Plumbing and Mechanical

NSF geothermal heat pump standard to be referenced in 2015 International Mechanical Code

January 22, 2013

NSF International, an independent global organization that writes standards, and tests and certifies products for the water, food, health sciences and consumer goods industries, has published the first in a series of American National Standards for Ground-Source Geothermal Piping Systems — NSF/ANSI 358-1. This new standard, which will be referenced in the 2015 International Mechanical Code, provides engineers, regulators and users assurance that certified geothermal products meet minimum performance and safety requirements, reducing potential liability, and increasing confidence and product acceptance in the marketplace.

Geothermal heat pump systems provide heating or cooling by moving heat, rather than by creating heat such as conventional systems such as furnaces do. While conventional heating systems rely on outdoor temperatures that may often vary, underground temperatures remain relatively constant; hence geothermal systems can produce the desired heating and cooling temperature year round.

Geothermal piping systems have gained popularity in recent years for residential and commercial building applications for their innumerable benefits such as low operating costs and environmental impact, long-term durability and ease of retrofitting. The International Ground Source Heat Pump Association reports that geothermal heating systems can reduce energy consumption by 20 % to 50% and last up to 50 years.

To help support the acceptance of this technology, NSF International worked with expert engineers, piping manufacturers, and academic and regulatory representatives to develop the consensus-based standard. NSF/ANSI 358-1: Polyethylene Pipe and Fittings for Water-Based Ground-Source “Geothermal” Heat Pump Systems establishes minimum physical and performance requirements for geothermal piping system components, including long-term strength and quality control requirements that are key to ensuring product performance in the field.

Additionally, the standard incorporates key requirements from standards developed by the American Society for Testing and Materials, the Canadian Standards Association and the American Water Works Association.

“This new NSF American National Standard helps manufacturers and regulators and provides a credible, science-based foundation for the expanding geothermal pipe industry to gain acceptance in the marketplace,” said Nasrin Kashefi, general manager of NSF International’s Plumbing programs. “Manufacturers that earn certification to NSF/ANSI Standard 358-1 will help increase confidence and product acceptance by ensuring geothermal pipe complies with all of the standard’s requirements.”

Allan Skouby at GeoPro added: “Having a consensus-based standard developed by an independent third party is essential for the continued growth and acceptance of geothermal technology by local regulatory officials. As we have seen this industry grow, so has the awareness level by local officials who look to organizations like NSF International for verification of compliance of the various system components. This new standard should help the industry gain credibility within the appropriate model codes and should prove to be a good blueprint for other materials for similar use as this technology matures.

To learn more about NSF International testing and certification services for water treatment and distribution products, visit NSF’s water programs web page.