Tuesday, March 17, 2009

Three Key Gases Are Targeted By GSA

As landlord for the civilian federal government, the Public Buildings Service--a principal division of the General Services Administration (GSA)--owns and leases over 354 million square feet of space in 8,600 buildings in more than 2,200 communities nationwide.

For several years, the GSA has been in the forefront of green building initiatives, and has written strong policies into its Solicitations for Offers (SFOs) to support its Green Lease Policies and Procedures for Lease Acquisition.

The agency has established indicator levels--figured as an eight hour time-weighted average--for three gases: Carbon monoxide (9 parts-per-million) carbon dioxide (1000 ppm) and formaldehyde (0.1 ppm).

Typically, carbon dioxide levels have been used to control building ventilation, since this gas is exhaled by humans, and any build-up would signify inadequate ventilation. In-duct carbon dioxide monitors are installed, and output the data to the facility's building automation system, which will adjust ventilation accordingly.

"However," says Grant McClure, Interscan's director of special projects, "similarly priced instruments, with appropriate sensitivity, are not available for carbon monoxide or formaldehyde" "In addition, few buildings now record even the carbon dioxide measurements as an eight hour time-weighted average"

Interscan sales personnel have fielded numerous inquiries from consulting mechanical engineers and contractors regarding the GSA standards, and have formulated a common sense approach to ease compliance.

1. Document carbon dioxide measurements with a data acquisition system, possibly available as part of your building automation software. Make sure that eight hour time-weighted averages are calculated and archived.

2. Keep portable carbon monoxide and formaldehyde analyzers on hand for intermittent survey work, and to respond to any tenant complaints.

3. While carbon monoxide levels are unlikely to be a problem unless smoking is allowed in the building, or if make-up air is drawn from a source contaminated with automotive exhaust, formaldehyde levels might well exceed the standards. McClure advises keeping a careful eye on installation of new carpet, drapes, furniture, and painting and finishing operations. Temporary adjustments to ventilation should be considered, as well as performing these tasks during off hours.

"The standards ensure good indoor air quality for all workers, and this increases productivity," notes McClure. "We at Interscan are pleased to be part of the green building revolution"