A modular refrigeration unit for use in a refrigeration cabinet has a condenser assembly, an evaporator assembly, and a bulkhead assembly positioned between the condenser assembly and the evaporator assembly. The refrigeration cabinet includes a condenser chamber and an insulated main chamber and mating surfaces defining an opening there between. The modular refrigeration unit includes a gasket assembly coupled to a periphery of the bulkhead assembly. The gasket assembly includes one vane mounted on a thermal breaker and engageable with the mating surfaces to form a substantially air-tight seal between the condenser chamber and the main chamber. The modular refrigeration unit is adapted for movement substantially transverse to the bulkhead assembly to engage the vane with the mating surfaces to form the substantially air-tight seal.