How Do Geothermal Heat Pumps Work?
Energy 101: Geothermal Heat Pumps
Geothermal Heating and Cooling
There is nothing magical about geothermal heat pumps. They basically work like every other heat pump. Heat pumps are machines that use a refrigeration cycle (the same as used in your refrigerator) to transfer heat — they make it hot on one side and cold on the other. In the winter you want the hot side in your house and the cold side outdoors, and the opposite in the summer.
What makes geothermal heat pumps special is that they are coupled to the earth, not the outside air. In Maryland the temperature 10-feet below ground is a constant 57-degrees, which is a great temperature for a geothermal system. When it is cold out, conventional heat pumps become less and less effective because they are trying to transfer heat into your house from cold outdoor air, which is inefficient and expensive, if not impossible. Geothermal heat pumps don't have this problem because they are transferring heat from the relatively warm 57-degree earth. Furthermore, geothermal heat pumps use water as the heat transfer medium. Water transfers heat 200-times better than air (air is actually an insulator). Voila, by coupling the geothermal heat pump with the earth you now have a super-efficient way to generate heat in the winter. In the summer, the refrigerant cycle reverses and you have a super-efficient way to cool your house. OK, maybe there is a little magic involved — but it's good magic that saves you money and keeps you comfortable.
Learn more about ground source geothermal heat pumps by reading this article entitled Geothermal Heating and Cooling in Maryland which features Earth River Geothermal.
- US Department of Energy's Geothermal Technologies Program: Geothermal Heat Pumps
- How A WaterFurnace Geothermal Heating and Cooling System Works
Residential Renewable Energy
A geothermal heat pump taps into the renewable solar energy stored in the ground to provide savings of up to 72% on heating and cooling costs. Although it operates similarly to a standard heat pump, a geothermal heat pump exchanges heat with the earth instead of the outdoor air. Outdoor air temperatures can vary greatly from day to night or from winter to summer, while the temperature just a few feet below the earth’s surface stays an average fifty-seven degrees to seventy degrees Fahrenheit year-round.
To see why that's so important, let's look at traditional conditioning systems. In order to cool your home an ordinary system collects indoor heat and expels it outside. Unfortunately summer temperatures can easily hit ninety or one hundred degrees which means outside air is already filled with heat and is less willing to accept more. The exchange process becomes harder and harder. The result is that an ordinary heat pump or air conditioner becomes least efficient exactly when you need it to be the most efficient.
Earth River Geothermal exclusively installs vertical closed loop
geothermal heating & cooling systems in the state of Maryland.
A geothermal unit never sees hot summer air. It collects heat from your home and moves it to the much cooler 57° earth. It doesn’t matter how much outdoor conditions fluctuate; the ground remains relatively constant. Thanks to the constant temperature of the earth, a geothermal heat pump is more than twice as efficient at cooling than any regular heat pump or air conditioner.
To warm your home, an ordinary heat pump reverses to collect outdoor heat from the air and move it indoors. Unfortunately, as winter temperatures drop, there’s less and less available heat to collect. Again, the exchange process becomes harder and the heat pump becomes least efficient at exactly the time you need it to be the most efficient. A geothermal unit never sees cold winter air. It draws from a reservoir of much warmer 57° temperatures, concentrates it, and moves it to your home.
Geothermal Heat Pump Efficiency
And unlike a traditional furnace which returns less than 96¢ of heat for each dollar spent burning expensive, polluting fossil fuel - a geothermal heat pump returns up to Five dollars of heat for each dollar spent on electricity. That’s because unlike a furnace, a geothermal heat pump doesn’t create heat through combustion - it simply collects and moves it.
Now that you know the benefits of using the earth, let’s look at how it’s accomplished. A geothermal system uses of series of underground pipes called a “loop.” The earth loop eliminates the need for fossil fuels. It’s the heart of a geothermal system, and its biggest advantage over ordinary heating and cooling technologies.
Closed Loop Geothermal Systems
Closed loop systems circulate a water based solution through a collection of small diameter, high density polyethylene underground pipes. There are three main types of closed loop systems. Where space is limited, vertical loops are used. Well drilling equipment is used to bore small-diameter holes, one hundred to four hundred feet deep. Horizontal loops are generally preferred where more space is available. Pipes are placed in trenches that range in length from 100 to 400 feet. If a nearby body of water is available it can be utilized for a pond loop. Coils of pipe are simply placed on the bottom of the pond or lake to capture the geothermal energy.
Open Loop Geothermal Systems
Open-loop systems are an option if water is plentiful and low in minerals. These systems use groundwater from a well as a direct energy source.
Environmentally-Friendly & Cost Effective
Geothermal systems are recognized by the United States Environmental Protection Agency as the most environmentally friendly, cost-effective and energy-efficient heating and cooling technology available. Geothermal heat pumps help electric utilities achieve significant reductions in their peak demand loads. By reducing the demand on electric utilities, geothermal systems reduce the need for new power plants which typically are powered by coal or natural gas. Compared to an electric resistance heating system, a typical 2,500-square-foot home with a geothermal system can save the electric utility company more than nine tons of coal a year.
These systems also minimize the threats of acid rain, air pollution, the greenhouse effect and global warming problems directly linked to the burning of fossil fuels. In fact installing a single geothermal unit is the environmental equivalent of planting seven hundred fifty trees or removing to cars from the road.
As you can see there are many reasons to switch to a geothermal heat pump. It's the most efficient conditioning system available. It's environmentally friendly. It has the longest life span... and it provides quiet comfort. That's why we call it smart from the ground up!
Ground Source Heat Pumps
Geothermal systems provide great comfort. Precise distribution of comfortable air all year long eliminates hot spots and cold spots. During the winter, you'll enjoy warm air without the hot blasts associated with furnaces. Compared to an air-source heat pump, the air coming into your home via a geothermal heat pump is much warmer and there are no more noisy outdoor fans running day and night.
Geothermal water to air heat pumps also generate free hot water for domestic use which further reduces utility costs.
These systems also make radiant floor heating cost effective to operate- for the first time - due to the fact that boilers are no longer required.
It is an especially rewarding experience to improve the comfort of your own home, reduce your carbon footprint, and save money on utility bills at the same time. Every one of our customers has been pleased with their switch to geothermal heating and cooling.