How Does a Water Cooler Work?

By Peter Brooks

Every water cooler, including both bottled and mains (plumbed in) water coolers, has a reservoir inside the casing that holds water. This reservoir is where the water is cooled prior to being dispensed.

The reservoir is kept topped up either from a large plastic water bottle, or from a water mains supply.

Mains, or plumbed in, water coolers often have a water filter between the incoming water supply and the reservoir to improve the quality of the water.

Once the water is in the reservoir it's time to cool the water.

There are two main ways of cooling the water: using a refrigerant or using thermoelectricity. 

The refrigerant system works in almost exactly the same way as your fridge at home. A compressor compresses a gas, this causes the temperature of the gas to rise, the gas is then passed to a condenser where the heat from the gas dissipates and the gas cools down until it becomes a liquid. Once the gas is cold it is forced through an expansion valve which causes it to drop in pressure and become even colder. At this point the gas is present in the evaporator which absorbs the heat from the water held in the reservoir. This then heats the refrigerant which then starts the cycle again. The cycle is kept going using electricity to drive a pump.

The thermoelectric method of cooling the water relies on the Peltier effect a Peltier device uses a thermoelectic effect, this means that when electricity passes through the Peltier device heat is transported from one side of the device to the other. This results in cooling on one side of the device and this is used to cool the water inside your water cooler.

Once the water is cold it's ready to be dispensed. The tap on the front of the water cooler releases a valve connected to the cold water reservoir which allows the water to flow into your cup.

In a bottled water cooler, the reduction in water level within the reservoir triggers another valve which allows more water into the reservoir ensuring the reservoir is always full.

You may have noticed that if you dispense too much water from the water cooler the water comes out warm. This happens when you have emptied the reservoir because it takes some time for the fresh water to be cooled within the reservoir.

© 2018 Office Water Coolers

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