Heat Pump for parts of the United States are more energy-efficient than gas furnaces and electric heat. The condenser is used to absorb heat from the outside air. Then it moves heat from the outside condenser into your warm house. They can provide heat as little as one quarter of the cost of operating gas furnace or electric heat.
air-source Heat Pump
The most common type is the air-source. It transfers heat between your house and the outside air. And it can reduce the amount of electricity you use by as much as 30% to 40%.The efficiency of most air-source drops dramatically at low temperatures outside. This generally makes them unsuitable for cold climates. Although there are systems that can overcome the problem.
For homes without ducts, air-source are also available in a ductless version. In addition, a special type of air-source called a “reverse cycle chiller” generates hot and cold water rather than air. Radiant floor heating systems use this method.
Geothermal (ground-source or water-source)
Geothermal systems achieve higher efficiency by transferring heat between your house and the ground or a nearby water source. Although they cost more to install, geothermal heat pump have low operating costs because they take advantage of relatively constant ground or water temperatures. Whether a geothermal heat pump is appropriate for you will depend on the size of your lot, the subsoil and the landscape. Ground source or water source heat pumps can be used in extreme climates. And customer satisfaction with the systems is very high.
A number of innovations are improving the performance.
Unlike standard compressors that can only operate at full capacity, variable refrigerant flow (VRF) compressors allow heat pumps to operate close to the heating or cooling capacity needed at any particular moment. This saves large amounts of electrical energy and reduces compressor wear. VRF heat pumps also work well with zone control systems. Zone control systems, often found in larger homes, use automatic dampers to allow the heat pump to keep different rooms at different temperatures.
variable-speed or dual-speed motors on indoor blowers, outdoor fans or both may also be used. The variable-speed controls for these fans attempt to keep the air moving at a comfortable velocity. This minimizes cool drafts and maximizes electrical savings. It also minimizes the noise from the blower running at full speed.
Hydronic heat exchangers installed with a heat pump.
A hydronic heat exchanger installed on high efficiency heat pumps. Which recovers waste heat from the heat pump’s cooling mode and uses it to heat water. Hydronic Heat exchanger installed can heat water 2 to 3 times more efficiently than an ordinary electric water heater.
Another advance in technology is the scroll compressor, which consists of two spiral-shaped scrolls. One remains stationary, while the other orbits around it, compressing the refrigerant by forcing it into increasingly smaller areas. Compared to the typical piston compressors, scroll compressors have a longer operating life and are quieter. According to some reports, scroll compressors provide 10° to 15°F warmer air when in the heating mode. This is compared to existing heat pumps with piston compressors.
Most use electric heaters as a backup for cold weather. Gas furnaces help solve the problem of the heat pump delivering relatively cool air during cold weather and reduces its use of electricity. These configurations share the same ductwork.
Actual energy savings depend on the relative costs of the combustion fuel relative to electricity.