The Canadian Standards Association (CSA) C448 standard requires that horizontal loops be buried at least 4 feet below surface. The deeper the depth the better, as thermal stability increases with depth. Many provinces demand the use of trench scaffolding if depths exceed 6 feet, which imposes a cost. Vertical boreholes have no limits on depth, although an average depth is 100-200 feet.

As of March 2002, both residential and commercial installations are covered under the Canada Standards Association (CSA) C448. We are not aware of any provincial regulations affecting Geoexchange installation, though some municipalities or other regulatory agencies may have guidelines or rules pertaining to the installation of systems.  CGC members should be informed and current on all relevant standards and regulations, though as always, the burden of information falls on the consumer.  We therefore recommend consumers raise the question with your local installer and local government officials, until you are satisfied that all necessary standards and regulations have been met.

Trenches are usually spaced 8-10 feet apart, while boreholes are spaced 10-15 feet apart.

Most contractors prefer to retain control over the entire job to ensure compatibility of all sections, but the digging of the horizontal trench (and backfilling) is one area that could reduce costs if done under the guidance and direction of the installing contractor.

It is recommended that a qualified and certified contractor be used to design and install the system. If a homeowner wants to save money and has access to a backhoe, the contractor may provide details on where to trench on the property, and when to backfill after the loop is installed.

Deeper is generally better, but there can be technical constraints. Most residential boreholes are 75-100 feet, but some can be as deep as 1000 feet depending on soil properties, heating requirements, and other factors.

The CSA C448 standard directs that the minimum depth is 4 feet; the former 445 standard required 2 feet. The objective is to install the loop as far below the frost line as possible. Many provinces require safety measures when a trench is more than six feet deep, so most contractors do not exceed that depth in order to reduce costs.

The high-density polyethylene pipe is socket fused (basically, melted together with a high temperature tool), which makes the joined plastic section more solid than the original resin. If done by a certified fusion contractor, there is virtually no chance of breakage or separation under normal conditions.

From one to six, depending on design considerations and the thermal characteristics of the soil.

Each pipe extracts heat from the nearby soil, so separation should be as wide as possible. The CSA standard demands at least 10 feet between sections of loop, which can be reduced under certain conditions.

A geoexchange system relies on a constant, low level of temperature for the building, and any sudden increase in heat demand will cause the supplemental backup heating unit to activate. Setback thermostats are not recommended for use with a geoexchange system.

It is unlikely that a certified loop installer would make any mistake since he/she is trained to fuse sections of loop. The CSA standard requires that a system be tested to a pressure above normal operating levels, to determine if there are any leaks or problems which can be corrected immediately.

In a closed-loop system, the water must be of good quality and meet the specifications of the heat pump manufacturer and the supplier of the anti-freeze solution with which it is mixed. In an open-loop system, some chemicals and minerals in the water may not be compatible with the heat exchanger. An analysis of the water should be performed before purchase to determine which model of exchanger is required. If the water content changes over time, this may have a detrimental impact on the system.

A dual system can be added to an existing furnace to provide a dual-fuel heating system, where the heat pump is the main source of heating and the combustion furnace provides the supplemental heat.

The ground loop can be difficult to install, depending on rocks, physical obstructions and topography. The interior heat pump is easy to install, and can be located in areas without proper ventilation (there is no combustion, so no need for exhaust). Most units are easy to install, especially when they are replacing another forced-air system. The air distribution may be difficult in a retrofit installation.

The only impact will be a period of settling for soil that is placed back in the trench. This visual evidence takes one year to settle.

The CSA standard specifically bans locating a ground loop near septic systems to avoid retarding the microbial action to decompose sewage. Grey water from the building can be used in some situations, if that collection unit is separate from the septic system.

The anti-freeze that is used in a closed-loop system must be approved by provincial authorities and acceptable to the heat pump manufacturer. Methanol and denatured ethanol are the most common fluids used (methanol is not approved for use in Ontario). The fluid must be mixed with water in accordance with instructions, usually on a 4:1 ratio of water-to-chemical.

It is not recommended. In addition to thermal fusion of the pipe, drilling and trenching are procedures best handled by licensed professionals. Non-professional installations may result in less than optimum performance, which could cancel out anticipated savings. Also, warranties are usually void if a non-authorized dealer installs the system.

No. Systems are installed away from trees to avoid damage to root systems when digging the trench.

Depending on soil conditions and the length and depth of pipe, a typical residential system can be installed in two days.  Commercial systems depend greatly on geography and system size for accurate estimation.

The CSA C448 standard contains a number of requirements to ensure that an open-loop unit does not abuse the increasingly valuable water resource.

A contractor can advise if an upgrade is required to accommodate the additional electricity required.

Geoexchange technology uses the earth’s renewable energy, just below the surface, to heat or cool a home or other building, and to help provide hot water.

A few feet beneath the surface, the earth’s temperature remains fairly constant -ranging from 7º or so in Canada’s northern latitudes to about 20ºC in the US deep south -year round. Geoexchange takes advantage of this constant temperature to provide extremely efficient heating and cooling.

In winter, a water solution circulating through pipes buried in the ground absorbs heat from the earth and carries it into the home. The Geoexchange system inside the home uses a heat pump to concentrate the earth’s thermal energy and then to transfer it to air circulated through standard ductwork to fill the interior space with warmth.

In the summer, the process is reversed: heat is extracted from the air in the house and transferred through the heat pump to the ground loop piping. The water solution in the ground loop then carries the excess heat back to the earth. The only external energy needed for Geoexchange is the small amount of electricity needed to operate the ground loop pump and fan.  It is more efficient and environmentally superior to ‘transfer’ heat than to ‘create’ it through combustion.

Not really.  The basic technology has been around for more than 20 years, and many homeowners and businesses have been enjoying the benefits of Geoexchange for much of that time. (Please see our section on ‘GeoSuccess Stories’ for some examples).

In recent years, though, many improvements have been made in the materials used, the installation methods, and the efficiencies of the compressors, pumps and other equipment.

Homeowners enjoy lower utility bills (25% to 50% lower than with conventional systems), lower maintenance, and higher levels of comfort, year-round. Even more than that, though, they have the peace of mind of knowing they’re being environmentally responsible.

Since a geoexchange system burns no fossil fuel to produce heat, it generates far fewer greenhouse gas emissions than a conventional furnace, and completely eliminates a potential source of poisonous carbon monoxide within the home. Even factoring in its share of the emissions from the power plant that produces electricity to operate the geoexchange system, total emissions are far lower than for conventional systems.

According to data supplied by Natural Resources Canada and by the U.S. Department of Energy and EPA, a typical 3-ton residential geoexchange system produces an average of about one imperial pound less CO 2 per hour of use than a conventional system. To put that in perspective, if just 100,000 homes converted to geoexchange, Canada could reduce its CO 2 emissions by 880,000,000 lb.

That would be the equivalent of converting about 58,700 cars to zero-emission vehicles, or planting more than 120,000 acres of trees.

And the waste heat removed from the home’s interior during the cooling season can be used to provide virtually free hot water-resulting in a additional savings in hot water costs of about 30% annually, and lowering emissions even further.

Installing geoexchange and enormously reducing your consumer electricity and heating bills, needs, and usage, are very helpful in helping Canada meet our national energy policy goals regarding Kyoto.  In that sense, geoexchange is a very Kyoto-friendly technology.

Geoexchange systems are indeed officially classified by Natural Resources Canada as a ‘renewable’ energy, meaning that they operate without destroying finite natural resources.  In practise, geoexchange is usually paired with conventional electricity generation, which uses some fossil fuel (though up to 80% less than a conventional system) to run system heat pumps.  CGC members and member installers will be pleased to discuss and/or help you plan a fully 100% renewable system, though costs may be higher.  Two ways to use more renewables are to participate in renewable-designated buying programmes like SaskPower’s GreenPower and PowerSmart, or through installing additional components such as solar panels or wind turbines.

Perhaps surprisingly, no. While many homes have been fitted with geoexchange systems, commercial enterprises, including factories, retail stores, office buildings and schools are the biggest users of geoexchange to save energy and protect the environment. In fact, there are more than half a million installations in North America today.

For example, worth particular note is the pioneering effort of Enwave District Energy Limited in bringing the geoexchange principle to the downtown Toronto core via a partnership with NRCan.  From Queen’s park to the waterfront, the Toronto Hydro subsidiary will cool 50 million square feet of office space by using the deep water of Lake Ontario, starting in 2003.

Particular advantages come to building heating systems which can generate scale, such as district systems (like Toronto, a utility or a developer could respond to customer demand and install geoexchange for an entire suburban neighbourhood street or a large apartment building) or common institutions.  In the United States schools have been a particularly popular place for the use of this technology. Across the continent, schools using geoexchange right now are saving an estimated C$45,000,000 in energy costs-which can be used instead for better educational equipment and more teachers. These schools also save all of us half-billion pounds of CO2 emissions per year.

If we make the same comparison across all commercial and residential segments in Canada, the potential for environmental benefit is staggering.

Yes, geoexchange technology can be used in any part of the country. Why? Because it transfers heat to and from the earth, which remains at a relatively constant temperature, rather than the air, where temperatures can vary greatly.  One of our most experienced members is Yukon Development Corporation, and many of our provinces aim to serve isolated customers, especially those in the far north, with geoexchange technology.

That depends on when you measure cost. While geoexchange costs more to install in homes than conventional systems, because of the ground loop piping, geoexchange systems typically have the lowest life-cycle cost of any heating and cooling system. Heating and cooling costs for a typical 2,000-sq.-ft. home can run as low as $1 a day.

Moreover, installation costs have declined substantially in recent years, and they’re expected to continue to fall, as more builders and contractors offer geoexchange systems, and as the industry develops innovative ways to install the systems faster and more efficiently.

Altogether, geoexchange systems are a very sound investment. The amount they save the homeowner every month in energy costs is more than enough to offset their higher installation cost.

Remembering that geoexchange also means extra savings on repair, maintenance, and hot water bills, the energy efficiency of geoexchange adds value to your building whether home, apartment building, condo, skyscraper, or sports stadium.