each building space and each window, depending on its size, material and the installer you choose. According to Ar. Kembhavi, double glazing should last for 20 years or more. Raman Sikka, Principal Architect, Sikka Associates observes that as energy consciousness grows, the benchmark for building energy performance is getting more stringent. Façade Design Techniques for Optimal Energy Savings Varied cladding options are now available which give good light transmission combined with less heat transfer, says Ravi Panjwani, Managing Director, Yantra Aluminium Window Systems Pvt Ltd. Specialized fenestration solution with forced natural ventilation can also support the cause to a major extent, he adds. According to Ar. Amit Kembhavi of DSP Design Associates, design techniques can optimise energy conservation. Some of them are as enumerated below. Use of solar gains: For tropical locations, solar energy can be utilized effectively if the buildings façades are oriented due south. Façades should be designed, considering solar path in winter and summer. If the façade is covered by windows and PV modules in equivalent proportion, then a large glazing
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Citilights IT Park At Navallur, Chennai by Oscar Ponni Architects
area is achieved. This glazing area (nearly 46 per cent of the south façade) interacts directly with the rooms which are permanently occupied and provide natural light and heat to these spaces. Louver shading devices: A louvered shading device, placed in the south east façade of the building, reduces sun gain in summer while allowing ventilation. Green roofing: Green roofing, with rooftops covered by grasses or plants over a waterproof membrane, is regarded as the best method of insulation. It also helps in greening the environment, producing oxygen, regulating air temperature, etc. Indirect radiant cooling: Indirect radiant cooling occurs due to the net emission of electromagnetic waves from warm to cool objects. The process continues until both the objects reach the same temperature.
Natural lighting and natural ventilation: A central skylight has to be the fundamental light distributor. Thus its location and dimension play an important role, as also vents in doors which communicate from north and south spaces to the corridor and glazing areas over the entire building envelope. Adoptions of these features in building design drastically reduce the power consumption. Natural cross ventilation is provided with the help of openings at façade and roof level. Integrated PhotovoltaicThermal (IPVT) systems: In addition to the direct solar gains through the windows, IPVT systems, integrated in the south façade of the building, can improve indoor climate. During summer, heat released in daytime hours in the process of converting solar energy to power can be successfully recovered. In winters, air can be heated and circulated in the room by the IPV-T. This air can