Climate control of office buildings involves using technology which is as energy-efficient and cost-efficient as possible, so as to realise the best possible indoor air quality and comfort at the workplace. Decentralised instead of centralised: In recent years, non-residential buildings have increasingly been equipped with ventilation systems integrated into the exterior wall, rather than with centralised heating and air conditioning systems. The air is no longer channelled and conditioned centrally, but rather decentrally, by means of separate devices in each room. As these new ventilation systems, integrated into the exterior wall or floor, can be controlled individually, they can be adjusted precisely to suit the operational requirements, as well as the employees' heat and comfort requirements.

To find out how the decentralised systems perform in practice, how they affect efficiency and what savings they entail in various buildings, was the goal of a research project, in which the Steinbeis Research Centre for Energy, Building and Solar Technology analysed 16 buildings with decentralised ventilation devices, with regard to thermal comfort and energy consumption. This project was sponsored by the German Federal Ministry of Economics and Technology (BMWi), the Heinz Trox Foundation and the Forschungsvereinigung für Luft- und Trocknungstechnik (FLT). It is part of the research area of Energy-oriented operation optimisation (EnBop), in which innovative non-residential buildings are examined, with the objective of optimising building operations and demonstrating exemplary possible improvements which can also be implemented in other buildings.

In this project, researchers investigated ten of the sixteen buildings in more detail, on the basis of invoices for energy costs and site audits. They obtained general information on the buildings and on how the decentralised ventilation devices were integrated into the building and energy concept. In an accompanying survey of occupants and operators, they also asked the operators for their opinions regarding the reliability, maintenance and operation of the devices, as well as obtaining feedback from the occupants. The goal was to identify possible improvements relevant to other projects, particularly with regard to energy requirements, costs and comfort-related criteria such as air quality, draughts, acoustics and ease of operation.