How air conditioning works The essential ingredients in an air conditioning system are a fan to blow air around, a cold surface to cool and dehumidify the air, a warm surface and a source of water vapour. In a large system there will also be a tangle of tubes to distribute the air and collect it again. This means that the air is cooled more than is necessary for temperature control, so that it must be heated again afterwards.
Air conditioning wastes energy.
It also wastes space, because air has to be pumped around in quite large tubes, so that it doesn't make a rushing noise. It does, nevertheless, generate a disturbing background noise if the room is otherwise quiet. The origin of this technological epidemic is not the subject of this article. Modern museums, and old ones as well, are showpieces designed to be admired for bold and original architecture. They tend to be massive, and those old museums which originally had courtyards to give light and air are now glassed over with domes and atria.