A modular
thermoelectric cooling / heating unit is installed through an opening in a wall separating first and second temperature zones. This modular
thermoelectric cooling / heating unit comprises a thermoelectric device including a cold surface, a hot surface, and a cooling / heating member between an electrical power supply and the cold and hot surfaces. A
heat conducting block has a proximal end for thermally contacting with a first one of the cold and hot surfaces, and a distal end. A first heatsink thermally contacts with a second one of the cold and hot surfaces, a second heatsink thermally contacts with the distal end of the
heat conducting block, and a thermally insulated housing covers at least a portion of the
heat conducting block between the proximal and distal ends of this block. In operation, the first heatsink is located in the first temperature zone, at least a portion of the heat conducting block and the thermally insulated housing extend through the wall opening, and the second heatsink is located in the second temperature zone. The above described modular
thermoelectric cooling / heating unit can be used in a modular cooling
system for retrofit into an existing
refrigeration unit.