Geothermal Heat Pumps
If you have heard about geo-thermal technology but are unsure about how it works and where and how to buy it for your home or business, here is a list of Frequently Asked Questions to guide you through the process:
What is geo-thermal Heat Pump technology?
Geo-thermal is a cost-effective, energy efficient, reliable and renewable energy source that totally eliminates the need for fossil fuel. Energy is the lifeblood of our economy and geo-thermal technology is one way to lessen our need for fossil fuel as our insatiable demand for energy continues to grow.
Simply, geo-thermal technology extracts existing heat from the ground and converts it into a system that heats and cools your home or business. It is like having an oil or gas well (energy source) buried in your own backyard.
The Earth, acting like a giant solar collector, absorbs about half the sun’s energy that reaches it. The Earth’s temperature a few feet below the surface remains fairly constant, from approximately 45-degrees F in northern latitudes, to about 70-degrees F in the deep south. The geo-thermal process taps into that free, renewable energy in the winter for heat, and returns it in the summer to cool things off.
How do Heat Pumps work?
Geo-thermal technology uses a system of polyethylene heat-exchange pipes placed strategically in the ground, in closed or open loops, and ground source heat pumps (GSHP) to circulate the energy. Closed system ground loops can be installed in multiple ways: horizontally, vertically or slinky loops in the ground, or in a pond or lake. The closed-loop system circulates water or an antifreeze solution through the pipes, while an open-loop system can be installed where an adequate supply of suitable water is available and discharge is feasible. The type of loop system chosen depends on the availability of land and the rock and soil type.
One system that heats and cools. Amazing. How can it do that?
The fluid in the geo-thermal system collects heat from the Earth in the winter and carries it into your home or office building. The system reverses itself in the summer, pulling heat from the building and placing it into the ground. The process creates free hot water in the summer and delivers substantial hot water savings in the winter. The heat pump is the heart of the system. It operates utilizing the basic principles of vapor compression and expansion, together with the factual law of physics that heat flows to cold. Heat is generated when the pump, using a compressor, raises the temperature of a vapor, from 55 degrees F (13 C) up to 150 F (66 C). In a similar way, cooling is provided. A pump can lower the temperature of a 55 F (13 C) vapor down to 20 F (-7 C) by expanding the vapor through an expansion device. So, there you have it — heat in the winter and cooling in the summer — all with one simple system.
How efficient is Geothermal Heating and Cooling?
You’ll be amazed. For each unit of energy required to run the system, geo-exchange creates four new units of heat energy — a coefficient ratio of 4-1. No fossil fuel system exceeds a ratio of 1-to-1. It is also a clean and green technology because no carbon dioxide is produced. Consumers will love the technology for a number of other reasons. First, it is cheaper. A geo-thermal system does the works that ordinarily requires two appliances — a furnace and air conditioner — and can reduce energy costs by as much as 70 per cent. A system can be installed indoors because there is no need to exchange heat with the outdoor air, and is so compact it easily fits within the footprint of your existing fossil fuel furnace. The equipment is also protected from mechanical breakdown that could result from exposure to harsh weather. And they are so quiet, homeowners hardly know they are operating.
Will it work in my geographic location?
Geothermal systems work in virtually any climate.
How much land do I need?
Not a lot of land is required. Small lots require vertical bore holes to be drilled to install the heat-exchange pipes in the ground, while larger lots may be able to utilize a horizontal ground loop or a vertical loop. Properties which have access to a lake or pond at least eight-feet deep may be able to utilize the water as the heat exchanger.
Can I use a hot water radiant system?
Yes, hot-water radiant systems can be converted to work with a geothermal heat pump. Recent introductions of high temperature heat pumps are capable of producing the required water temperature. However, converting an existing boiler with a high temperature heat pump poses other challenges. Often the diameter of the radiant pipes through the house are too small to deliver the volume of water required for a geothermal system. Larger pipes and radiators can be installed, but the cost of installation will increase accordingly.
Do I need a back-up system?
No. A properly designed and installed geothermal residential system can provide 100 per cent of your heating and cooling needs. Most geothermal heat pumps manufactured today include a built-in electric resistant heat source to supplement the ground loop if the outside temperature exceeds the system design parameters for extended periods of time.
Can I heat my swimming pool?
Yes. Many heat pump manufacturers produce units made specifically for swimming pools.
Can I heat my domestic hot water?
Yes. Most heat pump manufacturers offer what they call a de-super heater, which acts as a hot water heater. These systems do not typically replace your conventional hot water heater but are designed to capture the heat rejected from your home when you are in the cooling mode, thus providing free hot water during that time of the year.
Why do installers have such different prices?
Geo-thermal systems are very complex and have many variables to be considered. It can be difficult to sort through competitive quotes because, in many cases, consumers are comparing apples and oranges. Make sure you ask your contractor questions about the system, such as:
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What type of earth heat exchanger was quoted, horizontal, vertical, open or pond loops?
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Is an electrical upgrade required and included in the quotation?
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Is ductwork modification required and included in the quotation?
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Is the heat pump a variable speed or single speed?
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What is the EER (Energy Efficiency Rating) of the heat pump?
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What is the COP (Co-efficient of performance)?
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Does the quote include a de-super heater for domestic hot water?
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Does the quote include an extended warranty?
