Study On Night Ventilation Structure System Of Office Building In Xi’an

Nowdays, the widespread use of air conditioning system aggravate the rapidgrowth of energy consumption of building refrigeration, meanwhile the energy problemhas become tighter, which makes passive architectural design becomes the focus issueof the industry. The night ventilation as a passive method of architectural design, makeitself―initiatively‖adapt to the climate and make the maximize use of climate resourcesto create a healthy, comfortable and energy-efficient environment. Office building isconsidered suitable for this kind of cooling technique because it is not use during night.The big temperature difference between day and night in Xi’an provided a better climateresource for the utilization of night ventilation in this area.First of all, the heat transfer process of night ventilation is analyzed and factors thataffecting night ventilation is determined by the analysis of a series of heat balanceequations; On the basis of these factors, the relationship between night ventilation andindoor thermal environment are deeply analysed.Then, experimental study on night ventilation is done based on the results oftheoretical analysis. According to the experimental data, appropriate conditions for thepassive strategy of night ventilation in Xi’an are determined; the relationship betweenthe amount of heat storage capacity and the rate of night ventilation is given, as well asthe cooling effect under different night ventilation rates and heat storage quantitiesis isanalyzed; In addition, on the premise of thermal comfort of indoor thermalenvironment and the restricted arrangement of regenerator in the office buildings, theoptimum amount of the regenerator for room in different positions of the building aswell as the optimal airflow paths for the corresponding case are given. Finally, on the basis of the experimental results, a detailed ventilation structuredesign and regenerator arrangement is made for the floor, ceiling as well as the wall ofoffice building; constructions that suitable for the night ventilation of office building inXi’an are identified, and proper values of parameters for the key construction are given.With the help of numerical simulation, an optimized design of the ventilation structureis conducted. The comparison between the night ventilation combined with heat storagesystem and conventional air-conditioning system is also performed, and theenergy-saving effect as well as the cost-effective of the night ventilation has beendrawn.