Louisville HVAC clients often ask how they should operate their furnace fan – auto or continuous? So, what should you do? Well, it depends…

If you have a high efficiency filtration system and a variable speed ECM blower, you will want your fan running continuously to circulate the air at a low velocity. The lower speed of continuous fan allows for better filtration. The continuous fan will provide more air exchanges each day. Thus providing cleaner air to the home.

What about the rest of us with standard filters and blower motors? If you live in a humid area where the air conditioning system must remove a lot of moisture, you’re better to leave the fan in Auto. You can see as much as a 10% reduction in indoor humidity during the summer. Continuous fan will evaporate the water from the coil that the air conditioner just removed. So, there’s a trade off between circulating the air and humidity control.

Another consideration is register location. If they are placed low on the wall, then the air likely blows on you. You wouldn’t want room temperature air blowing on your skin during the winter. Probably wouldn’t feel to bad in the summer. So, maybe you’d be better only running continuous fan in the summer.

So many things to consider. I suggest running the fan in the mode that makes your home the most comfortable. If you just can’t get comfortable, then gives a call (244-HEAT), we’ll be more than happy to provide a system evaluation.