Water Heater Terms
Water heaters provide a constant supply of hot water and steam for basic personal, home and industrial use. In recent years, many modifications have been made to the standard tank-style water heaters in order to make them more energy efficient and less wasteful. If you are installing a new water heating system in your business or home, here are a few terms you might encounter during your research:
First Hour Rating: Measures the amount of hot water available during the peak hour demand. The factors that determine the FHR are the tank size and the speed at which cold water is effectively heated.
Recovery Rating: The recovery rating determines how efficient the heat transfer is from the heat source to the water.
Efficiency: Also known as Energy Factor (EF), this is a number listed next to the Energy Guide Label. The Efficiency or EF is determined by dividing the yearly output of useful energy coming from the water heater by the amount of energy going into the heater in order to heat the water. The higher the EF number, the greater the efficiency of the water heater.
Cycling Losses: The heat loss during the water’s circulation through the water tank and/or the inlet and outlet piping.
Tankless Water Heaters: Electric or gas powered heating units that heat ground water as it travels through a heat exchanger without the use of a water storage tank. Tankless water heaters are approximately 22% more energy efficient than traditional gas-fired storage tank alternatives. They are also called continuous flow, instantaneous and instant-on water heaters.
Point of Use Tankless Water Heaters: Water heating units that are located specifically where the water is being used. While these are the most energy efficient in practice, since water wastage is reduced because the water is heated almost instantly, individual water heaters must be installed at every sink, kitchen, laundry room and shower/bath, which can be economically prohibitive.