sensor that you can access via a smartphone.
5. R-value is the amount of heat that transfers from the inside of a home to the outside during the heating season, and from outside the home to the inside during the cooling season.
6. Delta T refers to the temperature difference reflected by heat transfer.
7. Imagine it’s zero degrees outside and the thermostat is set at 70 degrees, which is called the target temperature.
8. If you lower the thermostat to 60 degrees, less heat will transfer to the outside because there’s less of a temperature difference between the indoor and outdoor temperatures.
9. According to the Department of Energy, for every degree you lower the target temperature, you’ll save 1% of fuel over an 8-hour period. In the above example, you would save 10% on your heating bill.
10. The amount of energy it takes to reheat a home will always be less than if you didn’t lower the thermostat and the furnace kicked on and off all day. The same is true in summer with air-conditioning costs.
11. Don’t use a clock thermostat with an electric heat pump, super-insulated house, or radiant-heat system.