how does water cooler works

Does any one educate me on how a bubble top water dispenser works?

do we always need to have the water chamber below the bottle , or a bottle inverted on a pipe which in turn is conected to a container will also work.

you could connect the bottle to a pipe, as long as the discharge end of the pipe is not sealed off to the atmosphere until the container is filled to the level desired (level with the end of the pipe). the chamber is for cooling (or not) a quantity of water before dispensing, otherwise you could just cork the bottle with a valve and invert it. the valve also needs to let in air (the bubbles you see) to replace the volume of water as it leaves the bottle to prevent a vacuum from building up, preventing the water from leaving the bottle or the plastic bottle from collapsing. this should give you a few ideas on possible alternate methods of extracting the water from the plastic bottle, inverted or not.