lists out passive design strategies in composite & warm-humid climates in rural areas.

1. PASSIVE SOLAR DESIGN FOR MUD HUTS IN
JHARKHAND, CONSIDERING
MICROCLIMATIC PARAMETERS FOR
COMFORT
JANMEJOY GUPTA
PHD/ARCH/1053/2011
DEPTT. OF ARCHITECTURE
GUIDE: DR MANJARI CHAKRABORTY

2. IMPACT OF CLIMATE ON DESIGN OF RURAL
DWELLINGS IN COMPOSITE CLIMATE &
WARM HUMID TYPE CLIMATE.

3. RURAL SETTLEMENTS IN RESPONSE TO THE
NATURAL ENVIRONMENT
 Major natural features, such as mountains, rivers, lakes,
forests, and grasslands, influenced both the location
and organization of rural communities.
 Climate, influenced the siting of buildings, construction
materials, and the location of clusters of dwelling units.
 Early settlements frequently depended upon available
natural resources, such as water for transportation,
irrigation.
 Mineral or soil deposits, likewise, determined the
suitability of a region for particular activities.
 Locally available materials, such as stone or mud,
commonly influenced the construction of houses.
Source: http://www.nps.gov/nr/publications/bulletins

4. IMPACT OF CLIMATE ON BUILT FORM : CONCEPT OF
BIOCLIMATIC ARCHITECTURE
 Bioclimatic Architecture relates to the study of climate when
applied to Architecture, in order to improve the conditions of
thermal comfort of the occupants through the use of
appropriate building strategies, which differs from place to
place based on the prevailing climate of that place.
Source:
http://www.cres.gr/kape/energeia_politis/energeia_politis_bioclimatic_eng.htm
Centre for renewable energy sources and saving

5. PROCESS OF BUILDING CLIMATE-BALANCED
DWELLING UNIT
CLIMATIC DATA : TEMPERATURE,RELATIVE HUMIDITY,
RADIATION, WIND EFFECTS…
BIOLOGICAL EVALUATION: PLOTTING CLIMATIC DATA IN THE
BIOCLIMATIC CHART.
TECHNOLOGICAL SOLUTIONS
ARCHITECTURAL APPLICATION

6. CLIMATE DATA NEEDED FOR PASSIVE SOLAR
DESIGN
 Climatic data collected in meteorological stations, and published in
summary form usually consists of:
 Temperature: dry-bulb temperature.
 Humidity: expressed as relative humidity or absolute humidity. Wet-bulb
or dew-point temperatures may be stated, from which the relative
humidity can be determined.
 Air movement: wind speed and direction.
 Precipitation: The total amount of rain, hail, snow or dew, in mm per unit
time (day , month, year)
 Cloud Cover: based on visual observation and expressed as a fraction of
the sky hemisphere (tenths, or ‘octas’= eights) covered by clouds.
 Sunshine duration: The period of clear sunshine (when a sharp shadow
is cast), measured by a sunshine recorder which burns a trace on a
paper strip, expressed as hours per day or month.
 Solar radiation: measured by a pyranometer, on an unobstructed
horizontal surface, usually recorded as the continuously varying
irradiance (W/sq.meter)

7. THE FOUR ENVIRONMENTAL VARIABLES DIRECTLY
AFFECTING THERMAL COMFORT
 The four environmental variables directly affecting thermal comfort are
temperature, humidity, solar radiation and air movement.
 The following data is of interest :
 Temperature:
 Monthly mean of daily maxima (degree Celsius)
 Monthly mean of daily minima (degree Celsius)
 Humidity:
 Minimum Mean Relative Humidity (early morning) (in %)
 Maximum Mean Relative Humidity (early afternoon) (in %)
 Solar Radiation:
 Monthly mean daily total (in MJ/sq meter or Wh/sq meter)
 Sunshine: (percentage)
 Wind: (prevailing wind speed in m/sec and direction)
 Rainfall: (monthly total in mm)

8. AS PER NATIONAL BUILDING CODE, 2005
THE CLIMATIC ZONES IN INDIA IS-
1.HOT-DRY
2.WARM-HUMID
3.COMPOSITE
4.TEMPERATE
5.COLD
As can be seen from map the whole of
Jharkhand, except a small portion of it to the south,
falls within the composite zone of climate. Study-
Area Ranchi district falls entirely in composite zone.
Hot and dry summer,
followed by a humid
season with monsoon
rains. With the departure
of the monsoon it
gradually becomes
comfortable in autumn,
followed by a relatively
short winter (3 months)
with the cloudy and wet
as well as sunny periods.
Before the summer returns
there is a comfortable but
short spring season.

9. Source: www.mapsofindia.com

10. MAXIMUM AVERAGE TEMPERATURE FROM 1986-2013: RANCHI

11. MINIMUM AVERAGE TEMPERATURE FROM 1986-2013: RANCHI

12. MAXIMUM AVERAGE HUMIDITY FROM 1986-2013: RANCHI

13. MINIMUM AVERAGE HUMIDITY FROM 1986-2013: RANCHI

15. MAX & MIN TEMP: JAMSHEDPUR

16. HUMIDITY: JAMSHEDPUR REGION…WARM HUMID ZONE

17. BIOLOGY: COMFORT ZONE INDICATED IN BIOCLIMATIC CHART
FOR MEN AT SEDENTARY WORK IN WARM CLIMATES –
ORIGINALLY BY V OLGYAY IN BRITISH UNITS
Olgyay’s Bio-climatic chart
Source: Koenigsberger,Ingersoll,Mayhew,Szokolay. Manual of tropical housing and building. Orient Longman. 1997.

18. OLGYAY’S BIOCLIMATIC CHART DESCRIBES THE
HUMAN-CLIMATE RELATIONSHIP TO ENSURE
COMFORT
 A problem with Olgyay’s chart is that it does not
account for differences between low mass and high
mass buildings.
 It assumes that the outdoor conditions, plotted on the
graph, would be very close to the indoor conditions and
can thus be used as guidelines for building design.
 According to Bharuch Givoni this is only close to the
truth in naturally ventilated lightweight buildings in
temperate climates.
 Source: La Roche, Pablo Miguel, 2004. Passive cooling strategies for
buildings in hot climates with specific application to Venezuela. Pro
Quest Dissertations and Theses: The Sciences and Engineering
Collection.

19. BUILDING BIO-CLIMATIC CHART (BBCC)
 Givony (1969) developed the Building Bio-Climatic Chart (BBCC) to
address the problems associated with Olgyay’s charts.
 This chart is based on the temperatures inside buildings (expected on
the basis of experience or calculations) instead of the outdoor
temperatures. Givoni used the psychrometric chart to graphically
represent the interrelation of air temperature and moisture content and
is a basic design tool for building engineers and designers.
The BBCC suggests boundaries of the outdoor climatic conditions within
which various building design strategies, as well as passive and low-
energy cooling or heating systems can provide indoor comfort. (Givoni,
1994).
 Source: La Roche, Pablo Miguel. Passive cooling strategies for buildings in hot climates
with specific application to Venezuela.
 ProQuest Dissertations and Theses; 2004.

20. Revised Building Bio-Climatic Chart (BBCC) showing how building design strategies
causes adjustments in comfort zone. (generated in Climate Consultant Software).

21. Comfort zone in Ranchi’s Climate as indicated through Ecotect Simulation.

22. Comfort zone in Jamshedpur’s Climate as indicated through Ecotect
Simulation.

23. 3. IMPACT OF CLIMATE ON RURAL BUILDING DESIGN :
TECHNOLOGICAL ASPECTS
 SITE SELECTION
 ORIENTATION
 SHADING CALCULATIONS
 HOUSING FORMS & BUILDING SHAPES
 SIZE AND POSITION OF OPENINGS: WIND
FLOW, DAYLIGHT AND SHADING
 INDOOR TEMPERATURE BALANCE : CAREFUL
USE OF MATERIALS FOR IMPROVED INDOOR
CONDITIONS.
 SETTLEMENT PATTERNS & SITE PLANNING

24. SUMMER OVERHEATED PERIOD & WINTER UNDER-
HEATED PERIOD
RADIATION GAIN IN COLD MONTHS &
AVOIDING RADIATION IN HOT
MONTHS: THE DIRECTIONS
PROBABLE ORIENTATION
Source: Victor Olgyay, Design with Climate: Bioclimatic Approach to Architectural
Regionalism, Van Nostrand Reinhold.

25. PREVAILING WINDS: SUMMER & WINTER

26. LESS HEAT GAIN IN SUMMER & MORE HEAT
GAIN IN WINTER-OPTIMUM :ORIENTATION
 Optimum orientation
for least heat gain in
summer & maximum
heat gain in winter in
composite type of
climate prevalent in
Ranchi.

27. ADAPTING THE OPTIMUM ORIENTATION FOR
CAPTURING SUMMER TIME EARLY MORNING &
EVENING-BREEZE

28. TEMPERATURES INSIDE DWELLING UNIT IN
HOTTEST PERIOD OF YEAR..OPTIMUM
ORIENTATION..IN RANCHI DISTRICT
0 2 4 6 8 10 12 14 16 18 20 22
W/ m2C
-10 0.0k
0 0.4k
10 0.8k
20 1.2k
30 1.6k
40 2.0k
Outside Temp. BeamSolar Diffuse Solar Wind Speed Zone Temp. Selected Zone
NOTE: Values shown are environment temperatures, not air temperatures.
HOURLY TEMPERATURES - Zone 1 Tuesday 29th May (149) - Ranchi Jh IND, WMO#=ISHRAE

29. TEMPERATURES INSIDE DWELLING UNIT ON
HOTTEST DAY..OPTIMUM ORIENTATION..IN
EAST SINGHBHUM DISTRICT
 HOURLYTEMPERATURES - Tuesday 5th June
 Zone: Zone 1
 Avg. Temperature: 33.1 C (Ground 26.2 C)
 HOUR INSIDE OUTSIDE TEMP.DIF
 (C) (C) (C)
 ----- ------- -------- ---------
 00 33.7 29.0 4.7
 01 33.4 28.8 4.6
 02 33.2 28.0 5.2
 03 33.0 28.2 4.8
 04 32.8 29.2 3.6
 05 32.9 30.6 2.3
 06 33.0 31.6 1.4
 07 33.2 33.5 -0.3
 08 33.3 34.5 -1.2
 09 33.7 36.4 -2.7
 10 33.8 37.8 -4.0
 11 34.3 40.0 -5.7
 12 34.4 40.9 -6.5
 13 34.7 41.2 -6.5
 14 34.6 39.3 -4.7
 15 34.0 37.3 -3.3
 16 33.3 34.6 -1.3
 17 33.2 33.5 -0.3
 18 33.3 32.4 0.9
 19 33.5 32.5 1.0
 20 33.6 31.7 1.9
 21 33.7 31.5 2.2
 22 33.9 30.4 3.5
 23 33.8 30.3 3.5

30. POSSIBLE SHADING DEVICES
 Fins
 Chajjahs/sun-shades
 Horizontal shading
devices

31. SHADING DEVICES
 Krishan et al in ‘Shelter or Form’
in the compilation titled ‘Climate
Responsive Architecture’-‘A
Design Handbook for Energy
Efficient Buildings’, states that
in case of a composite climate,
one would need to design
shades that cut off the sun in
summer but allow the sun in the
under-heated period. Further,
the window section should
enhance air velocity while still
acting as a shade. This could be
achieved either by introducing a
planter at the window sill or else
by adding smaller shades at the
glazing.
Source: Krishan, A., Jain,K. and Rajgopalan,M.,2001. Shelter or Form. In A.Krishan, N.Baker, S. Yannas & S. V. Szokolay (Eds.), Climate
responsive architecture: A design handbook for energy efficient buildings. New Delhi: Tata McGraw-Hill Publishing
Company Limited.

32. SHADING CALCULATIONS-STUDIED HOUSE

33. 02
04
06
08
10
12
14
16
18
20
22
Hr
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Watts
600
480
360
240
120
0
-120
-240
-360
-480
-600
Indirect Solar Gains - Qs - Zone 1 Ranchi Jh IND, WMO#=ISHRAE
Indirect solar Gain:
South Zone
The above suggests that some form of temporary summer-time shading on the east side is
required, but something that doesn't adversely affect morning winter gains. Indirect solar gains
can be controlled by shading the east and west walls, or by using a white colour external finish on
facade.

34. 02
04
06
08
10
12
14
16
18
20
22
Hr
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Watts
110
88
66
44
22
0
-22
-44
-66
-88
-110
Direct Solar Gains - Qg - Zone 1 Ranchi Jh IND, WMO#=ISHRAE
Direct solar Gain: South Zone
Probable ‘removable in winter’ shading options on east wall.
No shading on Southern walls needed. Only
shading of south void with sun shade is
required for protection during summer. South
wall void is contributing to winter time
heating.

35. HOUSING FORMS & BUILDING SHAPES
 Source: The Energy and Resource Institute (TERI) guidelines, Solar Passive
Design for buildings, Page 7.
 Of all geometrical shapes, the lowest surface-volume ratio is
that in case of a circular building.
 The circular form of the building also enhances natural
ventilation inside the building.
 The lesser the Surface-Volume Ratio of a dwelling unit lesser
is the heat gained by the building.
 But since functionally, circular shape is not ideal, alternative
similar alternatives can be hexagonal or octagonal shaped
dwelling units.

36. PERIMETER TO AREA RATIO AND HEAT GAIN
 Krishan et al (2001) in ‘Shelter or Form’ in the
compilation titled ‘Climate Responsive Architecture’-
‘A Design Handbook for Energy Efficient Buildings’,
states that in case of radiative gains or losses, the
perimeter is a crucial factor. Greater the Perimeter to
Area ratio (P/A), greater the radiative heat gain during
the day and the greater the heat loss at night.
Similarly, smaller the P/A ratio, the lesser will the
heat gain be during the day and the lesser the loss at
night. In hot climates the P/A ratio should be kept to
a minimum to cause minimum heat gain.

37. HOUSING FORMS & BUILDING SHAPES
 Cylindrical forms as seen in
‘Namboothiri House’ by Laurie
Baker can be considered
preferable solution in
comparison to conventional
forms.
 Source: Induja, Chani PS,
October 2013. Passive
Strategies for Indoor Thermal
Comfort in Warm and Humid
Climate. Sustainable
Architecture: Journal of The
Indian Institute of Architects.
Volume 78. Issue 10, Pgs 43-
48.
 www.lauriebaker.net

38. HOUSING FORMS & BUILDING SHAPES
Huts with roof openings for ventilation
A Traditional Courtyard House of the Coastal Area Made from Mudbricks (Barka, Al-Batinah)
Source: Abdul Majid, N.H., Shuichi,H. and Takagi, N., 2012.
Vernacular wisdom: the basis of formulating compatible
living environment in Oman, in: Proceedings of the ASIA
Pacific International Conference on Environment-Behaviour
Studies, Procedia-Social and Behavioral Sciences 68
(2012),ElsevierScience Direct, p. 637-648.

39. AIR MOVEMENTS: SIZE & POSITION OF OPENINGS
 Well sealed windows and doors with maximum opening area
allow maximum exposure to cooling breezes and exclude hot,
dry and dusty winds.
 An air speed of 0.5m per second equates to a 3 degree drop
in temperature at relative humidity of 50 per cent.
 Night-time flushing out of heat is required for night time
cooling.
•Thermal currents are common in flatter, inland areas like Ranchi
created by diurnal heating and cooling. They are often of short
duration in early morning and evening but can yield worthwhile
cooling benefits with good design.

40. SIZE & POSITION OF OPENINGS:
VENTILATION
• Use of windows designed to deflect breezes from varying
angles. Locating windows on walls with best exposure to
common cooling breezes and design for effective cross flow of
air through the building.
• Directing airflow at levels suitable for the activity proposed
for the room.
 Design to maximize beneficial cooling breezes by providing
multiple flow paths and minimizing potential barriers.
• Elevated structures can increase exposure to breezes.
• Include evaporative cooling and water features.

41. CONVECTIVE AIR MOVEMENT
Convective air movement relies on hot air rising and exiting
at the highest point, drawing in cool air from shaded external
areas over ponds or cool earth.
Convection produces air movement capable of cooling a
building but has insufficient air speed to cool the occupants.
Solar chimneys can also be used to ensure effective
convective air movement.
Clerestory windows, roof ventilators, and vented ridges,
eaves and ceilings will allow heat to exit the building in nil
breeze situations through convection.

42. COURTYARDS ARE SEEN IN MANY CONTEMPORARY HOUSES BUT THE SUCCESSFUL DEPLOYMENT OF
STACK EFFECT WHICH MADE THE TRADITIONAL COURTYARDS THERMALLY EFFICIENT IS ABSENT IN MOST
CASES. INSTEAD SOME SUCH COURTYARDS WITH POLYCARBONATE ROOFS ACT AS SMALL ISLANDS
TRAPPING SOLAR ENERGY AND INTENSIFYING THE HEAT INSIDE THE HOUSES. ATRIA OR LIGHT COURTS
PROVIDED IN CONTEMPORARY HOUSES TO INCREASE DAY LIGHTING CAN BE LINKED WITH A SYSTEM OF
EVAPORATIVE COOLING BY PROVIDING WATER SPRAYS AT THE TOP OR PROPER OPENINGS CAN BE
PROVIDED ON TOP TO EXPEL HOT AIR TO INITIATE STACK EFFECT.
Source: Fathy,H., Architecture for the Poor: An Experiment in Rural Egypt Chicago, 1973. Chicago. (The book was originally published in Cairo in 1969
under the title, Gourna: A Tale of Two Villages.)

43. Model rural house with pitched roof with vented monitor for
ventilation
Source: Typical Design of Rural Housing, Institute for Steel
development & Growth. August 2003, Page 20.
building is ventilated at night, its
structural mass is cooled by
convection from the inside,
bypassing the thermal resistance
of the envelope.
During the daytime the cooled
mass, can serve as a heat sink.
By radiation and natural
convection it can absorb the heat
penetrating into it.
Attainment of such performance
depends both on the – i. climatic
conditions and ii. on the design
details of the building.
Nocturnal ventilative cooling

44. INDOOR TEMPERATURE BALANCE: CAREFUL
USE OF MATERIALS
 U: Thermal Transmittance : Is defined as the amount of heat in watts
passing through 1 sq meter of a medium or a combination of media
when a temperature difference of 1 Kelvin exists between the two sides.
 Well-insulated parts of a building have a low thermal transmittance
whereas poorly-insulated parts of a building have a high thermal
transmittance.
 The building material for the walls is mud and the roof material is
Mangalore Tiles in a majority of huts. The U value for mud is 1.9 -2 .0
W/sq m K & the U value for Mangalore Tiles is 3.1 W/sq m K. (approx.)
 Though U value of Mangalore/Clay Tiles and khapra used is not that
high, the insulating property of thatch is much more, as its U value is
even lesser. (0.35 W/sq m K) So in summer, it keeps the inside of the
hut even cooler than clay tiles do. The disadvantages with thatch can be
mitigated with modern day industrially improved hatch use.
 Unit: Watt/Sq meter Kelvin.

45. HEAT CAPACITY
 Heat capacity, or thermal capacity, is
the measurable physical
quantity of heat energy required to change
the temperature of an object by a given
amount. The SI unit of heat capacity
is joule per kelvin. The term heat capacity of a
wall or roof refers to the amount of heat
required to elevate the temperature of a unit
volume of the wall (volumetric heat capacity of
material), or unit area of the surface (heat
capacity of wall) by one degree.

46. INDOOR TEMPERATURE BALANCE: CAREFUL USE OF
MATERIALS
 In the tropics the two important criteria for thermal
design are the thermal resistance of a component
and its thermal capacity.
 Krishan et al (2001) suggests that in hot and cold
climates the roof should have a low thermal
transmittance value. Using insulation would
minimize the heat stored by the roof. Further, in
warm humid climates heat storage is undesirable.
The roof should, therefore, be light, having low U-
values and low heat capacities.

47. BETTER THERMAL PROPERTIES OF THATCHED ROOF AS
COMPARED TO CLAY TILED ROOF..BETTER THERMAL
COMFORT INSIDE. ACTUAL CASE.
 TOO HOT: 2700.0
 TOO COLD : 1529.0
 HOURS IN A YEAR (8760
HRS =365 DAYS)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Hrs
00
160
160
320
320
480
480
640
640
Too Hot Too Cool
DISCOMFORT PERIOD -CircularGeometry Ranchi Jh IND, WMO#=ISHRAE

48. CLAY TILED HUT..SIMULATED CASE
 TOO HOT: 3260.0
 TOO COLD : 1307.0
 HOURS IN A YEAR
(8760 HRS =365
DAYS)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Hrs
00
160
160
320
320
480
480
640
640
TooHot TooCool
DISCOMFORT PERIOD-CircularGeometry RanchiJhIND,WMO#=ISHRAE
0 2 4 6 8 10 12 14 16 18 20 22
W/m2C
-10 0.0k
0 0.4k
10 0.8k
20 1.2k
30 1.6k
40 2.0k
OutsideTemp. BeamSolar DiffuseSolar WindSpeed ZoneTemp. SelectedZone
NOTE:Valuesshownareenvironmenttemperatures,notairtemperatures.
HOURLYTEMPERATURES-CircularGeometry Tuesday29thMay(149)-RanchiJhIND,WMO#=ISHRAE

49. INDOOR TEMPERATURE BALANCE: CAREFUL
USE OF MATERIALS
 Modern day thatch treated and improved industrially can also be
used for mass use in rural areas, being low cost and having very
good thermal properties. Thatch is a natural reed and grass which,
when properly cut, dried, and installed, forms a waterproof roof. The
most durable thatching material is water reed which can last up to
60 years. A water reed thatched roof, 12 inches thick at a pitch angle
of 45 degrees meets the most modern insulation standards. The U-
value of a properly thatched roof is 0.35 W/sq m K, which is
equivalent to 4 inches of fibreglass insulation between the joists.
Only in the last decade have building codes begun to demand this
level of roof insulation. Yet, thatch has been providing insulation
since much longer.
 Source: http://www.thatchco.com/thatchpg/

50. MODERN DAY THATCH TREATED AND IMPROVED
INDUSTRIALLY VERSUS TRADITIONAL THATCH
Source: http://www.thatchco.com/thatchpg/
Gautam Avinash. (2008). CLIMATE RESPONSIVE VERNACULAR ARCHITECTURE:
JHARKHAND, INDIA. Masters Level Thesis, Kansas State University.

51. DURABLE, FIRE RETARDANT THATCH ROOF
 After prolonged research and development,
studies and field trials, Central Building
Research Institute (CBRI), Roorkee has
developed a new method of making thatch roof
fire retardant by manually pressing thatch panel
and making it water repellent and durable by
applying non-erodable mud plaster. The
principal behind developing this new method
and techniques of manually pressing lies that
the basic cause of catching and spreading of
fire is due to looseness of thatch grass in
traditional type of roofing.

52. DURABLE, FIRE RETARDANT THATCH ROOF

53. Reduction of solar heat gain Composite Warm and Humid
Small surface-to-volume ratio Square plan, Low Wall Height Circular plan, Low Wall Height
Shading by neighbouring structures Clustering of houses, Courtyard
Shading by vegetation Deciduous trees
Shading by overhangs Overhanging roof
Openings Small openings
Reduction of heat transmission into
into interior
Thermal Insulation Insulating roof Insulating roof
Reduction of air infiltration/ventilation Moveable curtains/louvers/covers on
windows.
Increase of heat loss
Ventilation Courtyard effect, wind scoop. Courtyard effect, openings close to
roof, windows facing wind direction,
ventilation under raised floor,
ventilation through thin walls and
roof.
Evaporation Vegetation, sprinkling water
A
R
C
H
I
T
E
C
U
R
A
L
S
O
L
U
T
I
O
N
S
(As per study by Bansal and Minke, 1988)

54. ARCHITECTURAL SOLUTIONS
• Thermal mass construction
• Wind towers
• Passive down draft evaporative cooling
systems
• Earth tunnel cooling
• Roofing systems
• Roof and wall insulation

55. THERMALMASS CONSTRUCTION
 A lot of heat energy is required to change the
temperature of high density materials like
rammed earth. They are therefore said to have
high thermal mass. Lightweight materials such
as timber have low thermal mass.
 During summer, it absorbs heat, keeping the
house relatively cool.
 In winter, the same thermal mass can store the
heat from the sun to release it at night, helping
the home stay warm.
 Higher the density of the material, higher is the
heat storage capability.

56. THERMALMASS CONSTRUCTION
 Thermal mass is most appropriate in climates
with a large diurnal temperature range. As a
rule of thumb, diurnal ranges of less than 6°C
are insufficient, 7°C to 10°C can be useful
depending on the climate; and where they
exceed 10°C, high mass construction is
desirable.
 Correct use of thermal mass can delay heat
flow through the building envelope by as much
as 10 to 12 hours, producing a warmer house
at night in winter and a cooler house during the
day in summer.

57. WIND TOWERS
A typical View of Wind shaft, source:
www.catnaps.org/islamic/gulfarch.html
SOURCE: Eco-housing Assessment Criteria- Version II
Implemented under Eco-housing Mainstreaming Partnership by IIEC with funding support from
USAID

58. WIND CATCHER
 DAY & NIGHT
Source: E. Hamzanlui Moghaddama, S. Amindeldarb, A.Besharatizadehb. New approach to natural
ventilation in public buildings inspired by Iranian’s traditional windcatcher. 2011 International Conference on
Green Buildings and Sustainable Cities. Procedia Engineering.

59. WIND TOWER
Evaporative Cooling, Source: Koenigsberger et al, 1997, Manual of tropical housing and
building: Climatic Design, Orient Longman.

60. WIND TOWER
R.Shanti Priya, M.C.Sundarraja, S.Radhakrishnan, L.Vijayalakshmi (2011). Solar passive techniques in
the vernacular buildings of coastal regions in Nagapattinam, Tamil Nadu,India-a qualitative and quantitative
analysis, Elsevier’s Science Direct, Energy and Buildings, Volume 49, Pages 54.

61. WIND TOWER
Source: H.P. Garg, R.L. Sawhney (1989). A case study of passive houses built for three climatic
conditions of India, Elsevier’s Science Direct, Solar & Wind Technology, Volume 6, Issue 4, Pages
401-418.

62. PASSIVE DOWN DRAFT EVAPORATIVE
COOLING SYSTEM (PDEC)
 This system relies on the principle of
evaporative cooling. Large amounts
of heat are consumed by water as it
evaporates. This is called the latent
heat of evaporation. This heat is
partially drawn from the surrounding
air, causing cooling.
 The PDEC system consists of
modified wind towers which guide
outside breezes over a row of
 water filled porous pots, mist spray
or waterfall. As the air comes in
contact with the water it cools
 and descends down the tower and
is let into the interior space. The
water is collected in a pool
 below and can be pumped up into
the system to be reused.
Evaporative Cooling, Source: Koenigsberger et al, 1997, Manual of tropical housing and building:
Climatic Design, Orient Longman.

63. TECHNIQUES OF INCREASING MUD WALL
INSULATION :
 By using loam mixed with additives : lightweight
straw loam for cob, adobe and rammed earth
walls.
 Cavity walls with compressed earth block are also
effective.
Earth Covered roof Flat roof with loam in a Dogon village,
Shanga Mali

64. TECHNIQUES OF INCREASING ROOF INSULATION
 Flat or inclined roofs with lightweight loam
on account of low thermal conductivity
 Vault and domes on account of a lower
surface volume ratio of roofing
 Flat or inclined roofs with lightweight loam
on account of low thermal conductivity
 Source: Minke Gernot.(2006). Building
with Earth: Design and Technology of a
Sustainable Architecture, Birkhauser,
Berlin.
Earth block vaults and domes
Vaulted roof building made of stabilized mud
blocks (composition: soil, sand, lime/cement
and water)

65. TECHNIQUES OF INCREASING ROOF INSULATION
Source: Minke Gernot.(2006). Building with Earth:
Design and Technology of a Sustainable
Architecture, Birkhauser, Berlin.
Persian dome with wind catchers

66. TECHNIQUES OF INCREASING ROOF INSULATION
 Commonly used tile-covered rafter
roofs can be filled with lightweight
loam in order to increase their
thermal and sound insulation.
 If the space created by a typical
16-cm-high rafter is filled with
lightweight loam with a density of
600 kg/m3 and the ceiling made
of timber boards, the roof
achieves an U-value of 0.8
W/m2K.
 Three solutions, B, C and D, show
possibilities for attaining higher
levels of thermal insulation, as
demanded in many countries.

67. ADVANTAGES OF VAULT AND DOMES ON ACCOUNT OF A
LOWER SURFACE VOLUME RATIO OF ROOFING
 Vaults and domes covering interior spaces and made from earthen
blocks are found mainly in religious buildings in Europe. In
southern Europe, Asia and Africa, nonetheless, they have also
been used in residences, offices and public buildings.
 These structures demonstrate several advantages in hot and dry
climates, especially in areas with a wide range of diurnal
temperatures.
 Given their inherent thermal mass and their greater heights at the
centre of a space, where light, warm air gathers and can be easily
discharged through openings, vaulted spaces provide better
natural climatic control than standard cubic ones. They have
smaller surface areas than cubic rooms of the same volume, and
therefore less heat gain.

68. ADVANTAGES OF VAULT AND DOMES
 In cold and moderate climates as well, vaults and domes
have several advantages. As the surface area is smaller
for the same volume, heat loss is lower, so heating
energy is reduced.
 In all climates, vaults and domes require less building
material to enclose a given volume.
 In all developing countries, vaults and domes are usually
cheaper in comparison with flat or slightly inclined roofs.
 Observation has shown that rooms with vaults and
domes have a pleasing and calming effect on inhabitants
in contrast to rooms with flat ceilings.
 Until recently vaults and domes of loam have been built
only with adobes.

69. ROOF INSULATION
Probable insulation using
gypsum/gyprock/glasswool in clay tiled pitched
roof.
Outside facade of traditional house, Yazd
Source: Hassan Fathy. Architecture for the Poor:
An Experiment in Rural Egypt (Chicago, 1973).
The book was originally published in Cairo in
1969 under the title, Gourna: A Tale of Two
Villages.

72. WALL INSULATION
 Sanjay Kumar et al (1994) in ‘Amalgamation of traditional and
modern cooling techniques in a passive solar house: A design
analysis,’ talks about the different roof and wall designs/treatments
that have been proposed, incorporating modern and ancient features
for passive cooling.
 Their research findings include:
 different roof and wall designs/treatments have been proposed,
incorporating modern and ancient features for passive cooling.
 evaporative cooling with an air cavity in the roof is the best option to
reduce the incoming heat flux through the roof if water is easily
available.
 a thin layer of cow dung slurry inside the wall cavity reduces the
incoming heat flux through the walls. It is better than solid walls and
air cavity walls.

73. Roof Material Figure
Straw thatch on pole timber on bamboo
substructure
Locally made country tiles on timber
substructure
Mangalore tiles on timber substructure
Wooden beams and boards covered with
straw and protective mud layer
Timber substructure carrying clay tiles
covered with mud
Composite Climatic Regions - (As per study by Bansal and Minke, 1988)

74. Roof Material Figure
Straw thatch on pole timber on bamboo
substructure
Locally made country tiles on timber
substructure
Mangalore tiles on timber substructure
Warm Humid Climate regions

75. Wall Material Figure
Compacted earth rendered with cow dung
slurry
Stone masonry in mud mortar
Poles and twigs plastered with mud mortar
c. Summary of Identified Wall Construction Materials in the Composite (As per study by
Bansal and Minke, 1988) , Composite Climatic Regions

76. Wall Material Figure
Compacted earth rendered with cow
dung slurry
Woven bamboo matting without plaster
Warm Humid Climate regions

77. BIBLIOGRAPHY
 http://www.nps.gov/nr/publications/bulletins.
 http://www.cres.gr/kape/energeia_politis/energeia_politis_bioclimatic_eng.htm
 Centre for renewable energy sources and saving.
 Olgyay Victor (1963), Design With Climate- Bioclimatic Approach to Architectural
Regionalism, Van Nostrand Reinhold, New York.
 Koenigsberger,Ingersoll,Mayhew,Szokolay. Manual of tropical housing and building.
Orient Longman. 1997.
 La Roche, Pablo Miguel, 2004. Passive cooling strategies for buildings in hot
climates with specific application to Venezuela. Pro Quest Dissertations and
Theses: The Sciences and Engineering Collection.
 The Energy and Resource Institute (TERI) guidelines, Solar Passive Design for
buildings, Page 7.
 Induja, Chani PS, October 2013. Passive Strategies for Indoor Thermal Comfort in
Warm and Humid Climate. Sustainable Architecture: Journal of The Indian Institute
of Architects. Volume 78. Issue 10, Pgs 43-48.
 Bansal,N.K. and Minke,G.,1988. Climatic zones and rural housing in India.
Zentralbibliothek Publishers, pp. 62-68, 132-149.

78. BIBLIOGRAPHY
Eco-housing Assessment Criteria- Version II
Implemented under Eco-housing Mainstreaming Partnership by IIEC with funding support
from USAID.
E. Hamzanlui Moghaddama, S. Amindeldarb, A.Besharatizadehb. New approach to natural
ventilation in public buildings inspired by Iranian’s traditional windcatcher. 2011 International
Conference on Green Buildings and Sustainable Cities. Procedia Engineering.

http://www.thatchco.com/thatchpg/
Minke Gernot.(2006). Building with Earth: Design and Technology of a Sustainable
Architecture, Birkhauser, Berlin.
Abdul Majid, N.H., Shuichi,H. and Takagi, N., 2012. Vernacular wisdom: the basis of
formulating compatible living environment in Oman, in: Proceedings of the ASIA Pacific
International Conference on Environment-Behaviour Studies, Procedia-Social and Behavioral
Sciences 68 (2012),Elsevier Science Direct, p. 637-648.
 Krishan, A., Jain,K. and Rajgopalan,M.,2001. Shelter or Form. In A.Krishan, N.Baker, S.
Yannas & S. V. Szokolay (Eds.), Climate responsive architecture: A design handbook for
energy efficient buildings. New Delhi: Tata McGraw-Hill Publishing Company Limited.
 Fathy,H., Architecture for the Poor: An Experiment in Rural Egypt Chicago, 1973. Chicago.
(The book was originally published in Cairo in 1969 under the title, Gourna: A Tale of Two
Villages.)
 http://www.eartharchitecture.com

79. THAT’S ALL
THANKS…