Thermostat Settings - Auto vs. On

Let's talk about one of your thermostat settings. Specifically, the "Fan" Auto vs. On.

I see a lot of homeowners with this setting at the "On" position. Go check yours now and if it's positioned to "On", then switch it back to "Auto". I'll wait while you check…..

If it was on Auto, Good Job. If it was on "On", read on as to the importance of leaving to Auto in our area.

This switch controls the blower motor only and only circulates air in the home. The other switch (Cool, Off, Heat) controls what mode you desire to be in. When In the "Cool" mode, your system as a whole is running, including your outdoor condenser. With the condenser running you are removing heat and humidity from your home (you are "cooling").

The problem with leaving the fan ON is when the cooling mode is satisfied, and the system shuts off, the blower will still run. In our area, this presents a few problems. The main problem is that now the blower is picking up moisture from your wet evaporator coil and dumping it back into the home, creating humidity. When the system was running as a whole, it was dehumidifying your home as it cooled/ removed heat. With just the blower running, you are canceling out what the cooling mode just accomplished by reintroducing humidity back into the home. You may also be adding heat back into the home from your ductwork as the cold air flowing through them is no longer cold and could be picking up heat that penetrates the duct. There are very few days in our area that you can turn the fan ON… and hot, humid summer days would not be one of those days. In wintertime maybe.

Just a quick tip that some may not know about.

One more thing Change Your Filters! They are NOT good for 90 days in our area! They need to be changed Monthly OR as needed. If you have construction nearby or "loose" old doors and windows, you may need to change more frequently."