The best and most efficient use of this heat was re-introducing the heat back into the dryer through the incoming air stream or by isolating the intake location to bring the heat to. One challenge was the prevention of the exhaust air, moisture, hydrocarbons and lint from getting into the incoming air stream. This would cause linen quality issues as well as defeating the goal of energy reduction as well as reduction of drying times. This was where previous designs by other manufactures failed.