Concern’s Experts at carrying out civil work use the technology of artificial freezing of soils – creation of an artificial stable and water-proof layer of any form from a frozen soil which interferes the penetration of underground water or watered unstable soils into a foundation pit. For freezing-up, the freezing columns connected to a refrigerating station are lowered on foundation pit’s perimeter into the thickness of water-bearing soils. The coolant is circulating in pipes and columns. In the course of heat exchange the soil temperature is gradually decreasing to a full freezing. As a result, there the uniform and self-contained mass of frozen soil is formed around the foundation pit. The refrigerating station is active throughout the whole period of construction. Ammonia, sometimes freon or liquid nitrogen is more often used as a coolant in the refrigerating stations.