Salt (NaCI) or calcium chloride (CaCI) added to water raises the temperature at which water will boil and lowers the temperature at which it will freeze. Some refrigeration and air conditioning applications require that the water be kept from freezing at temperatures considerably below the freezing temperature of 32 degrees. Also some heating and air conditioning applications require that water at atmospheric pressure be kept from boiling at temperatures above 212 degrees. There are some refrigerating and air conditioning installations which use tap water without the addition of any salt or other substance. Such water is referred to as "sweet water" as compared to brine.
