jailcd2015002: Factors Affecting Dewing of Radiant Air Conditioning System and DOAS

Abstract

Dewing is often regarded as a stumbling block of capillary tube radiant cooling air conditioning systems’ widespread application even though the system is comfortable, energy saving and noiseless. Some people try to solve the problem by pre-dehumidification using DOAS (Dedicated Outdoor Air System). So in order to clear up the factors influencing the dewing during the operation of fresh air and thus calculate the pre-dehumidification time, this paper analyzes the factors influencing the indoor dew point temperature based the moisture balance model, and found it includes outdoor temperature and relative humidity, air changes through windows and doors, number of occupants, fresh air volume, room volume and capillary tube supply water temperature. Then relation between every factor and indoor dew point is analyzed. After that a multiple regression formula is obtained, which can comprehensively reflect the influence of various factors on dew temperature point; Correlation between radiation surface temperature and capillary tube supply water temperature is got by FLUENT. At last, a multiple linear regression formula which can calculate pre-dehumidification time is obtained, which even though cannot cover all cases, it can provide some support for capillary tube air conditioning system design.