In our modern, high-tech society, we don't think much about some of the electronic gadgets in our homes. Take, for example, the ever-present thermostat—a staple of American households for decades. It usually takes the shape of an unassuming box on the wall, but that modest device controls the comfort of your family on the coldest day in January and the hottest day in July.

A thermostat is a temperature-sensitive switch that controls a space conditioning unit or system, such as a furnace, air conditioner, or both. When the indoor temperature drops below or rises above the thermostat setting, the switch moves to the "on" position, and your furnace or air conditioner runs to warm or cool the house air to the setting you selected for your family's comfort.

A thermostat, in its simplest form, must be manually adjusted to change the indoor air temperature. By taking some care in how you adjust a manual thermostat, you can achieve significant energy savings in your home.

You can also save energy, with even greater comfort and convenience, through the use of automatic or programmable thermostats.