Specifying Exhaust Systems to Minimize Energy Costs While Maintaining Acceptable Air Quality

Dr. Ron Petersen, Cermak Peterka Petersen, Inc.

Abstract:

An important element of laboratory design, especially one that obtains the "green" designation, is the quality of the indoor environment. An important aspect of the indoor environment is the potential impact of pollutants exiting laboratory stacks that subsequently reenter the building through air intakes, operable windows or entrances. To ensure acceptable air quality at these locations numerical and/or wind tunnel modeling techniques are employed to estimate the minimum acceptable stack height, volume flow and exhaust velocity required to achieve the specified air quality design criterion. The more restrictive the air quality design criterion the larger these parameters become. Since stack heights are usually fixed at a some low height, the volume flow and exhaust velocity are often increased using entrained air systems or larger conventional fans to meet the air quality design criterion. The larger horsepower fans needed to achieve the higher flows and velocities have a direct impact on day-to-day energy costs.

This presentation will discuss the relationship between the air quality design criterion, the fan size/type specification and annual energy costs. Examples from recent projects for the CDC and various university laboratories will be presented showing how initial fan size specifications could be reduced to save energy costs while at the same time meet the air quality design criterion.

Biography:

Dr. Ron Petersen has a B.S. in mathematics from the South Dakota School of Mines and Technology, an M.S. in Atmospheric Science from the South Dakota School of Mines and Technology and a Ph.D. in Civil Engineering (Specialty in Wind Engineering) from Colorado State University. Dr. Petersen is a Vice President and Principal at Cermak Peterka Petersen, Inc. (CPP), a firm that specializes in providing design information to account for the effect of wind on man and his environment. One of the areas that Dr. Petersen specializes in is providing design information for new and existing laboratories or hospitals so that the air quality impact of building exhausts can be minimized at nearby air intakes and other sensitive locations (i.e., operable windows, entrances, plazas, walkways, etc.). Some of the projects he has worked on include CDC Building 110, Cornell's Duffield Hall, National Institutes of Health Clinical Research Center, the UCLA Westwood Replacement Hospital, M.D. Anderson Cancer Research Center in Houston and the Fred Hutchinson Cancer Research Center in Seattle.

Dr. Petersen is also actively involved in several professional organizations to include AMS, ASHRAE, A&WMA, ISPE and AIHA. In 1996, Dr. Petersen was the program chairman for the Ninth Joint Conference on Air Pollution Meteorology and in 2000 helped coordinate and provide comments on behalf of the Air & Waste Management Association's meteorology committee for presentation at the 7TH EPA Modeling Conference regarding revisions to EPA's "Guideline on Air Quality Modeling." He has also served or is serving on committees related to pollutant dispersion and fume reentry for ASHRAE, AMS and A&WMA. Dr. Petersen has also presented a short course on fume reentry for the AIHA. He has authored or coauthored more than 300 papers and technical reports including technical papers regarding minimizing pollutant reentry into buildings to include a recent paper in the ASHRAE Journal.