Thermostats regulate the temperature using the air in a room to turn on and off heating and cooling to bring the air to a predetermined temperature. All thermostats use air current in their operation.

Identification - Thermostats use heat anticipators and cooling anticipators. A mercury bulb is also present in older thermostats to conduct electrical current.

Function - The heat anticipator has a small resistor that heats a bimetal strip to the setpoint temperature. When the air reaches that temperature, it shuts off. The cooling anticipator uses mercury and a bimetal strip. Mercury conducts electricity. When the bimetal strip expands and contracts, it tilts the mercury, turning on or off the cooling unit.

Types - There are different types of thermostats available on the market. The most popular is the digital thermostat.

Features - One of the most popular features in digital thermostats today is the ability to program the thermostat to raise and lower the temperature based on a schedule. This allows users to heat and cool their space with greater efficiency.

Warning - The mercury present in older thermostats is a poisonous substance and should be handled carefully especially if the bulb is broken and the contents spill.