The SuperTherm Series of semi-instantaneous water heaters from Diversified Heat Transfer are constructed of stainless steel pipe and other nonferrous materials to ensure long leak-free operation. Units are engineered using steam, boiler water or HTHW as the heating medium. Semi-instantaneous operation provides high output by channeling the incoming cold water directly over the heat exchanger tubes in a controlled manner to maximize the heat transfer rates. Velocity of water and pressure drop are controlled by changing water flow directly across the heat exchanger, which increases heat transfer and inhibits scale formation. Perfect for mechanical rooms where space is limited, the system has vertical configurations that require less than 4 square feet of floor space. Horizontal configurations are available. 800/221-1522; www.dhtnet.com.