Experiment And DeST Simulation Research Of Night Ventilation Technology In Office Building In Changsha

As the restriction of energy and environment, building sustainable development and energy conservation become to be the developing trend all over the world. Building night ventilation technology can improve thermal comfort and reduce energy comsuption, which is an important issue in international study. In this paper, we study the night ventilation cooling effect in office building in hot and humidity climate of Changsha by experiment and simulation. And also we study the mian factors that determine the efficiency of night ventilation.We review former studies on night ventilation from theory study, experimental study and simulation study. The main parameters that determine the effect of night ventilation are three groups: climatic parameters, building parameters and technical parameter. Some index are used for night ventilation cooling effect evaluation such as TDR, percentage of overheated hours, and thermal comfort and energy index.The experiments were performed in summer of 2006, including night ventilation series and whole-day-ventilation series. We used intelligent equipments to collect and record all data, that is, indoor and outdoor temperature, relative humidity and solar radiation values. There are 6 series in the experiment; we changed the window size, fan air change rate, thermal mass to study the ventilation in cooling effect.As the experimental conditions cannot be recreated and are limited, computer simulations with DeST are used for further study. The DeST simulation model is introduced in details, including the building modeling, basic parameters enactment and various ventilation strategies. We compare the simulation results and experimental data to validation the modeling. At this base, we study the factors of heat insulation envelop and non-insulation envelop, different window/wall ratio, ventilation rate and ventilation time on night ventilation cooling effect.