During mixing or filling, the undesired result of excessive aeration of a mixture.
A potential problem, occuring during rapid coolant filling operations as at the OEM factory. Foaming can lead to underfill situations and air entrainment. All good coolants will contain anti-foam agents as part of their add pack to eliminate foaming tencencies
Formation of foam in an oil-refrigerant mixture due to rapid evaporation of liquid refrigerant dissolved in the oil.