Engineered Systems Magazine

Public review underway for green buildings standard and 62.1-2007 addenda; mechanical requirements for naturally ventilated buildings finish review

October 1, 2009

The 4th ISC Public Review of BSR/ASHRAE/ USGBC/IESNA Standard 189.1P, Standard for the Design of High-Performance Green Buildings Except Low-Rise Residential Buildings, is underway, taking place through November 2.

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).

This fourth public review shows changes made to the third public review draft in response to comments received. Comments received will be discussed at the November 13-14 Interim Meeting.

Elsewhere, other addenda are in play regarding ANSI/ASHRAE Standard 62.1-2007. The proposed changes open for review in addendum r focus on the IAQ procedure, which is a performance-based approach to compliance with the standard, and allows for designers to adjust the ventilation requirements for a building or space based on performance factors which are unique to the building. These performance factors might include the use of low-emitting materials in the space or the known presence of a contaminant source.

The first public review draft of Addendum r removed a method of complying with the IAQ procedure by designing the ventilation system in the same way as an existing successful building. Based on public review comments, this approach was put back into the standard, but with new restrictions. These include a requirement that a mass-balance analysis of the building’s air quality be performed in every case. This will require that the designer identify contaminants of concern for every building or space where the IAQ procedure is used, along with associated concentration or exposure limits.

The proposed addendum is open for public review through October 26. ANSI/ASHRAE Standard 62.1-2007, Ventilation for Acceptable Indoor Air Quality, sets minimum ventilation rates and other requirements for commercial and institutional buildings.

Also open for public review during the same time period is proposed addendum g, which would add information on using demand controlled ventilation systems. Coverage of DCV systems in the standard is not yet comprehensive, but this addendum provides needed clarifications on the issue.

Requirements regarding mechanical ventilation for naturally ventilated buildings are actually included in addendum n, which has completed public review and will be included in the 2010 version of Standard 62.1, which is expected to be available in spring 2010.

“Most buildings using natural ventilation in the United States are high-rise residential buildings that often have no form of outdoor air intake other than operable windows,” Roger Hedrick, Standard 62.1 committee chair, said. “This results in buildings with inadequate ventilation, because the occupants then leave the windows closed in order to run the air conditioning, keep out noise, etc. The committee felt it needed to strengthen the existing prescriptive requirements for natural ventilation to improve their corresponding IAQ benefits.”

To view a copy of the addenda open for public review, go to www.ashrae.org/publicreviews. Copies of public review drafts are only available during public review periods.

ASHRAE, founded in 1894, is an international organization of some 50,000 persons. ASHRAE fulfills its mission of advancing heating, ventilation, air conditioning and refrigeration to serve humanity and promote a sustainable world through research, standards writing, publishing, and continuing education.