The ULT cold room is designed to operate at the following:
Lobby -25°C +/-5°C
Main chamber -70°C +/-5°C
The chamber takes circa 72 hours to reduce the storage temperature from ambient (typically 22°C) to -70°C, with no thermal load being present. Once the chamber has reached the operating set point of -70°C, it will remain at a minimum of -25°C.
Product to be stored in the main chamber at -70°C, should be a minimum of -25°C prior to being loaded into the main chamber.
The ULT cold room includes a dual, ‘cascade’ refrigeration operating system, which provides 100% redundancy. Each refrigeration ‘pack’ measures circa 2.5 metres high x 3.0 metres wide x 1.5 metres deep.
The refrigeration pack systems may be located internally or externally, but require to be as close to the room as possible to keep the refrigerant pipework to the absolute minimum. The refrigerant gas charge must also be kept to the absolute minimum. (The closer the better)