Cleaning the air ducts can save you money by increasing the efficiency of your heating and air conditioning system. A cleaner system does not have to work as hard to keep your home at a comfortable temperature. Research done by the EPA shows that a buildup of even .042 inches of dirt can result in a decrease of furnace efficiency up to 21%. The dust that stays in your system will accumulate on the fan blades of the blower motor, the coil and the inside of your ductwork, which can reduce air flow up to 40%. This translates into higher energy costs for you.