climate

TOPIC

7.1 Shelter for hot-dry climate

7.2 Shelter for warm-humid climates

BOOK

MANUAL OF TROPICAL HOUSING AND BUILDING

Nature of the climate

HOT DRY AND SEMI DESERT CLIMATES

VERY HOT DRY AIR AND DRY GROUND

• DAY TIME

AIR TEMPERATURE : 27° TO 49 ° C

( > THAN SKIN TEMPERATURE

36° TO 37° C)

• NIGHT TIME

AIR TEMPERATURE : 22° C (FALLS)

• LOW HUMIDITY

• NO CLOUD COVER ( FROM DIRECT SOLAR RADIATION )

HOT - DRY CLIMATES

Nature of the climate

WARM – HUMID CLIMATES

• AIR TEMPERATURE : 21° TO 32° C

(LITTLE VARIATION IN DAY AND NIGHT)

( OFTEN EXCEEDS NORMAL SKIN TEM.)

• HIGH HUMIDITY

(ALL SEASONS )

• HEAVY CLOUD AND WATER VAPOUR

• MOSTURE WITH MODRATE HEAT AND HIGH RAIN FALL

• PLANT COVER

• WIND

Nature of the climate

Nature of the climate

Warm-humid climate

Physiological objectives

HOT DRY CLIMATE

• it is the PHYSICAL HUMAN COMFORT FROM THE ENVIOURMENT.

•PHYSICAL COMFORT OF HUMAN PER DAY DEPENDS ON THE

REDUCTION OF THE INTENCE RADIATION FROM SUN, GROUND AND

SURROUNDING BUILDINGS.

•MAINTAINANCE OF INNER SURFACE TEMP. is LESS THaN THE SKIN

TEMP.

•THE BODY DISSIPATE SOME OF ITS HEAT TO THE SURROUNDING

MAKING TEMP. COOL BY CONVECTION.

NIGHT

•AT NIGHT THE AIR TEMP. IS FREQUENTLY LOW PERMITS EFFECTIVE

TEMP. ( TEMP. OF COMFORT ) .

•SUCH EFFECTIVE TEMP. AT NIGHT BECOMES BENEFICIAL.

•DUE TO LOW HUMIDITY EVAPORATION IS HIGHER COMPARED TO

OTHER CLIMATE.

•SPECIAL ARRANGEMENT IS NOT NECESSARY EG. A.C COOLER ETC.

Physiological objectives

HOT DRY CLIMATE

DAY TIME

CLIMATE IS TOO HOT DURING DAY, ARRANGEMENTS ARE

REQUIRED AS THE AIR IS NOT COOLED AND DUST

FILTERED.

Physiological objectives

WARM-HUMID CLIMATE

TEMP. IS NEAR TO SKIN TEMP.

HEAT IS TRASMITTED BY CONVECTION AND

CONDUCTION, WHICH IS NEGLIGIBLE

• FOR PHYSICAL COMFORT THERE SHOULD BE HEAT

DISSIPATION FROM BODY=TO THE AMOUNT OF METABOLIC

HEAT PRODUCTION OF THE BODY.

• HIGH HUMIDITY - SATURATED AIR ENVELOPE

- BLOCKING EVAPORATION CYCLE

THE SATURATION CAN BE AVOIDED BY

ALLOWING OUTSIDE BREEZE TO

PASS THROUGH THE BUILDING AND

TO THE OCCUPANTS.

AT NIGHT. NO SIGNIFICANT COOLING IS DONE.

THE WALL AND ROOF SURFACE TEMP. SETTLE DOWN TO THE

SAME LEVEL AS THE AIR TEMP.

prevention

Physiological objectives

WARM-HUMID CLIMATE

Form and planning

HOT-DRY CLIMATE

•LESS ACCOMODATION UNDER ONE ROOF - LESS HOT AIR AND

THERMAL LOADING

FROM THE SUN.

• LARGER DIMENSIONS OF THE BUILDING SHOULD PREFERABLY

FACE NORTH AND SOUTH.

• WORST ORIENTATION IS WEST.

• NON - HABITABLE ROOMS CAN BE USED AS THERMAL

BARRIERS.

• SHADING OF ROOFS,WALLS AND OUTDOOR SPACES IS

CRITICAL.

• LOW THERMAL CAPACITY MATERIALS SHOULD BE USED FOR

SHADING DEVICES.

• TO HAVE CLOSE GROUPS OF BUILDINGS,NARROW ROADS AND

STREETS , ARCADES , COLLONADES AND SMALL ENCLOSED

COURTYARDS – GET MAXIMUM AMOUNT OF SHADE AND

COOLNESS.

• DIFFICULT SHADING OF ROOF DOUBLE ROOF IS PREFFERED.

• NECESSIATE THE USE OF METAL SURFACE.

Form and planning

WARM-HUMID CLIMATE

• AIR MOVEMENT IS THE ONLY AVAILABLE RELIEF FROM CLIMATIC

STRESS.

• ELONGATED PLANS,IN A LINEAR, ACROSS THE PREVAILING

WIND DIRECTION,AFFORD LOW RESISTANCE TO AIR MOVEMENT

AND IS THEREFORE THE IDEAL SOLUTION.

Form and planning

Hot dry climate

Warm humid

climate

Form and planning

Hot-dry climate

Form and planning

Hot-dry climate

Form and planning

Hot-dry climate

Form and planning

Warm-humid climate

Form and planning

Warm-humid climate

Form and planning

Warm-humid climate

External space

HOT-DRY CLIMATE

•EXTERNAL SPACES ARE NECESSARY TO TREAT AS

IMPORTANTLY AS THE BUILDING.

•ADJACENT BUILDINGS,

PAVEMENTS (FOOTPATH KIND OF) HEAT UP QUICKLY

DRY GROUND

NIGHT DAY

RERADIATE THE HEAT STORED PAINFUL GLARE

DURING THE DAY. RELECT HEAT RADIATION

TOWARDS THE BUILDING

DURING THE DAY.

• TREES , PLANTS , WATER body WILL COOL THE AIR BY

EVAPORATION.

• thermal regulators :- 1. courtyard

2. water body

• WATER BODY – COOL AIR at night IS RETAINED, AS cool

AIR IS HEAVIER THAN THE SURROUNDING WARM AIR.

External space

WARM-HUMID CLIMATE

EXTERNAL SPACES

SHADING FREE PASSAGE

[IMPORTANT FOR AIR MOVEMENT IN

EXTERNAL SPACES]

• PARGOLAS OR FRAMING TO BE COVERED BY CLIMBING

PLANTS.

• PRIVACY IS NOT OBTAINED – FOR PRIVACY

- PALING FENCES

- SCREEN WALLS DO NOT

PERMIT DIRECT VIEW BUT

ALLOW BREEZE TO PENETRATE

EG. LOUVERS.

• THE DENSITY OF HOT-DRY IS MORE THAN WARM-HUMID

REGIONS.

– THREE REASONS

• TO ALLOW FREE MOVEMENT OF AIR THROUGH BUILDINGS

AND SPACES BETWEEN BUILDINGS.

• TO PROVIDE PRIVACY BY DISTANCES,AS WALLS AND

SCREENS CANNOT BE USED FOR THIS PURPOSE.

• MANY ACTIVITIES ARE CARRIED OUT-OF-DOOR.

External space

Hot-dry climate

External space

Hot-dry climate

External space

Hot-dry climate

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GHot – dry climate

•In hot dry climate roof and walls would absorb more heat during

day time due to heavy material.

• Thus the design of opening is governed by two requirements:

1.During the day the absence of opening would be most desirable,

or at least opening as small as possible, located high on the

walls.

2. During the night the openings should be large enough to

provide adequate ventilation for the dissipation of heat emitted

by the walls and roofs.

• Designer must study the occupancy pattern of the building.

• For eg.,

- office building must have time lag of 4-6 hours.

- residential building must have time lag of 9-12 hours.

• In regions where diurnal ranges are less extreme ,where the

night-time temperature does not fall below the comfort zone ,

the large thermal capacity should be restricted to internal

walls, partition and floors, whilst the outer walls and roof

would need to have a high resistive insulation.

• Alternatively separate day and night rooms could be provided in

the house.

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GHot – dry climate

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GHot – dry climate

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ALLS

WARM-HUMID CLIMATE

• THE CONSTRUCTION OF BUILDING OF LOW THERMAL CAPACITY

MATERIAL OF LIGHT WEIGHT IS ADVISABLE.

• THE ROOF IS PRACTICALLY THE ONLY ELEMENT WHICH HAS A

VERY GREAT SIGNIFICANCE.

• IT CANNOT IMPROVE THE CONDITIONS, I.E., IT WILL NOT PRODUCE

TEMPERATURES COOLER THAN THE OUT DOOR AIR, BUT ATLEAST ,

IF WELL DESIGNED ,IT CAN PREVENT THE INDOOR TEMPERATURE

INCREASING ABOVE THE OUT DOOR AIR TEMPERATURE , AND KEEP

THE CEILING TEMPERATURE AROUND THE SAME LEVEL AS OTHER

SURFACES.

• IT HAS BEEN SUGGESTED (97) AS A PERFORMANCE STANDARD,

THAT RHE CEILING TEMPERATURE SHOULD NOT EXCEED THE AIR

TEMPERATURE BY MORE THAN 4°C.

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WARM-HUMID CLIMATE

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HOT - DRY CLIMATE

IT DEPENDS UPON :

1. SURFACE MATERIAL

2. SURFACE TREATMENT

3. COLOUR

CONTROLS THERMAL

BEHAVIOUR AND PREVENTS

HEAT RADITAION

• COLOUR USED MUST BE LIGHT

• THE MATERIAL USED SHOULD BE SHINY

REFLECTS

LARGE AMOUNT

OF INCIDENT

RADIATION

ROOF

• ANY LOCATION NEAR THE EQUATOR RECIEVES GREATEST AMOUNT

OF SOLAR RADIATION DURING DAY TIME

•DURING NIGHT IT IS MOSTLY EXPOSED, THUS IT EMITS RADIATION

TO OUTER SPACES.

•ROOF SUFRACES MATTER MORE THAN THE WALL SURFACES.

•ABSORBANCE AND EMITTANCE VALUE REMAIN SAME FOR A

MATERIAL FOR SAME TEMPERATURE.

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HOT - DRY CLIMATE

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WARM-HUMID CLIMATE

• OPENINGS MUST BE PLACED SUITABLY IN RELATION TO THE

PREVAILING BREEZES TO PERMIT NATURAL AIR FLOW THROUGH

THE INTERNAL SPACES AT BODY LEVEL.

• SUCH OPENINGS SHOULD BE LARGE AND FULLY OPENABLE;

THERE IS NO POINT IN HAVING FIXED GLASS PANES.

• OPENINGS SHOULD BE FROM THE EFFECT OF OUTSIDE

OBSTRUCTIONS.

• AIR FLOW SHOULD NOT PASS OVER HOT SURFACES BEFORE

REACHING THE BUILDING.

• LARGE OPENINGS – GIVEN PROTECTION – DRIVING

RAIN,INSECTS,SMELLS AND NOISE WITHOUT RADICALLY

REDUCING AIR MOVEMENT.

• CEILING MOUNTED OR OTHER ELECTRIC FANS MAY BE USED

WHEN THERE IS LITTLE OR NO BREEZE,BUT THESE WILL

NORMALLY PROVIDE AN AIR MOVEMENT,NOT INDUCE THE

EXCHANGE OF AIR.

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FLO

WHOT - DRY CLIMATE

• DURING THE DAY-TIME OPENINGS SHOULD BE CLOSED AND

SHADED.

•AS THE HOTTEST SURFACE IS LIKELY TO BE THE CEILING OR THE

UNDESIRABLE OF THE ROOF, IT IS ADVISSABLE TO HAVE THE TOP

OF THE OPENINGS LEVEL WITH THE CEILING.

•ATTENTION MUST BE PAID TO THE DESIGN OF THE OPENINGS TO

THIS SPACE AND THEIR ORIENTATION IN RELATION TO THE

PREVAILING BREEZE.

•ROOF SLOPES SHOULD BE ORIENTED TOWARDS THE

PREVAILING BREEZE, AND ANY OBSTRUCTIONS WHICH WOULD

PREVENT THE AIR FLOW NEXT TO THE ROOF SURFACES SHOULD

BE AVOIDED.

•HIGH SOLID PARAPET WALLS AROUND THE ROOF WOULD ,

CREATE A STAGNANT POOL OF HOT AIR , AND SHOULD

THEREFORE BE AVOIDED.

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D AIR

FLO

WHOT - DRY CLIMATE

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TILATIO

NWARM-HUMID CLIMATE

• WITHOUT THE EXCHANGE OF AIR BOTH THE TEMP. AND THE

HUMIDITY OF ROOM AIR WILL INCREASE ABOVE THE OUT DOOR

VALUES, DUE TO THE HEAT AND MOISTURE OUTPUT OF HUMAN

BODIES AND OSF VARIOUS HUMAN ACTIVITIES (EG WASHING NAND

COOKING)

• IN THIS CLIMATE THERE IS A NEED FOR BOTH VENTILATION AND

FOR A SENSIBLE AIR MOVEMENT ACROSS THE BODY SURFACE.

• CARE MUST BE TAKEN TO AVOID AIR WHICH HAS PASSED

THROUGH A ROOF SPACED REACHING THE LIVING ZONE(EG.

VERANDAH) AS THIS WILL BE MUCH HOTTER THAN THE NORMAL

OUTDOOR AIR

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TILATIO

NWARM-HUMID CLIMATE

TRAD

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HELTER

HOT - DRY CLIMATE

DESERT REGION SHELTER

• HEAVY WALLS OF EARTH ,BRICK ,STONE AND ROOFS ARE OF

SAME MATERIALS .

•THICK WALLS PROVIDES GOOD

THERMAL CAPACITY

SECURITY

PROTECTION AGAINST NOISE

• STRUCTURES TENDS TO BE HOT AT NIGHT DURING HOT SEASONS.

OUTER PRIVATE SPACES SUCH AS

COURTYARDS AND ROOFS

PREVENTION

• ROOMS BUILT AROUND A CENTRAL COURTYARD WHICH PROVIDES

COOLER ATMOSPHERE AT NIGHT.

•WINDOW DOORS ARE SMALL IN SIZE AND LESS IN NUMBER.

•WINDOWS LOCATED HIGH ON WALLS.

ADMITTING LESS HEAT AND DUST,

REDUCING GROUND GLARE.

•VENTILATIONS ARE INADEQUATE AND ALSO THE HOUSES ARE

CLOSELY BUILT.

TRAD

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heLTER

WARM- HUMID CLIMATE

BASICALLY TWO TYPES OF SHELTER

EARTH TIMBER

•POOR AND NON-INTENSIVE

AIR CREATES UNBEARABLE

CONDITION.

•INTENSE HEAVY RAIN

ERODE THE BASES AND

SURFACES OF EARTH

WALLS.

•ANNUAL MAINTAINANCE IS

ESSENTIAL.

•UNVENTILATED INTERIOR

REMAIN CONSTANTLY DAMP.

•SHELTER IS ELEVATED BY STILTS

•LOCAL TIMBER AND BAMBOO IS

USED.

•THATCH COVERS BAMBOO ROOF-

FRAME WITH OVERHANGING EAVES.

•THATCH IS BETTER THERMAL

INSULATOR.

•THATCH ROOF IS CONVENIENT TO

THE BREEDING OF INSECTS AND

TERMITES.

•LIGHTWEIGHT TIMBER HOLDS LESS

HEAT AND COLS ADEQUATELY AT

NIGHT

•ELEVATED SHELTER

BROAD EAVES

•SHADE THE WALLS AND OPENING, PROVIDE PROTECTION FROM

DRIVING RAIN AND SKY GLARE AND PERMIT THE OPENING TO BE

KEPT OPEN MOST OF THE TIME.

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LIM

ATES HOT-DRY CLIMATE

• THESE CLIMATES DIFFER ONLY SLIGHTLY FROM THE HOT DRY

DESERT REGIONS - THE MAIN DIFFERENCE BEING THE HIGH

HUMIDITY.

• THE COASTAL WIND BLOWING OF THE SEA DURING THE DAY

MAY BE UTILISED FOR BETTER THERMAL CONDITIONS.

• THE NIGHT TIME WIND BLOWING TOWARDS THE SEA , BRINGS

THE HOT INLAND DESERT AIR, POSSIBLY DUST,AND IT CAN BE

DECIDEDLY UNPLEASANT.

• THE ONLY SOLUTION TO PROVIDE –

• A) ONE WITH HIGH THERMAL CAPACITY WALLS AND ROOFS,

FOR USE AT NIGHT,ESPECIALLY DURING THE COOLER PART OF

THE YEAR. THIS SHOULD HAVE NO OPENINGS FACING THE

INLAND DIRECTION.

• B) ONE OF LIGHT WEIGHT CONSTRUCTION , THE ROOF ONLY TO

PROVIDE SHADE, THE SIDE FACING THE SEA, AS WELL AS THE

OPPOSITE SIDE BEING ALMOST COMPLETELY OPEN. THIS IS THE

BEST SOLUTION FOR DAY TIME USE, ESPECIALLY DURING THE

HOTTEST PART OF THE YEAR.

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LIM

ATES HOT-DRY CLIMATE

Warm-humid island climate

WARM-HUMID CLIMATE

• TEMPERATURES ARE SLIGHTLY LOWER, BUT THERE IS A

STEADY WIND OF 6-7 M/S AND ALMOST CONSTANT DIRECTION TO

RELY ON FOR COOLING .

• THE ORIENTATION AND CONSTRUCTION OF THE BUILDING TO

CATCH THE MAXIMUM AMOUNT OF AIR MOVEMENT WILL BE EVEN

MORE IMPERATIVE THAN IN WARM-HUMID CLIMATE.

• MOST OF THESE ISLANDS LIE IN THE TROPICAL CYCLONE

BELT.

• CONSTRUCTION AND STRUCTURE MUST BE DESIGNED TO

WITHSTAND THE WINDS OF UPTO 7O M/S .

Warm-humid island climate

WARM-HUMID CLIMATE

climate

Common factors

SHIVAM PATEL 12SA131

VAIBHAVI LUHANA 12SA139

MEET PATEL 11SA120

SHIVANI PATEL 12SA132

SWAPNIL PATEL 12SA137

RAHUL MAKWANA 12SA128