Multi-objective optimization of heating operation of stratum ventilation under different clothing insulations using Taguchi method, RSM, and SPA-TOPSIS

Abstract

Stratum ventilation (SV) for heating can provides a comfortable indoor environment, good intake air quality, and energy efficiency when operated correctly. The studies that have been conducted have focused on the operations of SV that occupants’ clothing insulation was set to a fixed value (i.e., clothing insulation of cooling season and heating season is 0.5 clo and 1 clo, respectively), with little attention to different clothing insulations. This study aimed to access the optimal ventilation parameters (i.e., supply air velocity, supply vane angle, and supply air temperature) to satisfy the requirements of thermal comfort for occupants with different clothing insulations, whilst improving indoor air quality and achieving energy savings. Firstly, based on experimentally validated Computational Fluid Dynamics (CFD) simulations, the Taguchi method was used to analyze the effects of operation parameters (i.e., supply vane angle, supply air velocity, supply air temperature, and outdoor air temperature) on the thermal comfort of occupants with different clothing insulations. The results show that the operation parameters affected the thermal comfort of occupants with different clothing insulations inconsistently. Then, taking clothing insulation as one of the important influencing factors in the optimization process, the multi-objective optimization of stratum ventilation for heating conditions was performed by a sequential preference technique based on the set pair analysis method (SPA-TOPSIS) of similarity to the ideal solution. To reduce the costs of computational, response surface models (RSMs) of ventilation performance was formulated and then used to assess the ventilation performance for all operations optimized by SPA-TOPSIS. The results showed that the dynamical optimization of ventilation parameters significantly improves ventilation performance considering different clothing insulations.