On Oct. 21, 2009, the American National Standards Institute (ANSI) approved the 2009 Uniform Solar Energy Code (USEC), a consensus-based model code for the installation, inspection, and maintenance of solar energy systems and component products, for accreditation as an American National Standard. While a uniform solar energy code has been in existence since 1976, the 2009 document is the first such code to be designated as a national standard.

Developed by the International Association of Plumbing and Mechanical Officials (IAPMO), the ANSI/IAPMO USEC 1-2009 Uniform Solar Energy Code contains several new provisions and updates from the previous version, published in 2006. Every three years the IAPMO produces new code updates. The new code covers solar thermal systems and photovoltaic systems comprehensively, setting out new requirements and allowances that address technological advances for both types of systems.

The ANSI/IAPMO USEC 1-2009 Uniform Solar Energy Code:

  • allows for the installation of single-wall heat exchangers for solar thermal systems;
  • requires access to a solar collector and its components for maintenance and repairs;
  • establishes protection requirements against freezing temperatures, "water hammer," rodents, corrosion, ultraviolet radiation, decay, and termites; and
  • sets out waterproofing requirements for solar collectors installed on a building to prevent leaking.

    In jurisdictions that adopt it, the new ANSI-accredited code will impact every industry involved in the sale, installation, and servicing of solar thermal and photovoltaic systems, from specifying designers, builders, and code-adopting jurisdictions to system installers, inspectors, and purchasing homeowners.

    ANSI/IAPMO USEC 1-2009 Uniform Solar Energy Code is expected to be available at www.ansi.org by Nov. 15, 2009.