Modern office buildings are smaller, new considerations for the modern office include flexible room layout and effective thermal mass storage. Modern architecture uses more glass for external walling, which increases the solar gains. The thermal load in the area is also substantially increased by the technology used in the modern office. Bearing this in mind the critical comfort requirements of air quality and space temperature can only be achieved in new buildings by employing the latest air conditioning technology. At the same time there is also pressure for cost reduction imposed by rising energy prices and government controls to limit primary energy consumption.

Due to the changing requirements a trend in space and building air conditioning is to have decentralised air conditioning or partial conditioning. These approaches, which have been developed in the last few years, provide solutions for both heating and cooling. This is now proving popular in the latest modern offices. The main arguments for this technology are the high degree of flexibility, the individual control as well as the local energy monitoring and the small spatial requirements. Disadvantages of this system are e.g. increased inlet temperatures from outside, condensation removal and above all maintenance. The advantages and disadvantages, which arise as a result of decentralised air conditioning compared with centralised plant, are evaluated in this report.