| 摘要 |
From a plurality of preset operation modes, an optimal mode is selected to let the supply air 206 attain a predetermined temperature and humidity. Upon adjusting the opening degrees of dampers 116 - 119, a cold water valve 156 and a humidifying water valve 154, the system measures the outside air 201, supply air 206 and return air 207 for temperature and humidity to see if a mode boundary is exceeded. If the boundary is exceeded, an assessment time is set. The humidity of the supply air 206 in the mode in effect before the boundary is exceeded is further predicted so as to determine whether the predicted value exceeds the upper limit of a tolerable humidity range or drops below the lower limit thereof. If the limit is exceeded, the operation mode is changed immediately. If the mode in effect before the boundary is exceeded is never resumed upon elapse of the assessment time, the mode is changed. If the mode in effect before the boundary is exceeded is resumed at least once, the mode is not changed. This make it possible to provide an air-side free cooling system which, if outside humidity abruptly changes, controls an air handling unit to prevent the humidity of supply air into the interior from suddenly fluctuating so as to optimize the indoor environment. |
