A method of cooling an operative surface of a cryoablation device, comprises the steps of providing a primary refrigerant under pressure and pre-cooling the primary refrigerant to a temperature below a critical temperature thereof using a non-charging refrigeration system to liquify the refrigerant in combination with the steps of expanding the pre-cooled primary refrigerant in proximity to an operative surface of the cryoablation device and removing the expanded primary refrigerant from the proximity of the operative surface. An apparatus for cooling an operative surface of a cryoablation device, comprises a primary refrigeration system supplying primary refrigerant to the device, the primary refrigeration system including an expansion chamber adjacent to an operative surface of the device, the primary refrigerant being expanded into the expansion chamber to cool the operative surface and a second refrigeration system to pre-cool the primary refrigerant before it reaches the expansion device, the second refrigeration system being a non-charging refrigeration system in combination with a heat exchanger coupling the primary and second refrigeration systems to one another in a heat exchange relationship.