Heat Pump Furnaces
Quiet, efficient and environmentally friendly
Heat pumps use refrigeration technology rather than simple heating in order to both heat and cool your home with the same device. They operate on the principle that there is still heat present even in very cold air (i.e. several hundred degrees below freezing). So, by extracting heat from the cold outdoor air, heat pumps are able to warm the inside of your home. This is very similar to the way that your refrigerator is able to extract heat from the air inside of it and emit that heat through the heat exchanger coils on the back. If you've ever seen this happen, then you already know how a heat pump works.
Heat pumps transfer heat by circulating a liquid called a refrigerant through cycles of evaporation and condensation. A condenser pumps this refrigerant between a pair of heat exchanger coils. In one of these coils, the refrigerant evaporates at low pressure and absorbs heat from its surroundings. This refrigerant is then compressed on its way to the other coil, in which it condenses at high pressure. At this point, it releases the heat that was absorbed from the air earlier in the cycle.
By operating this way, heat pumps make far more effective use of electricity than they would if they were simply "burning" electricity as fuel to make heat. For a longer explanation of why just "burning" electricity as fuel is so unfavorable, you may want to check out our "Electric Furnaces" section.
As an added bonus, during the summer, a heat pump simply reverses its operation, grabbing heat from the interior of your home and dumping it outside where you want it! In other words, it doubles as a cooling system. Depending on your location, this can make the difference in economic viability for a heat pump system.
There are several different types of heat pumps. Currently, the most common heat pumps are air-to-air and earth-to-air. Earth-to-air heat pumps are also known as "geothermal," "geo-exchange," "earth energy" or "ground-coupled" heat pumps. These systems take advantage of the stored heat energy in the earth, generally using large holes bored in the ground and filled with fluid, or in some cases making use of bodies of water nearby. They require more construction than air-to-air systems, which look identical to a central air system.
Geothermal heat pumps can typically provide all of a household's heating, air conditioning and hot water with larger units, and generally at significant savings. Unfortunately, the retrofit is comparable to a major renovation, and in many urban or suburban areas, there is not enough space available for the equipment necessary to do the excavations and other installation tasks.
