Warm air supply temperatures
Air density is inversely proportional to absolute temperature (see section 2.5). As a consequence, if the temperature difference between the warm supply air and the air in the room is too large bundle will occur. The air layer near the ceiling, will be higher than the temperature of the air and under the heat loss conditions, and the air in the occupied part of the room will be cool, uncomfortable. This puts an upper limit supply air temperature, when it is used to compensate for the heat loss in winter. Although the supply air temperatures above 60C were used in the past, with direct-fired warm air heaters, these were of high discharge, air speed (10 m s"1) from the supply openings were for industrial applications.
Recommended for comfort air conditioning in commercial applications, the maximum supply air temperature should not normally exceed 35C at room temperature of approximately 20C. the absolute limit should be 40C. risk stratification becomes worse if the person speed supply grille is low, and if the extract and recirculation grille are at a high level.
Large floor-to-ceiling height with the filing of the lattice at high level, increase the chances of cold discomfort from unwanted stratification. The consequence of this is that the achievement of increased heating power in the preheating time periods intermittently operated systems is not always easy, when warm air is used, supplied at a high level...
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Air-Conditioning