CLIMATE ANALYSIS TROPICAL WET AND DRY CLIMATE HOT AND HUMID HOT AND DRY DESIGN STRATEGIES ORIENTATION AND POSITIONING SHADING DEVICES VENTILATION AND CROSS VENTILATION PASSIVE COOLING TECHNIQUES COLOR SCHEME ENERGY EFFICIENT TECHNIQUES CONSTRUCTION TECHNIQUES AND MATERIALS TO BE USED - ROOF, WALL, WINDOWS

1. DATA COLLECTION
-LIPIKA PANDEY
3RD SEM

2. CLIMATE AND ITS CHARACTERISTICS
 Transition between the tropical wet and dry climate of Kolkata and the more
humid subtropical climate further north.
 High temperature during summers accompanied by average humidity (40-
45°C)
 Average rainfall (250mm)
 Average winters (10-15°C)
 Winter winds from North
 Summer winds from South – prevailing wind
 Sun path from East to West via South

3. DESIGN STRATEGIES
 Minimization of the high day temperature
 Avoidance of direct exposure of facades to solar radiations. Orientation and
placement, to minimize sun exposure in summer.
 Reduction in the humidity levels
 Continuous air circulation to reduce heat and relief from stickiness
 To create a temperature difference between the inside and outside
environments to facilitate evaporation and heat dissipation.
 Shade, for maximum sun protection in summer.
 Allow adequate heat gain in winter by movable shading devices.
 Ventilation, for regulation of air movement – Cross ventilation
 Passive cooling techniques
 Keep the exteriors, light in colour to avoid absorption of heat
 Large glass areas should be avoided

4. ORIENTATION AND POSITIONING
 Orientation of smaller side of structure along east-west.
 The larger building dimension should face north and south sun orientation
of building, west orientation is the worst. The main elevations and rooms
should be placed facing north and south and towards the prevailing wind.
 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.
 Bedrooms - on the east side. Bedrooms should be oriented to receive cool
night air.
 Living rooms - on the north or south side.
 More windows should be provided in the north facade of the building as
compared to the east, west and south as it receives lesser radiation
throughout the year. Windows must be small on the east and west sides and
must be adequately shaded. Larger windows can be placed on the south
side as it is relatively easier to shade the south side from the high summer
sun with a horizontal sun-shade this can also allow desirable winter sun.
Larger windows could also be placed on the north facade as direct solar
radiation is least on this facade
 Outlets at higher levels serve to vent hot air. Ventilators are preferred at
higher levels as they help in throwing out the hot air. Window sill should be
higher to provide dust protection

6. SHADING DEVICES
 Adequate shading measures are also necessary to protect the
building from direct solar radiation.
 Should be shaded either by shading devices, roof overhangs or
by deciduous trees.
 Deciduous trees shade there leaves in winter and regain them
during the summers. The word deciduous is from the Latin
word ’decider’, meaning “to fall off.” Example – oak, maple,
willow, etc
 Eastern and western walls should be shaded with trees or
some other screens.
 Deep sun shades are required to shade windows effectively

8. VENTILATION AND CROSS VENTILATION
 Larger windows for ventilation. Semi – open spaces for
light and air movement
 Voids in roof, use of double roofs and courtyards
provide maximum light, cross ventilation and natural
cooling
 Catch an unobstructed breeze at a high level and
channel it to areas in the bottom parts of the building.
 Night Ventilation – build heat gain in day time and
removes that heat during night
Night Ventilation

9. VENTILATION TECHNIQUES

10. PASSIVE COOLING
 Cooling can be achieved by the evaporation of water.
 The courtyard to be provided with water and plants, it acts
as a cooling source, evaporative cooling effect
 Most openings can be to the internal courtyard rather than
exterior surface
 During the day-time openings should be closed and shaded. -
Decreasing the surface of the building exposed to the
outside. - Using materials that take a longer time to heat up
- providing buffer spaces (lobbies, etc.) Between the living
areas and the outside
 Hollow block construction technique also help in thermal
insulation of buildings.
 Double roof technique protect main structure from solar
heat
 Providing as much green surface as possible as this will cool
the surroundings
 Avoid hard paved surfaces as these may create glare and
radiate heat inside the building

11. Evaporative cooling
Earth Air Tunnel SystemEarth Berming
Thermal Mass
PASSIVE COOLING TECHNIQUES

12. COLOR SCHEMES
 Building materials with insulating/reflecting properties that resist heat
transfer
 Light colors and reflective surfaces on roofs will deflect solar radiations and
keep the building cool - The surface of the roof can be of white broken glazed
tiles - A light coloured or totally white terrace surface will reduce effect of
hot solar radiations
 Faint/pale colours on outer surfaces. Colors that absorb less heat should be
used to paint the external surface - Darker shades should be avoided for
surfaces exposed to direct solar radiation - Light coloured /shiny reflective
surfaces should be used to reflect solar heat
 Light cool colours should be used for interiors - Surfaces that may reflect
radiations should be painted dark to reduce glaring effect

13. ENERGY EFFICIENT TECHNIQUES
 Double roof technique to protect main structure from solar heat
 Hot solar radiations can be converted in useful electricity by
using photovoltaic cells - Solar panels - Solar Photo Voltaic
Installation the ideal orientation for optimal performance of a
solar cell is at an angle equivalent to the latitude of the place of
installation.
 Sun protection devices(pergolas) are used to protect front
facades of hot dry region
 Solar Water Heater use of solar energy for water heating is one
of the most commercialized and easily available options. Hot
water supply to building cold water inlet storage tank hot water
from collector to tank collector (flat plate or evacuated tube)
 Rainwater Harvesting (RWH) water conservation and reuse is of
utmost priority in the hot-dry climate. Catchment area on roof
jaali on roof to prevent pollutants into water filtration tank
recharge system or pervious paving - Cascade System RWH For
Rainwater Reuse rainwater from 2nd terrace collected & used on
the lower floor. Rainwater from 1st terrace collected and used
for irrigation etc.

14. Solar Heater
Rain Water Harvesting
Solar Panel
ENERGY EFFICIENT TECHNIQUES

15. CONSTRUCTION TECHNIQUES AND MATERIALS
TO BE USED
ROOF –
 Primary requirements for roofing materials (supporting structure and cladding): high thermal capacity (to
absorb solar heat during the day and release it during the night, when the temperature drops considerably);
good reflectivity (to reduce heat load and thermal movements); resistance to embrittlement (caused by
repeated cycles of heating and cooling) and abrasion (caused by wind-blown sand); smooth surfaces to
prevent collection of sand and dust.
 Light materials such as timber are used in construction - sloping roof can also be used, as it drains off rain
water - barrel-vaulted roof can also be seen - the flat roof is a good reflector and re-radiates heat
efficiently, especially if it consists of a solid, white painted material - high solid parapet walls along the edge
of the roof can on the one hand provide daytime shade and privacy - vaults and dome shaped roofs are also
common, providing good thermal comfort.
 Materials - Asphalt Shingles, Cedar Shake Roofing, Metal Roof, Spanish Tile, Slate Roofs, Terracotta Roofing,
Concrete Roofing, Membrane Roofing, Photo Voltaic Shingles, Ceramic Roofing
 Double layered roofs (with sufficient air space to dissipate hot air and with the upper surfaces of each layer
designed to reflect heat) can be of lightweight, low thermal capacity materials, whereby the outer layer can
be of insulating material.
 Wind catchers (towers with openings facing the main direction of wind) are advantageous to redirect higher
level breezes into the building.
 White roofs:- A white roof is painted with solar reflective white coating and reflects up to 90% of sunlight.
 Green roofs: A green roof or living roof is a roof of a building that is partially or completely covered with
vegetation and a growing medium, planted over a waterproofing membrane

16. White Roof Green Roof

17. CONSTRUCTION TECHNIQUES AND MATERIALS
TO BE USED
WALL –
 The walls of day time living areas should be made of heat storing materials
so that these can store heat in day time and keep the inside cool and radiate
hot solar radiation back in to atmosphere during night
 Solid walls - they transfer the absorbed heat to the interior with a time lag,
thus restraining the heat when external temperatures are high, and releasing
it when temperatures are low. - Typical solid walls are made of stone, earth,
burnt clay bricks and concrete.
 Cavity walls , Rat trap wall
 Double wall construction with proper ventilation may also be constructed on
western side - Double walled construction - the outer layer protects the inner
layer from direct solar radiation, which first heats up the outer layer. With a
reflective outer surface, this heat absorption is greatly reduced
 Lightweight walls - these are usually thin panels, matting, sheets or tiles of
low thermal capacity, fixed to a framework. In some rare cases they can be
thermally insulating.
 Its better if there are rooms with two exterior walls. This will allow for better
airflow through cross-breezes.

18. Cavity wall Light weight wall
Double wall Solid wall Rat trap wall
TYPES OF RECOMMENDED WALLS

19. CONSTRUCTION TECHNIQUES AND MATERIALS
TO BE USED
WINDOWS –
 High-quality vinyl window and door frames are typically the best choice. They
stand up to moisture and insect damage in our climate. They are virtually
maintenance free and last for years even in the harshest weather Louisiana
can throw at them.
 In terms of window glass, double- or triple-paned low-e glass can help
improve the energy efficiency of your home.
 Use of oriel windows and different type of louvered sun shades also reduce
sun’s harshness
 Various screens that can be used –
 Mesh screen (lets in some light, heat, cold and dust; keeps out insects,
some light and some breeze)
 Fixed screen (lets in some light, fresh air, heat breeze, and insects; keeps
out some light, glare, sun)
 Double-door shutter (when open lets in everything; when closed, keeps
out everything)
 Glass (lets in light and heat; when closed, keeps out cold, wind, rain,
dust, and insects)
 Solid wood (lets in heat, light; keeps out some light, cold, wind, rain, and
when closed, dust and insect)
High quality vinyl window frames

20. TYPES OF ORIEL WINDOWS

21. CONSTRUCTION TECHNIQUES AND MATERIALS
TO BE USED
SOME OTHER MATERIALS AND CONSTRUCTION TECHNIQUES ARE –
 Permeable indoor wall coverings: these allow moisture to escape from the building
 Fasteners: stainless steel and aluminium fasteners will be the best choice to repel rust
 Vapor barriers: vapor barriers under the house can keep moisture from seeping up
through the ground
 House wrap: house wrap protects the home from moisture but also allows moisture to
evaporate
 Siding: siding that allows moisture to evaporate quickly is the best choice
 Engineered hardwood, natural plaster, concrete, spray foam insulation, vinyl siding
 Insulation Materials : Fiberglass, Mineral Wool, Flexible Elastomeric, Cellular Glass,
Plastic Foam Insulation
 Use of deeper entrance door and broad eaves - eaves to protect from glare of sun

22. Permeable indoor wall covering
Vapour barrier House wrap
Siding
SOME OTHER CONSTRUCTION TECHNIQUES