A number of innovations are improving the performance of heat pumps.
Unlike standard compressors that can only operate at full capacity, two-speed compressors allow heat pumps to operate close to the heating or cooling capacity needed at any particular outdoor temperature, saving energy by reducing on/off operation and compressor wear. Two-speed 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.
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.
Some high-efficiency heat pumps are equipped with a desuperheater, which recovers waste heat from the heat pump's cooling mode and uses it to heat water. A desuperheater-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 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, heat pumps with scroll compressors provide 10° to 15°F (5.6° to 8.3°C) warmer air when in the heating mode, compared to existing heat pumps with piston compressors.
Aunque la mayoría de las bombas de calor usan calentadores de resistencia eléctrica como respaldo para el clima frío, las bombas de calor también se pueden equipar en combinación con un horno de gas, a veces denominado sistema híbrido o de combustible dual, para complementar la bomba de calor. Esto ayuda a resolver el problema de la bomba de calor que funciona de manera menos eficiente a bajas temperaturas y reduce el uso de electricidad. Hay pocos fabricantes de bombas de calor que incorporan ambos tipos de calor en una caja, por lo que estas configuraciones suelen ser dos sistemas estándar más pequeños, uno al lado del otro, que comparten el mismo conducto.
En comparación con un horno alimentado con combustible de combustión o una bomba de calor estándar, este tipo de sistema también puede ser más económico. Los ahorros reales de energía dependen de los costos relativos del combustible de combustión en relación con la electricidad.