Development and application of an underfloor air-conditioning system with improved outlets for a 'smart' building in Tokyo

A newly developed underfloor air-conditioning system was introduced into a high technology 'smart' building in Tokyo. Prior to the introduction of the system, experiments and numerical simulations were carried out to preestimate its thermal comfort and energy saving effects. By conducting field measurement of the indoor environment and occupancy surveys, it was assessed whether the system actually achieved its anticipated performance. Improving the floor diffuser design prevented draft and local cooling of effect observed under the high cooling load condition. In general, the results suggest that the system should be considered as an appropriate choice available for air-conditioning systems in future smart buildings.