Video:Anatomy of a Thermostat

Transcript:Anatomy of a Thermostat

Hi I'm Matt Ediger for about.com and this is the anatomy of a thermostat.

Basic Anatomy of a Thermostat

Thermostats can be divided into three basic elements; the thermometer, the dial, and the switches. More modern thermostats are typically digital with an LCD screen. The anatomy is still the same however. We'll talk about these parts and how they work. Here's a very simple thermostat that controls baseboard heaters. With the cover removed you can see all the parts mentioned earlier.

Parts of a Thermostat

Here we have the dial. Thermometer and the switch that turns on the heater The thermometer is the basis for all thermostats this is what controls when the furnace or AC unit kicks on or turns off. Some older units use a small amount of mercury on an adjustable balancing point when the mercury reaches the desired temperature or tipping point it turns on or off the switch this works both ways. When the mercury cools it tips the other way. As we all know mercury is dangerous so it's not wise to play with this too much as the consequence of breakage is severe. Other older units use a calibrated spring type device that expands and contracts completing a circuit and turning on and off the device.

Structure of a Thermostat

The switches control when and what happens with your heating and cooling unit from this you can control if you want heat, ac, or just a fan to circulate the air in your homeDials adjust the tipping point of the thermometer telling the furnace when to turn on or off. Digital thermostats allow more customizable operation of your furnace or ac unit you can program the unit to a certain extent. For example you can tell the unit to turn off after you leave for work and to turn on an hour before you get home maximizing energy efficiency. They can appear to be a little intimidating but are usually user friendly. Here's a digital thermostat you can see there's a lot of options here we can control different zones or areas of your home, and when they turn on and how hot or cool they get.

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