A smart thermostat can cut heating and cooling costs by roughly 10 to 12 percent simply by adjusting the temperature when nobody is home.
Install it yourself in about half an hour, since most models fit existing wiring with basic tools.
Set a schedule that drops the temperature while you sleep or work, then warms up just before you return.
Use the geofencing feature if available, so the house eases back automatically as you drive toward home.
For most homes, the device pays for itself within the first year of use.