Climatology of various areas such as hot and wet, hot and dry, cold and wet, cold and dry

1. Climatology
(Hot & Wet)
A presentation by – Azleen F. Kazi

2. Introduction
• The scientific study of climate is termed as Climatology.
• Hot and wet climate is also known as the monsoon season in India.
• There are several conditions that initiate the rainy season.
• With the advance of the summer season, heat accumulates and
temperature rises gradually in the country.
• In the mid of may, temperature rises.
• In the plains of northern India and in some of the low level areas of
central India, maximum temperature is recorded during the summer
season. At times, it exceeds 46 degree celsius.

3. • The west coastal low lands, the western ghats, and the southern parts
of assam have this type of climate. It is characterized by high
temperatures throughout the year, even in the hills. The rainfall here is
seasonal, but heavy is above 78cm in a year.
• Evergreen forests are a typical feature of the region.
• Hot and wet climate is typically found in the coastal regions such as
Mumbai, Chennai, Kolkata.

5. Areas influenced by this climate
I. GOA
II. MUMBAI (MAHARASHTRA)
III.VISHAKHAPATNAM (AP)
IV.THIRUVANANTHAPURAM (KERELA)
V. CHENNAI (TAMIL NADU)
VI.KOLKATA (WEST BENGAL)
VII.PURI (ORISSA)
VIII.TRIPURA
IX.KOZHIKODE
X. GULF OF KUTCHH

7. Due to relatively small
amount of cooling at night it
becomes pointless to try
and utilize night air to
produce comfort during the
day.
Its humidity, furthermore,
makes it difficult to use
natural water-evaporation
as a means of cooling the
surroundings.

8. The architect must
therefore logically begin by
selecting a suitable site for
the dwelling.
Sea-side locations,
windward side of rising
ground, hilly areas, these
most frequently have
natural breeze.

9. The solution then, lies in opening
up the interiors as much as
possible to the prevailing direction
of the breeze .

10. This means a shallow plan, i.e., one in which the principal spaces are
strung out in a linear manner at right angles to the breeze direction.
Subsidiary spaces may be arranged within the linear pattern, or inclined
to it to form a funnel for incoming breeze.

11.  It will be seen that each principal space has two external
walls on opposite sides, each external wall broken by large
openings, so that breeze can flow straight through it
uninterruptedly.
 This kind of ventilation is called as cross-ventilation.

12.  Humid regions usually have heavy rainfall, so that
sharply pitched roofs are a necessity in order to
rapidly throw off water.

13.  The placing of openings wrongly, or obstruction to the
flow of breeze, can result in defective ventilation, as
shown in the figure.

14.  It can happen when
the breeze
direction coincide
with the direction
of the unpleasant
solar radiation.
 In such a case,
admitting breeze
means admitting
hot sun as well.

15.  The second
difficulty is that the
linear pattern of
spaces results in
long distances
between them.
 Spatial
relationships are
lost, and long
corridors have to
be introduced. Cost
goes up!

16. The main design objectives should be-
I. Resisting heat gain
a) Decreasing surface area of the building exposed to the
out side
b)Using materials that take a longer time to heat up
c)Providing buffer spaces between the outside and the
inside.
d)Increasing shading of the building in general
e)Using materials that reflect heat.

17. I. Promoting heat loss
To promote heat loss, it is essential to
ensure :
a) Applainces used are well ventilated
b)Proper ventilation occurs throughout the
day
c)Humidity levels are redued as much as
possible.

18. General recommendations for building design in hot and wet
climate are:
(1)Site
a) Landform :
For flat sites, design considerations for the landform is immaterial.
In case of slopes and depressions, the building should be located
on the windward side or crest to take advantage of
cool breezes

19. (b) Open spaces and built form
buildings should be spread out with large open spaces in
between for unrestricted air movement.
In Cities, buildings on stilts can promote ventilation and
cause cooling at the groung level.

20. (2) Orientation and platform
• As temperatures are not very high, free plans can be
evolved as long as the house in under protective shade.
• An unobstructed air path through the interiors is
important to ensure proper ventilation.
• The building could be long and narrow to allow cross-
ventilation.
• For eg, a single loaded corrider plan (one with rooms
on one side only) is preferable over a doubly loaded
one.

21. • Heat and moisture producing areas like toilets and kitchens must
be ventilated and separated from the rest of the structure.

22. • Semiopen spaces such as balconies, verandahs and porches can be
used advantageously for daytime activities as well as give protection
from rainfall.
• In multistoreyed buildings a central courtyard can be provided with
vents at higher levels to draw away the rising hot air.

23. (3) Building Envelope
(a) Roof
In addition to providing shelter from rian and heat, the form of the
roof should be planned to promote air flow.
Vents at the roof top effectively induce ventilation and draw hot air
out.

24. (b) Walls :
• The walls must also be deigned to promote air flow so as to
counter the prevalent humidity.
• Baffe walls, both inside and outside the building can help to
divert the flow of wind inside.

25. (3) Fenestration :
• Cross-ventilation is of utmost importance in warm and humid
climatic regions. All doors and windows should preferably be kept
open for maximum ventilation.
• The openings should be shaded by external overhangs.
• Outlets at higher levels serve to vent hot air.

26. Examples showing how the air movement within a
room can be better distributed

27. (d) Colour and texture :
• The walls should be painted with light pastel shades or whitewashed,
while the surface of the roof can be of broken glaze tile (china mosaic
flooring) to reflect the sunlight back to the environment, and hence
reduce heat gain of the building.
• The use of appropriate colours and surface finishes is a cheap and
very effective technique to lower indoor temperatures.
• The surface finish should be protected from/ resistant to the effect of
moisture.

28. Conclusion
Ceiling fans are effective in reducing the level of discomfort in this
type of climate.
Dessicant cooling techniques can also be employed as they reduce
the humidity level.
Careful water proofing and drainage of water are essential
considerations of building design due to heavy rainfall.
In case of air conditioned buildings, dehumidification plays a
significant role in the design of the plant.

29. Thank You