Unit 3
Alkylbenzene|A type of synthetic hydrocarbon oil that is compatible with mineral oil but has better oil return properties. It is widely used in low-temperature applications. it is not compatible with synthetic oils.
Azeotrope|A blended refrigerant that behaves like a pure refrigerant. The refrigerant evaporates and condenses at one give pressure and temperature. From the technician's standpoint, working with an azeotropic blend is like working with a pure refrigerant compound.
Binary blend|A blended refrigerant consisting of two refrigerants.
Bubble point|The point at which refrigerant starts evaporating when heat is added to a zeotropic refrigerant. It is also the point that refrigerant finishes condensing when heat is removed from the refrigerant. See dew point.
Chlorofluorocarbon(CFC)|The most dangerous refrigerants to the environment since they contain more chlorine atoms in their structure. Production of CFCs in the United States ended in 1995.
Compound|A substance made up of different elements. A refrigerant that is not a blend is a compound.
Dew point|The point at which refrigerant stops evaporating when heat is added to a zero-tropic refrigerant. It is also the point that refrigerant starts condensing when heat is removed from the refrigerant. See bubble point.
Dielectric strength|The ability of refrigerant oil or any material to resist breaking down in the presence of voltage.
Flash point|The temperature at which heated oil vapors burst into flame. It is a measure of the flammability of the lubricant. Ideally, compressor lubricant oils should have a high flash point for safety reasons. The temperature at which oil gives off ignitable vapors.
Floc point|The temperature at which a 90/10 mixture of oil/refrigerant forms a cloudy or flocculent precipitate of wax in the mixture.
Fractionation|A process in which the component refrigerants of a blended refrigerant boil off into a vapor state at different temperatures.
Glide|The temperature range in which a zeo-tropic refrigerant blend evaporates and condenses.
Global Warming Potential(GWP)|A measure of a substance's ability to contribute to global warming that is expressed as a number. The higher the number, the greater the warming potential.
Greenhouse effect|An effect in which atmospheric gases such as carbon monoxide trap solar heat in the atmosphere in the same way that a greenhouse captures and holds solar heat.
Halogen|A class of elements that include cholorine and fluorine that are used in the manufacture of refrigerants. A fully halogenated refrigerant is one in which all hydrogen atoms of a hydrocarbon molecule are replaced by halogen atoms.
Hydrocarbon|A compound composed only of carbon and hydrogen atoms. When some or all of the hydrogen atoms in a hydrocarbon are combined with a halogen such as chlorine or fluorine, the end result is a compound known as a halogenated hydrocarbon or halocarbon. Most common refrigerants are halocarbons.
Hydrogenated chlorofluorocarbon(HCFC)|A refrigerant that contain chlorines atoms in its structure, but fewer than found in CFCs. They are kinder to the environment than CFCs, allowing them to be phased out over a longer period of time. By 2030, all HCFC refrigerants will no longer be manufactured.