What is a Heat Pump?
Rather than generating heat, like a furnace or boiler, a heat pump actually transfers existing heat. Essentially, they take warm air and transfer it to cool areas and take cool air and move it to warm areas. Because they expend no energy creating hot or cool air, they can actually provide roughly four times the energy that they consume. For this reason, using heat pumps can save you a considerable amount of energy and money.
Heat pumps are more appropriate for moderate climates, so you probably won’t want to rely on one if you live somewhere where it feels like winter nine months out of the year. In that case, your best bet would be to go with a system that generates heat using natural gas, propane or oil rather than a heat pump. The most common kind is an air source heat pump. These simply transfer heat between the interior and exterior of your home. Extremely cold temperatures will make it difficult for the pump to extract heat from the exterior of your home. It can also lead to cracks in the pump, which further decrease its efficiency and life expectancy.
Geothermal heat pumps transfer heat from the ground or nearby water sources, rather than moving heat between the air inside and outside your house. These machines are a little more versatile in that they have higher efficiency ratings in colder climates than air source pumps, and their operating costs tend to be lower due to relatively constant temperatures of ground soil and bodies of water. Both types of pumps are powered by electricity.
Geothermal pumps are often more expensive, especially with regard to installation. The installation may also be tricky, depending on the surrounding landscape and soil conditions. Not all areas will be able to accommodate geothermal pumps. So find out ahead of time if your area can even support a geothermal heat pump before you make that purchase. Check with your state energy office about this matter.
With these types of heat pumps, it is highly recommended that you hire a qualified contractor. Even if you are pretty handy around the home, installation requires very specific expertise, heavy equipment, and landscaping experience. And make sure your contractor follows the guidelines set forth by the International Ground Source Heat Pump Association
Other heat pumps are powered by natural gas, propane, solar or other forms of energy. Absorption heat pumps use an ammonia-water cycle to heat and cool your home. Evaporated ammonia (a refrigerant) is basically absorbed into the water in the pump and boiled out by the heat source. As this cycle continues, the pump can provide heating or cooling. This kind of heat pump is relatively new and has not yet reached the popularity of its predecessors.