The moisture content distribution of a room with radiant ceiling cooling and wall-attached jet system

Radiant ceiling cooling is a comfortable and energy saving air conditioning system, but condensation on the panels limits its application. The moisture distribution of a radiant cooling room is one of the key factors affecting the condensation of radiant panels. This paper uses a simulation model validated by experimental data to investigate the influence of wall-attached jets on the moisture content distribution of a room with radiant cooling. The influence of diffuser types and air velocities on the moisture content distribution is analyzed in the pre-dehumidification stage. This paper also studies the moisture content distribution and dew point temperature variation of the attached air layer with the cooling system operating with and without pre-dehumidification. The results show that a linear diffuser has a better attach effect, and the moisture content distribution is more uniform. The time it takes to reduce the moisture content to the design value of different diffusers is similar, approximately 25 min. With increasing air velocity and decreasing linear diffuser length, the non-uniformity coefficient (NUC) of the moisture content distribution increases and the pre-dehumidification time becomes longer. When the radiant cooling system operates without pre-dehumidification, the attached layer moisture content is high at the beginning, which may cause condensation in the first 7 min. Pre-dehumidification can decrease the moisture content and dew point temperature and effectively prevent condensation.