Guidance and tools for chilled ceilings combined with a wet cooling tower

The combination of an open wet cooling tower with chilled ceilings is a CFC free, cheap and low energy cooling solution. The efficiency of this alternative to mechanical cooling is very dependent on climate. There is a need for specific tools to help designers to size the system and to estimate its energy and water consumption. A building simulation tool, called ConsoClim, has been used to predict the performance of this system for different French climatic locations, thermal inertia, internal loads and solar gains. Since the system is climate dependent and has a limited maximum cooling power, an adapted control strategy is proposed to take advantage of the building thermal mass, allowing night cooling. The air conditioning plant and its control strategy are presented. A radiant system model and an open wet cooling tower model with possible air flow rate variation have been implemented in the simulation tool ConsoClim. From the calculations of the detailed design tool, pre-design guidance are given. The results show the promising potential of this technology in most of the climatic zones of France when associated with an anticipative control strategy and for buildings with low or medium loads.