Of lights gone green

switches on the plug to find that lights should be, and increasingly are, going green.

If you look carefully at space, you'l find that it resembles water. You can perceive, mould and utilise it in any way you want... just by filling it with the right ingredients.

True, space doesn't generate energy quite like water does, but it can conserve energy within its boundary. We talked of green homes last week and this time we follow it up with green lighting for commercial buildings. So, how will you make your space conserve energy?

In 2004, ITC's brand new office complex in Gurgaon was awarded the Platinum Green Building rating by the US Green Building Council - Leadership in Energy and Environmental Design (LEED).

For the next two years not much was heard on the green front in India. But curiously enough, following danger signals from global warming experts, there has been a rush of corporates vying for LEED approval throughout the country.

More recently, IIT Kanpur in a trendsetting step has built two new wings "" both green and both driven towards conserving energy through design and green lighting.

In any commercial or office building, lighting consumes 20 per cent of the total energy consumed, air-conditioning consumes 50 per cent while all other appliances and equipment account for the remaining 30 per cent.

In green buildings, architectural design ensures enough cross-ventilation to minimise the energy consumed by A-Cs. When it comes to lighting, architectural design needs to be integrated with lighting design to achieve optimum lighting at minimum energy consumption.

According to HS Mamak of the Indian Society of Lighting Engineers, environment-friendly lighting is most critical in any indoor space because not only does it strive to maintain ecological balance but it also conserves energy.

Since the idea of a commercial building is work and production, there is little scope of playing around with light, shadow, colour and mood. The target is simple "" ample lighting for a productive environment.

"Artificial lighting, even in a green building, is designed assuming the absence of sunlight in a commercial complex. So, green lighting does not mean installing fewer lights," says Navin Krishen, managing director, Kanwar Krishen Associates, who also designed the ITC building along with that of IIT Kanpur.

"On the contrary, it means installing lights as per the maximum requirement when a building is enveloped in still darkness... however, the amount installed is never the amount used," he adds. The goal is to utilise the least number of watts per square metre of the building.

Once you've decided to make the lighting in your building green, the first step is to choose lamps and light fixtures that will help in your endeavour. Incandescent lamps are banned in the green lighting world.

What works are fluorescent tubular lamps and compact fluorescent lamps that are energy efficient and highly luminous. Most designers and architects prefer the combined use of compact and tubular lamps as both serve different purposes.

However, due to their linear design that enables them to cover a larger area while using the same amount of energy, tubular lamps have an edge over compacts.

The fixture you choose for the lamps must also allow for maximum illumination and not confine it in small spaces. Energy consumption by lights is not determined by lamps alone. While designing for green lighting, a lot of thought goes into the colour of the walls, doors, furniture and even upholstery.

Says Krishen, "A green building will never accept any colour or material that absorbs light." Thus, dark colour walls are a strict no-no. Hence the light shades in office buildings.

As per LEED standards as well as standards laid down by TERI, light, in green commercial buildings, cannot fall beyond the boundary wall of the building. In fact, the amount of light that is reflected into the sky is also restricted. Like we said, green lighting not only attempts to conserve energy but also tries to maintain ecological balance by reducing light pollution.

So, restricting the artificial light that illuminates the sky restricts the damage caused to the natural habitat of nocturnal creatures. Inside the building, closer to windows and other areas that are flooded with sunlight in the day, lighting designers install daylight sensors.

These sensors are handed the job of monitoring and maintaining the wattage of light in a given space. If, due to the combination of natural light and artificial light, a space is overlit, these sensors dim the artificial light to maintain the level of wattage required, thus saving energy.

Despite green lighting being the need of the hour, especially in commercial complexes "" where light (and thus energy) consumption is very high, awareness towards green lighting is still narrow.

And even where there is awareness, acceptance becomes an issue, primarily because investment in green lighting is higher than normal. But Krishen argues that the difference is no more than 3 per cent, which is hardly substantial to support normal lighting.

Agrees Mamak, "What extra you invest in green lighting is less than what you save in energy and, as a result, in monthly electricity bills. Green lighting is saving energy and money."