A water cooler with a dispenser is a common product found in offices, hospitals, schools and homes. The water cooler offers an alternative to individual water bottles in the home and provides a sanitary water supply for large groups. While all water coolers provide chilled water, some models also provide both hot and cold water. Some models even provide water hot enough to use in soups or other instant foods. Aside from units that offer hot water, there are two main types of water coolers. Both bottled water coolers and bottleless water coolers provide a chilled water supply, but receive the water from a different source. Bottled water coolers are freestanding units that use a large plastic bottle to deliver water, and can be either bottom- or top-loaded. Bottleless water coolers hook up to the main water supply and utilize filtration services to provide clean, crisp-tasting water. Both types of water coolers have an on/off switch that controls the cooling and/or heating functions of the dispenser.
Cooling the Water
In order to chill the water prior to dispensation, water coolers have a reservoir within the dispenser that holds a set amount of water. The reservoir is the place where the water is chilled by a refrigerant, or through thermoelectricity. Water coolers using a refrigerant use a compressor within the machine to work with a refrigerant such as Freon. This chemical has the ability to absorb heat, which cools the water within the reservoir. When the refrigerant passes through the water cooler system, it is compressed and evaporates into a gas. The gas absorbs the heat surrounding the reservoir, which cools the water within the reservoir. As people dispense water, the machine will refill the reservoir and the process begins again. Should the water reservoir empty completely during dispensing, it will take a few minutes before the water cooler chills the water to a low temperature.
Water coolers using thermoelectricity to chill the water operate using a method of cooling based on the Peltier effect. The Peltier effect occurs when electric current passes from one material to another, such as a ceramic or metal wafer. As the current passes from one side to another, the heated energy absorbs into the conductive material. This effect results in the cooling of the water in the reservoir. Thermoelectric coolers in hot locations will not cool down as quickly as coolers that use a compressor system.