The low temperature chamber is a large cryogenic or high-cryogenic test device, which usually separates the refrigerator from the test part and makes the test part into a room type, so the staff can work in it. Such a test room is called a low temperature chamber.

The low temperature chamber usually adopts brick-wood structure or concrete structure, or steel structure, and its insulation layer is generally laid on the indoor side.

Low temperature environment will have a negative impact on the performance and reliability of machinery, vehicles, weapons, electronics and other equipment. It is the basic requirement for all kinds of ground equipment to be able to adapt to the low temperature environment that may occur in the use area. Before the development and finalization of all kinds of equipment, it is necessary to carry out low-temperature environmental test to test its adaptability to low-temperature environment.

The environmental laboratory is different from the environmental laboratory. It usually carries out the whole machine test, so its space is usually large, especially the large and medium-sized low temperature environment chamber. It must simulate the low temperature environment of – 60 ~50 C in a large space, so its investment and energy consumption are very large.

Cooling time is a basic parameter requirement of environment room. It is directly related to the installed capacity and investment of refrigeration system. Cooling time is shortened and the capacity and investment of refrigeration equipment will increase. In order to shorten the test preparation time, users often set a shorter cooling time. For large and medium-sized environment rooms, this will increase the investment of refrigeration system. How to reasonably determine the cooling time of cryogenic test is an urgent problem to be solved in the design of low temperature environment chamber.