Standardised measurements of the cooling performance of chilled ceilings.

One important aim for the development of new air conditioning systems is the reduction of the total energy consumption. This can be reached by separation of cooling and ventilation in air conditioning systems, because it is more effective to transport energy by using water systems instead of air to deliver cooling energy to the consumers. This strategic was the base for the development of several chilled ceilling systems during the last years, so that at present there are many different systems on the market. One problem during the design period is to calculate the cooling performance of these systems depending on different operating conditions. So it is necessary for the companies to find characteristic data to describe the heat transfer of these elements. But an objective comparison of different systems and an accurate planning is only possible, if these data were investigated under comparable boundary conditions. Parallel to the Germany standard organisation (DIN) the working group "Heating and cooling surfaces" of the German FGK e.V., in which the leading manufacturing, planning and installation companies of chilled ceiling systems are represented, had outlined a guidline to guarantee standardized measurements under clearly dehed boundary conditions. It is planed to discuss the main aspects of this guideline and the conditions for measurements of the cooling performance of open convective chilled ceiling systems.