- Author
- Persily, A. K.
- Title
- Assessing Ventilation Effectiveness in Mechanically Ventilated Office Buildings.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Sponsor
- Department of Energy, Washington, DC
- Contract
- DOE-DEAI01-91CE21042O
- Book or Conf
- American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. Room Air Convection and Ventilation Effectiveness, International Symposium, 1992. 1993, Murakami, S.; Kaizuka, M.; Yoshino, H.; Kato, S., Editors, 201-212 p., 1993
- Keywords
- office buildings | ventilation | effectiveness | systems engineering | zone models
- Identifiers
- concentration ratios; two-zone models; quasi-equilibrium approach; age of air
- Abstract
- Mechanical ventilation systems are designed and operated to bring outdoor air into buildings, distribute ventilation air within the occupied space, remove internally generated contaminants, and maintain thermal comfort. While standard measurement techinques exist to evaluate thermal comfort, air change rates and some aspects of ventilation air distribution in mechanically ventilated buildings, procedures to assess the uniformity of air distribtuion within a building and the degree of mixing within an occupied space are still being developed. This paper presents a general dicusssion of ventilation effectiveness in mechanically ventilated office buildings as the ability of the ventilation system to provide ventilation air in a manner consistent with the design goals of the system. The design and performance of air distribution systems are discussed on a range of scales, from the air handler to the individual workspace, as are the means for assessing ventilation effectiveness on each of these scales. Various approaches to the assessment of mixing within ventilated spaces, the most common conception of ventilation effectiveness, are presented and discussed in relation to their use in mechanically ventilated office buildings.