computational optimization of a ufad system using large eddy simulation

In the present study, the large eddy simulation (les) turbulence closure is implemented, for the first time, to the best of our knowledge, to investigate the air conditioning system in a large space. the results of les simulations are validated against experimental measurements and the model is used to study the effect of different design variables, including the air changes per hour (ach), supply temperature, and return air vent height, on design objectives, such as local and global thermal comfort indexes and the energy saving parameter, via a systematic multi-objective optimization approach. the sensitivity analysis shows that the global and local thermal comfort indexes are most sensitive to the air supply temperature while the energy saving is sensitive to ach and the supply temperature to the same extent. in addition, the return air vent height affects the energy saving more than the other objectives. finally, with the best design proposed by the multi-objective optimization, an energy saving of 22.9% is achievable while keeping the thermal comfort indexes within the allowable range.