Proton exchange membrane fuel cell (PEMFC) is being considered as a promising power source for automotive,stationary and portable equipments because of its high power density,energy conversion efficiency and environmental benefits.To maintain polymer electrolyte membranes conductivity during the operation of fuel cell,extra water is supplied to fuel cell stack via reactant gases humidification process.However,some of PEM fuel cell powered equipments such as portable devices and uninterruptable power systems (UPS) may not comprise any external humidifier considering the cost,reliability and complexity.