C M C.Computer Maintenance Corporation Limited
BANDRA (EAST),
MUMBAI.
ARCHITECT: Vinod Gupta & Rasik Bahl.
INTERIOR DESIGNER: Carl Christiansson.

Introduction

The C M C (Computer Maintenance Corporation) building is basically an office complex which is situated at Bandra (East), Mumbai, in the midst of other Govt. office buildings in the area. The orientation, location and overall form were governed by the Development Control Rules as well as restrictions in the size of plot available which resulted in a cubical form with a plan size of 25m x 25m and a height of 30m. The climate in Mumbai is hot and humid with summer temperature reaching 37 degrees C compounded by high year round humidity in the range of 70% to 80%. Winters are mild requiring no heating for maintenance of comfort levels. The major concern in design was therefore to reduce cooling load on the air-conditioning system by preventing heat gain, ensuring proper insulation and providing adequate day-lighting in the interior office space to reduce the cost of artificial lighting during day-light hours.

Set-up and activities

The offices in the C M C building employ the open-plan concept thus economising on office space and lighting requirements, at the same time circulation and visibility are improved providing a better working environment. The offices also employ the dynamic seating system where each employee is allotted a different workstation every day depending upon availability. This practice is economical, as not all the cubicles are occupied every day.

The Building Automation System is used to control the level of lighting, angle of the venetian blinds and the air conditioning system. The building has been centrally air-conditioned, but the cooling load has been calculated using the more commonly occurring ambient temperatures, rather than the normal practice of using the worst combination ambient factors that might occur on one or two days of the year. The capacity of the air-conditioning plant is thus limited to 17sq.m. of cooled space per tonne of air conditioning which is much better than the Mumbai norm. The plant itself consists of 40 and 60 tonne water cooled chiller units controlled by a micro-processor which increases efficiency and reduces wastage by adjusting the cooling depending upon factors such as occupancy, level of activity and mean ambient temperature. This mix of chiller capacities also allows the plant to operate more efficiently. In addition cooling load is further reduced insulation in all exposed wall and roof surfaces and fixed double glazing-sketch- provided in the windows, which reduces infiltration.

Built Form

Day lighting is a major energy consumer in commercial buildings and has therefore been given due consideration in the design. The building form as well as circulation revolves around a central atrium which brings light into the interiors of the building which would otherwise be dark due to the 25m width of the building, requiring artificial lighting. The atrium-section- also reduces the depth of office space to 10m which have external lighting on one side and diffused light filtering in through the atrium on the other side, largely reducing dependence on artificial lighting during day light hours. The atrium also improves visibility and improves circulation.

Double glazed continuous windows are provided where the upper half is used for day lighting and the lower half provides the view. The upper window incorporates small light shelves in the form of reflective (mirror-coated) blinds. Motors connected to the Building Automation System operate these blinds, which tilt the slats at the appropriate angle depending on the angle of incidence of sunlight on different faces of the building. The blinds reflect daylight onto the ceiling which has white painted, angled and flat panels to provide more light to the back of the office space. For better maintenance the blinds are enclosed within the outer and inner sheets of glass. The effect of these measures is that practically no artificial lighting is required during daylight hours. Day lighting is also provided in the staircase and lift lobby through slits in the wall and also from the atrium.

However, supplementary artificial lighting has also been provided but along with energy conservation measures integrated into the system. The general lighting level has been designed to achieve an illumination of about 150 to 200lux only as compared to the normal standard of 300lux. Task lamps, 9W PL lamps, achieve higher illumination at workstations. 40W fluorescent lamps are provided with high frequency electronic ballasts, mirror optic reflectors and parabolic louvers-detail- to improve efficiency and uniform dispersion of light. The Building Automation System also controls the artificial lighting by switching the tube lights on or off or dimming them in different parts of the office depending on available daylight. The office space has been divided into different zones for supplementary lighting, which allows for control of individual zones depending on local levels of day lighting. A Monitoring System has been incorporated in the Automation System to measure energy consumption in different parts of the building so that cost-effectiveness of the energy saving measures employed in the building can be measured.

BASIC DESIGN ASPECT.

Visually the C M C building is very simple in composition, which is also reflected in the interior space. The cubical form of the building with a height of 30m gives a definite feeling of verticality but this impression is relieved by the horizontal bands of the windows. The curtain wall glazing lends transparency to the structure giving an impression of lightness to an otherwise bulky mass. Also, the tinted effect of the glass is contrasted by the blue and grey shades used on the exterior surface. In the interior, the whole height of the building is tied together by means of a dynamic sculpture of seven figures reaching for the skies, suspended in the atrium. The sculpture provides a sense of motion and is meant to represent man’s quest to attain higher goals. Externally, the building creates an image befitting a high tech organisation reflecting the use of modern materials at the same time maintaining strict controls on energy use with the interest of future generations in mind.

Reference

ARCHITECTURE + DESIGN magazine, May - June 1992.

INSIDE OUTSIDE, August 1992.