Building design in hot and dry climate

1. Building
Design in
Hot and Dry
Climate
S H I VA N G M A D A A N
R O L L N O - 1 7 0 7 1 9 7 8 1 4 2
B . A R C H . S E M - 3

2. Objectives
This report describes the
characteristics of the given climate
type and also details the building
design/construction techniques that
may be undertaken there.

3. Introduction to the Hot and Dry
Climate Type
Hot and dry type of climate is characterized by high mean temperatures in the summers and cold
temperatures in the winters. Humidity stays very low over the whole year along with marginal rainfall.
High differences between day and night temperatures can also be noted. The following table gives
the aforementioned characteristics values: -
Climate Type
Mean Monthly
Temp.
Mean Monthly
R.H.
Mean Monthly
Rainfall
No. of clear days
in a Month
Locations
Hot and Dry >30°C <55% <5 mm >20
Thar Desert,
Sahara Desert

4. Traditional Building Forms
The traditional courtyard house, which has become the indigenous urban and rural standard in the
areas with such a climate, has developed from many civilizations. The courtyard house typology with
surrounding rooms is the most basic response to the hot arid climatic regions.
Surrounding rooms enclose the outdoor space with often only the depth of one room. In urban
settings, the courtyard house is completely bounded by the wings of the house, and in more rural and
farm situations on only one or two sides. The form of the courtyard is deliberately regular and
contained.
The hotter the climate, the taller the proportions are for the courtyard. In very hot arid areas, multi-
story courtyards are not uncommon. This increases the shaded area of the courtyard and makes for a
cooler microclimate.

5. Traditional
Courtyard Houses
in Hot-Dry Climates

6. Traditional Building Forms
In order for an opening to provide for air movement, it must be small which however, reduces natural
lighting for the room. This is why wind towers, called Badgirs, are made which serve the sole purpose
of air movement.
Wind captured at the top of the tower has less solid material such as sand and is cooler and stronger
than at ground level. Towers allow cool air passing across the sky to be caught and brought down
through enclosed rooms at and below grade.

7. Traditional Wind-
catchers in Hot-Dry
Climates

8. Types of Wind Catchers
Simple Windcatcher Water Cooled Windcatcher Solar Exchange Windcatcher

9. Plan and section
through a Persian
house showing a
unidirectional badgir
which is open to cool
breezes from the
north but rejects the
hot winds from the
south. A vacuum at the
mouth of the badgir
pulls cool air into the
rooms from the
patio

10. How Are Cities and Villages Now After Many
Years of Development
This shows the city Jodhpur and how how close the buildings are to reduce heat gain
from outer walls of a building. The same goes for the case of the village Keru.
This results in heat gain mostly through the roofs

11. Heat Gain From Walls
Heat gain from walls can be controlled by using
different construction materials and the wall
thickness.
The more the thickness of the wall, the more will
be its resistance to heat gain.
Heat insulating materials can be used and cavity
wall construction can be adopted to resist extra
heat from entering the building.

12. Types of Walls Used
Many different types of walls can be used to provide
thermal comfort in a hot and dry climate. They are as
follows: -
1. Cavity Walls - These are walls that have a cavity
sandwiched between two layers of walls. The
cavity can remain empty, that is air only, or it can
be filled with some insulating materials.
2. Insulating Walls – These walls are insulated on
either the outside or the inside of the building.

13. Types of Walls Used
3. Radiant Barriers - Radiant barrier is a shiny, reflective
building material used to reflect heat radiation. A
radiant barrier is a type of building material that
reflects thermal radiation and reduces heat transfer.
4. Light colored whitewash can be applied on the
exterior of the walls

14. Types of Walls Used
Wall with reflective and ventilated outer skin –
The double-skin facade is a system of building consisting
of two skins, or facades, placed in such a way that air
flows in the intermediate cavity. The ventilation of the
cavity can be natural, fan supported or mechanical.

15. Working Sketch
for Double Skin
Facades

16. Types of Roofs Used
A normal roof made from brick tiles and mortar absorbs
about 83% of the solar heat.
If the roof is covered with metal sheets or is coated with
other reflective material, the absorbtion decreases to
12% and reflects about 88%

17. Types of Roofs Used
oDouble skinned Roof - Highly reflective and
ventilated double-skin roofs can be used to
improve passive cooling in summer. In such a
system radiation heat transfer is highly coupled
with natural convection

18. Other Types of
Ventilated
Roofs

19. Blocking Solar Radiation