1. Climatology (AR-307)
Presented to : Miss ST
By: Gwahyulo Semy (Roll no: 08)
R.Saizampiua Colney (Roll no: 06)

2. Topic
Hot and Dry Climate
Hot and humid Climate
Composite Climate
Tropical Upland Climate

3. CLIMATE IN INDIA
India is home to an extraordinary variety of
climatic regions, ranging from tropical in the
south to temperate and alpine in the
Himalayan north, where elevated regions
receive sustained winter snowfall. The
nation's climate is strongly influenced by the
Himalayas and the Thar Desert.

4. Zonal Distribution

5. Nature of the climate
 Hot-dry desert and semi-desert climates are characterized by very hot, dry air and dry ground.
 Day-time air temperatures may range between 27 and 49°C (normally higher than the 31 to 34°C
skin temperature), but at night it may fall as much as 22°C Humidity is continuously moderate to low.
 There is little or no cloud cover to reduce the high intensity of direct solar radiation.
 The clear skies do, however, permit a considerable amount of heat to be reradiated to outer space at night.
 The dry air, low humidity and minimal rainfall discourage plant life, and the dry, dusty ground reflects the
strong sunlight, producing an uncomfortable ground glare.
 Local thermal winds often carry dust and sand.

6. CHARACTERISTICS OF HOT AND DRY CLIMATE
• Hot dry weather in summer and cold in winter
• Very little rainfall
• Very low humidity
• Sandy or rocky ground with very low vegetation cover
• High temp. difference between night and day
• Hot winds and frequent dust-storms
• High summer day time temp.(32° C - 36 °C)
• High solar radiation

7. AREAS INFLUENCED BY THIS CLIMATE
• GUJARAT
• MADHYAM PRADESH
• MAHARASTRA

8. The climates in Hot and Dry involves diverse conditions. The winters are mild, pleasant, and dry with average daytime
temperatures around 29 °C (84 °F) and nights around 12 °C (54 °F) with 100 percent sunny days and clear nights. The
summers are extremely hot and dry with daytime temperatures around 49 °C (120 °F) and at night no lower than 30 °C (86 °F).
In the weeks leading up to the arrival of the monsoon rains the temperatures are similar to above but with high humidity which
makes the air feel hotter. Relief when the monsoon season starts around in mid June. The day temperatures are lowered to
around 35 °C (95 °F) but humidity is very high and nights are around 27 °C (81 °F). Most of the rainfall occurs in this season,
and the rain can cause severe floods. The sun is often occluded during the monsoon season. Though mostly dry, it is deserted
in the north-west, and wet in the southern districts due to a heavy monsoon season.

9. Form and planning
• Out-door conditions are so hostile in this climate, that both the buildings and the external living spaces need
to be protected as much as possible from the intense solar radiation and the hot, dusty winds.
• Shading of roofs, walls and out-door spaces is critical. Projecting roofs, verandahs, shading devices, trees and
utilization of surrounding walls and buildings are familiar techniques of solving this problem.
• By aligning buildings close to each other, especially if east and west walls are placed close together, mutual shading will
decrease the heat gains on external walls.

10. 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.
Building Design

11. Orientation Of building
Sun orientation
• West orientation is the worst
• The larger building dimension should
face north and south

12. 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.

13. General arrangement
Houses arranged around courtyards in hot dry regions

14. Interiors
• Deep room arrangements can be used as a cooling contrast to intense outdoor heat.
• Use of flow emissive “cool” colors reduce heat reflection on interior surfaces.
• Connections with patio areas, verandas and courtyards covered with pergolas have cooling effect on
adjacent spaces.
Main building connected with patio areas
usually getting advantage of cooling
elements
Window below ground alley covered by
balconies on a steep slope in hot dry
climate

15. Colors
• light external colors will minimizing internal daytime temperatures, and is better than
increasing thermal resistance or capacity
• It has added advantages that comfort at night is also improved
• White paint has high reflection ratio on sun exposed surfaces. Dark absorptive colors
are adaptable where reflections towards interior are expected (such as under eaves).

16. Vegetation Near or around the building
• The roof, walls, windows and play and rest areas can be shaded with trees and plants.
• Vegetation in turn reduces the temperature and filter’s the dust in and around the house and elevates the
humidity level in too dry climates.
• It may reduce as well as increase the wind speed where it is desired.
Vertical Pergolas
shade the facades

17. Openings and windows
• Relatively small openings reduce intense radiation. Openings should be tight closing as protection against high
diurnal heat.
• Openings should be located on South, North, to a lesser degree, on East sides.
• Low solar angles may bring radiation deep into the house from windows placed on either the eastern or
western sides.

18. • Effective shading of windows and other glazed areas is one of the major requirements for indoor comfort in these
regions during hot summer.
• Such shading can be provided either by fixed shading devices; which are integral elements of the building’s
structure, or by operable shades.
• Operable shading devices, such as shutters,Awnings,Venetian blinds, etc., can be either internal; or external to
the glazing.
• Internal devices are much less effective than external shading in preventing solar heating of the interior space,
although they can be very effective in controlling indoor natural lighting.
SHADING
Building
fenestration
and
sun
protection
This south-facing view
shows how the
narrowness of the
pathways and the use
of
vines trellised
overhead
both provide shade for
pedestrians on
summer
days.

19. • The walls of daytime living areas should be made of heat-storing materials, while walls of night rooms of materials
with light heat capacity
• East and west walls should preferably be shaded.
• Heavy masonry walls are desirable on the west and should be shaded by trees if possible.
• Double wall construction with proper air ventilation should be constructed on westward side.
• High reflective qualities are desirable for both thermal and solar radiation.
WALLS

20. • Generally, heat storage insulation is the best, which uses the flywheel effect of out-going radiation for daily heat
balance.
• This can be accomplished by thick insulating materials, evaporative cooling on the exterior or radiation screen with
ventilation between it and the roof.
• A double roof or a damp-proof or white single roof will reduce the accumulation of heat. Water spray or
pool on roof is effective.
• High solar reflectivity is a basic requirement ; emissivity is essential for long-wave radiation.
ROOFS

22. Hot And Humid Climate

23. Nature of the climate
• The most prominent characteristics of this climate are the hot, sticky conditions and the continual
presence of dampness.
• Air temperature remains moderately high, between 21 and 32°C, with little variation between day
and night. It seldom exceeds normal skin temperature.
• Humidity is high during all seasons.
• Heavy cloud and water vapor in the air act as a filter to direct solar radiation; it is thus reduced
and mostly diffused – but clouds also prevent reradiating from the earth at night.
• Moisture in the air combined with moderate heat and high rainfall is favorable to the growth of
vegetation.
• The plant cover of the ground reduces reflected radiation, and lessens the heating up of
the ground surface.
• Winds are generally of low speed, variable in speed, but almost constant in direction.

24. CHARACTERISTICS OF HOT AND HUMID CLIMATE
• PRECIPITATION
2000 TO 5000 mm OF RAINFALL
• WIND
TYPICALLY LOW WIND VELOCITIES.
STRONG WIND WITH TORRENTIAL RAINS.
• SOLAR RADIATION
THE INTENSITY OF SOLAR RADIATION IS HIGH
DURING SUMMERS AND MODERATE DURING
WINTERS.

25. AREAS INFLUENCED BY THIS CLIMATE
COASTAL PLAINS OF PENINSULAR INDIA
• GOA
• MUMBAI (MAHARASHTRA)
• VISHAKHAPATNAM (AP)
• THIRUVANANTHAPURAM (KERALA)
• CHENNAI (TAMIL NADU)
• KOLKATA (WEST BENGAL)
• PURI (ORISSA)
• TRIPURA

26. TEMP. VARIATIONS THROUGHOUT INDIA
CITY SUMMER
DAY
SUMMER
NIGHT
WINTER
CITY SUMMER
DAY (°C
SUMMER
NIGHT
WINTER
DAY
WINTER
NIGHT
CHENNAI 37.3 27.6 28.2 21
KOLKOTA 34.1 26.7 27 14
MUMBAI 31.9 26.3 30.9 20.8
PURI 31.7 27.4 27.2 17.7
TRIVANDRUM 29.4 23.6 30.9 22.5
TRIPURA 36.2 20.5 27.1 7
GOA 30 20 25 15

27. CLIMATE AND ARCHITECTURE
• Since beginning, climate has its effects on man, surroundings
and architecture
• Weather elements forced man to look for shelters
• A climate responsive architecture takes advantage of the free
energy in the form of heat and light.
• An adaptive thermal comfort design is essential.

28. REQUIREMENTS IN A HOT AND HUMID CLIMATE
• Minimization of the high day temp.
• Avoidance of direct exposure of facades to solar radiations.
• Reduction in the humidity levels
• Continuous air circulation to reduce heat and relief from
stickiness.
• To create a temp. difference between the inside and outside
environments to facilitate evaporation and heat dissipation.

29. From and planning
• Building will have to be opened up to breezes and orientated to catch whatever air movement there is. Failure
to do this would produce indoor conditions always warmer than a shaded external space which is open to air
movement.
• In this type of climate buildings tend to have open elongated plan shapes, with a single row of rooms to allow cross-
ventilation. Such rooms may be accessible from open verandahs or galleries, which also provide shading. Door and
window openings are, or should be, as large as possible, allowing a free passage of air.
• Groups of buildings also tend to be spread out. Extended plans, in a line across the prevailing wind direction, afford low
resistance to air movement and is therefore the ideal solution.
• As the openings are far larger than in hot-dry climates, the shading devices will be much larger on both counts.
Openness and shading will be the dominant characteristics of the building.
• Shading of all vertical surfaces, of both openings and solid walls will be beneficial. This task will be much easier, if the
building height is kept down. Very often the roof will extend far beyond the line of walls, with broad overhanging eaves,
providing the necessary shading to both openings and wall surfaces.

30. Over Hanging Eaves

31. open elongated plan shapes, with a single row of rooms

32. THERMAL COMFORT
• Comfort has been defined as the condition of mind which expresses satisfaction with the environment.

34. FENESTRATION
•Semi – open spaces for light and air movement
•Larger windows for ventilation.

35. FACADE ARTICULATION
•Max. ventilation
•Orientation of smaller side of structure
along east-west
•North-south orientation for maximum air
movement
•High density of façade that is open and yet
shaded.
•Faint/pale colors on outer surfaces
•Building materials with insulating/reflecting
properties that resist heat transfer.

37. ROOFING PATTERN
• Voids in roof and
courtyards provide max. light
and cross ventilation
• Houses are tall with large
openings to catch breeze
• Light colors and reflective surfaces on roofs will
deflect solar radiations and keep the
building cool.
• Light materials such as timber are used in
Construction
Sloping roof is a characteristic of these
regions as it drains off rain water. Barrel vaulted
roof can also be seen.
• Dense growth of plantations in the outdoors

38. Composite climate

39. Composite climate
• Usually occures in : Large land masses near
the tropic of cancer and capricrn, which are
far from equator.
• Examples : New Delhi
• Two seasons : 2/3 of the year is hot dry
and 1/3 is warm humid.
• Specific locations : in further north and
south often have a third
season, best described as
cold-dry.

40. Building type
• Courtyard type building are very
suitable
• A moderate dense , low rise
development
• Large projecting eves and wide
verandahs are needed in the warm
humid season as our door living
ares, to reduce sly glare, keep out
the rain and provide shades
• Shading device should be of low
thermal capacity

41. Exterior productes
• Roofs and walls are
constructed of solid masonry
and concrete.
• Resistance insulation are
need and they are placed at
the exterior wall or on the
roof.
• Large openings in opposite
walls they are preferred with
solid shutters.

42. Season
Temperature(°C)
Hot and dry Warm and humid Cold and dry
Day time
(Max temperature)
32-43 27-32 <27
Night time
(min temperature)
21-27 24-27 4-10
Diurnal range 11-12 3-6 11-22
Humidity
RS is low in day time : 20-55 %
Wet season : rises to 55- 95 %
Air
tempearture

43. Topography
• The geographical coordinates of New Delhi are 28.636 deg
latitude, 77.224 deg longitude, and 712 ft elevation.
• The topography within 2 miles of New Delhi contains
only modest variations in elevation, with a maximum elevation
change of 177 feet and an average elevation above sea level
of 721 feet. Within 10 miles also contains only modest variations
in elevation (328 feet). Within 50 miles contains
only modest variations in elevation (797 feet).
• The area within 2 miles of New Delhi is covered by artificial
surfaces (99%), within 10 miles by artificial surfaces (79%)
and cropland (14%), and within 50 miles by cropland (91%).

44. Temperature Of Delhi
• The temperature in the summer months can be unbelievably hot with temperatures soaring as
high as 113°F (45°C), often accompanied by dry desert winds – not a good combination in
anyone’s books. But the cooler months of October to March can be pleasant and mild with warm
sunny days and little rainfall, most of which falls between July and September.

45. Precipitation Of Delhi
• New Delhi earns an average of 790 mm
(31.1 in) of rainfall per year, or 65.8 mm (2.6
in) per month.
• On average there are 57 days per year with
more than 0.1 mm (0.004 in) of rainfall
(precipitation) or 4.8 days with a quantity of
rain, sleet, snow etc. per month.
• The driest weather is
in November & December when an average
of 9 mm (0.4 in) of rainfall (precipitation)
occurs.
• The wettest weather is in July when an
average of 237 mm (9.3 in) of rainfall
(precipitation) occurs.

46. Sky Condition Of Delhi
• Clouds
• In New Delhi, the average percentage of the sky
covered by clouds experiences extreme seasonal
variation over the course of the year.
• The clearer part of the year in New Delhi begins
around September 2 and lasts for 10 months,
ending around July 5. On October 14, the clearest
day of the year, the sky is clear, mostly clear,
or partly cloudy96% of the time,
and overcast or mostly cloudy 4% of the time.
• The cloudier part of the year begins around July
5 and lasts for 1.9 months, ending
around September 2. On July 31, the cloudiest
day of the year, the sky is overcast or mostly
cloudy 59% of the time, and clear, mostly clear,
or partly cloudy 41% of the time.
Rainy season
Winter season
Summer season

47. Solar Radiation in Delhi
• Solar radiation is radiant energy
emitted by the sun, particularly
electromagnetic energy. About half of
theradiation is in the visible short-
wave part of the electromagnetic
spectrum. The other half is mostly in
the near-infrared part, with some in
the ultraviolet part of the spectrum
Monthly Average
JAN 3.24
FEB 4.92
MAR 6.32
APR 5.79
MAY 5.38
JUN 4.13
JUL 2.79
AUG 3.50
SEP 4.67
OCT 4.24
NOV 3.45
DEC 3.12
Annual Average : 4.29 kWh/m2/day
Unit : kW/m2

48. Humidity
• We base the humidity comfort level on the dew point, as
it determines whether perspiration will evaporate from
the skin, thereby cooling the body. Lower dew points feel
drier and higher dew points feel more humid. Unlike
temperature, which typically varies significantly between
night and day, dew point tends to change more slowly, so
while the temperature may drop at night, a muggy day is
typically followed by a muggy night.
• New Delhi experiences extreme seasonal variation in the
perceived humidity.
• The muggier period of the year lasts for 5.0 months,
from May 20 to October 20, during which time the
comfort level is muggy, oppressive, or miserable at
least 25% of the time. The muggiest day of the year
is August 17, with muggy conditions 99% of the time.
• The least muggy day of the year is January 28, when
muggy conditions are essentially unheard of.

49. Wind Condition
• Wind
• This section discusses the wide-area hourly average wind
vector (speed and direction) at 10 meters above the
ground. The wind experienced at any given location is
highly dependent on local topography and other factors,
and instantaneous wind speed and direction vary more
widely than hourly averages.
• The average hourly wind speed in New Delhi is gradually
decreasing during June, decreasing from 4.5 miles per
hour to 4.0 miles per hour over the course of the month.
• For reference, on May 30, the windiest day of the year,
the daily average wind speed is 4.5 miles per hour, while
on October 16, the calmest day of the year, the daily
average wind speed is 2.7 miles per hour
The hourly average wind direction in New Delhi throughout
June is predominantly from the west, with a peak proportion
of 63% on June 1.
N 8 %
NE 3 %
E 18 %
SE 8 %
S 5 %
SW 5 %
W 33 %
NW 19 %
Wind-direction ( 2000 - 2017)

50. Vegetagtion
• The main kinds of topography that exist
in Delhi are the Yamuna Food Plains,
• The Delhi Ridge and The Plains.
• The vegetation in each of this condition is
quite distinct and unique. Rich and rare
varieties of cactus plants and acacia grow
on the ridge during the dry seasons.
• when it rains during monsoons, there are
lots of herbaceous plants that one can
see along the ridge. The Plains of Delhi
have an abundance of Shisham trees on
it whereas the Yamuna Food Plains have
a lot of vegetation that resembles the
riverine type.

51. Tropical upland
climates
Regions throughout
the globe

52. Tropical upland climates
Nature of the climate
• Climate is similar to the composite or
monsoon climates
• It is dominated by strong solar radiation
• Warmest part of the year air
temperature rarely reaches 30°C
• Diurnal variation can be as much as 20°C
• Humidities are not excessive and there is
an almost constant air movement

53. Form and planning
• Compact building type slowing down
the response to changing thermal
conditions
• The building plan should be reasonably
compact
• Compact building type reduce heat
gain during the day and heat loss
during the night.
• Windows and openings have to be
protected from solar radiation.

54. Orientation
• Orientation of the building and of its
major openings can greatly influence
the solar heat gain.
• North and south facing vertical walls
receive the least amount of radiation.
• facing north on the northern
hemisphere and facing south on the
southern half of the globe.
• East, south-west and northwest walls
will receive about the same amount of
radiation
• West will receive the most.
Building orientation
proposal
•the longer walls should face north and south
•major openings should be located in these
walls
•Windows facing east would admit the sun
• If air temperature is still quite low. Windows
facing west should be avoided.
•This arrangement would reduce incident solar
radiation and would also minimise the extent
(and cost) of shading devices, as north and
south facing windows can be shaded by the
simplest of means.
•This arrangement would reduce incident solar radiation and
would also minimise the extent (and cost) of shading devices,
as north and south facing windows can be shaded by the
simplest of means.

55. Openings
• As the air temperature rarely reaches
the upper comfort limit
• no need for cross-ventilation
(if solar control is adequately solved)
• there is no need to capture winds and
cooling breezes.
• the wind direction need not be
considered.
(since ther are no strong wind)
• It is essential to provide for the
adequate closing of openings
• Solar heat gain will be the only factor
governing the orientation of windows
• In summer Well-shaded external spaces
should be provided:-
1. many activities are going on out-of-doors -
as in all warm climates
2. the very strong radiation would create hot
discomfort, even with quite low air
temperatures
• In the cooler period of the year sunshine
may be welcome in external spaces. Two
possibilities are open to the designer:-
1 to provide some form of adjustable
shading device to the external activity area
2 to provide alternative external spaces for
use in the different seasons: shaded for the
hot period and unshaded, wind protected
for the cool part of the year .

56. Shading

57. Shading
• In summer Well-shaded external spaces
should be provided:-
1. many activities are going on out-of-doors -
as in all warm climates
2. the very strong radiation would create hot
discomfort, even with quite low air
temperatures
• In the cooler period of the year sunshine
may be welcome in external spaces. Two
possibilities are open to the designer:-
1 to provide some form of adjustable
shading device to the external activity area
2 to provide alternative external spaces for
use in the different seasons: shaded for
the hot period and unshaded, wind
protected for the cool part of the year .
• The former can be achieved by
some form of canvas awning
• cantilevered or supported by a
pergola-like frame
• In some situations the same
external space may be shaded or
unshaded in different parts of
the year.
The latter arrangement may be wasteful of space, duplicating
the out-door area, but where space
is not at a premium, it may be the easier and more economical
solution.

58. Roofs and walls
Nights are cool and solar radiation can cause overheating of buildings during the day
Effective Factors
• High thermal capacity structure.
• A time- lag of 8 hours is advisable
inner and outer temperature.
• East, and especially the west walls
should also be massive.
• North and south walls will not
receive much radiation and they may
be of a lightweight construction,
Aim
1 to limit the heat
admitted during the
strong sunshine hours
2 2 to store some heat,
to be re-emitted during
the cool perio
(A 200 mm concrete slab, with
screed and felt or a 150 mm
concrete slab with an insulating
screed would give this
performance.)

59. Characteristics of Tropical Climates
• Air temperature rarely reaches 30°C in
summer
• IN winter air temperture goes down to 16
°C
• Diurnal variation 20 °C.
• Temperature – average mean temperature
(dbt) 20 – 30 deg.C
• • Humidity Level – 50% to 100% Relative
Humidity
• • Wind Conditions – Slow wind flow