Air source heat pumps
The most common type of heat pump uses air as the medium of heat exchange. When acting as an air conditioner, they draw heat from your indoor air and remove it to the air outdoors. For heating, they reverse the process, drawing heat from the outdoor air and placing it indoors. Although these heat pumps have high energy efficiency (a family of four can see savings of 30%-40% on their heating bills if they switch from a furnace), they can struggle with providing effective heat during temperatures that drop freezing.
Ground source heat pumps
These are also called geothermal systems, since they use the earth itself as the medium for heat exchange. Through coils buried in the ground around a home, they draw heat to move indoors—and can reverse the direction to put heat back into the ground. Because the temperature of the earth remains fairly steady at a level of 10 feet below the surface, these pumps rarely encounter trouble from heavy cold weather. They also provide even greater energy savings. However, they do not work for all homes and can cost much more to install than other systems.
Mini split heat pumps
These heat pumps—usually air-source—do not use ducts to distribute heated or cooled air. Instead, the outdoor unit hooks up to various individual blower units mounted in different rooms (or “regions”) throughout your home. These blowers send the conditioned air directly into your living spaces. Mini split systems are ideal for new homes that do not have any ductwork installed.
The kind of heat pump you need for your house will depend on many factors, and it requires the work of an HVAC expert to balance all of them and come up with an answer to the question: “What heat pump will provide me the best performance and energy-efficiency?” You will also need experts to handle the installation (ground-source heat pumps in particular involve extensive work) so that your new system will operate as it should with few repair needs in the future.
