Recently, membrane-based vacuum air dehumidification (MVD) systems have been studied as an advanced cooling scheme. In general, the working principle of these systems is based on the separation of water vapor from air caused by a vapor pressure gradient between the feed and permeate side of a membrane when humid air passes over the membrane. After permeating, the vapor is discharged to the atmosphere through a vacuum compressor or pump. Several types of MVD systems with different operation drivers have been introduced recently, but the comparative analyses with the working properties were limited. In this study, three promising MVD systems of the sweep air mixed (S-MVD) type, water vapor discharge (W-MVD) type, and condenser combined (C-MVD) type, are analyzed comparatively with an idealized membrane with infinite selectivity on H2O. From the simulation, the W-MVD system exhibited the best dehumidification performance because of the lowest compression ratio and water vapor flow rate. However, the C-MVD system, which is relatively simple to implement, practically exhibited better performance under limited conditions of a hot and humid climate. After the comparison of the three MVD systems, the applicability of each MVD system for different climates was discussed in detail.
