If you plan on green home remodeling, consider an alternative energy source such as geothermal. It seems counter-intuitive that a technology which depends on circulating liquid through pipes in the ground could be used to both heat and cool a house, but that’s exactly what a geothermal heat pump (GHP) or ground-source heat pump does.
What is a Geothermal heat pump?
While large-scale geothermal installations used by utilities rely on hot water under the ground, the geothermal heat pump heats and cools an individual building using the constant temperature of the Earth (the top 10 feet of the Earth’s crust are usually between 50 and 60 degrees Fahrenheit).
A typical GHP system includes pipes buried near the home, a heat exchanger, and ductwork in the house. During the winter, the ground is warm compared to the air temperature so this warmth goes through the heat exchanger into the house. During the summer, the house’s warm air is pulled through the heat exchanger into the cooler ground. The system can save additional energy and money during the summer by heating water with the hot air removed from the house.
What are the savings?
GHPs consume 25-50 percent less electricity compared to conventional HVAC equipment, so installing one is a great green home remodeling project. In other words, a GHP needs only one unit of electricity to move three units of heat compared to a ratio of 1:1 or 1:2 for other systems. GHPs can decrease energy consumption and the accompanying emissions by as much as 44 percent compared to air-source heat pumps and as much as 72 percent compared to standard electric heat. GHPs can achieve efficiencies of 300-600 percent on the coldest winter night; air source heat pumps can only reach 175-250 percent on just a cool day. GHPs also maintain an approximate 50 percent indoor humidity level, making them desirable in humid areas.
The up-front cost of geothermal as a home renewable energy source is steep. However most experts agree that you can recoup this investment in 5-10 years through lower energy bills, making it even more attractive as a green home remodeling project. Federal, state, and local tax incentives and other programs can help offset the cost of the initial investment as well. With few moving parts, a GHP system is also durable and needs little maintenance. Many manufacturers warranty the pipes for 50 years and the pump itself usually lasts 20 years.