"STUDY ON HIGHLY EFFICIENT VENTILATION SYSTEM BY USING VENTILATION TOWER : Part 1 Evaluation of age of air by the full-scale experiment

The full-scale experiment was carried out to know advantage of a highly efficient ventilation and air-conditioning system we proposed. In this system, the fresh air is directly supplied to the breathing zone by using the ventilation tower (VTS: the ventilation tower system), considering the efficient distribution of fresh air in a room. The comparison and the examination were carried out on different ventilation and air-conditioning systems. (1) The age of air at the breathing point (5cm ahead from the mouth of occupant, 0.6m from the outlet of the ventilation tower) of VTS is about 60% shorter than that of the ventilation system of mixing the fresh air with the return air from the room in the air-handling unit (MS: the mixing system). (2) The age of air at the breathing point, around the occupant and in the room space does not change significantly, even if the supplement of fresh air from the ventilation tower is reduced from about 30 (m^3/h・person) to about 20 (m^3/h・person). (3) The concentration of the contaminant at the breathing point of VTS is about 70% smaller than that of MS