SHELTER FOR COMPOSITE CLIMATE

Most complex one from the designer’s point of view

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 FEATURES OF COMPOSITE CLIMATE
• Composite climate is the combination of hot dry & warm humid
climate, which prevails for different parts of year.
• Summer season is experienced during months of April –June.
• Monsoon season is experienced during months of July-
September.
• Winter season is experienced during months of October- March.
• Hot –dry season (April – June) –In this season protection from
sun is required.
• Dry – winter season (October-March)- Low temperature & low
humidity
• Warm- humid season (July- September)- Moderate temperature
& high humidity.
 Hot –Dry Season Monsoon Season/ Winter Season
(April – June) Warm Humid climate (October-
(July-September) March)

Temperature
Day 32-43C 27-32C up to 27C
Temperature 21-27C 24-27C 04-10C
Night

Relative 30-55% 55-95% nearly 20%

humidity
 OBJECTIVES OF DESIGN
• The main objective of the
design is to consider all the
three different climates
prevails through out the
year.
• The temperature during the
day should remain nominal
inside the building, during
the summers.
• Heat gain during the winters as the temperature during winters falls
below normal.
• For the physiological comfort temperature should be below human skin
temperature & wind should flow near the skin.
 SO THE MAIN POINTS ARE…
• Keep a balance between
conflicting requirements.
• Seek solar radiation gain in
winter and provide shading in
summer
• Provide wind protection in
winter and proper ventilation in
summer
• Construct “good-natured”
houses, with moderate heat
storage capacity.
 SHELTER FOR COMPOSITE CLIMATE SHAPE & VOLUME
• Buildings are preferably rather compact.
• High thermal capacity walls are required for
this type of climate. i.e. 9”-13.5” thick brick
walls.
• Thick walls are useful for winter season as they
retain the heat gain during day time so that at
night the interiors of building remains warmer.
• Openings with louvers as shading device is very
useful for this climate.
• Wide chajjas at opening protects the building
from solar heat during summer season as well
as protects interior from rain during monsoon.
 Topographical location of settlements
• In lowland regions settlements should be exposed to the wind & protected from sun.
• In winter the opposite is required: Exposure to the sun and protection from the wind.
• In upland regions, shelter against the wind and orientation for maximum solar
radiation gain are required all the year round.
• In areas of intensive land use, buildings should be located on south slopes
where the sun exposure is adequate.
• Depressions should be avoided because cold air accumulates there.
• Above the bottom of the valley the microclimate is more favourable.
• Houses should be located behind a wind shield, but be assured of
exposure to the sun.
• This shield can be formed by existing or newly planted vegetation, by
other structures or by topography.
 Urban forms and external space: Settlement pattern
• Aspects of appropriate sun orientation & wind protection should already
be considered while working out the basic pattern of a settlement.
• This pattern should be of a semi-compact type.
• The plot dimensions should allow the positioning of a building with its
wider side facing S & sufficient distance from the neighbouring buildings.
• Provision for row buildings along the E-W axis may also be favoured.
• Streets are best planned in the direction of summer winds, avoiding the
direction of winter winds.
• The outdoor space - as in all warm regions - should be actively used.
• It should be planned to provide a well-balanced mix of open, sunny areas
for the cold season and shaded, well-ventilated areas for the warm period.
• Open squares with groups of trees to provide shade are desirable.
• Planting of deciduous trees & pergolas with deciduous creepers are a
possibility.
• A good example is
Bhumra, a village in
the higher hilly region
of West Nepal.
• This settlement also
provides efficient wind
protection and takes
full advantage of the
sun’s radiation.

• Flat roofs are actively used as outdoor living and working

spaces, where favourable climatic conditions prevail during
the daytime.
Building design
• Orientation and room placement
should be south facing.
• Form depends on precipitation
pattern.
• Shade in summer and heat gain in
winter is necessary.
• Ventilation must be controllable.
COMPACT BUILDINGS WITH HIGH VOLUME.

Thick walls Courtyard Planning

Schematic layout of a house in Marpha, Nepal
FORM AND PLANNING OF BUILDING
THE CONCEPT OF THERMAL ZONES

• The areas of the building can be

segregated, as per the usage and the
climate.
• The rooms which are less in use can be
arranged in lower portion of the
building.
• The main areas of the building i.e. bed
rooms can be planned on upper floor
of the building
Room arrangements
• A moderately compact internal
room arrangement is of benefit
for most of the year.
• Courtyard buildings are suitable,
terraced buildings facing south
may also be appropriate.
• In cooler areas, exposure of the
main rooms to the winter sun is
essential, whereas in warmer
areas these rooms can also be
placed north facing.
The concept of thermal zones: colder areas only
• Heat losses can be efficiently reduced by dividing the house into
zones with higher & lower heat demands, accor. to their functions.
• The zone with the higher heat demand, such as living rooms, is
placed facing towards the sun (south).
• The zones with less heat requirements, e.g. sleeping areas, kitchen,
stores, entrance etc., are arranged around the warm zone on the
W, N and E side, providing protection against heat loss & wind.
• This zone functions as a thermal buffer.
• An external belt of vegetation or other adjoining buildings and
parapet walls may provide additional protection.
This concept applies in the colder areas only.
 Ventilation in warm zones
• In the warmer areas, humidity can cause problems
during the monsoon period, Hence, arrangements for a
proper cross-ventilation are necessary.
• The separation of humidity-producing areas such as
kitchen and bathrooms from the rest of the building is
recommended
BUILDING COMPONENTS FOR DIFFERENT SEASONS:
• One solution would be a building type
which is also useful in hot-dry and maritime
areas, ground floor with massive walls and
an upper floor of a light structure .
• The ground floor would be relatively cool in
the daytime & relatively warm at night.
• The light structure on the upper floor would
perform the opposite way.
• RESULT- In the winter time the inhabitants
would use the upper floor in the daytime
and the ground floor at night. In the
summer time the pattern would be
reversed.
Economic limitation
• In reality, however, for both economical and
organizational reasons, such day and night rooms or
summer and winter houses are often not feasible, and a
building or room has to be designed to serve all year
round.
• The large range of thermal conditions requires the
utilization of radiation and wind effects, as well as
protection from them.
• Hence, the arrangements have to play a dual role.
Immediate external space
• The outdoor space should also
be designed as a compromise
with ventilation and shade in
summer, and wind protection
and solar radiation gain in winter.
• The vegetation should be
planned accordingly, to provide
partly sunny and partly shaded
spaces.
• Deciduous trees are an excellent
medium with which to achieve
this goal.
VEGETATION COVER ON FACADES

DECIDUOUS TREES PROVIDE ACCESS TO WINTER SUN

BUT PROTECT AGAINST SUMMER SUN
• Plants can be arranged to achieve the desired
ventilation effect
The basic idea
• Capturing as much winter sun as possible
• Keeping out solar radiation in summer time sun
• Using a thermal buffer zone towards the north
The function of the solar gain process using glazed surfaces is based on the “greenhouse
effect”. This means that solar radiation can easily pass through glass. When it strikes an
absorptive surface behind the glass, it is converted into longwave heat radiation which
cannot pass directly through the glass anymore. As a result the materials behind the
glass heat up.