Study of Climatic Potential for Natural Ventilation in Buildings for Typical Indian Cities

摘要

The potential of climatic driving forces for natural ventilation to ensure acceptable indoor air quality in a conceptualised low rise building are assessed for six typical Indian cities representing all the climatic conditions of India. A simple analytical model is used for the evaluation of climatic driving forces viz. the effective wind pressure difference available for natural ventilation and the desired wind pressure difference. The concept of Pressure Difference Pascal hours (PDPH) is introduced to represent the natural ventilation potential at a location. The higher the value of PDPH the higher will be the climatic driving forces available for natural ventilation. Weather data for a typical Meteorological Year (TMY) from Transys simulation software was used in the analytical model. Monthly mean ambient temperature, monthly mean wind velocity, annual wind rose diagrams, cumulative frequency of effective pressure difference and PDPH profiles for six cities were evaluated and compared. Analysis showed that Indian climatic zones experience an effective pressure difference across indoor and outdoor in the range 0.0 - 3.0 Pa throughout a year. PDPH values assume higher values in summer (250 - 750 Pa. hrs) and low values in winter (80 - 200 Pa. hrs) for most sites except Leh. Cities on high land (Leh) and on the coast (Goa and Kolkata) have high wind velocity and PDPH, hence, theses cities have high climatic ventilation potential as compared to the other cities that were studied. The aim of this study is to help building planners at the early strategic planning of ventilation systems for indoor air quality in buildings in India.