The integration of technical services in architecture played a crucial role in the history of post-war construction. The Centre Pompidou, conceived and realized between 1971 and 1977 by the architecture studio Piano and Rogers and the engineering firm Ove Arup and Partners, is an excellent example in this regard. Instead of reverting to traditional solutions such as service areas or suspended ceilings, Piano and Rogers chose to exhibit all the services of the building – from the air conditioning ducts to the movement system of people and goods – both in the interiors and exteriors. Exiled outside the envelope and placed within the “three dimensional walls” of the building, or rather clipped onto them, the Centre Beaubourg services were designed to serve the principle of “the maximum flexibility of use”. During the design process the refinement of these elements and the surrender to the pioneering audiovisual screens intended to animate the Centre’s main facades, created an unprecedented aesthetic value. Initially conceived as simple functional tools, the Centre Beaubourg services became symbolic and didactic devices designed to make the building a man-scale machine, both joyful and understandable. This paper focuses on one of the Centre Beaubourg main services, the air conditioning system, and aims to retrace the genesis and evolution of this element thorough all the phases of the design process, from the first ideas animating the preparation of the competition’s proposal to the prefabrication of the built solution.