Heat Pump Water Heaters
DOE- Heat Pump Water Heaters
Most homeowners who have heat pumps use them to heat and cool their homes. But a heat pump also can be used to heat water-either as stand-alone water heating system, or as combination water heating and space conditioning system.
How They Work
Heat pump water heaters use electricity to move heat from one place to another instead of generating heat directly. Therefore, they can be two to three times more energy efficient than conventional electric resistance water heaters. To move the heat, heat pumps work like a refrigerator in reverse.
DOE- Heat Pump Water Heaters |
ORNL: The "Drop-In" Residential Heat Pump Water Heater
The Problem: How to Convince Consumers to Save Energy in Water Heating
About half of all domestic water heating is done with electric resistance storage water heaters. The most efficient resistance water heater has an energy factor (EF) of 0.95, only 5% below the maximum efficiency possible for that type of water heater. Yet by using electricity to "pump heat" from the surrounding space, the residential heat pump water heater (HPWH) can attain much higher efficiencies, reducing the electricity needed for water heating by at least half.
The "Drop-In" Residential Heat Pump Water Heater |
Water Heating: Heat Pump Water Heaters
Heat pump water heater (HPWH) systems mine the energy content of air to produce hot water very efficiently (Figure 1). Depending on cold-water and ambient-air temperatures and on patterns of hot water use, heat pump water heaters do the same job as standard electric water heaters using two to three times less electric energy.
Water Heating: Heat Pump Water Heaters |
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