Monthly Archives: August 2014
If people think that eco-friendly ideas should have been incorporated in the design right upfront and all the existing houses with stuffy air, dark corners and badly heated-up bedrooms need to stay so for ever, they are wrong. Any building can be worked upon towards becoming a green structure, with some studied ideas, thoughts and interventions.
The green technology can be divided into 2 broad sub-divisions – passive systems and active interventions. The former is rooted in non-mechanised, no or low energy ideas, locally applicable and easy implementation possibilities. In contrast the active ones need machines, power, maintenance, skilled execution, high-ended materials and such others.
In existing buildings both are possible, but the active ones would effect the building envelop more due to the need to run wires, cable and pipes. It is wiser to start with the passive solutions first, check out for their implications and then decide upon the alternative solution.
To start with…
Making a small displacement ventilation hole just below the roof level is the easiest one to start with. The opening needs to have a chajja to stop rain water from spraying in or be a perforated opening. There could be a mosquito mesh, so fixed that it could be removed for cleaning it periodically. If it does not work, only then there could be an electric exhaust fan to throw the foul air out. Every site has certain directions of predominant breeze, which the occupants might have observed.
Alternatively, small hand-held equipment can be used to check them out during the different periods. Using this knowledge, openings could be created in windward and leeward directions, that let in air automatically.
If light is the issue, skylights should be first considered before going in for more windows in the wall. The latter can be made ineffective by the space between neighbouring structures, orientation of the window and presence of chajjas. As such, let us look out for factors that may negate the idea of window before we decide on them. People have started with fitting mirrors outside the house, to reflect light inside during sunlit hours, of course in extreme cases. Putting on the electric bulb should be the last option.
Many buildings from the olden days come with too many walls, doors and compartmentalised spaces which neither allow free flow of air nor let the light spread. Removing the possibly unnecessary walls could be a tricky decision, but open planning helps a lot with air, light, sense of space and functionality.
Tackle the south and west
Watching out for heated interiors always point out to some walls in south and west that face direct solar radiation. Roofs also receive much of the heat. Simply block the radiation from reaching the building by tress, sunshades or shading screen walls and we see the room being cooler.
Cladding the walls with hollow core materials and clay products with heat sink qualities also helps a lot. Generally, we can work upon an existing building, but mostly people do not. Why? One would have got accustomed to the structure!
Can we imagine a hospital with interior courts full of flowering plants? How about a hotel lobby naturally lit by sunlight? Can there be a long hotel corridor, one side lined up by rooms, but the other side opening to the nature outside? All these are possible and happening, where the designers, developers and builders together have been conscious about green interiors.
Interiors could be air conditioned, despite them being energy consuming, affecting indoor air quality or leading to sick building syndrome, which are rooted not in the technology, but in the management. The mantra towards A.C. should be to install minimally and maintain meticulously. If we can reduce our greed or some of the needs, thereby avoiding the complete site being built upon, ideas like staggered walls, diagonal planning, internal courts and such others can bring in more air and light.
Indoor plants do wonders, by taking in carbon dioxide to give out oxygen during the process of photosynthesis. They also emit water molecules through the leaves in a process called transpiration which increases humidity. Placing potted plants is a great idea to turn any dull and stale interiors into a vibrant work place. Looking at greenery impacts us psychologically, besides increasing fresh air and humidity.
Colour is definitely a personal choice, but if we can work with non-provocative colours, the interiors can be given a dignified feel. As such, lot of designers work with light colours and pastel shades, which coupled with good day light factor, create a cheerful interior. They also tend to reflect more light, reducing the need for artificial lights. Even if the artificial light is inevitable, the fixtures can be so designed to emulate day light patterns with varying intensities and corners distinguished from the centre. Though lighting design is a small measure, it is proved to influence people. Along with colour, light can set the moods of people, either to quieten them or to provoke them.
Even if such materials are not feasible, soothing colours, varied textures and different surface treatments can be adopted to the interiors, thereby creating a perceptional difference from a non-expressive dull indoors. After all there is no proof to claim that luxurious interiors, opulent finish, posh looks or costly gadgets make up a better interior. Where necessary, we may give the opulent touch, but if not warranted, interiors can be earthy. They may let us stay normal, without feeling conscious of being somewhere conspicuous.
Such human moods may not be a part of sustainable designs today; however, buildings designed in a more earthy way with stone, bricks, mud, wood and tiles tend to appeal to us differently compared to the mainstream conventional buildings. May be for such reasons, most health centres, nature resorts, weekend cottages, holiday homes and such others adopt designing with nature. If so, why not extend such design approach to our places of work and stay as well?
Twenty years ago this question would have got brushed aside as a nonsense statement, but today many subject experts feel, in its present form, air conditioning cannot be sustained towards a greener future. We condition the air such that we need not sweat or shiver, but we are making the earth sweat and shiver.
Humans can easily adopt their bodies to live in 4 to 40 degree Celsius temperature, with appropriate clothing. So, all our past generations have lived without air conditioning, even in climates harsher than the range mentioned. Our bodies are biologically made for gradual transitions in temperatures and humidity, on daily and seasonal basis. In reality, the body cannot adjust from 22 to 40 degree C. variations as we come out of an air conditioned office, hence moving in and out of A.C. creates body stress and strains.
We need a balance and parity between outdoor and indoor temperatures for smoother body adaptions, but in India we follow the western standard of 22-23 degrees Celsius, which is more suited to their colder climates. No wonder when we walk into an A.C. bus or office, most often they feel like freezers. Also, the impact on body varies in auditoriums or offices with the number of occupants.
In urban contexts, people quote sound, smoke and dust to justify A.C., which is valid. But, how many of us can live 24 hours inside the A.C. and even if we can, would it be a greatly healthy life? The choice between letting the body get acclimatised or get conditioned is left to the individual, but what follows the A.C. is a fact — living with artificial ventilation, inadequate air change cycles, increased carbon dioxide intake, questionable indoor air quality and finally, the now much discussed sick building syndrome.
As a nation, India today is embracing this technology at a frenzied rate in every type of building, be it a college or a coffee shop, without being fully aware of the havoc it is creating. Fortunately, industrialised nations are worried about it, considering the energy it consumes, urban heat it increases and the potential it has to deplete the ozone layer. They have realised that HVAC systems (Heating Ventilation Air Conditioning) cannot perform without equipment, electricity, gas generation or creating waste at the end of the life cycle.
As such, many options for indoor comforts without air conditioning such as air cooling through humidifiers, chilled water pipe systems, earth tunnels, wind catchers with water pots, passive cooling systems, designing for the climatic zone, and design ideas with sky-lit atrium lobbies are being explored. Besides such ongoing research towards alternatives to A.C., the technology of air conditioning is also being improved for low energy consumption, efficient heat transfer systems, long life for machine components or environmentally safer refrigerants.
However, sustaining the growing popularity of air conditioning is still a big challenge.
There is hardly any seminar today, focused on the themes of energy conservation and sustainability, which goes without reference to air conditioning (A.C.). Considered to be among the fastest expanding human needs, just like flights, phones or cars, air conditioned indoors are on a fast track in every developing country, while the affluent nations have already conditioned most of their indoors.
Impacts of air conditioning on green living is much debated, ironically, most often sitting inside A.C. rooms, suggesting how inseparable it has become from our routine urban lives. The need of the hour is to understand the problems and potentials of the technology behind A.C. Human attempts to control the indoor air must have started right when our ancestors stopped their nomadic lifestyle and became settlers. Mere wrapping up of the body was not adequate to protect us from heat and cold, especially in climatic zones with extremities of temperature. There are records to prove that as early as 2nd century A. D. the Chinese were trying to cool the indoors using ingenious ideas. St. George’s Hall in Liverpool, England, built in 1854, is believed to be the first air conditioned building in the modern era. The credit of adopting modern technology, using electrical energy, for air conditioning goes to Willis Carrier, who in the early 1900s started the trend of air conditioned buildings in the U.S. So, the urge to condition the air has been both historic and human, and cannot be wished away now a century later.
As heat would naturally flow in the opposite direction, we need machines to achieve this. Air conditioning happens by a simple rule of physics which states that liquid absorbs heat when changed from liquid to gas and gases give off heat when changed from gas to liquid. The system follows cycles of expansion, evaporation, compression and condensation, all inside a closed loop. First, the refrigerant liquid is expanded at low pressure and is let into the indoors. In contact with the indoor air, this low pressure liquid absorbs heat, becoming low pressure gas, in the process resulting in lower temperature inside. This heat laden low pressure gas is collected and goes through compressors to become high pressure gas. This hot gas is passed thorough condensers, releasing the heat to outside, becoming high pressure liquid. This pressurized liquid is expanded to become the low pressure gas, repeating the cycle already explained.
In principle, it is the same refrigerant that moves from one machine to another, passing through hot indoors, cooling it and releasing the heat to outside. If we try standing near these machines outside, we can feel the heat being released, so too while crossing a jammed road with majority of air conditioned cars around. So, in the name of air conditioning, while we are cooling the indoors, we are actually heating the outdoors!