الفهرس 
ABSTRACT
Motivations and BackgroundOnly 14 pages are availabe for public view
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Abstract
Using false ceilings (FC) for decoration and covering different ducts in modern buildings is spreading so much nowadays. This study was conducted to introduce new benefits of false ceiling (FC) in reducing the roof heat gain. So, a one- dimensional transient mathematical model has been developed for this purpose.
A controlled temperature space of dimensions 4 m×3 m×3 m with a flat concrete roof of thickness 0.12m has been considered throughout the study. The effects of parameters such as: distance between false ceiling and concrete roof (air gap height), using ventilation with FC and pasting reflector sheet on the upper side of FC facing the concrete roof on the roof cooling load are studied. Modeling and solving the transient heat transfer processes in the different components of the space has been conducted.
The results showed that using of false ceiling (FC) only with gap height of 0.6m reduces the maximum thermal load (design load of air conditioning unit) by 73.3% and the saving in total energy consumption is 68 % per day. The effect of changing the air gap height has been studied and the results showed that increasing the air gap height (H) from 0.3 m to 0.6 m decreased the maximum load by 21%. While increasing the air gap height to 0.9 m decreased the maximum roof load by 36%. Using Ventilation in the air gap between FC and concrete roof reduced the maximum load by 5.1% of that when using FC only and the reduction in total energy consumed per day is 11.5% of that when using FC only. Finally, using reflector sheet pasted on FC reduces the maximum roof load by 50.5% of that when using FC only and the saving in total energy consumption per day is 53% of that when using FC only.