A test bed has been designed and constructed for measurement of air flow rate, and Ventilation Efficiency Ratio (VER) of residential exhaust fans. The test bed can provide accurate measurement of air flow rate, fan energy efficiency, and other air flow parameters. The test bed described here will also be useful for improvement of design of residential exhaust fans constructed in the country. Presently, the test bed is being used in an on going project for compilation of standards for consumption and energy labeling of fans in Iran.