ASHRAE Standard 90.1 now incorporates energy efficiency and building design requirements.

ATLANTA - The new version of ASHRAE Standard 90.1, "Energy Standard for Buildings Except Low-Rise Residential Buildings," has undergone changes that the association says will lead to greater energy savings and more environmentally friendly buildings.

"Standard 90.1-2004 has undergone a dramatic make-over, resulting in a document with a more readable format that is easier to use for practitioners," said Jerry White, chairman of the American Society of Heating, Refrigerating and Air-Conditioning Engineers committee in charge of the standard. "New technical requirements and stringency levels are presented in a more consistent format, making them easy to find and apply to building designs."

The standard contains a new informative appendix to rate the energy efficiency of building designs that exceed its minimum requirements. According to ASHRAE, the appendix will benefit HVAC designers trying to achieve the required points for either a "silver" or "gold" certification from the U.S. Green Building Council's Leadership in Energy and Environment Design program. LEED rewards structures that use less energy.

Changes to the major sections of the standard include a new exterior-lighting section that includes specific lighting power limits for a variety of applications. The mechanical section has been reorganized for easier reading. New climate-zone data simplifies requirements from economizer requirements to duct insulation.

In addition, energy efficiencies were increased for fans, single-package vertical units and three-phase air-cooled air conditioners. Also, the number of primary climate zones for heating and cooling was reduced to eight from 26. Each county in the United States has been mapped to a particular climate zone. As a result, building envelope and mechanical criteria will apply on a countywide basis, and often to many adjacent counties.

The standard has been recommended for inclusion in the 2006 International Energy Conservation Code and the National Fire Protection Association 5000 Building Construction and Safety Code.