This paper reports the results of an experimental investigation on a pilot compression chiller working with R407C and R410A as R22 alternatives using compact heat exchanger. Experiments are conducted and the influences of the cooling water mass flow rate (200-2500 kg/h), cooling water inlet temperature (20-45 degrees C) and chilled water mass flow rate (200-1500 kg/h) on performance characteristics of chillers are evaluated for R22, R407C and R410A. Increasing the cooling water mass flow rate or decreasing its inlet temperature causes the operating pressures and electric input power to decrease while the cooling capacity and coefficient of performance (COP) increase. The pressure ratio is reduced while actual loads and COP are increased with the chilled water mass flow rate. The effect of cooling water inlet temperature on the system performance is more significant than the effects of cooling and chilled water mass flow rates. Comparison between R22, R407C and R410A under identical operating conditions has been done. An enhancement is obtained when using compact heat exchanger than shell and tube heat exchanger, this enhancement is about 8.5% in the coefficient of performance. (C) 2012 Elsevier Ltd. All rights reserved.