When it comes to HVAC systems, most homeowners tend to focus on two main components: the AC unit and the furnace. But there's another component to your HVAC system that deserves more attention and understanding: the fan. The fan propels the heated or cooled air into your home, so it gets use throughout the year. Understanding how to use this fan to your advantage can help maximize system efficiency, lower your energy bills, and keep your home more comfortable.

How does the fan operate?

Most thermostats have two fan settings. If your fan is set to "auto," which most homeowners use as the default, the fan will only kick on when the AC or heat kicks on. If it is set to "on," the fan will remain constantly on, whether or not the home is being heated or cooled at the moment. With the fan on the "on" setting, air will just be cycled through the home and ducts between heating or cooling cycles.

How can you use various fan settings to your advantage?

It often uses less electricity to set the fan on auto, since it won't run as often. On a moderate day (for instance, when it's 80 degrees outside and you're just cooling your home to 74), using this setting is just fine.

 However, when there's a bigger difference between the temperature outside and inside, you may want to consider leaving the fan set to "on." This way, the air will continually be circulated through your home. There won't be a chance for hot air to accumulate upstairs while the downstairs grows colder and colder. Your home's temperature may stay more even, and you may end up using less AC in the long run since you won't keep cranking the temperature down to get the upstairs cooler. The same concept applies in the winter when it's really, really cold outside and you're trying to keep your home warm.

Using the "on" fan setting can be helpful if your AC unit is older and struggles to keep your home as cool as you'd like. With air at least flowing through the home, you'll feel cooler, so you may be able to get away with keeping the thermostat at a slightly higher temperature.

If you're the kind of person who parks your thermostat at the "fan auto" position and never touches it, perhaps it's time to rethink that strategy. For more tips on keeping your indoor air healthy and comfortable, contact a company like Tailor Made Maintenance Inc.