|
The
International Journal of Ventilation
Volume 3 No 2 September 2004:
Paper 2: Robustness of Air Distribution in Plenum-Based Ductless
Ventilation Systems
Yuguo Li1, Mats Sandberg2
and Sam Hui3
1Department
of Mechanical Engineering, the University of Hong Kong,
Hong Kong SAR, China
2Centre
for Built Environment, Division of Indoor Environment Ventilation, KTH Research
School
and the University of Gävle, Gävle, Sweden
3Department
of Architecture, The University of Hong Kong,
Hong Kong SAR, China
Abstract
This paper introduces a concept of robustness of an air
distribution method, which is defined as being capable of meeting the
ventilation requirements during varying operational conditions. The robustness
performance may be particularly important when the system allows individual
control of the supply air parameters. As a preliminary example, plenum-based
(ductless) air distribution methods are studied using computational fluid
dynamics. Among the four basic air distribution methods in plenum-based systems,
it is found that the floor supply and ceiling return system does not always
produce the conventional displacement ventilation system performance when the
heat sources are not concentrated. The
ceiling supply with ceiling return produces the best robustness performance over
a wide range of supply velocities.
Key words:
Robustness, air distribution, ventilation effectiveness, ductless
ventilation, underfloor plenum, mechanical ventilation.
|
|
