Introduction to climate and its variables

CLIMATE –
A region with certain conditions of temperature, dryness, wind, light etc.
An integration in time of the physical states of the atmospheric environment, characteristic of a certain geographical location.
The climate of a location is affected by its latitude , terrain , and altitude , as well as nearby water bodies and their currents.

The Intergovernmental Panel on Climate
Change (IPCC) 2001 glossary definition is as follows:
Climate in a narrow sense is usually defined as the
"average weather," or more rigorously, as the statistical description in terms of the mean and variability of relevant quantities over a period ranging from months to thousands or millions of years.
The classical period is 30 years, as defined by the World
Meteorological Organization (WMO).

To Summarize
Climate is the long-term pattern of weather in a particular area. Weather can change from hour-tohour, day-to-day, month-to-month or even year-toyear. A region’s weather patterns, usually tracked for at least 30 years, are considered its climate.

Climate Information –
We as designers are interested specifically in those aspects of climate which affect human comfort and use of the buildings.
 Temperature
 Humidity
 Wind Data
 Sky Clearance
 Annual Precipitation
 Radiation

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• changes and extremes of temperature, temperature differences between day and night (diurnal), humidity, sky conditions, incoming and outgoing radiation, rainfall and its distribution, air movements and special features such as trade-winds, thunder-storms, dust-storms and hurricanes .

Climate Classification
According to the Köppen climate classification system, there are five climate groups:
 tropical,
 dry,
 mild,
 continental, and
 polar

These climate groups are further divided into climate types.
The following list shows the climate groups and their types:
Tropical
Wet (rain forest)
Monsoon
Wet and dry (savanna)
Dry
Arid
Semiarid
Mild
Mediterranean
Humid subtropical
Marine
Continental
Warm summer
Cool summer
Subarctic (boreal)
Polar
Tundra
Ice cap

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Zone Climate ( Zone location at a global scale)
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Regional Climate ( geographic unit and topographic unit : rivers, lake , mountains)
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Local Climate - Macro Climate ( topographic subunit, settlement patterns, altitude, vegetation, relation to water bodies, development/ density/ traffic)
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Micro Climate ( plot/site, topography, soil condition, surface features, vegetation )

 Essential for the designer to be familiar with character and location of climate zones-
8 climatic zones
 Hot and Dry
 Cold and Dry
 Cold and Cloudy
Island Climate
Composite Climate
Moderate Climate
 Hot and Humid
 Warm and Humid

Climate Zones as per
ECBC
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Hot - Dry
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Warm – Humid
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Composite
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Temperate
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Cold

Climatological
Data
Name of the City:
Latitude:
Longitude:
MSL:
Time Zone:
Sr.No.
Temperature
Mean Monthly Maximum
Mean Monthly Minimum
Mean Highest of Month
Mean Lowest of Month
Extremes
Maximum Ever Recorded
Minimum Ever Recorded
Relative
Humidity (%)
Morning
Evening
Wind
Mean Monthly Speed (Km/hr)
Prevailing Directions
Morning
Evening
Sky Clearance Factor (%)
Sunrise to Sun set
Radiation (W/m2)
Mean Monthly Maximum
Mean Monthly Minimum
Precipitation (mm)
Mean Monthly Rainfall
Mean Annual Rainfall
Heaviest Within 24 hrs
Climatic Zones
Comfort Conditions
Jan May August November

Design Criteria
 resisting heat gain by providing shading, reducing exposed area, controlling and scheduling ventilation, and increasing thermal capacity.
 presence of “water bodies” is desirable as they can help increase the humidity, lot of heat in the afternoons and evenings.
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Heating should be avoided by appropriate design features.

Design Criteria :
 reduce heat gain by providing shading
 promote heat loss by maximizing cross ventilation.
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Dissipation of humidity is also essential to reduce discomfort.

Design Criteria:
 resisting heat gain by providing shading, reducing exposed area, controlling and scheduling ventilation, and increasing thermal capacity in summers .
 presence of “water bodies” is desirable to increase the humidity in summers.
 maximizing cross ventilation is desirable in the monsoon period.
 indirect heating in winters.

Design Criteria:
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 reduce heat gain by providing shading, and promote heat loss by ventilation.

Design Criteria:
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 resisting heat loss by insulation and infiltration promoting heat gain by directly admitting and trapping solar radiation within the living space.

Design Criteria:
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 resist heat loss by insulation and controlling infiltration.
Simultaneously, heat gain needs to be promoted by admitting and trapping solar radiation within the living space.

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Contents of Bioclimatic Checklist
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Solar Radiation
Temperature
Wind Condition
Precipitation/ Humidity
Vegetation
Geological Data
Water Resources
Building Materials
Urban Features

Site Inspection
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Diurnal Sun path
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Seasonal Sun path
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Existing vegetation
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Topographic figures
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Surrounding buildings
Technical Review
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Sun angles
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Incident radiation
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Sunshine hours
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No. of days without sunshine
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Solar reduction by pollution.

Site Inspection
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Shape & Slope in relation to valley, basin, mountains.
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Slope location
(bottom, top etc.)
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Shading areas
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Relations to water
(lake , river)
Technical Review
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Site data: altitude,
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Meteorological data:
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Max. & min temperatures
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Diurnal temperatures
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Growing seasons
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Weather Conditions

Site Inspection
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Windward – leeward relationships
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Local wind conditions
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Wind deformation
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Wind barriers, turbulence
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Distribution of wind influenced by vegetation, topography, buildings etc.
Technical Review
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Wind speed (km/hr, m/s)
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Annual frequency
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Distribution of wind direction
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Days without air movement

Summer Winter

Site Inspection

Windward &
Leeward Relationship
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Site drainage
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Vegetation
Technical Review
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Precipitation data – total amount, kind, distribution
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Humidity data ( % of humidity : seasonal variations)

Site Inspection

Kind & distribution of covered and uncovered areas
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Identification important plants of
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Location of trees according to species, no. , ht. age, diameter of trunk. Etc.
Technical Review
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Maps of existing vegetation
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Location landscapes water bodies
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Zoning plans of and

Site Inspection

Inspection topography of
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Surface structures
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Artificial modeling ground
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Soil condition
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Traditional building material
Technical Review
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Topographical sections
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Geological maps

Site Inspection
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Underground water
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Drainage paths
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Quantity & quality of water
Technical Review
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Geographical conditions
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Seasonal water masses
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Precipitation

Site Inspection
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Availability of natural building material
(clay, stone, gravel, lime)
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Organic building material ( timber, reed etc.)
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Traditional architecture.
Technical Review
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Ability of application and treatment.
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Expenses

Site Inspection
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Kind & density of buildings
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Kind, density & distribution of planted
& natural vegetation.
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Distance to roads
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Noise disturbance
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Air pollution
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Traffic yield
Technical Review
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Checks – air & water pollution
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Noise & sound level measurements
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Utility infrastructure
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Frequency of traffic & future increases
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Additional information of dense urban areas