Feature Articles
NSF Creates New Certification Program for Geothermal Heating and Cooling Applications
by Tim Haenftling
September 1, 2008
Third-party program ensures product quality and safety for pipes and fittings used in these systems.
Since long before the Roman Empire, people have
used the earth’s natural heat for their benefit. Long after the Roman Empire
fell, in 1904, a prince in Italy tested the world’s first geothermal generator.
Today, more than 100 years after the initial start up, the generator is still
in use. Since that first test more than a century ago, geothermal power,
heating, and cooling systems have become more and more widespread across the
world. The spread of geothermal systems started very slowly, but in the past
few decades their use has skyrocketed.
According to the Geothermal Energy Association, the use of geothermal heat
pumps has been increasing at a rate of 15% every year. The GEA estimated that
there were more than 600,000 units in 2005 with 50,000 to 60,000 heat pumps
added every year. With energy costs seemingly ever on the rise in today’s
world, it is no surprise that both people and businesses are turning more and
more toward geothermal heating and cooling – a system that has been estimated
to save consumers up to 50% on heating and cooling (according to the
EPA).
As a green source of energy, geothermal systems have been shown to be both cost
efficient and plentiful. Geothermal systems utilize the earth’s natural steady
temperature to heat in the cold months and cool in the hot months. Simply put,
a geothermal system consists of pipe placed deep in the ground where the water
is pumped in order to absorb the temperature of the earth and then pumped back
into the building for heating or cooling. These systems have shown the
potential to end up ‘paying for themselves’ within a short time, typically 3 –
5 years. The economic advantages of geothermal systems are enormous, especially
in large applications such as shopping malls, hospitals or
schools.
The green benefits and long-term cost effectiveness of a geothermal system has
elevated the system’s popularity into the public eyesight. Yet how can a
consumer or inspector know the system (typically polyethylene [PE] pipe and
fittings) is safe? Providing reliable heat and cooling to homes or businesses
is critical. Homes, hospitals or
schools that have lost heat in the cold winter months or cooling during the
heat waves of summer can experience disastrous and costly results.
Manufacturers who comply with these requirements have available to them the legitimate marking of this information. This becomes very important when the identification marking (such as the print strip on a pipe) may vary depending on the manufacturer, especially when the product is not certified to a standard that specifies marking requirements. However, a product that has been certified will be identified with the appropriate certification mark of the agency; for example: NSF – geothermal, along with but not limited to, material specification, performance standard, whether or not the product is authorized for use in potable water systems, and the pressure rating of the pipe.
NSF has also developed a certification program for products sold in Canada, which includes:
The certification of these products adds two further items to give reassurance in the quality of the products: auditing of the facility and quality control testing.
Quality Control Requirements for PE Pipe
Standard 14 identifies specific testing requirements for manufacturers to perform critical quality control testing at the products facility at specified frequencies. This is in addition to quality control requirements established by the product design standards. The following table is an example of requirements for PE pipe:
Monitoring testing
A requirement of continued certification is
annual inspections and testing. During the facility inspections (where it is
ensured the correct formulation is used in the production of geothermal
products), samples are collected by NSF from production or from inventory for
annual testing. NSF provides a detailed report that summarizes the results of
the product testing. Monitoring testing combined with unannounced facility
inspections and required quality control testing document continued product
compliance.
New technologies applied to the very old ideas of using the Earth’s natural
warmth ensures that geothermal will be a viable source of energy long into the
future. Setting and following requirements on these products will, likewise,
ensure continued confidence in the quality of the products and create a high
level of confidence in their dependability.
Tim Haenftling
Tim Haenftling is technical manager – plastic
piping system components for NSF Intl. and can be reached at
haenftling@nsf.org.
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