Field Measurement And Simulation Optimization On Natural Ventilation Building In Guiyang

Effective natural ventilation can not only cut down the energy consumption, reduce the equipment investment and save the economic cost, but also dilute the indoor pollutants and improve the thermal comfort. Integrated with local climate conditions and construction materials, proper building structures could be designed to enhance natural ventilation. This paper studies the application of natural ventilation in Guiyang based on the local climate characteristics.Firstly, this paper elaborates the fundamental principle and calculation formulas of natural ventilation. For the single-sided opening natural ventilation, the ventilation rate is relations among the pressure difference, opening height and air density difference. For the cross ventilation, the pressure difference is associated with the wind direction, velocity and pressure coefficient. For other common natural ventilation types, the atrium ventilation, shaft ventilation and solar induced ventilation, their basic theories and major influencing factors are also summarized.Secondly, in accordance with the climatic and geologic features in Guiyang, Guizhou, local natural ventilation potential is appraised. Analysis results have shown that Guiyang is suitable for applying natural ventilation. Furthermore, indoor thermal comfort is possible to be achieved only rely on natural ventilation during the hottest month.The revised natural ventilation methods in the library and training workshop in Guizhou University are proposed based on the original design, to satisfy their structure and functional requirements. To be specific, the library uses the atrium ventilation due to its large space and height as well as the ventilation and lighting demand; the training workshop uses the chimney ventilation due to its great height and inner heat source, and large height difference is set between inlet and outlet in order to promote the natural ventilation. In addition, the MIX model and FLUENT software are applied to simulate the macroscopic and microscopic natural ventilation of the two buildings to evaluate the ventilation effects. Also, ventilation rates and indoor airflow organizations are calculated and compared under different opening sizes, indoor and outdoor pressure differences and vertical temperature gradients. In this way, suggestions on natural ventilation are offered for building design and management.Finally, a field measurement is carried out by tracer gas method in the library and training workshop. Then actual ventilation effects are compared with those from simulations. It turns out that simulated and measured data are in good agreement, which validates the previous modeling. Accordingly, some economic and practical modification schemes are provided to help the current natural ventilation meet the indoor environment demands.