and changing those out, every two to three months, depending on your type of environment. Now, in particular type times of the year, if it tends to be drier and dusty around the house, then you may actually want to keep your fan in an on position. What this will do, is it will keep your fan on running, it will keep circulating the area, and it will allow those high efficiency filters, to draw more of that dust out of the air, and that's opposed as the auto position, where the fan only comes on if you're actually heating or cooling, so I'm Tim Gipson, and that's some tips on how to reduce dust in your home.