Paper 2: Volume 5 No.3 Dec 2006 Edition
Performance of Underfloor Air
Distribution in a Field Setting
W.J. Fisk1,
D. Faulkner1, D.P. Sullivan1, C. Chao2,
M. P. Wan2, L. Zagreus3 and T. Webster3
1Indoor
Environment Department,
Lawrence
Berkeley
National Laboratory,
Berkeley
,
CA
,
USA
2Department
of Mechanical Engineering,
Hong Kong
University
of Science and Technology, Hong Kong
3Center
for the Built Environment,
University
of
California
,
Berkeley
,
CA
,
USA
Abstract
Underfloor air
distribution (UFAD) is a new method of supplying heated or cooled air
throughout a building. Reported advantages of UFAD include energy savings
and improved indoor air quality (IAQ). We measured several aspects of the
performance of a UFAD system installed in a medium-size office building.
The measured air change effectiveness was very close to unity, which is
comparable to that measured in buildings with typical overhead air
distribution. The pollutant removal efficiency for carbon dioxide was 13%
higher than expected in a space with well-mixed air, suggesting a 13%
reduction in exposures to occupant generated pollutants. The increase in
indoor air temperatures with height above the floor was only 1 to 2 oC.
This amount of thermal stratification could reduce the sensible energy
requirements for cooling of outdoor air by approximately 10%. The
occupants’ level of satisfaction with thermal conditions was well above
average and this high satisfaction rating could possibly be due, in all or
part, to the use of a UFAD system. The results of this study provide some
evidence of moderate energy and IAQ-related benefits of UFAD. Before
general conclusions are drawn, the benefits need to be confirmed in other
studies.
Key words: air
distribution, energy, pollutant removal, survey, underfloor, ventilation
efficiency.
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Contents
Editorial
Ventilation
for Better Indoor Air Quality: Yuguo
Li
and Xianting
Li
Paper 1
Ventilation
for Better Indoor Air Quality: Yuguo
Li
and Xianting
Li
Paper
2
Performance
of Underfloor Air Distribution in a Field Setting: Fisk, W. J., Faulkner,
D., Sullivan, D. P., Chao, C., Wan, M. P., Zagreus, L. and Webster, T.
Paper 3
Applying
the Local Dynamic Similarity Model and CFD for the Study of
Cross-Ventilation: Hu, C-H.,
Kurabuchi, T. and Ohba, M.
Paper
4
Levels
of Indoor Airborne Microbes Associated with Ventilation Efficiency in
Naturally-Ventilated Residences: Su, H. J., Wu, P. C. and Chien, H. P.
Paper 5
Air
Quality and Thermal Comfort in an Office with Underfloor, Mixing and
Displacement Ventilation:
Cermak, R. and Melikov, A. K.
Paper
6
Passive
Tracer Gas Measurement of the Long Term Variation of Ventilation in Three
Swedish Dwellings: Stymne, H., Emenius, G. and Boman, C. A.
Paper
7
Validation
of a CFD Model for Research into Stratum Ventilation: Lin,
Z., Chow, T. T. and Tsang, C.F.
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