A water cooler or water dispenser is a device that cools and dispenses water. They are generally broken up in two categories: bottleless and bottled water coolers. Bottleless water coolers are hooked up to a water supply, while bottled water coolers require delivery (or self-pick-up) of water in large bottles from vendors.

Water cooler may also refer to a primitive device for keeping water cool.

Dispenser types

Wall-mounted

The wall-mounted type is connected to the building's water supply for a continuous supply of water and electricity to run a refrigeration unit to cool the incoming water, and to the building's waste disposal system to dispose of unused water.

In the standard wall-mounted cooler, also commonly referred to as a water fountain or drinking fountain, a small tank in the machine holds chilled water so the user does not have to wait for chilled water. Water is delivered by turning or pressing a button on a spring-loaded valve located on the top of the unit, that turns off the water when released. Some devices also offer a large button on the front or side. Newer machines may not have a button at all; instead a sensor that detects when someone is near and activates the water. Water is delivered in a stream that arches up, allowing the user to drink directly from the top of the stream of water. These devices usually dispense water directly from the municipal water supply, without treatment or filtering.