الفهرس 
Introduction and Literature SurveyOnly 14 pages are availabe for public view
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Abstract
he present study is directed toward investigating experimentally the room air distribution behaviour, and the influence of the governing parameters on air flow pattern. Also, air diffusion system performance for a certain type
of openings is evaluated. Moreover, conditioned air
characteristics in the occupied zone are studied to have better insight into the effective parameters contributing in comfort conditions.
A central air conditioning plant has been designed and constructed in order to supply the required conditioned air to a psychrometric test chamber through different ventilating
openings. Only one opening is used for each experiment
whereas others are tightly closed. All openings have the
same aspect ratio (3:1), but at different locations from the
ceiling. The ratio of supply opening width to room width is
1:3.
Temperature distribution measurements throughout the
psychrometric test chamber were carried out using thermocouples
xiv
of type K. Also, velocity distributions were measured using the constant temperature anemometer, CTA.
The experimental results were analyzed to illustrate the nature of the flow inside the conditioned space. The influences of the governing parameters, such as Reynolds and Archimedes numbers and relative humidity, on both comfort index, ADPI, and ventilation efficiency, e, have been studied
for free space with no obstacles at no load. Results of the study show that high velocities in the chamber occur in the vicinity of surfaces, and the maximum velocity in the occupied zone is close to the floor at distance about 0.7 of the chamber
length from the air outlet. Also, the results indicate that ADPI is profoundly affected by inlet air flow rate more than the temperature difference between supply and room air, whereas ventilation efficiency depends more strongly on the
Archimedes number than Reynolds number. The results also show
that the supply opening located near the ceiling is optimum
for both comfort index, ADPI and ventilation efficiency. It
can be used adequately to supply and distribute the required
conditioned air flow rate. Moreover, results illustrate that there is an optimal value of relative humidity relevant to both the supply air temperature and velocity which achieves highly
rated comfort conditions. Comfort humidity is in the range of
50-60% for conditioned air supplied at temperature of 25°c and
velocity of 2 m/s. Also, the same range of humidity gives the
highest value of ventilation efficiency.