How Can I Tell That My Furnace Filter Needs to be Changed?

Article Found on HVAC.com
Signs your furnace filter needs changing:
- The filter is noticeably gray in color, and you can see dirt and dust built up on the filter media.
- Your home is dustier than usual.
- Your heating or cooling system is cycling longer than it usually does.
- Your current filter has been in use longer than the manufacturer’s recommendation (anywhere from one to six months, depending on your filter). Read more