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Thermostat “On” or “Auto”, Which Setting Should You Use?

small_4732676839There are all kinds of different thermostats on the market. Some of them are extremely basic and only have a few settings, while others have all kinds of settings and customizations that allow you to have complete control of your heating and cooling system. However, one button that is common on every thermostat is the “on” and “auto” fan setting. Many customers get confused about which setting they should be using, so today we’re going to talk about the advantages and disadvantages of using both!

What’s the difference between the thermostat’s “on” and “auto” setting?

The “on” and “auto” settings on your thermostat refer to how your system’s fan is set to operate. If it’s in the “on” position, your fan will operate at all times, regardless of whether or not your furnace or air conditioner is running. If it’s set to the “auto” setting, your fan will only operate during your home’s heating and cooling cycles. When those cycles finish, the fan will turn off until the next cycle.

What are the advantages and disadvantages of the “on” setting?

When your fan is constantly running, it continuously mixes the air from warmer and cooler spots in your home. This can result in more even temperatures throughout your house. In addition, the “on” setting allows air to constantly cycle through your air filtration system. This can make your home’s air healthier because particles and contaminants will be captured more frequently.

The biggest downside of using the “on” setting is that it uses more energy than the “auto” setting. The fan plays a big role in your system’s energy consumption, so keeping it running all the time can be a bit expensive.

What are the advantages and disadvantages of the “auto” setting?

The biggest disadvantage of the “on” setting translates into the biggest advantage of the “auto” setting. If your fan is only running when your furnace and air conditioner are on, your system will consume less energy.

The downside of using the “auto” setting is that you don’t get the extra filtration and comfort benefits that using the “on” setting can provide.

How can you have the best of both worlds?

If you’re interested in the benefits of using the “on” setting but you don’t like the idea of spending more on energy bills, installing a system with a variable speed fan motor is the perfect compromise. Variable speed fans run almost all the time (gaining the advantages of the “on” setting), but have multiple different speeds that are used depending on the airflow needs of your home at any given time (gaining the energy-saving benefits of the “auto” setting).

If you have any questions about your thermostat’s “on” and “auto” settings, or if you’d like a heating and cooling system serviced or installed in your home, contact Jerry Kelly, your St. Louis heating and air conditioning contractor. We service the St. Louis area, including towns like Wentzville, Winghaven and Ballwin.

photo credit: Lee Bennett via photopin cc