In this study, a membrane liquid desiccant air conditioning (M-LDAC) system is modeled using the TRN-SYS building energy simulation software. Liquid-to-air membrane energy exchangers (LAMEEs) are used as a dehumidifier and regenerator in the proposed M-LDAC system to eliminate the carryover of desiccant droplets in supply and exhaust air streams, which may occur when direct-contact conditioners are used. A sensitivity study on the sensible, latent and total effectivenesses of the LAMEEs is performed under 36 operating and design conditions. The technical, environmental and economic performances of the proposed M-LDAC system are evaluated, and compared to those of a conventional air conditioning (CAC) system. The influences of installing an energy recovery ventilator (ERV) under balanced and unbalanced airflow rates conditions are investigated. Results show that the annual primary energy consumption and the life cycle cost (LCC) of the proposed M-LDAC system are 19% and 12% lower than that of the CAC system, and they reach 32% and 21% when an ERV, which operates under balanced airflow rates, is installed in the M-LDAC system. (C) 2013 Elsevier Ltd. All rights reserved.