A portable, refrigerant recovery unit for transferring refrigerant from a refrigeration system to a storage tank. The recovery unit includes two, opposed piston heads rigidly attached to respective piston rods that extend along a common fixed axis. The piston rods are rigidly attached to the yoke member of a scotch yoke arrangement. In operation, incoming refrigerant from the system is simultaneously and continuously directed to the opposing piston heads wherein the forces of the pressurized refrigerant on them counterbalance or neutralize one another. The recovery unit also has a cooling fan driven by the motor for driving the scotch yoke in which the fan is driven through a step up gearing arrangement. In operation, the drive shaft of the motor is rotated at a first rate and the driven shaft of the fan is driven at a greater rate (e.g., twice the first rate) by the step up gearing arrangement.

The refrigerant management system has a service port connection, refrigerant treatment elements and a wet circuit connecting the service port connection to the refrigerant treatment elements. The refrigerant treatment elements are comprised of a refrigerant filter, a compressor, a condenser coil and a tank. The tank has tank head manifolds mounted thereto. The filter, the compressor and the condenser coil being mounted to the tank and connected to the tank head manifolds by respective pairs of tubing. The wet circuit being partially incorporated inside the tank head manifolds and inside the tank between the tank head manifolds. The first tank head manifold connects the service port connection to the refrigerant filter. The second tank head manifold connects the compressor to the condenser coil and to the tank. Conduits inside the tank extending between the first and second tank head manifolds connect the refrigerant filter to the compressor.