The PowerStor Series™ indirect-fired water heater features a super-efficient heat exchanger coil. The coil's 1.5 dia carbon steel tubing is Vitraglas® coated. The commercial models are available in 65, 80, and 120 gal capacities and have a total heat surface area of 27.2 ft. Other features include an immersion temperature sensing control, the Hydrojet® total performance system, three anode rods, and 2 in. of non-CFC foam insulation.