Analyzing Sun Angles of Solar Time Dial for Design of Building Envelope Components for the Region of Andhra Pradesh, India

The solar radiation is a major factor for thermal condition in built forms. The residential and commercial
buildings consume 45 to 55 percentage of the energy for thermal comforts. It was evident that the higher the
energy consumption through fossil fuels leads to the remittance of CO2 in the atmosphere. Building industry
in India is having predominant share for consumption of energy resulting in the 22% of CO2 emission into
atmosphere. Environmental quality and conservation of fossil fuels may become important in the context of
limiting of GHGs emission. So the present paper deals to curtail the direct beam radiation on the building
envelope in ‘hot and humid’ regions of Andhra Pradesh so that the internal heat gain, diffusivitity, solair
temperature and time lag of heat flow in to the building can be influenced for providing better thermal
condition . This will lead to the reduction of energy consumption and energy savings in the buildings.
Angle of incidence of solar beam radiation dose play a major role to admit the amount of heat in to the
building internal spaces through its envelope. Sun angle varies from time to time and this Local solar time is
a measure of sun’s actual position with respect to the sun path from east to west. This work sheds light on
understanding the importance of angle of incidence of solar beam radiation in designing various
architectural elements like Jali’s, shading devices, built form projections, inclined/ vertical walls, and also
to analyses the drama of light & shade by pergolas for different directions of envelope surface facing
towards different directions with respect to sun-path and with reference to surface azimuth, day of the year,
declination, hour angle, location consideration and with different inclinations’ of the façade / exposed wall .
This paper tries to establish the best possible ways of shading the building with regard to orientation of a
built form, effective textured wall, chajja projections, roof projections, trees /shrubs and functional jail
design for various azimuth angles for four cities of Andhra Pradesh of India so as to reduce the amount of
heat gain from solar beam radiation to facilitate to contribute to thermal comfort and conserve the
conventional energy by natural means.