All Year - How Does a Thermostat Work (And How Can It Help Me Save Money) 02

How Does a Thermostat Work (And How Can It Help Me Save Money)?

Most homeowners likely know what a thermostat is but don’t usually give it a second thought beyond adjusting the temperature within their homes. An integral part of your home’s HVAC system, you can maximize the usage of your thermostat and save money with more responsible usage.

A thermostat is a device that detects temperature and regulates it to create a comfortable indoor environment. In homes and offices, this gadget is typically mounted on a wall to display the temperature that an HVAC system makes.

You can consider the thermostat as the endpoint for user control over the HVAC system. Through the thermostat, the homeowner relays instructions throughout the home’s heating/cooling system. Depending on how complex your system is, and how much it needs to communicate with various devices, several sensors or electrical inputs may be needed for your thermostat.

How A Thermostat Works

In a nutshell, thermostats turn the HVAC on and off and control the flow of heat or cooling to maintain the desired temperature. While they come in different types and technologies, one thing stays the same – they all use some kind of sensors designed to read and detect temperature.

A homeowner controls the heat at home by adjusting his room thermostat.

A homeowner controls the heat at home by adjusting his room thermostat.

What is a Mechanical Thermostat?

Mechanical thermostats read temperature through their sensors made of bimetallic strips and gas-filled bellows, which change in size depending on the temperature. If a matter comes into contact with heat, it expands, and when it’s exposed to the cold, it decreases in size. This law of physics is the basis of the thermostat’s sensor design.

The bimetallic strip acts as a bridge that connects the thermostat switch and the electrical circuit. This strip expands and bends inward when it gets hot to stop the electricity’s flow, and stays straight when exposed to the cold to let the electrical currents flow and start up the heating.

Because it takes a bit long for the bimetallic strips to respond to temperature fluctuations, mechanical thermostats of heaters are also equipped with gas-filled bellows located between two metal discs that respond well to heat.

The gas filling the bellows inflates when it becomes hot, forcing the two metal discs apart. Meanwhile, when the room cools down, the bellows shrink and the discs move away from the switch, activating the heating systems in the process.

Instead of gas-filled bellows and strips, some thermostats like those with electronic designs use other types of sensors such as semiconductors, resistance temperature detectors, thermistors, and other heat-sensing circuits and elements.

What is a Smart Thermostat?

A smart thermostat– also referred to as a communicating or connected thermostat– allows users to create programmable and automatic temperature settings based on weather conditions, heating and cooling needs, and even their lifestyle (i.e., daily schedules).

Contrary to popular belief, not all WiFi-enabled thermostats are “smart” if you take into account the functionality mentioned above.

Installing a smart thermostat is the same as a regular model – i.e., you need to adjust it manually for the first few days or weeks. Then, the system “learns” your preference and lifestyle patterns (i.e., waking up, leaving the house for work, going to bed, etc.) and adjusts the temperature based on them.

If your schedule changes, a smart thermostat also takes note of this, which means you don’t have to make manual adjustments just to save on money.

Can I Save Money with a Thermostat?

A homeowner relaxing in the comfort of her Sacramento home.

A homeowner relaxing in the comfort of her Sacramento home.

The short answer is yes – and that doesn’t include making sacrifices like turning off your AC amidst the sweltering summer heat or your furnace in the middle of the winter.

If you want to slash your energy cost, start at your thermostat. And to save more money, you may want to throw on a sweater in the winter or rely more on your fan during summer.

According to a study published by the Department of Energy, homeowners can save an average of 1% for each degree of thermostat adjustment every eight hours.

Using this estimation, you can slash up to 10% of your electricity bill if you turn your thermostat back to 7-10 degrees from their usual settings even for just eight hours every day.

These are some hacks you may want to consider if you like to reduce your energy costs without making a huge sacrifice on your comfort:

In the winter, keep your thermostat at around 68 degrees while residents are at home and awake; however, turn it down by 10 degrees or so when they are away or sleeping. Don’t completely turn off your HVAC if everyone is away because you may end up having an expensive problem – frozen and damaged pipes.

Keep your thermostat at 78 degrees but adjust it to 85 degrees when no one is at home.

A Final Word About Thermostats

A smart home uses a digital thermostat as part of its automated heating and cooling system.

A smart home uses a digital thermostat as part of its automated heating and cooling system.

Ideally, your thermostat should be placed in the part of the house where residents spend most of their time and away from windows and external walls (there should be at least an 18-inch distance between them). Also, it should not be exposed to any heat sources like sunlight, heater vents, appliances, stove, etc.

With some simple hacks and the correct placement of the thermostat, you can reduce your energy cost without having to sacrifice your comfort.


Give the All Year team a call today!