shelter for composite climate -...
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SHELTER FOR COMPOSITE
CLIMATE
Nature of the climate
Neither consistently hot and dry , nor warm and
humid.
Characteristics change from season to season.
Significant differences in air temperature , humidity
, wind , sky and ground conditions
Physiological objectives
Set out for warm humid and hot dry climate apply
to the respective seasons of composite climate.
The designer tries to increase the heat dissipation in
warm season and vice-versa in cold season
according to the physical comfort.
Design Criteria
Average Temperature of Islamabad
Seasons Month Discomfort
level
Durati
on
Index Percentage
Hot dry May +3⁰C 1
month
3
June +5.5⁰C 1 5.5
Seasonal
total
8.5 13.5
Warm humid July +8⁰C 1 8
August +6.5⁰C 1 6.5
September +4.5⁰C 0.5 2.25
Seasonal
total
16.75 26.5
Cold dry November -8⁰C 0.3 02.4
December -11⁰C 1 11
January -11⁰C 1 11
February -10⁰C 1 10
March -6.5⁰C 0.5 3.25
Seasonal
total
37.65 60
Annual total 62.9 100
Discomfort Index = discomfort level x duration
Form And Planning
Compact internal
planning
Courtyard type
buildings
Dense low rise development for
o Mutual shading of external walls.
o Shelter from wind in cold season.
o Shelter from dust.
o Reduction of surfaces exposed to solar radiation.
Separate day and
night rooms are
preferable for the
hottest month.
EXTERNAL SPACES
Large projecting eaves and wide verandahs
o To reduce sky glare and provide shade
o To keep out the rain
Brise-soleils, louvers and
other sun breaks
o To protect openings
o Serve as protection
against rains
Pergolas
o To provide shade in hot season but admit the sun in
the winter
Roofs and walls
More time lag – Thick solid walls , concrete walls .
Thermal capacity is an advantage in both cold and try season .
In warm humid climate – low thermal capacity , good insulating wall and roof .
Thermal capacity in floors , partitions and ceiling .
Resistance insulation provided only in external walls .
Advantage of low rise development .
Low thermal capacity
More time lag
Thermal storage
Surface Treatment
In cold seasons – absorbing
surface .
Light color
• Surface exposed to sun –
in hot and warm seasons
Dark color
OPENINGS
Orientation
Towards breeze prevailing- warm humid season-for
cooling effect.
Towards sun-cold season-for heating effect
VENTILATION AND CONDENSATION
Best protection is to use to use porous and moisture
absorptive materials
Traditional Shelter
Relative predominance
of hot dry or warm
humid conditions.
An urban solution for
housing is ground floor
with massive walls with
large shuttered
openings, laid out
around a courtyard ,
and a first floor
structure of light
weight materials.
The walls of floors cool
quickly at night
because they are made
up of light weight
materials, to allow
fairly comfortable
sleeping condition .
SHELTER FOR TROPICAL
UPLAND CLIMATES
Nature of the climate
This climate is similar to composite climates , with its
distinct rainy seasons.
Strong solar radiation.
Temperature rarely reaches 30degC.
Maximum diurnal variation 20degC.
No excessive humidities.
Almost constant air movement , never very strong.
Physiological Objectives
Air temperature rarely
exceeds the upper
comfort limit.
Protection against
overheating-
o Adequate shading for
windows.
o By limiting heat
admission like
insulation of walls
By provision of adequate ventilation.
FORM AND PLANNING
Orientation of the building and its major openings
greatly influence the solar heat gain.
Solar radiation hierarchy :
West > east = south west = north west > south >
north
North and south : Longer walls and major openings.
West : openings should be avoided.
EXTERNAL SPACES
Adjustable shading devices : pergolas, awnings
Alternative external spaces for use in different
seasons where space is not a premium.
Shade can be provided by the building itself
Roofs and Walls
For offices – 5 hours of time lag
light weight walls in multi storage building .
Good insulation and shaded windows .
Limit heat during day time
Store heat during night time
For residency – time lag of 8 hours and high thermal capacity structure
-east and west facing walls should be massive
- north and south facing walls are light weighing
More time lag
Less time lag
Surface Treatment
For day time buildings – white and reflective
surfaces can be used .
For continuous – fabric is
used to store heat for night
and dark , more absorbent
surface finish .
Building with high thermal
capacity .
Roof – 8 hour time lag
Black bituminous or asphalt finish – absorbs solar heat during day and release after sunset
For light weigh roof –bituminous polished roof is covered with aluminum or marble chips .
At high altitudes well tested material should be used .
Polished with bituminous
OPENINGS
No need for physiological cooling by air movement
No need for cross ventilation-feeling of cold
discomfort
BUT where soar overheating does occur, cross
ventilation may provide relief
Closing of openings and less opening(20% of
elevational area)- easier to control solar heat gain
Traditional shelter
Traditional rural
shelter-
o Round huts.
o Mud and wattle walls.
o Thatched roof.
Plastered with mud.
Maximum thickness of
0.25m, for substantial
thermal capacity.
Urban areas-
o Stone masonry walling.
o Slate roofs.
Roof may be thatched
or of wood framework.
Plastered with mud.
Small openings.
THANK YOU!!!
Aabha 12SA101
Ankita 12SA104
Anmol 12SA105
Pratyashi 12SA127
Divyakshi 12SA152