Abstract: A finned-coil heat exchanger has a housing with spaced walls defining an internal chamber with air flowing from an upstream end to a downstream end, spaced transfer tubes with heat conducting media flowing therein from the downstream chamber end to the upstream chamber end, a series of spaced fins in contact with the tubes to transfer heat to flowing air, and a fan unit to move air through the exchanger. An air inlet is defined at the upstream end of the housing or in the lower end of one of the walls so that air can enter the internal chamber. The tubes each extend tortuously back and forth on a plane parallel to the direction of air flow so that there is a counterflow effect across the various segments of each tube. The tubes have at least six segments extending transversely across air flow with the tubes and fins being sized and spaced to provide for better air flow through the heat exchanger housing.

Abstract: A storage tank for water heaters and the like having a vertical, cylindrical tank, with a curved top wall, means for heating water within the tank, a cold water inlet and a hot water outlet at the top includes an inlet dip tube with means for transferring heat from the upper portion of the tank to the lower portion of the tank. The dip tube has a relatively large surface area to effect increased heat transfer between incoming water and heated tank water.

Abstract: A storage tank having a vertical, cylindrical tank, a fluid inlet, and a fluid outlet, includes an inlet diffuser for introducing inlet cold water uniformly across a horizontal cross section of the tank bottom and thereby foil convection currents that cause mixing of hot and cold fluid so that more hot fluid is recovered at the outlet over time. The tank may comprise a hot water heater where the water stored in the tank is heated within the tank by means disposed internally or externally of the internal storage chamber. Alternately, the water may be heated externally of the tank and stored within the tank.

Abstract: A storage tank having a vertical, cylindrical tank, a fluid inlet, and a fluid outlet, includes a collector outlet dip tube for collecting hot fluid evenly across a horizontal cross section of the tank and thereby foil convection currents that cause mixing of hot and cold fluid so that more hot fluid is recovered at the outlet over time. A dispersing inlet dip tube may be also employed to introduce cold fluid evenly. The tank may comprise a hot water heater where the water stored in the tank is heated within the tank by means disposed internally or externally of the internal storage chamber. Alternately, the water may be heated externally of the tank and stored within the tank.

Abstract: A hot water heater having a vertical, cylindrical tank with a curved top wall, means for heating water within the tank, a cold water inlet and a hot water outlet at the top includes an inlet dip tube disposed along the central vertical axis of the tank for foiling internal thermal convection currents rising along the center of the tank and minimizing the mixing of hot and cold water so that the temperature of hot water delivered at the outlet remains relatively constant over time.

Abstract: A hot water heater having a vertical, cylindrical tank with a top wall, means for heating water within the tank, a cold water inlet at the bottom and a hot water outlet at the top includes damping vanes associated with the top wall of the tank for foiling internal thermal convection currents at the top of the tank and minimizing the mixing of hot and cold water so that the temperature of the hot water delivered at the outlet remains relatively constant over time.

Abstract: A compartmentalized storage tank-type electric liquid heater includes a housing with upper and lower portions. A fluid inlet is defined in the lower portion and a fluid outlet is defined in the upper portion. A plurality of panels or other partitioning structures are mounted within the housing to divide the interior into a plurality of subcompartments. A first subcompartment includes a cold water inlet and a final subcompartment includes a hot water outlet. The first and final subcompartments are in fluid communication with a plurality of intermediate subcompartments. All or most subcompartments include a heating element. In one embodiment of the invention, the heating elements in the first and final subcompartments are electrically connected to a first temperature control and the heating elements in the intermediate subcompartments are electrically connected to a second temperature control.

Abstract: A hot water heater having a vertical, cylindrical tank with a curved top wall, means for heating water within the tank, a cold water inlet at the bottom and a hot water outlet at the top includes a baffle in the upper portion of the tank for foiling internal thermal convection currents moving along the side and top walls and minimizing the mixing of hot and cold water so that the temperature of the hot water delivered at the outlet remains relatively constant over time.