Should Your Thermostat Be On Auto or Fan?

Your HVAC unit blower function depends on the fan setting on your thermostat. The blower aids in circulating cold or hot air in your house until the thermostat degrees are attained. Depending on the homeowner’s needs and preferences, the thermostat has two settings that control fan usage—fan on or Auto.

So should you leave your thermostat setting to fan on or auto? It is a question that is on most homeowners’ minds, especially those looking to save on energy bills.

Here, we shall look at what each thermostat fan setting entails, its pros, and its cons. It should help you make a decision on whether you should keep your thermostat fan on or auto

Deciding Between Thermostat Fan On or Auto Mode

Auto Setting

When selecting the auto setting for your thermostat, your fan will automatically turn on only when your unit is actively cooling or heating air around your home. Once the thermostat achieves the needed temperature, your entire system will turn off until the next cycle or if the temperature once again drops out of the setting range.

Factors to Consider Using Auto Setting

  • Fewer repairs

If you frequently run your system, you will be stressing it more. This means your system experiences more wear and tear and ends up requiring more repairs, which is true if you run any machinery regularly over long periods of time.

With the auto setting, your fan will only be ON when needed to provide cold or warm air around your home. There’s less stress on your fan system, leading to greater longevity and requiring less repairs in the long run.

  •  Reduced energy costs

Whenever your fan is in the ON position, it will consume more energy as it runs almost all the time. It may not be a great deal to have your fan on all day, as it’s sure to have a big impact on your monthly energy bills.

On the other hand, in the auto setting, your fan usage will be limited to a few times a day in most cases. This will let you use significantly less energy and enjoy big savings on your monthly energy costs.

  • Safeguards your house from unnecessary duct leakage

Operating your fan more often blows out more of the warm or cold air through small leaks in the air ducts. This results in higher temperature differences that reduce the efficiency of your HVAC systems. Not only will it take longer to heat or cool your home, but you’ll spend more energy and money doing it.

However, if the fan is on the auto setting, your temperatures will remain more balanced and allow natural equilibrium to help direct heat or cooling where it needs to go. 

  •  Exceptional dehumidifying

Your system is perfect at dehumidifying when it is set to auto. When the AC runs for a while and stops, it gives ample time for the moisture on the AC coils to properly be released outside.

This leads to more balanced indoor humidity, which is a big factor in how comfortable your living spaces are.

  • Less noise

Auto settings will run your fans only when it is necessary. You’ll only hear operation noises at the very minimum, which makes it a great setting for homeowners with HVAC systems that run louder than most.

Fan ON setting

Should you leave your thermostat fan on or auto mode? Let’s find out what the ON setting has to offer.

Selecting ON means that your fan will keep running even when your system is not cooling or heating your house. This leads to continuous air flow throughout your ducts and HVAC system, which comes with its own set of benefits and caveats.

Factors to Consider Using Fan ON Setting

  • Indoor air is usually cleaner

Naturally, since your HVAC fan is on throughout the day, it’ll pull more air in through the in-built filtration unit that keeps your indoor air clean.

  •  Reduces the risk of a fault or short circuit

There will be fewer starts and stops of the fan since it is always in motion. In turn, this reduces the change in electricity and reduces the risk of a short circuit or fault that can lead to a malfunction or potential breakdown of your HVAC system.

  • More extreme temperature changes

 Whenever the fan is constantly running, it blows more hot or cool air through your vents and into your home. This leads to a more significant shift in your indoor temperature, which might be a good thing in some cases, but can also be unwanted in moderate seasons like spring or autumn.

  • Increased energy bills

The on-setting consumes a lot of energy since the fan is always running. To keep the fan operating 24/7, you’ll also be spending more money on your utility bills.

However, if you want the fan to keep running but avoid the costs, you can consider installing a variable speed motor, which can help adjust the fan speeds and save on energy usage.

  •  Clogged air filters

Another demerit of having the ON setting is that the air filters can get blocked quickly. You have to change your filters more frequently since your fan is always operational.

  • Produces a lot of noise

The ON function tends to produce a lot of noise since the fan is running 24/7. It can be unpleasant for you and your family if you’re sensitive to background noise.

 Which is the best between the two settings?

So, should the thermostat be on auto or fan mode? Well, this will mostly depend on your personal preference, as well as your household’s needs.

 For instance:

  • Do you have aged parents or relatives living with you? The ON setting will guarantee more comfort as the fan runs throughout. It is also the best option during a heatwave.
  • Do you have allergic people in your household? The ON setting option allows for consistent air circulation, which reduces the number of allergens indoors.
  • If you are tired of paying high monthly power bills, the auto setting consumes less energy and leads to more savings.

Factors like these are unique to your needs and should be able to help you decide which setting to choose. 

If you’re looking to learn more about HVAC systems with settings like these for your thermostat, or are considering installing a new thermostat within your home, you can reach out to Anderson Air to help you determine which one works best for you.

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