How Thermostats Work

Thermostats are a small yet essential part of every modern air conditioner. It’s the “face” of your HVAC system, and with the right kind of thermostat, it can help improve the A/C’s overall efficiency. Amber Air Conditioning shares a closer look at how it works.

How Do Thermostats Work?

Most homeowners might be surprised to know that thermostats do not have anything that resembles a thermometer, despite being used to regulate your home’s indoor temperature. Instead, it relies on a much simpler mechanism: thermal expansion. Materials expand when exposed to heat, but at different rates. This principle is the backbone of the traditional thermostat: two strips of different metals, usually steel and copper, are fused together.

The difference in expansion rates bends the strip as the temperature increases. This triggers a switch that turns on the air conditioner (or dampers, if you have a ducted system), which then begins pumping out cool air. As the room temperature cools down, the bimetallic strip relaxes and eventually triggers another switch that stops pumping out cool air. The knob at the front panel adjusts the tension of the strip, which as far as the user is concerned, adjusts the desired room temperature. Homes that also require heating may have thermostats with reversible settings that switch heating on instead.

Types of Thermostats

There are several types of HVAC thermostats available today. Amber HVAC experts have all types including the bimetal thermostat, which we’ve discussed, and is still in use in many homes. It’s the most affordable option, though it takes several minutes for this kind of thermostat to react to temperature changes. A gas-filled bellows thermostat uses small circular bellows filled with a kind of gas that replaces the bimetallic strip, which triggers the switch as it expands or contracts. A wax thermostat uses expansion and contraction to trigger the air conditioner switch.

Digital thermostats are a newer type of thermostat that use electronic sensors, which are either built-in or are installed elsewhere in the room. Various models allow advanced features such as programmed temperatures at specific times, or trigger events which are when someone enters or leaves the room. Some can even be operated using a smartphone and can learn your usage habits for even better efficiency.

Learn More About Temperature Control at Amber Air Conditioning Inc.

To learn more about thermostats and other air conditioning products and services, call Amber Air Conditioning Inc. today at (951) 674-6974. You can also fill out our contact form to schedule an appointment.