Despite the advance of modern technology and electricity, modern machines still need a kind of cooling system to prevent them from heating something that can lead to a meltdown of component and a failure of the said machine. Take for example machines like computers which are the most advanced currently and are even used to drive other larger machines including launching rockets. If the computer cpu is not cooled it will lead to overheating of cpu components and failure of the computer including damage to hard drives which can lead to information loss. The cpu cooling system employ an inbuilt fan system, although some computers have more sophisticated computer cooling system.
Some systems employ water cooling systems while other use liquid cooling systems. It all depends on the type of machines to be cooled. A machine that runs on electricity will probably not be cooled using water but cold air. Some types of liquid cooling system include water cooling systems. Where water is used to cool down machines there should be is no danger of reaction with electricity.
The same technology is employed to develop home cooling system to keep homes cool in the summer. The heating and cooling systems installed in homes can function as cooling as well as heating systems. The heating and cooling system is equipped with metal grill which can be heated and a fan is used to push out warm air and warm up the building or home. To cool the home or building the fans circulate and pull out warm air from condenses it and blow back cold air.