Change your filter

 Your home's air filter removes dust, allergens and more from the air passing through the

 system. You must replace these lightweight cardboard-and-wire constructs regularly. After six months or so, that filter becomes so choked with dirt that air has a tough time getting through, and the unit can't really do its job anymore. That not only increases the dust in your home, it greatly decreases airflow for your air conditioning unit. You can improve energy use for your air conditioner by five to 15 percent just by replacing a dirty filter. So make sure you install a new filter a couple of times a year. And remember to check and change it after particularly dusty activities, like cleaning ductwork, a big demolition or refinishing a wood floor.