Heat pump water heater

What it is

HPWHs have been available for more than 40 years. Current heat pump water heaters are designed like refrigerators to operate as a fully sealed system.

Heat pump water heaters use electricity to move heat from one place to another instead of generating heat directly. In many cases they replace gas-fired water heaters and are significantly more energy efficient, reducing on-site Scope 1 emissions and often resulting in reduced total emissions.

Heat pump water heaters are also commonly referred to as Hybrid Electric water Heaters.

When a heat pump water heater is actively operating (in heat pump mode), it generally is providing 2,500 to 5,000 btus/hr of cooling.

Split systems are heat pump water heaters in two parts, with the air-to-refrigerant heat exchanger commonly designed to be located outside. With the heat pump outside and the tank inside or in a garage, the two components are then connected with piping.

Source: ENERGY STAR · U.S. Department of Energy

Its parts

Compressor

There are two broad categories of compressors: positive displacement and dynamic.

Source: ASHRAE

Evaporator coil

Evaporator coil means a component of a central air conditioner that is designed to absorb heat from an enclosed space and transfer the heat to a refrigerant.

Source: Code of Federal Regulations

Condensate drain

Related pages

• Glossary: Heat pump water heater

  Its entry, and the guide's pages that use it.

• Gas water heaters

  Gas water heater types, burning air, venting and the signs of backdrafting

Sources

1. ENERGY STAR. ENERGY STAR NextGen Certified Homes June 2024 Heat Pump Water Heater Guide.
2. U.S. Department of Energy. Heat Pump Water Heaters.
3. ENERGY STAR. Heat Pump Water Heaters.
4. ASHRAE. ASHRAE Handbook—Compressors.
5. Code of Federal Regulations. 16 CFR Part 305 Energy Labeling Rule.