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What is a geothermal heat pump?
How does it work?
How is heat transferred between the earth and the home?
Does the system do both heating and cooling?
How efficient is a geothermal heat pump?
What does a system like this cost?
How long is the payback period for your ground-source heat pump system?
Q: What is a geothermal heat pump?
A: A geothermal heat pump or “ground-source” heat pump is an electrically-powered device that uses the natural heat storage ability of the earth and/or the earth’s groundwater to heat and cool your home or business. Back To Top
Q: How does it work?
A: Ground source heat pumps can be categorized as having closed or open loops, and those loops can be installed in three ways: horizontally, vertically, or in a pond/lake. The type chosen depends on the available land areas and the soil and rock type at the installation site. These factors will help determine the most economical choice for installation of the ground loop.
For closed loop systems, water or antifreeze solution is circulated through plastic pipes buried beneath the earth's surface. During the winter, the fluid collects heat from the earth and carries it through the system and into the building. During the summer, the system reverses itself to cool the building by pulling heat from the building, carrying it through the system and placing it in the ground. This process creates free hot water in the summer and delivers substantial hot water savings in the winter.
Open loop systems operate on the same principle as closed loop systems and can be installed where an adequate supply of suitable water is available and open discharge is feasible. Benefits similar to the closed loop system are obtained. Back To Top
Q: How is heat transferred between the earth and the home?
A: The earth has the ability to absorb and store heat energy. To use that stored energy, heat is extracted from the earth through a liquid medium (Water or an anti-freeze solution) and is pumped to the heat pump heat exchanger. There, the heat is used to heat your home. In the summer the process is reversed and indoor heat is extracted from your home and transferred to the earth through the liquid. Back To Top
Q: Does the system do both heating and cooling?
A: One of the things that makes a heat pump so versatile is its ability to be a heating and cooling system in one. You can change from one mode to another with a simple flick of a switch on your indoor thermostat. Plus, a geothermal heat pump can assist in heating hot water year-around. Back To Top
Q: How efficient is a geothermal heat pump?
A: Geothermal heat pumps are 3.5 -5 times as efficient as the most efficient fossil fuel furnace. Instead of burning a combustible fuel to make heat, they simply move heat that already exists. By doing so, they provide 3.5-5 units of energy for every unit used to power the heat-pump system. Back To Top
Q: What does a system like this cost?
A: A system for the typical home will cost more that if you bought a separate forced-air furnace and central air conditioning system. But you wouldn’t be comparing “apples to apples.” To get an accurate comparison of costs you need to consider the following:
- Payback, or how long it takes to recover the difference in costs between the two systems using energy savings. Payback for most geothermal heat pump systems runs three to five years.
- Energy efficiency of the two systems. To get an accurate measurement, make sure efficiency claims are substantiated. Your lifestyle an how well your home is insulated affect how economical a system will be
- Total operating savings from heating, cooling and domestic hot water must be combined to get an accurate picture of total energy savings.
- Energy costs and availability, both present and future
- Maintenance costs and system reliability Back To Top
Q: How long is the payback period for your ground-source heat pump system?
A: To figure this accurately, you must know how much per year you’ll save in energy costs with a ground-source system, and the difference between it and a traditional heating system and central air conditioner. As an example, if you’ll save $700 per year with a ground-source system and the costs difference is $2,000, your payback would be less that three years. Back To Top
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