Plumbed-in water coolers are available as floor mounted free-standing models, table top models or unobtrusive undersink units. All water chillers use integral electrically powered refridgeration units to chill the water, with some models also supplying unchilled water from the incoming cold mains or limited quantities of heated water for tea/coffee etc. Modern plumbed-in water chillers have many advantages over bottled water chillers, especially in higher demand situations.