CFC and HCFC refrigerants are detrimental to the breakdown of the ozone layer and the greenhouse effect. CFC is an abbreviation of chlorofluorocarbon; HCFC is an abbreviation of Hydrochlorofluorocarbon. They describe the molecules’ atom content.
A channel impeller works directly on the pumped liquid with the liquid passing through the impeller itself. A channel impeller can be described as a closed, semi-open or open impeller.