This paper presents the results of testing of des/ccant materials and dehumidifier matrices for desiccant cooling and dehumidification applications. In testing desiccant materials, we used a gravimetric technique to measure the moisture capacity of four desiccant materials, These materials were microporous silica gel powder, macroporous silica gel powder, polystyrene sulfonic acid sodium salt, and a silica-gel-epoxy composite, The microporous silica gel powder had the most desirable moisture capacity properties of the four materials tested for desiccant cooling applicationsl The polystyrene sulfonic acid sodium salt showed some promise, Our testing of dehumidifier matrices included measuring the pressure drop and heat and mass transfer rate characteristics of a silica-gel/corrugated dehumidifier matrix under conditions typical of desic: cant cooling systems. The matrix is a section of a commercial dehumidifier. The transient dehumidification capacity of the matrix was calculated from the tests and compared with previously tested matrices.