What is Geothermal heating and cooling for your home?
Geothermal heat is a heating or cooling system that is powered by heat generated within the earth.
Geothermal heat pumps are the most energy-efficient, environmentally clean and cost-effective systems for temperature control, according to the U.S. Environmental Protection Agency. Although most homes still use traditional furnaces and air conditioners, geothermal heat pumps are becoming more popular, and that is in part because the US Department of Energy and the EPA are partnering with industry to promote geothermal systems.
By using a geothermal heat pump, you can tap into the Earth's constant temperatures to heat and cool your home. The pump transfers heat to the inside from the ground in winter and reverses the process in the summer.
Huh? Heat generated within the Earth ….?
While temperatures above ground vary greatly from day to day and season to season, temperatures in the upper 10 feet of the Earth's surface hold nearly constant at 50 to 60 degrees Fahrenheit. For most areas, this means that soil temperatures are warmer than the air in winter and cooler than the air in summer.
So what does the pump — pump?
The geothermal heat pump moves air or an antifreeze liquid through pipes that are buried underground and then integrated into your home. In the summer, the liquid moves heat from the building into the ground. In the winter, it does the opposite, providing pre-warmed air and water to the heating system of the building.
Heat naturally flows downhill from higher to lower temperatures. The pump causes the heat to flow in a direction opposite to its natural tendency.
What does it look like?
The heat pump is the heart of your home’s heating and cooling system and all of its components are usually contained in a single enclosure about the size of a small gas furnace.
Most of these will provide your hot water, too. And it’s also possible, but expensive, to use heat from your geothermal system to melt the snow on pavement.
Can I save money with a geothermal heat pump?
Geothermal energy will cost more to get started, but will save you money over time. The installation price of a geothermal system can be several times that of an air-source system of the same heating and cooling capacity, but you’ll save that much in energy costs in 3-7 years. It’s also estimated that your geothermal system will last 25 years for the inside components and 50+ years for the ground loop.
In a typical air source heating/cooling system, air at a hot temperature outside is cooled down inside, or cold air from outside is heated up inside. The system is working between a wide range of temperatures.
By contrast, a geothermal pump is always working with constant temperatures from within the earth to either heat or cool. The need for energy will be less because the geothermal pump, regardless of the season is always pumping the heat over a shorter temperature distance.
Some sources say that a geothermal system can reach fairly high efficiencies (300%-600%) on the coldest of winter nights, compared to 175%-250% for air-source heat pumps on cool days.
Typical costs
We do know that the installation cost for a conventional-type air source heating system and air conditioning system will be about $8800 to heat and cool the air in a typical home. Compare that with the total installed cost of a groundwater geothermal system of about $6,837- it's fairly close.
Can I install a geothermal pump myself? Say yes!
Sorry. That’s probably not a good idea. The quality of installation profoundly affects the efficiency of a geothermal system. If you get it wrong, it won’t work well and you’ll have to start all over again. Best to call on a professional and get it right the first time.
What kind of system is right for me?
You’ll encounter three terms for this heating/cooling technology when you start your research: These are geothermal, geoexchange and ground source heat pumps. To decide what kind of system to use you’ll have to answer all kinds of questions: Open loop or closed loop? How good is the water quality? Vertical or horizontal? Sound confusing? It can be.
Some models of geothermal systems are available with two-speed compressors and variable fans for more comfort and energy savings. Relative to air-source heat pumps, they are quieter, last longer, need little maintenance, and do not depend on the temperature of the outside air.
Some people might consider a dual-source heat pump that combines an air-source heat pump with a geothermal heat pump. Dual-source heat pumps have higher efficiency ratings than air-source units, but are not as efficient as geothermal units. The main advantage of dual-source systems is that they cost much less to install than a single geothermal unit, and work almost as well.
