Ultra low temperature split door freezer

摘要

An upright split door, ultra low temperature freezer which includes a single chamber cooled by a cold wall refrigeration system and accessible by separate upper and lower doors. The refrigeration system maintains the chamber at a substantially constant, ultra low temperature, such as within the range of about -50° C. to -90° C. Short term items may be stored in and accessed from an upper portion of the chamber by the upper door without causing the very cold air in the freezer chamber from spilling out the lower portion of the chamber. Long term items may be stored in the lower portion of the chamber and accessed by the lower door. A horizontal mullion is mounted to the freezer side walls and extends between the two doors to provide a seal for respective lower and upper edges of the two doors. A self-regulating heater strip is disposed within the mullion between upper and lower resilient sealing bulbs extending horizontally to prevent condensation build up in the mullion area.