This paper describes an experimental study of an ejector refrigeration cycle using R11 as the working fluid. The system was tested with boiler temperature from 100 to 110 degreesC, the condenser temperature from 35 to 41 degreesC, and the evaporator temperature up to 12 degreesC. Two different mixing chambers with throat diameter of 8 mm were used. Choking of the fluid was always found in the first mixing chamber, but not in the second one. The system was more flexible to operate when there was no choking in the mixing chamber. A cooling temperature as low as - 5 degreesC could be obtained with COP between 0.1 and 0.25 and cooling capacity between 500 and 1700 W. Copyright (C) 2001 John Wiley & Sons, Ltd.