The minimization of laboratory air changes, where appropriate, serves to both minimize expense and foster environmental sustainability. Advances in variable air volume (VAV) technology in heating, ventilation, and air-conditioning (HVAC) systems have allowed Facilities Managers to reduce the amount of energy consumed to condition laboratory spaces. The VAV systems allow for precise control over the number of air changes per hour (ACH) and can be interlocked with occupancy sensors to reduce ACH during unoccupied periods of time, where appropriate.
Prior to implementing energy set-back controls, consideration for the health and safety of the laboratory occupants must be examined. The American Industrial Hygiene Association (AIHA) developed a Laboratory Ventilation Standard (ANSI Z9.5-2003, updated in 2012) to address the balance needed between financial optimization and occupant safety. Research conducted by Klein and colleagues (2009), indicated airborne concentrations of volatile chemicals are most effectively removed from a laboratory when ventilation rates range from six to eight ACH1. Further, in some instances, laboratory spaces are even being set back to four during occupied times and two during unoccupied times with comprehensive collaboration between Facilities, Sustainable Energy personnel, and Health and Safety personnel. The University of California-Irvine accomplished an approximate 61% cost savings through implementation of energy set-backs in laboratory buildings.2
By conducting a thorough laboratory risk assessment, considering chemical health hazards, quantity, frequency of contact, and the potential for contaminants becoming airborne, sound judgments can be made for deciding whether laboratories can safely be “set-back” to a lower ACH during unoccupied times.
Colden has conducted initial and routine risk assessments for a Fortune 500 company’s research and development facility, where over 150 laboratories were evaluated for set-back eligibility. Comprehensive risk assessments were performed in each with consideration for the processes conducted, chemicals in use and all controls employed. Of the 150 reviewed, over 70 percent were eligible for set-backs from 10 to six ACH during unoccupied times. To increase savings even further, the facility hopes to move toward six and three ACH in the future.
1Laboratory air quality and room ventilation rates, Robert C. Klein, Cathleen King and Anthony Kosior. Journal of Chemical Health and Safety, Volume 16, Issue 5, September-October 2009, Pages 36-42. doi:10.1016/j.jchas.2008.12.004
2Brase, Wendall. University of California-Irvine. Smart Laboratories Cut Energy Consumption More Than Half. August 2013.