Water, or H₂O, is commonly used as a refrigerant. Water is a natural and reusable source. Water as a refrigerant is also economically cheaper then chemical refrigerants. It is also more environmentally friendly. Chemical refrigerants can pollute the environment and atmosphere. Chemical refrigerants take longer to break down and cause toxic waste buildup, if they are not disposed of properly.
Water is great for direct contact heat exchangers which functions utilizing two streams. The inlet stream provides cool water to the heat exchanger, while the outlet stream carries hot water away from the exchanger to the cooling tower. These ease the process of heat exchange between two fluids. One advantage of using water as a refrigerant in a direct contact heat exchanger is the lack of corrosion that will occur. Because the two streams are the same material, corrosion/contamination is reduced. Another advantage of using water as a refrigerant is the heat transfer temperature is lower compared to a glycol and water mix. Water as a refrigerant is available for all cooling applications.