Abstract
Recently, a lower type free-access floor system which realizes improved ease of walking and less sense of confinement has been attracting attention. However, it is known that the lower the design of the air supply chamber, the larger the non-uniformity of the supplied air velocity at each diffuser and the greater the deterioration in room temperature distribution. In this report, an analytical model is proposed for predicting the non-uniformity of supplied air velocity at the design stage. The validity of the analytical model was confirmed by the good-coincidence of results obtained in scale model tests. It was found that the limit of the floor height at which a uniform supplied air velocity is obtained was 50 mm. Moreover, a relation was found whereby the inverse of coefficient of resistance at a diffuser up to a value of 1 is proportional to the maximum non-uniformity. This indicates the possibility that design work aimed at constructing a pressurized type under floor air-conditioning system with a uniform supplied air velocity profile may be readily performed from parameters of the coefficient of resistance at a diffuser by utilizing this relation.
