HOT &

DRY CLIMATE

Submitted by-

Sumit Ranjan

Yuvraj Chopra

Sumit Kumar

Sonam Yadav

Swati Raina

Submitted to-

Jaspreet Kaur

introduction

According to a recent code of bureau of Indian standards, the country may be divided into five major climatic zones.

• Hot and dry (mean monthly temperature >30 and relativelyhumidity <55%).

• Warm and humid (mean monthly temperature >25-30 andrelatively humidity <55-75%).

• Cold and dry (mean monthly temperature <25 andrelatively humidity- all values).

• Composite (this applies, when six months or more do not fallwithin any of the other categories).

Hot & Dry regions: Ahmedabad, Rajasthan, North Africa, Kutch, Pakistan, etc.

• Orientation and placement, to minimize sun exposure in summer.

• Form, compact to reduce surface areas of heat gain.

• Shade, for maximum sun protection in summer.

• Allow adequate heat gain in winter by movable shading devices.

• Ventilation, for regulation of air movement

outdoor planning

Outdoor spaces:• As most day-to-day activities take place outside, it is

important to treat the external spaces just as carefully as

the indoors.

• Adjacent buildings, pavements, roads heat up quickly and

cause a glare onto the building during the day and

at night, they radiate the heat stored during the day.

• One way to avoid this is to place walls protecting external

spaces, to keep out dust and winds.

• Also, landscaping like trees, plants and water in enclosed

spaces will cool the air by evaporation.

• But the best solution is courtyards. In these a pool of night

air is retained, as this is heavier than surrounding warm air

• A small courtyard is excellent as a thermal regulator.Courtyard design with evaporative cooling

settlement planning

• Topography, to enhance the efficiency of passive

means

• Orientation, to reduce the sun exposure in

summer.

• Air movement, to provide ample ventilation in

summer and protect from winds in winter.

•

Form, to design compact settlements for mutual

protection

• Hazards, to avoid dangerous sites

Typical settlement for hot-dry regions

OVERVIEW OF DESIGN PRINCIPLES..

PAGE: 01-06

• Courtyard or Patio

• White Colored walls (“cool” colours reduce heat reflection )

• Arrangement of the houses in is very closely packed to each other.

• Vegetation (reduces the temperature, filter’s the dust in

• and around the house, elevates the humidity level may reduce as well as

increase the wind speed)

• small openings

• double roof or white single roof

• thick walls

• big basin to collect rainwater

• louvered windows

• pergolas

• a water body

PAGE: 01-06

HOT & DRY CLIMATE

The main points:

• Orientation and placement, to minimize sun exposure in summer.

• Form, compact to reduce surface areas of heat gain.

• Shade, for maximum sun protection in summer.

• Allow adequate heat gain in winter by movable shading devices.

• Ventilation, for regulation of air movement.

Sun orientation

• west orientation is the worst

• The larger building dimension should face north and south

Wind orientation• Main walls and windows should face the wind

direction in order to allow maximum cross-ventilation of the rooms.

• To reduce the effect of hot dusty winds, the leeward side of the house is better.

Room arrangement

• 1. Bedrooms-on the east side.

• 2. Living rooms-on the north or south side.

Building material• Sun-dried earth bricks one of the poorest conductors

of heat.

• Traditionally constructed with thick walls and roofs and with very small openings

walls

• Walls of daytime living areas should be made of heat-storing materials.

• East and west walls should preferably be shaded.

• Double walls with insulation in between are a suitable solution.

Opening and windows• Openings and windows are necessary for natural

lighting and ventilation.

• More windows should be provided in the north facade of the building as compared to the east, west and south as it receives lesser radiation throughout the year.

• Windows should be shaded either by shading devices, roof overhangs or by deciduous trees.

• The size of the windows on the west and east sides should be minimized in order to reduce heat gains into the house in the early morning and late afternoon.

Roofs• The flat roof is a good reflector and re-radiates

heat efficiently, especially if it consists of a solid, white painted material.

• High solid parapet walls along the edge of the roof can on the one hand provide daytime shade and privacy.

• The principle involved is to catch an unobstructed breeze at a high level and channel it to areas in the bottom parts of the building.

Natural ventilation

Passive cooling• Cooling can be achieved by the evaporation of

water.

• The courtyard is provided with water and plants, it acts as a cooling source.

• Internal courtyards provides cross ventilation & natural cooling.

• Most openings are to the internal courtyard rather than exterior surface.

Courtyard

Stack effect• Outlets at higher levels serve to vent hot air. Ventilators are preferred at higher levels as they help in

throwing out the hot air.

Other features

• Colors that absorb less heat should be used to paint the external surface.

• Darker shades should be avoided for surfaces exposed to direct solar radiation.

• The surface of the roof can be of white broken glazed tiles.

• During the day-time openings should be closed and shaded.

• Decreasing the surface of the building exposed to the outside.

• Using materials that take a longer time to heat up.-Providing buffer spaces (lobbies, etc.) between the living areas and the outside.

Elements of Vernacular ArchitectureFor different Hot-Dry Regions around the world

Main Objective:the common basic function is to protect the structure from weather conditions

1. Mediterrean House

•Walls made in raw earth bricks, cooked

bricks, stone or tuff. 50 cm - 100 cm thick

walls accordingly to the construction materials.

•Roof characterized by light wood structure,

more often in bricks and lime.

•Closed volumes, few and little windows.

•There isn’t roof projection, but often there are

stairs outside to reach the flat terraced roof.

Region around the Mediterrean sea, like in

Greece, South Italy, Spain & South France

2.Trulli House, South Italy

•the huge massive stone is usually joint to a big basin to collect rainwater used to

decrease of 6-7°C the interior temperature in summer.

•This allows the natural ventilation through the dome holes and is improved by the

white color of the exterior surface made in lime

3. Arabic House

•the climate is so dry, the temperature range is so high, there’s a strong solar radiation and the winds can

transport huge amount of dust and sand.

The architecture design was developed following tradition, culture, religion and climate answers. The features

are:

•building shape

•wall typologies

•interior spaces distribution openings

•ventilation and cooling systems

The whole design is focused

around the central square-

shaped patio: an empty

space where all the

rooms face to.

Around the patio often

there are porches on one or

more sides and one or more

stored.

1. NIGHT: the cool air comes down in the court and goes inside each room that face to

it. The flat roof and the thick walls also improve the cooling system.

2. AFTERNOON: the sun directly heat the walls that face to the court. The air heats and

goes up providing for the natural ventilation. The court works as a chimney. The massive

walls and doors protect the interior spaces from the direct solar radiation.

3. EVENING: the air is so hot and the court door heats creating a natural air flow from

the rooms that face to it through the patio. The last cool air goes out from the rooms

in the evening, but also the shadows are longer and quickly the court is protected from

the radiation.

To improve these passive systems they usually fix a wet curtain on the court and a

fountain in the middle.

BUNGHA HOUSE“Architecture without Architects”

•A circular space enclosed by mud walls is the most typical dwelling

construction in the Kutch district of the Gujarat state & Rajasthan in India, which has a very high earthquake risk, is called a Bungha.

Materials used

1. Stone 2. wood 3. Bamboo4. burnt brick masonry either in mud mortar

or in cement mortar.5. Straw

Characteristics

•consists of a single cylindrically shaped room.•has a conical roof supported by cylindrical walls. •inner diameter of the Bungha is between 3m to 10m.•has only three openings one door and two small windows.

•construction has existed for several hundred years.•This house is quite durable and highly appropriate for hot & dry conditions.•The entire construction process, which is carried out by the mason with very few unskilled laborers, can be completed within 30 days.

•typically found in flat terrain.•do not share common walls with adjacent buildings. (the typical distance from a neighboring building is 3m)

Gives protection from

Rain

Solar radiation

Cracks

Earthquake

Wind circular design and the mesh of mud plaster and twigs make them resist any wind pressure and quake.

The different spaces (for

men & women-children) are

not interconnected.

A horizontal clay

platform about 50

cm high, is a way to

avoid rainfalls inside

the house

Circular spaces are the main

living zones, rectangular

spaces are for secondary

functions, like cooking cleaning

and storing. They are smaller

and not so strong. They do not

resist very well to earthquakes

or cracks.

The thick walls, made of mud, keep the interior cool

when the temperature rises to 40 degrees Celsius in

summer and warm when it beam and posts drops to

10 degrees in winter.

The roof is made of wooden top dome

where bamboo sticks are fixed with a

thick layer of grass put on roof and tied

together.

The walls can not bear the wood beam

of the roof, which runs across the space

diagonally and rests on two wooden

posts. The beam is often kept exposed

outside the circular wall.

PLAN

•Due to circular shape of

wall in plan, inertial forces

developed in wall are

resisted through shell

action providing excellent

resistance to lateral forces.

•wall is extended below ground

up to the required foundation

depth, and separate foundation is

not traditionally constructed.

•The construction technique is such

a way that improves seismic

resistance of the inertia force

generated in the roof

•a very unique aspect of traditional desert architecture in which the size, location

and orientation of the Bungha are planned for very good structural and functional

results.

The ``modern’’ version had given a go by

to traditional architecture replacing the

twigs of

the `babul’ trees with stones.

T h a n k y o u !