Optimal HVAC Fan Setting for Air Quality and Lower Utility Bills

Your HVAC fan is running every time your AC is operating. However, it is all up to you to decide whether your fan should still run when your home achieves the desired temperatures. This choice is split between comfort and cost.

The Auto Versus On Settings

Many HVAC systems have only two furnace settings: on and auto. Whenever you set your thermostat to the auto option, your fan will run simultaneously with your AC to assist it in distributing the cooled air. On the other hand, when you choose the on setting, forced air will flow through from your vents until the setting is changed.

There are benefits of using the auto setting. For one, this setting helps in conserving energy and reducing the wear and tear on your HVAC parts especially the fan motor. Secondly, the auto setting can help lengthen the lifespan of your HVAC filter because air doesn’t pass through it all the times.

However, the downside to the auto setting is that your household air will gradually become stagnant in between cooling cycles. This means if you don’t open your windows during mild sessions, your home could become stuffy before the AC comes on back again.

The on setting is opposite that of the auto setting. When this option is effected, air gets replaced continuously and this helps your indoor air to remain fresh and you won’t even notice the household odors.

Allergy sufferers especially choose this option because of the endless circulation benefits it gives them. While the on setting delivers the best experience, the problem comes in the cost. Since your AC runs 24 hours, the impact of that will be felt in your monthly energy bill and the frequency with which you will have to replace your air filters. In line with this, you will also experience frequent maintenance, repairs, and replacement needs for your fan motor.

Another downside of the on setting which a majority of households may not be aware of is that it can potentially draw in humid outdoor air into your indoor space between cooling cycles. If you live in a dry region or with arid-like climatic patterns, this doesn’t become a concern. However, in humid environments, this problem can be so pronounced that getting a whole-home dehumidification becomes necessary to counteract the effect.

The Compromise

Now that you have seen the two sides of the coin, it is up to you to consider the best option based on your needs. You may settle for the on settings, but try to reduce the operational cost associated with it. One of the best solutions is to go for variable speed fans which offer you greater customization of air flow during the cooling cycles and in between.

You can program the variable speed fans to give you higher fan speeds while the AC is on and slower speeds when the AC is circulating air. Get a local HVAC technician to help you in assessing the best system for your home.