A number of relatively new innovations are improving the performance of heat pumps.
Unlike standard compressors that can only operate at full capacity, 双速压缩机 allow heat pumps to operate close to the heating or cooling capacity that is needed at any particular moment. This saves large amounts of electrical energy and reduces compressor wear. Two-speed heat pumps also work well with zone control systems. 区域控制系统, 通常在较大的房屋中发现, use automatic dampers to allow the heat pump to keep different rooms at different temperatures.
Some models of heat pumps are equipped with variable-speed or dual-speed motors on their indoor fans (blowers), outdoor fans, or both. The variable-speed controls for these fans attempt to keep the air moving at a comfortable velocity, minimizing cool drafts and maximizing electrical savings. It also minimizes the noise from the blower running at full speed.
Many high-efficiency heat pumps are equipped with a 减温器, which recovers waste heat from the heat pump's cooling mode and uses it to heat water. A 减温器-equipped heat pump can heat water 2 to 3 times more efficiently than an ordinary electric water heater.
Another advance in heat pump technology is the 卷轴压缩机, which consists of two spiral-shaped scrolls. 一个是静止的, 而另一个绕着它转, compressing the refrigerant by forcing it into increasingly smaller areas. Compared to the typical piston compressors, 卷轴压缩机s have a longer operating life and are quieter. According to some reports, heat pumps with 卷轴压缩机s provide 10°–15°F (5.6°–8.3°C) warmer air when in the heating mode, compared to existing heat pumps with piston compressors.
Although most heat pumps use electric resistance heaters as a backup for cold weather, heat pumps can also be equipped with burners to supplement the heat pump. 备用燃烧器 help solve the problem of the heat pump delivering relatively cool air during cold weather and reduces its use of electricity. Since there are few heat pump manufacturers that incorporate both types of heat supply in one box, these configurations are often two smaller, 并排, standard systems sharing the same ductwork. The combustion fuel half of the system could be propane, natural gas, oil, or even coal and wood.
In comparison with a combustion fuel-fired furnace or standard heat pump alone, this type of system is also economical. Actual energy savings depend on the relative costs of the combustion fuel relative to electricity.
DOE - U.S. 能源部