Install a heat pump
Heat pumps are an energy-efficient alternative to both air conditioning and furnaces, though it functions best in climates that have moderate heating and cooling needs.
Heat pumps can provide water and atmospheric cooling for homes and can be used to control an office's thermal comfort, too. They cut carbon dioxide emissions, reduce air pollution, and result in significant financial savings.
How to install a heat pump
Heat pumps work by transferring heat from cool spaces to warm spaces. Using liquid-filled tubes or pipes, heat is exchanged through processes such as compression, evaporation, condensation, and expansion. These temperature-regulators can cool and heat a building as well as perform water-heating tasks. There are several types listed below. Be sure to consider ENERGY STAR models
, which are 8 percent more energy efficient than standard new heat pumps and 20 percent more efficienct than older models.
- Air-source: Good for warmer climates (and not suitable for the extreme cold), the air-source heat pump exchanges outdoor air for indoor air using a compressor and two copper coils (one inside and one outside). Although they do consume electricity to operate, they can provide one and one half to three times more heat energy to a building than the electrical energy they use.
- Ductless, mini splits: Built much like air-source heat pumps, ductless, mini-split heat pumps are useful in buildings that lack comprehensive duct systems. They're ideal for retrofits, additions, and for buildings that use hot water heat, radiant heat, or space heaters.
- Absorption: Using the same mechanisms found in air-source devices, absorption heat pumps (also known as gas-fired heat pumps) use solar- or geothermal-heated water, propane, or natural gas rather than electricity. Ammonia is absorbed into water, then pumped to a high pressure, and then boiled to separate water from ammonia. These systems are only appropriate for larger buildings at least 4,000 square feet in size.
- Geothermal: Relatively stable underground temperatures range from 45°F to 75°F. Air above ground is generally hotter during the summer and colder during the winter compared to these constant deep-earth temperatures. Geothermal heat pumps (alternately known as GeoExchange, ground-source, water-source, or earth-coupled heat pumps) rely on these constant temperatures rather than unstable outdoor temperatures. By installing liquid-filled pipes underground, cool air is brought into a building during warm months, and heated air is exchanged for cool air during winter months. Check out Consumer Energy Center's animated illustration to get a general idea of how these systems work. There are four main types of geothermal heat pumps:
- Horizontal closed-loop: Two pipes are buried between 4 and 6 feet deep. This is the most cost-effective and especially suitable for new construction where sufficient land exists.
- Vertical closed-loop: Pipes are inserted into 100-400 feet deep holes, connected by U-bends at the bottom and horizontal pipes at the top. This system is useful for land-limited buildings and where shallow trenches are not possible.
- Pond/lake closed-loop: Coiled pipes are placed at least 8 feet under the surface of existing bodies of water, such as lakes or ponds. This is a very cost-effective option.
- Open-loop: Using well- or surface-water as the fluid for heat exchange, these systems circulate water within an open body of water. Open-loop heat pumps can only be installed where local groundwater discharge regulations permit.
Depending on the system's configuration, heat pumps can also extract warmth from hot spaces (during the summer) which is then used to heat domestic water supplies. Heat pumps can also reduce water heating costs by nearly half during cold months.
Find it! Heat pump service providers
Installing a heat pump generally requires the services of a professional contractor. Here are some resources for finding one in your area:
- ServiceMagic Listing of heat contractors who specialize in heat pumps.
- Air Conditioning Contractors of America Look for the "Ask About ENERGY STAR" logo on the search results to find those who specialize in selling and installing the more energy efficient models.
Installing a heat pump helps you go green because
- It requires less energy to heat and cool a building compared to conventional methods.
- Carbon dioxide emissions are significantly reduced for heating and cooling.
- It avoids toxic air pollutants associated with the burning of coal and other fossil fuels.
Close to 40 percent of all US carbon dioxide emissions are associated with heating water and the heating and cooling of buildings. Heat pumps are very efficient systems for heating and cooling buildings of all sizes and in all locations.
One hundred thousand geothermal heat pumps would reduce US carbon emissions by 2.18 million metric tons, saving consumers $750,000 over the average 20-year lifespan of the equipment. On average, they save homeowners 30 to 70 percent in heating costs and 20 to 50 percent in cooling costs.
- High initial cost: Many of these heat pump systems are relatively expensive ($2,500 per ton of capacity) to have installed, though the costs are generally returned to the owner in energy savings. In the case of geothermal heat pumps, return on investment generally ocurrs within five to 10 years. Operating costs for heat pumps can save the average owner between 20 and 70 percent in energy costs.
- Difficult maintenance: For systems with underground piping, repairs can be quite difficult. However, since most systems come with a 25 to 50 year guarantee and rarely break-down, they are relatively worry-free.
Tax breaks and subsidies
In the US, installing a heat pump may qualify you for tax breaks at the federal, state, or local levels. For detailed information, see these resources:
- Consumer Energy Center - Geothermal Heat Pumps
- GeoExchange - What are the environmental benefits
- GeoExchange - Heating and Cooling Systems: Fascinating Facts
- US Department of Energy - Geothermal Heat Pumps
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