Geoexchange & Quality
Since 2006, sales of ground source heat pumps, otherwise known as GeoExchange™ technology, have been growing at over 100% annually in Canada. Part of this growth is attributable to the fact that...
Since 2006, sales of ground source heat pumps, otherwise known as GeoExchange™ technology, have been growing at over 100% annually in Canada. Part of this growth is attributable to the fact that government programs have provided financial incentives for these systems. Indeed, over the course of the last 35 years — essentially since the OPEC crisis of the mid-1970s — energy efficiency programs for ground source heat pumps have been introduced around the world, with varying levels of success.
The relatively quick growth of the industry, however, has not been without its pitfalls. Where incentives have been introduced without a direct and firm link to a meaningful quality assurance program, such as in Sweden in the 1970s and here in Canada in the 1980s, 1 unqualified and incompetent contractors have actually harmed the industry. Poorly trained, or even totally untrained, contractors and engineers sold heat pump systems to consumers –in some cases even marketing the subsidy before the system –and helped create numerous failed systems. In both Sweden and Canada these trends led to a widespread assumption that geo “doesn’t work” or that no contractor may be trusted.
In fact, geoexchange technology, first patented in Switzerland in the 19th century, has a proven performance and great potential for energy and carbon emission savings. When executed properly, ground source heat pumps (GSHPs) deliver heat and cooling at efficiencies as high as 1,200% by sourcing ambient heat in the ground and moving and/or compressing it. 2 By providing on-site heating and cooling energy for buildings, they can help to smooth the demand for utility power and reduce overall greenhouse gas emissions.
Training and certification
As the national association for the ground source heat pump industry, the Canadian GeoExchange Coalition (CGC) represents the industry’s public and private interests. Based in Montreal, the coalition manages the voluntary national quality program and serves as the industry centre for accrediting non-P. Eng. professionals.
Realizing that the industry had some quality control problems, in 2004 CGC began to build a voluntary, national quality program.
The program is called the Global Quality GeoExchange Program, and it was driven by a dedicated national effort to develop training relevant to Canadian geology, climate, standards, and regulations.
Those accredited by the program must follow best practice, such as:
• analyzing heat load and using design software
• supervising and documenting drilling
• proper purging and flushing
• proper system start-up
• delivering an as-built book to customers
• operator/customer training. The CGC quality program culminates in CGC System Certification. Certification requires that installers and designers of residential systems deliver systems according to Canada’s Standard CSA C-448-02, “Design and Installation of Earth Energy Systems.”
To qualify for residential system subsidies, the Canadian government and several provincial governments have required CGC System Certification since 2007. Though only Toronto has thus far offered a geoexchange-related rebate for commercial properties, CGC expects to see such incentive programs come on line by 2010.
CGC has trained over 2,800 individuals in the past two years, and has accredited over 850 designers and installers who are focused on the residential market. Meanwhile, CGC has deployed courses for commercial system designers in Alberta, Ontario, British Columbia and Quebec. The courses are written by a technical committee of ASHRAE. This year, CGC will work with its member engineers and provincial governments to design a commercial-level certification form for projects.
The CGC assists in developing standards and codes, revising its own training materials annually. The link between industry self-regulation based on recognized standards and incentives has been a powerful tool in uniting and professionalizing Canada’s geoexchange industry.
Expanding in scope
The industry continues to expand in interesting ways. Consulting engineers may be aware, for example, of CGC’s efforts to incorporate direct expansion technology into Canada’s governing standard, CSA C-448.
CGC is also working with industry stakeholders to comprehensively revise CSA C-448, including incorporating previously excluded technologies such as standing column wells and hydronic applications, and rewriting various sections to reflect significant innovations.
As well, CGC has begun an initiative with the Canadian Water and Wastewater Association to explore the use of wastewater systems for heating and cooling in Canadian municipalities. One idea is to run heat exchanger pipe on the exterior of sewer mains where it could absorb heat. CGC hopes to engage partners to develop pilot sites across the country for demonstration and monitoring.
Other developing practices include: the more sophisticated use of diurnal and inter-seasonal thermal storage to increase the efficiency and flexibility of systems; the integracontinued tion of solar thermal preheating; seawater and lake water cooling such as in Halifax and Toronto; and integration with low-exergy approaches. Creative engineers are working with clients to find new heat sources and heat sinks, to reconceive how buildings are heated and cooled, and to lower life-cycle costs.
A word of caution
While Canada’s most creative and experienced engineers have shown great skill in designing geothermal systems, a word of caution is necessary.
CGC’s engineering course instructors and some engineering members have expressed grave concerns that engineers and designers of all types must be better trained and more consistently vigilant than they often are for commercial geoexchange applications to match the success of the systems at the residential level.
We expect that involving an engineer guarantees a level of technical competence and protection. However, CGC’s engineer members have reported seeing problems such as loop fields oversized by 150% or more; the use of out-of-date or wholly inappropriate software; the misuse of appropriate software; improper specification of pipe, fittings or screening, leading to system seizure or under-performance; failure to oversee key project aspects such as vertical drilling; a general failure to act in a client’s best/fiduciary interest; and so forth. Engineers are reminded by CGC instructors in their classes that without proper training in a given area, an engineer is violating their Code of Conduct in executing work on geoexchange systems.
CGC’s engineer members are also finding some engineers who take and pass the CGC Training for Commercial System Designers course and yet fail to engage in best practices consistently, including failing to call on colleagues who may have a valuable knowledge to contribute. As CGC trains more municipal inspectors, and continues to train installers and other trade-level professionals, it will also seek to work with engineers and engineering bodies to help educate those who are designing these systems and to ensure they do the best work possible.
Geoexchange technology can deliver outstanding benefits when designed and installed properly. It’s the engineer’s responsibility to become as well trained as possible and to check with more experienced colleagues when any doubt arises.
Geoexchange technology has arrived. It’s up to us all to make sure it’s implemented well.
Ted Kantrowitz is the vice-president of the Canadian GeoExchange Coalition in Montreal,www.geoexchange.ca
1 Martin Forsn, Survey of Markets in Europe (Address). Proceedings of the 3rd National Business & Policy Forum, pub. Canadian GeoExchange Coalition Montreal, 2009. www.geo-exchange.ca/en/national_conference. php
Denis Tanguay, CGC Response to
Market Barriers and Market Failures in the Ground Source Heat Pump Industry, GeoConneXion Magazine pp. 25-30, September 2008, Montreal.
2 CGC’s national metering project, begun in 2008, will deliver first results in late 2009; CGC case studies show that commercial-sized simultaneous heat-cool geoexchange systems can achieve 1,200% efficiency routinely, and can peak at 1,800% efficiency.
What Is Geothermal Energy? Why Should Engineers Care?
“Geothermal” energy translates from Latin literally as “ground heat.” Below the frost line, ground temperatures stay more constant than in the atmosphere, ranging from about 7 to 13 degrees in the first 100 metres of the earth’s crust. GeoExchange™ a. k. a. ground-source heat pump systems, circulate a heat transfer fluid through a series of pipes installed below the frost line to capture this low-temperature heat.
In summer the ground can be used as a heat sink, cooling buildings or processes. Because this shallow ground heat is essentially inexhaustible, the sourced heat is considered renewable energy by the governments of Canada, the United States, and other bodies like the European Commission. GeoExchange systems qualify as renewable energy systems in Canada and can earn a 50% capital cost allowance tax benefit for large customers.