The working mechanism of water dispensers cum coolers.

Well i an talking about those machines , made by various manufacturers such as carrier, bluestar and usha.

these machines have a provision by which a water tank (commercially available) can be inverted on the top of it.

they then have three valves for dispensing the water at different temperatures, hot , cold, and normal.

the normal water valve is directly connected to the tank outlet.

now how do the other two valves, provide the temperatures ?

from what i feel, a refrigeration system is present within the machine. while the cold water valve is connected to the contents of the evaporator section, then the hot water valve is connected to that section where the removed heat gets rejected.

Is this so ? or do they have a seperate heating coil for the hot water valve.