BEAT the HEAT, the DESIGN way!!!

It’s summer in India once again, and with the above-average temperatures that are being recorded, it is once again time for intellectuals to start discussing global warming and the effect it has had upon the planet. However, discussing the cause does not always bring a proper solution of dealing with the effect, does it? Switching on the air-conditioners adds to the carbon footprint, and indirectly causes global warming, creating a vicious loop.  But is there really another way to keep cool during the summer season, other than using air-conditioning, and having mini heart attacks when the electricity bills arrive? And for those of us who cannot really afford to have air-conditioners switched on throughout the day, or doesn’t have an air conditioner in the house at all, the only way to combat the heat seems to be to suffer in silence! But is it?

There lies an answer in architecture, as always. Have you ever visited Rajasthan, and wondered how the forts stayed so cool, even in the sweltering heat? Or rural Bengal, where the mud huts have temperatures near 24-25⁰C even when the outer temperature is around 35-36⁰C?

Well, you can say that they are built out of different materials, and we cannot really change our building materials to mud and stone overnight just for the summer. But building materials are not the only factor that helps to keep your rooms cool. There are many passive cooling techniques which you can use in your houses to lower the temperatures and keep the scorching heat at bay.

In any building, the roof and the walls are the surfaces that receive the maximum amount of heat. One of the first ways to keep cool is by keeping the roof cool. Those with access to your building roofs can build a mini garden there, right above your bedrooms. To do that, use large flat containers made of any material that is lightweight. Using the typical pots used in India, or decorated ceramic pots does not help too much, because the contact area with the roof slabs is far too less. Create large beds where you can place the mud for planting. Mud not only acts as an insulating layer, it also holds the water in it for a long time keeping the roof cool. The ideal plants to be used are coriander, mint, basil, beans, tomatoes, cucumbers. You can also use plastic gardening sheets so that there is no water leakage.

Another method that can be used is to give a coating of white lime (chuna) on the terrace. However, this is not so effective as it washes away during the rains, so constant reapplication would be necessary.

The next step would be to effectively cool up the room. In order to do this properly, many small steps can be taken. If your house has cross ventilation, then utilise it during the best hours. Keeping the windows open throughout the day only increases the heat gain. One should open the windows only when the diffused sunlight can enter through them. This time may vary from place to place, as it all depends on the angle of the sun. A general effective time in India would be from 5.30-8 in the morning, and after 7.30 in the evening.

Nowadays people love to use large amounts of glazing in their houses. Be warned, that style is not meant for Indian climate at all! Large glass windows create a greenhouse effect inside your house, and heat it up considerably, especially if they are aligned in the east-west direction. Louvred window with less glazing is the most effective style of window in India. However, if you were unaware of that, and have already invested in large numbers of glass window, there is no need to fret. Tinted glass generally reduces the solar glare to some extent. Curtains are an effective way to prevent the room from heating up. Use bamboo, jute or khas-khas screens in plenty, and hang them over the windows. Keep the blinds closed for the major part of the day. If it is possible, you can also install awnings over your windows, because they are one of the most effecting shading devices. However, the awnings must be aligned properly if they are to give maximum shade to the rooms.

If you have box windows, or windows with sills extended outwards, you can use these spaces to install planter beds. These not only add colour to your house and make it vibrant, they also help in reducing the temperature of the hot air flowing through the window.

Another underutilised element of our houses is the balcony and window grills. These can be used to grow vines and creepers that create beautiful natural shading for the house, and significantly reduce the solar glare from heating up the house. And who doesn’t love an abundance of the colour green in the concrete jungles?

One important way to reduce the heating of your homes during summer is to change the incandescent lamps to CFLs and LED lamps. LED and CFL lamps produce the same amount of brightness (lumens) by consuming a far less power than incandescent bulbs, and at the same time, they do not give off heat into the surroundings. They may have a higher installation cost, but they run for a longer time, and need not be replaced every now and then. Moreover, since they consume less power, they prove to be far more effective in the long run. Most of you may have already switched to CFLs and LEDs in case of tube lights in your home, but replace those incandescent bulbs of your kitchen and bathrooms as well! You may be surprised at their efficacy in the future.

The next thing that I am about to tell you may surprise you, but it is a fact nonetheless. Changing the time when you take your bath is crucial to keeping your home cool! If you take your bath late during the day, the water evaporates to create a humid environment inside your home, making it highly uncomfortable. Early morning or late evening baths help in a small way to keep your home cooler during summer.

Those people with energy and resources can use mud plaster on the exterior walls, as mud is one of the best insulators of heat. If you are someone who is going to build a house, make sure you request your architect to design louvred windows, roof overhangs, extended eaves and pergolas if possible. Designing skylights over the stairwell creates a stack effect by drawing cool air into the house and releasing the hot air, besides creating a well lighted stairwell during daytime. If you have patios, use soft landscaping elements like water bodies and planter beds in plenty, to reduce heat from the hard paving elements like brick or stone.

Besides these, there are a few small ways that help to keep your interiors cool in this season. You can keep small potted plants inside your home, on the bookshelves. Abundance of furniture in a room increases the effective number of surfaces that absorb heat, so try to keep the room less cluttered and more airy. Hang heavy white window shades that reflect the heat to a large extent. Switch off electronic gadgets like computers, laptops, tablets, televisions when they are not in use, to prevent the heat radiating from them. Remember, ceiling fans are only effective in cooling you when you are in the room, so switch them off when you leave. A highly effective cooling method was used by us in the hostels when we were students, which was to hang wet cloths over table fans or windows to create a cooling effect. But remember, this also increases the humidity level in the room, so always keep the air circulating from outside if you use this. Try to use light pastel colours while painting the rooms. Black and grey rooms may look extremely attractive in advertisements, but they are not good at keeping the heat out.

This concludes my design ideas on keeping a cooler home during summer in India. Not all of these methods may be applicable for everyone. However, by using even a few of them, you will be surprised how much of a difference you will notice.

This article has been authored by Ar. Shayantani Mukherjee. Images have been sourced from the internet and neither the author, nor Sthapatya claims any ownership for the same.

স্থাপত্য সাধারন মানুষের মধ্যে আর্কিটেকচার ও ডিজাইন নিয়ে সচেতনতা গড়ে তোলার উদ্দেশ্যে বাংলা ভাষায় একমাত্র অনলাইন ম্যাগাজিন। আমাদের পাশে থেকে ও সমর্থন করে এই উদ্দেশ্য সফল করতে আমাদের সাহায্য করুন।
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