Available in early July 2009, the units will be offered in 40- and 50-gallon sizes with both standard inputs and high inputs (40,000 to 65,000 BTU per hour). These water heaters draw all the air needed for combustion directly from outside the home through PVC, CPVC or ABS piping. The by-product gases of that combustion process are then vented to the exterior with the use of a blower through a second pipe line, also made of plastic.