Evaluation of a Method for Determining Air Exchange Rates in Occupied Buildings

Details

• Personal Author:
  Feigley C ; Salzberg A ; Salzberg D ; Feigley C ; Salzberg A ; Salzberg D
• Description:
  Outdoor air exchange rate (Qo) is one of the most critical determinants of room air quality, yet the performance of methods for estimating Qo has received little attention. Here such a method for estimating Qo in occupied rooms using indoor and outdoor CO2 concentrations (CMB method) was developed and refined using simulated schoolroom CO2 data. It was then applied to actual data collected from two schools. Simulated data were generated for four factorial combinations: two Qo values and two emission rate (G) values. The CO2 mass balance equation was linearized and Qo was estimated by regression. Refinements considered included: intercept/no intercept, smoothing the occupancy variable, and selective use of data (entire school day, occupied periods only, and unoccupied periods only, e.g. lunch and recess). The best method performance was found for no intercept, smoothing, and unoccupied room; errors for the four Qo-G combinations ranged from -4.08 to 0.63% (RMS error = 2.1%). The second-best method performance was found for no intercept, smoothing, and entire school day, which had errors ranging from -6.21 to 0.12% (RMS error = 3.3%). Use of data from the entire school day or from exclusively occupied periods allowed estimates of both G and Qo' but tended to underestimate both parameters. The CMB method has several advantages. Estimates represent air exchange over time periods of any length, can be made while the room is occupied, and include the effects of all air exchange pathways. The data required can be obtained easily and unobtrusively. [Description provided by NIOSH]
• Subjects:
  Air Movements Air Pollution, Indoor Environmental Monitoring Occupational Health Safety
• Keywords:
  Air Flow Air Monitoring IAQ Indoor Air Quality Indoor Environments Sampling Methods
• Publisher:
  American Industrial Hygiene Association
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Abstract or Summary ; Abstract or Summary
• Place as Subject:
  New York ; OSHA Region 2 ; OSHA Region 4 ; South Carolina
• CIO:
  National Institute for Occupational Safety and Health (NIOSH) ; National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health ; Workplace Safety & Health
• Location:
  North America ; North America
• Pages in Document:
  49
• NIOSHTIC Number:
  nn:20057788
• Citation:
  American Industrial Hygiene Conference and Exposition, May 8-13, 2004, Atlanta, Georgia. Fairfax, VA: American Industrial Hygiene Association, 2004 May; :49
• Federal Fiscal Year:
  2004
• Performing Organization:
  Arnold School of Public Health, University of South Carolina, Columbia
• Peer Reviewed:
  False
• Start Date:
  19940701
• Source Full Name:
  American Industrial Hygiene Conference and Exposition, May 8-13, 2004, Atlanta, Georgia
• End Date:
  20040630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:29200b7031c70420d106f3ebc53793dd5a1904573836eecd0a7cc4bedcc37244f201de13c400be278bfd9a4fcff0124b0044c8d250458e8976fc2152f23c420a
• Download URL:
  https://stacks.cdc.gov/view/cdc/215020/cdc_215020_DS1.pdf
• File Type:
  [PDF - 1.21 MB ]