Changes to ASHRAE Standard 62.1 Ventilation Rates Proposed

By Consulting Specifying Engineer Staff April 4, 2006

Ventilation requirements for high-rise residential buildings are among changes being proposed for ASHRAE’s indoor air quality standard.

Three proposed addenda to ANSI/ASHRAE Standard 62.1-2004, Ventilation for Acceptable Indoor Air Quality, are available for comment until May 1. To obtain drafts of or comment on proposed addenda e, f and h, go to .

Addendum 62.1h would add requirements for high-rise residential buildings to the standard’s ventilation rate table. These ventilation rates are somewhat higher than the residential rates included in ANSI/ASHRAE Standard 62.2, Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings, according to Dennis Stanke, chair of the Standard 62.1 committee.

“Standard 62.2 bases its rates on the assumption that infiltration always provides some ventilation and on the requirement that each dwelling unit includes operable windows for supplemental ventilation,” he said. “The Standard 62.1 rates, on the other hand, assume that ventilation requirements are independent of infiltration and operable windows.”

For example, the required mechanical ventilation rate for a two-bedroom apartment or condo could double compared to Standard 62.1-2001. Stanke noted that increased outside air rates could mean more outside air-conditioning tons, especially in humid climates.

Addendum 62.1e would add an informative appendix that summarizes the requirements for documentation found throughout the standard.

“Good documentation aids communication between all parties involved with the design, installation, operation and maintenance of ventilation systems,” Stanke said. “Reducing communication failures reduces building-ventilation and indoor-air-quality problems.”

Addendum 62.1f would change the purpose and scope of the standard to make them more consistent with its body. The purpose retains its dual goals of providing indoor air quality acceptable to human occupants that minimizes the potential for adverse health effects.

The scope no longer includes single-family houses or multiple-family buildings with three or fewer stories. These structures are covered by Standard 62.2.

The scope also states that the standard includes no specific prescribed ventilation rates for smoking-permitted spaces or for improperly separated non-smoking spaces (since these spaces might also contain environmental tobacco smoke).

“Although they contain no specific compliance requirements, statements of scope and purpose must be clear and accurate to help users of the standard apply it properly,” he said.

In other news about Standard 62.1, the impact of ventilation rates on occupant health is being studied through ASHRAE research.

“ASHRAE’s guidance is widely referenced in the HVAC&R industry because it stays on top of new developments,” said lead researcher, Jan Sundell, DanishTechnicalUniversity, Copenhagen, Denmark. “The study will lead to an improved understanding of what science can tell us about the relationship between ventilation and health, which in turn will lead to more reliable information on the benefits of building ventilation. It also will give information about where there is a lack of knowledge, providing the basis for new research.”

A panel of leading authorities on indoor air pollution and health within medicine and engineering will review existing research and literature on the effect of ventilation on health in schools, offices, residences, etc. While the focus will be on ventilation rates, they also will look at pollutant sources, source strength and pollutant concentrations.

Results may be used to update ASHRAE Standard 62.1, Ventilation for acceptable Indoor Air Quality, and Standard 62.2-2004, Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings.