Clear and present

Clear and present
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First Published: Thu, Jul 05 2007. 12 24 AM IST
Updated: Thu, Jul 05 2007. 12 24 AM IST
Daylight is among the best things in life that come free. And when correctly integrated with adjustable artificial lighting, it can actually be an important factor, particularly in the stressful modern workplace. Its links with general well-being are well documented: It is the most comfortable kind of light for the eyes, reduces fatigue on the job, keeps us connected to the cycle of the day and season, and sustains our morale. And yet, rare is the office in which the “skydome” is the predominant source of light. Why?
Some reasons have to do with the difficulties of harnessing daylight itself. Others are rooted in broader factors such as city planning, cost of real estate and building plans. The difficulty is that light always comes with heat and glare, whether it is from the sun or a lighting system. Thus, improperly managed direct sunlight in a glazed building, say, can make air conditioning very costly. Properly managed, however, daylight generates less heat for the same amount and better quality of light than most electrical lighting systems, and can actually reduce the air-conditioning load. Architectural and interior design are also implicated. For instance, where an office has closed cabins hogging the limited windows length, daylighting for the open office core is quickly sacrificed. Since few decision makers know about the positive relationship between daylight and productivity, the sacrifice is easily made.
Good daylighting design begins with simple principles. In India, almost always, light from the north sky is relatively glare-free and consistent across the day. Of course, other daylighting strategies have to be region-specific. In hot, dry parts, such as in North India, it is best to bring the sun in indirectly and sideways. Here, small openings to the exterior, especially to the west and east from where the sun enters at a low angle and penetrates deep, are appropriate. Bounce sunlight off vertical or horizontal baffles or light wells—such as tiny courtyards of desert houses—before it enters indoors, so that it has already lost some heat and glare. In the humid coastal areas where temperatures don’t reach New Delhi’s levels, however, windows may have to be larger to let in breeze to blow away sweat from the skin. Here, in fact, it may be useful to have one set of openings for breeze and local light and another higher up for general lighting. This only illustrates the most important fact: If it is to work, daylight must be integrated intelligently with many other systems that make up a building.
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First Published: Thu, Jul 05 2007. 12 24 AM IST
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