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Lighting up hearts

3 Comments
Feb 15, 2013 | From the print edition

A hospital for cardiac patients in Ahmedabad is sunlit to cheer up patients. It saves energy, too

An open courtyard outside the hospital’s OPD reduces need for artificial lights

Hospitals are difficult to design. There are far too many health safety concerns that must not be ignored and very high hygiene standards to be adhered to. Architects, therefore, rarely choose to construct hospitals as eco-sensitive buildings, says senior architect Ashok B Lall. The Care Institute of Medical Sciences (CIMS) building at Ahmedabad has achieved this feat of integrating eco-sensitive elements of design into the building without compromising on the hospital’s standards. The 150-bed hospital was inaugurated in July 2010. It has three floors, a basement, eight operation theatres and two catheterisation laboratories.

Architect Surya Kakani built the 10,000 sq m CIMS where patients could feel at home and get ample movement and breathing space. He brought natural light inside the hospital’s grimmest areas—the ICU and the operation theatre. The building has a thick and tough outer shell yet soft insides, says Kakani.

Sunlit insides

Drawing inspiration from traditional courtyards, each of the four blocks in the building stand independently and are connected with courtyards. “Open spaces were either used to plant locally available tree species or turned into courtyards. This allows entry of natural light and cuts down electricity consumption,” says Kakani.

Natural light has a calming affect and the green environment lifts spirits up, says a patient in the hospital’s ICU. “In operation theatres it is difficult to keep track of time. Entry of natural light is very helpful here,” says anesthetist Ketul Patel. “Eighty per cent of the patients in this super-specialty hospital have cardiac problems. They need natural light, seamless services with less congested environment for fast recovery,” says cardiologist Milan Chag. “All these have been well thought out,” he says.

To give more movement space in the hospital, services such as cables, gas pipes and plumbing occupy once common duct. Minimising service area space reduces false ceiling area and thus cost. It also gives 3.6 m clear height of the rooms, and, therefore, better air quality to patients. The wardrooms have been plastered with washable smooth lime to reduce the risk from volatile organic compounds in paints. They can cause allergies and affect kidneys and the nervous system.

Taking off the load

Four years ago, a group of doctors, mostly established cardiologists, approached Kakani to construct an eco-sensitive building. He chose to use the largely forgotten load-bearing technique rather than the much-too-prevalent RCC (reinforced cement concrete) structure. RCC structures have steel bars for tensile strength and concrete for compressive strength in the beams and columns of buildings. The walls cover the building like a curtain. Load-bearing structures use building blocks such as bricks or stones. The walls are the primary means of transferring the building’s load to the ground.

Such structures cut down energy consumption and provide better insulation because of minimum use of steel, which has high embodied energy. Embodied energy is the total energy used in making a construction material. The walls are made primarily of flyash bricks. Flyash used to make bricks come from refuse of large thermal power plants. A total of 0.3 million bricks were used to construct the hospital. Load-bearing structures make the building earthquake-resistant up to four storeys. Ahmedabad has witnessed severe earthquakes in the past.

The hospital’s load-bearing structure transfers the building’s load to the ground

An intelligent balance of right materials and suitable design strategies go a long way in making a building energy-efficient. Glass is highly used in modern buildings because of its mass appeal for naturally lighting up buildings. However, most of the glass used has only contributed to rising electricity bills (see ‘Reflections on glass’, Down To Earth, December 15, 2012). “Glass retains heat inside the building which leads to reliance on air-conditioners. Glass has high embodied energy,” says Kakani.

Making a load-bearing stucture also increased work opportunities for skilled labour. “Masons are dwindling in number because most of the real estate construction is moving towards pre-fabricated techniques and machinery,” Kakani says.

Taking a cue from the local practice, flooring of the terrace is done by broken glazed tile leftovers from bathroom constructions. These heat-reflective tiles insulate and water-proof the terrace.

And when it rains, efforts have been made to recharge the water. Also, the hospital’s sewage treatment plant, which has 75,000 litres per day capacity, allows reuse of water in the toilet flush, cooling tower and for gardening. Water requirement has been reduced by planting local plant species which have adapted themselves to the environment and require less water.

Thinking green

When making a building take a holistic approach, says Kakani. Do not spend a lot of money to create energy-efficient spaces. “It will go a long way in achieving economy of resources, which is a more fundamental way of thinking green,” says Kakani. He was able to reduce the building cost to Rs 1,800 per square foot (1 sq foot=0.09 sq m). This includes cost of civil work, interiors, electricals, HVAC (heating, ventilation and air-conditioning), plumbing, fire-fighting, site development, and even municipal and professional fee. In Ahmedabad and neighbouring areas, the cost for a similar building is Rs 2,500 to Rs 3,000 per square foot.

In his other projects, too, Kakani has managed to reduce cost in different ways. He used rubble from the earthquake that hit Gujarat in 2001 to construct a school building in Rajkot. Most of the rubble was dumped outside the city.

Kakani’s home, too, is a model example of green living. When he renovated his house, among the first things he initiated was removal of air-conditioners. With a wind-catcher installed on top of his two-and-a-half-storeys house, Kakani created vents that bring cool air down to the rooms in summer nights. “This does not work when it rains, but it rains only for a brief period. I do not feel the need for air-conditioners,” he says.

Designing an eco-sensitive building is all about using locally available materials, local architectural techniques and local skill, says Kakani.

AddThis

Thanks for this wonderful article. I wish more architects, and developers would think green for the environment and not green as in money..

4 February 2013
Posted by
Anonymous

This is indeed a wonderful development in our country and we learn about it thanks to CSE. Recent scientific research on mind-body connection has encopmassed areas such as recovery of patients when they are in better contact with nature. It's being pursued very systematically. For example, trials such as comaprison on recovery of patients when they stare at the regular white wall of the hospital compared to looking at a beauiful landscape on a digital window vs being able to peep out of a real window to look at a tree or a garden outside have proved that recovery rates are faster when they are in contact with natural surroundings. For more related information on subtle positive effects of being with nature, you may refer to the work of Foundation for Contemplation of Nature at the above mentioned website.

4 February 2013
Posted by
Ajay Rastogi

Excellent article.

The West spends most of the energy on heating while sunbelt countries on cooling. There is a saying, “ Banyan tree shade,well water and Brick Houses are cooler in summer and warmer in winter."

There is the need to revive the traditional methods of house construction improving with modern techniques. Studies have shown that the application of all the above techniques in buildings may decrease their cooling load up to 50% - 70%. Generally, concern for energy consumption is only marginal in the majority of architectural-design practices, even in the developed countries. Passive solar energy-efficient building design should be the first aim of any building designer, because, in most cases, it is a relatively low-cost exercise that will lead to savings in the capital and operating costs of the air-conditioning plant. In today’s architecture, it is now essential for architects and building engineers to incorporate passive cooling techniques in buildings as an inherent part of
design and architectural expression and they should be included conceptually from the outset. Incorporation of these passive cooling techniques would certainly reduce our dependency on artificial means for thermal comfort and minimize the environmental problems due to excessive
consumption of energy and other natural resources and hence will evolve a built form, which will be more climate responsive, more sustainable and more environment friendly.

Passive cooling of buildings:
A ‘passive’ solar design involves the use of natural processes for heating or cooling to achieve balanced interior conditions. The flow of energy in passive design is by natural means: radiation, conduction, or convection without using any electrical device. Maintaining a comfortable environment within a building in a hot climate relies on reducing the rate of heat gains into the
building and encouraging the removal of excess heat from the building. To prevent heat from entering into the building or to remove once it has entered is the underlying principle for accomplishing cooling in passive cooling concepts. This depends on two conditions: the availability
of a heat sink which is at a lower temperature than indoor air, and the promotion of heat transfer towards the sink.

Environmental heat sinks are:
Outdoor air (heat transfer mainly by convection through openings)
Water (heat transfer by evaporation inside and / or outside the building envelope)
The (night) sky (heat transfer by long wave radiation through the roof and/or other surface adjacent to a building
Ground Passive cooling techniques can reduce the peak cooling load in buildings, thus reducing the size of
the air conditioning equipment and the period for which it is generally required.

Here are some of the Passive Cooling Techniques adopted in Designing Big Buidings:
Shading by overhangs, louvers and awnings etc.
Shading of roof
Shading by trees and vegetation
Shading by textured surfaces
Insulation
Induced ventilation techniques:
Solar chimney
Air vents
Wind tower
Radiative cooling
Diode roof
Roof pond
Evaporative cooling
Passive downdraft evaporative cooling (PDEC)
Roof surface evaporative cooling (RSEC)
Earth coupling
Earth air tunnel
Earth berming
Desiccant cooling

The design of old houses(mud) in Rajasthan is a fine example of passive cooling.

In hot climates it is necessary to adopt measures to lower the average indoor temperature to a level below the outdoor. Specially designed mud walls are still poplar in the hamlets (Dhanies) of western Rajasthan to deflect the hot winds. These are some of the conventional methods of passive cooling, typical in hot and dry climatic condition. India has a very diversified climate heating of buildings in also required especially in upper latitudes and hilly areas and cooling of buildings is required in lower latitude and desert areas. Solar passive architecture provides proper orientation and design of fenestration i.e. doors and windows to take maximum advantage of sun and wind. For heating the aim is to admit the sun's energy as much as possible and to reduce he loss of heat in the nights. This is achieved by direct gain through windows, therm-wall, or solarium and other such means. The heat loss is minimized by the proper design of walls, by insulation of walls and roof, by night insulation on windows, by double glazing of window- etc.

In this connection the design of East Gate Centre,Harare,Zimbabwe needs to be considered for adoption.

The Eastgate Centre is a shopping centre and office block in central Harare,Zimbabwe whose architect is Mick Pearce. Designed to be ventilated and cooled by entirely natural means, it was probably the first building in the world to use natural cooling to this level of sophistication. It opened in 1996 on Robert Mugabe Avenue and Second Street, and provides 5,600 m² of retail space, 26,000 m² of office space and parking for 450 cars.

The Eastgate Centre's design is a deliberate move away from the "big glass block". Glass office blocks are typically expensive to maintain at a comfortable temperature, needing substantial heating in the winter and cooling in the summer. They tend to recycle air, in an attempt to keep the expensively conditioned atmosphere inside, leading to high levels of air pollution in the building. Artificial air-conditioning systems are high-maintenance, and Zimbabwe has the additional problem that the original system and most spare parts have to be imported, squandering foreign exchange reserves.

Mick Pearce, the architect, therefore took an alternative approach. Because of its altitude, Harare has a temperate climate despite being in the tropics, and the typical daily temperature swing is 10 or 14 °C. This makes a mechanical or passive cooling system a viable alternative to artificial air-conditioning.

Passive cooling
Passive cooling works by storing heat in the day and venting it at night as temperatures drop.
• Start of day: the building is cool.
• During day: machines and people generate heat, and the sun shines. Heat is absorbed by the fabric of the building, which has a high heat capacity, so that the temperature inside increases but not greatly.
• Evening: temperatures outside drop. The warm internal air is vented through chimneys, assisted by fans but also rising naturally because it is less dense, and drawing in denser cool air at the bottom of the building.
• Night: this process continues, cold air flowing through cavities in the floor slabs until the building's fabric has reached the ideal temperature to start the next day.

Passively cooled, Eastgate uses only 10% of the energy needed by a similar conventionally cooled building. 1
Eastgate is emulated by London's Portcullis House (2001), opposite the Palace of Westminster. The distinctive giant chimneys on which the system relies are clearly visible.
Modern use of traditional solutions to work well, the building must be very carefully designed. After computer simulation and analysis, the engineering firm Ove Arup, gave Pearce a set of rules.

They said that no direct sunlight must fall on the external walls at all and the north façade [direction of summer sun] window-to-wall area must not exceed 25%. They asked for a balance between artificial and external light to minimize energy consumption and heat gain. They said all windows must be sealed because of noise pollution and unpredictable wind pressures and temperatures, relying on ducted ventilation. Above all, windows must be light filters, controlling glare, noise and security.

To help with this last, the windows have adjustable blinds, but Pearce also used deep overhangs to keep direct sun off windows and walls. Deep eaves are a traditional solution in Africa, shading the walls completely from the high summer sun, while allowing the lower winter sun to warm the building in the morning.

Further, passive cooling systems are particularly appropriate for this part of Africa because, long before humans thought of it, passive cooling was being used by the local termites. Termite mounds include flues which vent through the top and sides, and the mound itself is designed to catch the breeze. As the wind blows, hot air from the main chambers below ground is drawn out of the structure, helped by termites opening or blocking tunnels to control air flow.

Pearce's practice is in Harare, and he specialises in buildings which are low cost, low maintenance, and have low environmental impact. His projects try to make best use of locally available resources, and include Harare International School Arts Centre, Harare Hindoo Temple and Chinhoyi Provincial Hospital, Zimbabwe.

Dr.A.Jagadeesh Nellore(AP),India
E-mail: Anumakonda.jagadeesh@gmail.com

12 February 2013
Posted by
Dr.A.Jagadeesh

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