Climatology: Scientific Study of Climates & Affecting Factors

  • Climatology is the scientific study of climate, and the factors that affect it.

Why there is a need to study Climatology?

  • To determine the climatic patterns of a particular region for functional building design.

Climate Zone

  • According to BIS, India can be broadly classified into five regions with distinct climates:

Climate zone map of India, Source: National Building Code 2005

Classification of Climates

Characteristics of Different Climate Zones

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Building Design Factors affected by Climate Change

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Design Considerations for a Climate Zone

A. Building Orientation

1. Hot and Dry Climate
  • An East-West orientation is preferred.
  • Orient Building long faces along North- South axis.
  • Smaller walls from East to West facade to reduce heat gain.

2. Warm and Humid Climate
  • Building should be located on wind direction to take advantage of cool breeze.
3. Temperate Climate
  • North and South facade should receive least amount of radiation.
  • Landform Building the structure on the windward slopes is preferable for getting cool breeze.
4. Cold Climate
  • Building should be located on the South slope of a hill or mountain for better access to solar radiation.
  • Exposure to cold winds can be minimized by locating the buildings on the leeward side.
5. Composite Climate
  • Building should be located preferably in North-East and South-West direction.
  • This helps in receiving less radiations and more natural light and ventilation.

B. Plan Form

1. Hot and Dry Climate
  • The building must be compact.
  • Smaller surface (s) to Volume (v) ratio to reduce heat loss.
2. Warm and Humid Climate
  • The building could be long and narrow to allow cross ventilation.
  • Elongated plans for maximum cross ventilation.
  • The surface finish should be protected from the effects of moisture.

3. Temperate Climate
  • The building plan should be reasonably compact.
  • It would reduce heat gain during the day and heat loss during the night.

4. Cold Climate
  • The building must be compact with small surfaces to volume ratios.
5. Composite Climate
  • The building must be compact and low rise.
  • Buildings with courtyard are more suitable.

C. Building Envelopes: Walls

1. Hot and Dry Climate
  • Heat storing material is more preferable.
  • Double wall construction with insulation in between resist direct heat.
  • East and West walls should preferably be shaded.
2. Warm and Humid Climate
  • The walls must be designed to promote air flow, to counter the prevalent humidity
  • Baffle walls, both inside and outside the building can help to divert the flow of wind inside
3. Temperate Climate
  • East and especially the West walls should also be massive.
  • North and South walls will not receive much radiation and they may be of a lightweight construction.
4. Cold Climate
  • The walls should be insulated.
  • The South facing walls (exposed to solar radiation) could be of thermal capacity (such as Trombe wall) to store day time heat for later use.
5. Composite Climate
  • Solid masonry or concrete wall.
  • Insulated walls are preferable.

C. Building Envelopes: Roofs

1. Hot and Dry Climate
  • Flat roofs or vaulted roofs are ideal in this climate.
  • Roofs should be made higher so that radiations from ceiling are less harsh.
  • Light colored or totally white terrace surface will reduce effect of hot solar radiations.
2. Warm and Humid Climate
  • The form of roof should be planned to promote air flow and provide shelter from rain and heat.
  • Double roof with vents at the rooftop effectively induce ventilation and draw hot air out.
  • Â Sloped roofs are suitable for this region.
3. Temperate Climate
  • Insulated with reflective material to reflect heat and retain warmth.
4. Cold Climate
  • A sufficiently sloping roof enables quick drainage of rainwater and snow.
  • Skylights with shutters on the roof admits heat as well as lights in winter
5. Composite Climate
  • It should be of Solid masonry or concrete.
  • Insulated roof is preferred.
  • Roof pond system can be used as insulator.

C. Building Envelopes: Fenestration

1. Hot and Dry Climate
  • More windows should be provided on the North facade of as it receives lesser radiation throughout the year.
  • All openings should be protected from the sun by using external shading devices such as chhajjas and fins.
2. Warm and Humid Climate
  • Smaller windows can be placed on the windward side.
  • The corresponding openings on the other sides should be bigger for facilitating a plume effect for natural ventilation.

3. Temperate Climate
  • Windows can be larger in the North, while those on the East, West and South should be smaller.
  • Maximize daytime cooling with high level vents/windows to let out the hot air and draw in cool air.

4. Cold Climate
  • It is advisable to have maximum window area on the Southern side of the building to facilitate heat gain.
  • Sealed and double glazed windows to avoid heat loss.
5. Composite Climate
  • Large openings (preferable with solid shutters in opposite walls are suitable which helps in cross ventilation.
  • Recessed windows to reduce external solar heat gains.
  • Two small openings, One at high level and one at low level.

C. Building Envelope: Colour and Texture

1. Hot and Dry Climate
  • Darker shades should be avoided for surfaces exposed to direct solar radiation.
  • Light colored / Shiny reflective surfaces should be used to reflect solar heat.
  • Avoid hard paved surfaces as these may create glare and radiate heat inside the building.
2. Warm and Humid Climate
  • The walls should be painted with light pastel shades or white washed.
  • The surface of roof can be of broken glazed tile to reflect sunlight back.
3. Temperate Climate
  • Pale colours are preferable; dark colours may be used only in recessed places protected from the summer sun.
4. Cold Climate

The external surfaces should be dark in colour so that they absorb heat from sun.

5. Composite Climate
  • The external surfaces should be painted in medium tone colours.

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