Frequently Asked Questions
What is GSHP?
Sometimes our industry is referred to as geothermal, geoexchange, ground source heat pump technology, earth energy systems, solar geothermal, and probably more I don't know of. All of our systems however employ a machine called a heat pump. When coupled to a series of pipes in the earth (or lake, pond, river) we call them Ground Source, or Water Source Heat Pumps. GSHP or WSHP. This is the technical name for the machine that extracts heat energy and pumps it into or out of your building.
What Does It Cost?
There are three costs to consider in any heating/cooling system choices you make, whether you choose geothermal energy or conventional energy: initial installation cost, annual operating costs, and annual maintenance costs. In larger buildings annual operating costs and maintenance costs have a greater impact on system choices than they do in a small building or residence. A budgetary guideline based on figures for 2006 is as follows:
Installation Costs
Costs vary with location and type of installation. On the high side in a cold climate like northern Alberta or northern Saskatchewan we need to utilize what is called a closed loop vertical install (the most expensive system configuration) consisting of a series of vertical boreholes 200 to 300 feet deep. A detached single family house could need 5 or 6 of these boreholes at a cost of $1600-$2000 each. Add to that the cost of trenching from the borefield to the house, the cost of the heat pump itself, as well as controls, pumps, wiring, antifreeze, and labour; the total package could figure approximately $1.30 per cubic foot of structure volume. An 1100 square foot home on a finished basement would have a volume of about 1100 X 8 X 2 floors totalling 17600 cu.ft. Multiplied by our factor of $1.30 we would estimate that project to cost $22,880.
That same house in southern B.C would not need as large a heat pump, nor would it need as large a ground exchanger. And since frost in the ground rarely gets deeper than a couple feet, we could use a less expensive horizontal trench loop field, saving thousands. Better yet, if the house is near the Atlantic, Pacific, the Great Lakes or other large water body, we could use a lake exchanger saving thousands. We could see the turnkey cost well under $20,000 even for a larger home.
To get an accurate estimate of geothermal systems in your area contact qualified local geothermal contractors.
Operating Costs
These are directy related to your cost of electricity since geothermal systems all utilize electric pumps to move both the refrigerant, the exchanger fluid, and indoor air or water. In Alberta the cost of electricity (0.083 /Kw) is double that of Manitoba (0.044/Kw) so operating costs will vary dramatically from region to region.
Using Alberta's higher cost of electricity (2007) a geothermal system to heat, cool, and provide all domestic hot water for a family of four in a 1400 square foot bungalow with a finished basement would range anywhere from $1300 to $1700 per year. Compared to a conventional system comprised of a high efficient natural gas furnace, mid efficient gas hot water heater, and an R22 air conditioner that same family could spend $2200 to $2500 annually.
Maintenance Costs
These costs are exponentially lower the larger the building gets. Due to the proven reliability of sealed refrigeration compressors and ECM electric motors used in most mainstream geothermal systems today, reliability and durability combine to give relatively non-existent maintenance issues. Regular changing of filters, and cleaning of equipment and ductwork will give many years of trouble free operation.
What is a Cupro-Nickel Water/Water Exchanger?
All geothermal units have some kind of heat exchanger inside that is a double walled device carrying refrigerant on one side and ground loop fluid or water on the other side. This is the hardest working part of your equipment and determines your degree of efficiency and the longevity of your unit. Insist on a coaxial Cupro-nickel exchanger. They are the only ones I am aware of that can withstand a freeze should something go wrong, and tough enough to use on lake, pond, or water well type systems. Yes they cost more, but you will not regret it. A number of GSHP/WSHP manufacturers use cheaper and less durable copper exchangers but most offer Cupro-nickel as an option. Hydron Module is one manufacturer that uses only cupro-nickel in all their units. They have proven to be extremely durable.
What are ECM Blower Motors?
Electronically commutated motors are another great energy saving innovation to look for in geothermal equipment These highly efficient motors will move the same amount of airflow needed to blow the air around your house, but using only a fraction of the electricity and at a fraction of the noise level compared to the old PSC style of electric blower motors.
What are desuperheaters?
Free hot water! A wonderful side benefit of the technology used in all GSHP units is the heat energy produced by the pumps inside. Ever notice when pumping your bicycle tire by hand the pump body gets hot? A desuperheater strips a portion of that heat away and sends it into your hot water tank. Since your geothermal equipment was going to be running anyway providing heat (in winter) or cool air (in summer) why waste that pumping heat? Order your geothermal equipment with a desuperheater and get free hot water!
What is GHEX?
Ground Heat Exchanger, the fluid piping buried in the ground.
What is meant by heating and cooling dominant?
In general, Ground Source Heat Pumps fall under two categories: heating dominant and cooling dominant. For our Canadian climate we need to choose equipment that is "heating dominant". That means the manufacturer has designed and engineered his equipment to provide maximum efficiency in the production of heat from relatively cool earth. The inner piping of these units will be heavily insulated to prevent frost buildup. These units will also cool, and do it very efficiently too, but the cooling cycle is staged so that the unit can provide cooling at a level suitable for our moderate summers, and still jump up to maximum on those rare super hot days. Cooling dominant equipment has its engineering focus on maximum cooling capability. It will provide heat too, but that is not the engineering focus, so you will find cooling dominant equipment less able to provide adequate heating for our Canadian winters, may lack necessary insulation on piping and cabinet, but well able to provide lots of cooling for those folks down in the deep south.
What types of refrigerant are used?
There are two types of refrigerant being used by geothermal equipment producers today. R22 and the newer "ozone friendly" R410A. Although R410A units are slightly more expensive, they operate at a higher efficiency than the old R22. Refrigerant has a unique property of rejecting or absorbing great amounts of energy as it changes state from vapour to liquid. By manipulating this property we capture small amounts of energy from the earth many times over, compound them, and then release that energy into your home.
