Heat Pump Water Heaters
The good news for electricity users is that heat pump water heaters are becoming more common. Heat pump water heaters (like any other heat pump) take energy from the air to heat water. At the same time the heat pump water heater dehumidifies the air, saving the cost of buying and operating a separate dehumidifier. This is especially beneficial when the water heater is located in a basement and/or in a humid climate.
Compared to a standard electric resistance water heater, models that use a heat pump are more efficient because the electricity is used for moving heat from one place to another rather than for generating the heat directly. The heat source is outside air or air in the basement or room where the unit is located. They are available with built-in water tanks called integral units, or as add-ons to existing hot water tanks.
A heat pump water heater uses one-third to one-half as much electricity as a conventional electric storage water heater. In warm climates they may do even better. Electric heat pump water heaters because of their high efficiency ratings are very Title 24 friendly.