Experimental And Simulation Study On Single-sided Natural Ventilation Caused By Buoyancy

Natural ventilation once had been neglected for the development of air conditioning. But recently the application of air conditioning systems in airtight buildings cause a lot of problems related to indoor air quality and human health. Furthermore, for the energy crisis and the demand of sustainable development, natural ventilation has been attracted more and more interests from scientists and other related researchers or engineers again. Rational application of natural ventilation is necessary for it can reduce initial construction costs and operating costs to maintain ventilation rates consistent with the requirement of acceptable indoor air. Today the increasing building density seriously affects across natural ventilation. In office building and dwelling house for most the time the windows are open and the doors are close. As a result, single-sided natural ventilation becomes common in buildings. However, there are few studies about single-sided natural ventilation in our country. The single-sided natural ventilation, which has academic and realistic signicicance in improving our habitation, was studied comprehensively in the paper. The background and practical meaning of ingle-sided natural ventilation were firstly presented. Then the state of study on natural ventilation theory and its application were reviewed.A single-sided natural ventilation experiment was carried out in a typical office building in ChangSha. The experimental results indicated that there was a considerable discrepancy between ventilation mass obtained by experiment and by theoretical calculation. The reason is that it is impossible to achieve the assumed condition for theoretical calculation in practicl experiment. In this text the theoretical formula is revised to obtain a new amendatory formula which is more fit for practical calculation of natural ventilation mass coused by single-sided openings.The software Computer Fluid Dynamic (Fluent) is applied to simulate experiment condition. The Simulation results tally closely with the experiment results. So it proved that the computation module is right. Then the software is used to the further study of single-sided natural ventilation effect. Different open area, difference temperature between indoor and outdoor, and different heat power are all included in the simulation. The result can provide theoretical support for building design. Finally, the effective depth of fresh air distribution was analyzed. The computed result can provide instructional support for house depth design.