Experimental Study on Dehumidification Performance of a Vacuum-Based Membrane Dehumidifier

Abstract

Dehumidification performance in HVAC systems for decoupled air conditioning becomes more important as the airtightness and insulation in buildings increases. The vacuum-based membrane dehumidifier (VMD), which creates a partial vapor gradient between membrane layers using a vacuum pump, has high energy saving potential when employed for isothermal dehumidification. Most previous studies have focused on evaluating the dehumidification and energy performance of vacuum-based membrane dehumidifiers with theoretical or numerical analysis. Experimental studies on vacuum-based membrane dehumidifiers with various air conditions are very rare for HVAC systems. In this study, we fabricated a prototype of a vacuum-based membrane dehumidifier made of a hollow fiber membrane and evaluated its dehumidification performance in terms of various air conditions (i.e., inlet air temperature, inlet air humidity ratio, inlet air velocity, and vacuum pump pressure). The experimental results showed that the main parameters affecting the dehumidification performance were the vacuum pump pressure and the inlet air velocity. Furthermore, a regression model based on a statistical analysis was derived using the Design-Expert program. The prediction model showed an R2value of 95.4% compared with the experimental data.