Post 539 –by Gautam Shah
A building is affected by various aspects of the climate, which are, mainly external to it. A building as a shell modulates the climate, and creates an improvised climatic (interior environment) not only within it, but over the vicinity. Modern buildings have systems that consume energy to provide lighting, ventilation, cooling, heating, conveyance, and various types of kinetic power. Operations of such systems affect the environmental conditions of the building and the surroundings. Occupants of the building are also active energy processors, and leave their imprint in the place of inhabitation.
Building level climate is formed by following factors:
1. Climate of the region
2. Climate at the location
3. Building structure or shell
Ideally a building design should begin with the climate of the region and its location related variant. A building shell is formed of many materials and form-compositions. The materials due to their constitution and forms of composition offer a complex but unique set of interactions with the various climatic aspects.
As a design, the tasks are scheduled and located through appropriate orientation, and so are expected to benefit from the climate. Specific activities are spatially designated and timed in the sections of the building for their density of occupancy in terms of humans, facilities and amenities. These activities, however, often stretch beyond their nominally defined space, overrun the schedules, and have varied levels of occupancy. The adequacy of a building for the climate and possible environmental comfort is thus an averaged experience.
In dense urban localities the site size, shape and the predefined exposure due to the surroundings, all constrain perfectly oriented planning. The interrelationship between sections and linkages add to the contradictions. From a climate point of view, a building shell behaves like a biological entity, that is in a continuous process of achieving equilibrium. But the permanency of the site size, shape and predefined exposure, limit the climatic adjustments. There are two sets variable factors that require climatic management: the externally, the unpredictability of climate, and internally changing task profiles, related space occupancy, and time scheduling. The variable factors cannot always be managed in the size, shape and form of the building form, however, amenities, and facilities mitigate the situation.
At an extreme level, with the use of ‘universal services’ (central air conditioning, auto ventilation, etc.) environmentally consistency is achieved for the entire building shell. In another approach, relocatable amenities and facilities, help time+space shifting of tasks. Designers also use materials and techniques of composition to make energy exchange favourable. The techniques include architectonic features such as parapets, barricades, curbs, chowks, cutouts, ventilators, ducts, chimneys, shafts projections, chhajjas, balconies, galleries, canopies, and textured surfaces. Landscape features like slopes, hills, mounds, gorges, valleys, water bodies, shrubs, plants, shrubs, hedges, groves etc. are used for the same purpose. The success of a climatic design depends on how the active and passive means can hasten, delay, curtail or terminate some of the environmental processes.
Some of the problems that designers face while designing with the climate are:
1 Building is often required to be located in a climate region that is essentially inappropriate for the intended activity. A dehydration plant to be located in tropical rain forest area.
2 A building consists of several sub units (limbs), some of which will have either inferior or superior climatic orientation. Placement of parking on a west side of a building / bedroom on a windward side.
3 Environmental requirements are often so exact or acute that traditional climate modulation techniques like building shape, materials, orientation etc. is inadequate.
4 Activities within a building cannot be located permanently, because there are many hourly, daily and seasonal variations in a climate.
5 An activity though accurately located in a building, may last longer than the affective duration of the particular type of climate in that section.
6 Activities often require specific climate conditions, but whose occurrence is not easily predictable.
7 Some activities cannot be relocated to new areas to suit the hourly or seasonal changes in a climate, because the amenities with which they flourish are fixed.