SOLAR ENERGY CENTRE
GWAL PAHARI,
GURGAON,
HARYANA.
ARCHITECT: Vinod Gupta, Delhi.

Introduction

The centre is located at Gurgaon in Haryana, around 40 to 50 km from New Delhi. Transport to the site is not easily available, with rented vehicles being the alternative to reach the centre from Delhi. Staff buses of the Solar Energy Centre are available at fixed times to reach the centre.

The centre is located on a gently sloping site covering about 200 acres in a suburban setting. The climate is hot and dry with summer temperatures reaching as high as 47 degrees C. Therefore, the major concern in the region with respect to building design is summer cooling, at the same time winters are also quite harsh requiring heating during the winter months. The Solar Energy Centre building is designed to reflect the principles of energy conservation and application of solar heating and cooling concepts.

Brief history

The Solar Energy Centre was completed in 1991 but most of the facilities have been put to use at a much later stage. The institute was set up with a view to encourage research in the field of solar technology as a viable alternate energy system. At the same time the centre itself is built taking into account principles of passive solar design to reduce energy consumption in the building. This is achieved by reducing heat gain in summer, encouraging effective ventilation, natural cooling and effective insulation to prevent heat loss during the winter, thus reducing both heating and cooling costs..

Set-up and activities

The Solar Energy Centre consists of a number of different structures, which include a guesthouse, a workshop, offices and laboratories. Apart from the buildings the campus includes a 50 kW solar power plant, biomass plantation and large outdoor space for testing solar devices. The solar Energy Centre is a recognised by the Ministry of Non-conventional Energy Sources as a centre for the testing and evaluation of solar based devices.

Built Form

FUNCTIONAL ASPECT

The built form has been largely influenced by the climatic conditions and the design has been evolved keeping in mind the comfort requirements of the users and also minimal use and wastage of conventional energy. The planning is made compact and facilities requiring identical services are grouped together to save on cost and improve efficiency, for example, all the laboratories requiring air- conditioning are placed in one well-insulated block. The building has been conceived as a low, spread out structure arranged around courtyards, maximising the use of a roof surface evaporative cooling system.

The entire office and laboratory space were designed as general spaces since specific uses for different rooms were not defined and had to be flexible enough to allow for partitioning later. Corridors are centres of activity, therefore single loaded corridors are used which are naturally lit and ventilated, at the same time providing shading to the areas behind. The different blocks are arranged around courtyards allowing for adequate natural day lighting and cross-ventilation.

For comfort cooling the strategy used is to reduce ingress of heat by using hollow, concrete block walls, properly shaded windows and a reflective finish on the roof surface in the form of china mosaic. The windows are protected by means of fins and deep recesses or chajjas that are meticulously designed so that at no time of the summer day does direct sunlight enter into the building. The baffles and fins also help in glare reduction. In the guesthouse building, the walls are finished in roughcast plaster, which provides a degree of shading to the exposed wall surfaces. Special, openable, louvered shutters have been used on the East and West facing windows. A roof cooling system has been employed in the form of a water spray which is used to wet coir mats placed on the roof which in turn leads to natural evaporative cooling. The roofs are designed as shallow concrete vaults to facilitate drainage of water. Adequate availability of water at the site, the simplicity of the system and reduced maintenance as compared to other cooling systems such as earth air-tunnel and active solar air-conditioning led to the selection of this cooling system. Earth berming has been used to reduce heat gain in the buildings especially in the guesthouse where the guestrooms are practically sunk into the earth. The roof was designed as terrace garden but this has now been removed due to problems of water seepage resulting from inadequate waterproofing.

For comfort during the milder months of summer, cross-ventilation is provided in all rooms. Aluminium sections are used for glazing as they provide tighter fitting joints reducing infiltration heat gain. The windows are split into two parts, one located at normal height and the other just below the ceiling vault. The lower windows provide ventilation and view, and some day-lighting close to the window. The upper windows ensure day-lighting deep inside the workspace in the event of subsequent erection of internal partitions. The ceilings are higher than usual to facilitate adequate ventilation and dispersal of daylight. Nearly all rooms have windows on two opposite faces avoiding glare and uneven distribution of daylight. The building can therefore be used without artificial lighting during daylight hours saving on the needless use of energy.

The workshop building has an interesting system of day lighting. The building has a stepped cross-section with a reflective finish on the roof surfaces. Daylight is reflected from the lower roofs into the building providing glare-free lighting. The drawing offices have deep recesses for shading with baffles to cut out the glare.

Active systems like solar water heating are also employed with solar water heaters provided in each toilet, integrated with the design. Back-up electric heaters are provided in individual toilets rather than as a heating element in the water storage tank itself as it is quite wasteful. The system has, however been modified now due to maintenance problems. A sunny terrace for solar cooking has also been provided near the kitchen. At the same time toilets have been placed in visible location to facilitate monitoring and maintenance.

BASIC DESIGN ASPECT
The composition of the centre comes across as very homogeneous even at the risk of becoming too monotonous, due to the compact nature of planning and the repetitive use of typical arched sunshades and recessed windows. The buildings are painted in light, reflective shades relieved by the use of darker colours to break the monotony. The texture used on the wall is roughcast not entirely for aesthetic purposes as it also provides a degree of shading to the wall surface thus reducing heat gain. The use of green in the form of courtyards contrasts well with the earth colours used in the main building.

Reference

ARCHITECTURE + DESIGN magazine, May - June 1992.