TECHNICAL - UPDATE

by Eli Howard

Public Review of BSR/ASHRAE/USGBC/IESNA Standard 189P, Standard for the Design of High-Performance, Green Buildings Except Low-Rise Residential Buildings

This standard provides minimum criteria that apply to new buildings and major renovation projects (new portions of buildings and their systems): a building or group of buildings, including on-site energy conversion or electric-generating facilities, which utilize a single submittal for a construction permit or which are within the boundary of a contiguous area under single ownership and address sustainable sites, water use efficiency, energy efficiency, the building's impact on the atmosphere, materials and resources and indoor environmental quality (IEQ).

The public review and comment period began on May 25 and ends July 9. The standard covers a wide range of topic areas new to ASHRAE, such as building site selection. This is the first time the US Green Building Council (USGBC) has partnered with ASHRAE to develop a standard. The Illuminating Engineering Society of North America (IESNA) and ASHRAE have previously partnered on standards development related to energy efficiency and lighting.

All three organizations are ANSI Standard Developing Organizations.

USGBC's LEED Green Building Rating System, which addresses the top 25 percent of building practices, was referenced as a key resource. When public review is completed, Standard 189P will provide a baseline to drive green building into mainstream building practices.

To review the ASHRAE news release, link to: .

To access the proposed standard, link to: .

SMACNA was a voting member of ASHRAE's Special Projects Committee 189. SMACNA members are encouraged to review the proposed standard and submit comments directly to ASHRAE using the above link.

Of particular interest to SMACNA members are the higher ventilation requirements, a requirement for the lowest leakage class of ducts and the limitation of HVAC fan horsepower. Many paths were considered for reducing fan horsepower, including limiting allowable duct friction rates to 0.05 in wg/100 feet of duct, but limiting the available fan horsepower was considered the best way to provide duct designers a clear and simple metric to design the most efficient duct system possible. High duct pressures and fitting frictional losses increases HVAC system operating costs by increasing fan horsepower requirements. It was noted that in many existing commercial buildings, fan horsepower accounts for as much as 40 percent of the annual electrical energy use.

Of interest to architectural sheet metal contractors are the requirements related to high albedo and solar reflectance type roofing.

Official Journal of Record for SMACNA-BC