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Special Reports

The Energy Factor

With EMS fast gaining importance in the Indian construction sector, the government is taking initiatives to develop energy conservation codes.

There are buildings. And there are smart buildings with energy management systems and services.
An 'Energy Management System' (EMS) aims to extract maximum advantage from the sun and wind, while minimising the wasteful heat load from the sun into the building and roof. Hence, various services in a building are integrated to the microprocessor-based EMS for cohesive and reliable hands-free operation with minimum human interface. These systems incorporated in a building automatically coordinate with the management of power supply and distribution system, lighting system, air-conditioning system, fire-fighting and detection, ventilation system, water supply system and security system in such a way that minimum energy is consumed in carrying out all these activities for maximum consumer satisfaction.
In order to address energy conservation issues, the Indian Buildings Congress recently organised a national seminar on 'Energy Management in Buildings and Services'. Dr APJ Abdul Kalam, President of India, inaugurated the seminar and the recommendations that emerged out of this seminar were finalised mainly on the basis of observations made by Dr Kalam during his inaugural address.

Design perspective
Energy efficiency starts from well planned, self sufficient district centres, where residents have access to services and can implement the concept of walk-to-work.
Thereafter, the need of the day is to produce energy-efficient designs by adopting an 'Integrated Design Approach', where 'energy managers' should be involved along with the other consultants right from the initial stage.
The use of lower-energy structural systems like load-bearing masonry in place of reinforced concrete or steel frames helps in reducing the total energy in a built environment. Accordingly, designers can look for ways to reduce the thickness of walls, finishes, storey heights, etc. The design of low-rise buildings in place of high-rises would also do the trick. Thermal insulation of roof with under deck or over deck insulation would reduce heat gain from roof. Similarly, cavity walls, hollow bricks or aerated concrete blocks can also provide thermal insulation. The use of well-designed shading devices in buildings that employ 'daylighting' would reduce building peak heat-gain and improve the natural lighting quality of the interiors. Depending on the amount and location of fenestration, the annual cooling energy consumption can be reduced from 5 per cent up to 15 per cent. Moreover, regular maintenance of all building components will save energy in the long run.
The use of computer simulation techniques like EMS helps to analyse building energy performance, determine the suitability and contribution of solar passive features and study energy management to optimise the building design.
Manufacturers of building materials like steel, aluminium, cement, clay bricks, tiles, glass, etc, can conserve energy by carefully studying all production processes, as well as by using cheaper or non-premium fuels in production.

Light and energy
In order to cool the indoor environment, appropriate landscaping and horticulture designs should be put in place. The use of passive solar heating concept in extreme cold climates using trombe walls acts as a thermal mass. Similarly, passive solar cooling concepts can be adopted by using thermal chimneys, wind towers, courtyard effect, earth air tunnels, etc. The use of solar systems, windmills, biomass and biogas for heating and lighting in buildings is recommended.
The power consumed by lighting systems in India is quite high compared to developed nations, implying poor end-use efficiency. Moreover, energy is given to many either free or at highly subsidised rates, which results in wastage of power. Such measures should be minimised or discontinued. In most developed countries, higher tariff is charged during peak hours, thus economising energy consumption during peak hours.

Government policies
As energy-efficient items are expensive, it is necessary for the government to evolve suitable procurement methods, whereby comparative cost should be worked out on the 'lifecycle cost concept' and not on 'initial cost' alone. Besides, the government needs to help set up 'energy centres', which can provide R&D and manage it on corporate terms. Programmes launched through the media, and books for architects and engineers, etc, will help in creating awareness.
To stimulate energy saving, the Bureau of Energy Efficiency set up under the Energy Conservation Act 2001 will come up with 'state-of-the-art building energy standards', to be made mandatory for all new and old buildings. In addition, Energy Service Companies (ESCO) will undertake energy-efficiency projects through third party financing, to enable consumers to save on costs without incurring any expenditure. Therefore, a periodic energy audit should be made mandatory for all buildings that consume energy above a threshold limit.
It's time to get smart about energy.