In hot climates, the overall energy usage rises as you increase the glazed area. Curtain walls, therefore, are highly inappropriate.
I have ranted about glass façades for a long time and this editorial by Sunita Narain of DTE has inspired me to add a couple of paragraphs to the original one. Among other things, she has written about a recent study by IIT-Delhi which found that, in our hot climate, the manufacturers’ claims of special coated glass or double/triple glazing being able to reduce heat gain are rather hollow.
One of the other specious arguments put forth in an attempt to portray glass curtain walls as green systems is to say that it reduces the electricity consumed for lighting. This is a half-truth. Leave aside the uncomfortable glare that people working inside such buildings have to put up with, let us make s simple comparison.
Consider a 10m² conventionally designed space. Assuming that we don’t take passive cooling techniques into account, the air-conditioning load will be in the region of 3,500W (1 ton). Lighting the same space, on the other hand, will need just 50W with fluorescents or 40W if we’re using LED fittings.
Now, imagine a similar sized curtain-walled space. The maximum saving that can be achieved by reducing lighting is a puny 50W. However–and this is the big problem–air-conditioning requirements will probably have risen to a whopping 5,000W. Even with all the specially coated and multi-layered of glass in the world, the total requirement is unlikely to be anything less than 4,500W.
So yes, we may not use as much electricity for lighting but, I’m afraid, the energy usage for cooling will go right through the roof and no amount of marketing spin can get around this simple fact.
It’s the day after the popular Ganesh festival here in Bombay and, as every year, I headed to the beach to clean up the mess the revellers left behind. Being an old hand at this, I was put in charge of the volunteers who came from various colleges in the area. As usual, it was a depressing sight when they arrived in the early morning. By the time we were through though, there was some semblance of cleanliness. The municipal workers were there too and some of them did give us strange looks…
Anyone not familiar with the festival can read this article. Some time late last month on an Yahoo Group called Indian Environment, someone had written defending this method of celebrating the festival. My response to his original mail follows:
If you want to read the entire thread you’ll have to be a member of the IndianEnvironment group.
As someone who has been involved with cleaning up after the revellers for the last several years, let me reiterate:
- Most of the idols are made of Plaster of Paris. PoP does not float back to our already dirty and polluted shores but becomes a mucky layer that chokes the sea-bed.
- Pieces of thermocole and styrofoam do settle on beaches – sometimes many miles away. Are volunteers able or willing to monitor our entire Konkan coast? I don’t think we have either the time or the resources for that.
- Most important, these idols are coated with paints containing toxic heavy metals even though less harmful alternatives exist. There is no need to tell you what damage these colours cause.
Yes, we do have a huge country and people do need entertainment to liven up their otherwise dreary lives; yes, it does happen only once a year (thank goodness!) and yes, these things will not change overnight.
But that doesn’t make it right or desirable. We do need to make people aware – and as a professor you are in a better position to do so than most of us. It is nobody’s case that the festival be scrapped; but it can be carried out in a way that is as holistic as it is holy.
Naturally it will be a long and uphill battle. But it is a battle that can – nay, it must – be won.
Simply accepting it is no longer an option.