BASIC OVERVIEW OF HOT,DRY AREAS
• Very hot,dry air and dry ground
• Day-time temperatures range between 27-49 degC
• Night-time-falls to 22 degC
• Humidity-continuously moderate to low
• Dry air,low humidity and minimal rainfall discourage
• Local thermal winds carry dust and sand
• Clear sky most of the year
• Depends on reduction of the intense radiation from
the sun,ground and surrounding buildings
• During day, the designer must select walls and roofs which can
maintain inner surface temperatures less than the skin
• At night, the air temperature is low enough to permit an
increase in effective temperature by surfacetemperatures higher
than this air temperature.
• Low Humidity-Hence evaporation is greater than any other
• Breeze-cannot be used to advantage indoors.
Form and planning:
• As outdoor conditions are very hostile, both the interior and the
exterior of the building need to be protected. Hence , an enclosed
, compact in-ward looking building will be suitable.
• Hot dry climates occur in a wide range of latitudes and geographic
locations. This creates a variety of diurnal ranges and winter
heating requirements with hot to very hot, dry summers.
• Evaporative cooling from ponds, water features and ‘active’ or
mechanical cooling systems is ideal for arid climates where low
humidity promotes high evaporation rates.
• Evaporative cooling or a ceiling fan should be used if required.
• Use high mass solutions with passive solar winter heating where
winters are cool or cold and diurnal ranges are significant.
• Use low mass elevated solutions where winters are mild and
diurnal ranges are lower.
• Consider high mass construction for rooms with passive winter
heating and low mass for other rooms.
• Shade all windows in summer and east and west windows year
• Well sealed windows and doors with maximum opening area
allow maximum exposure to cooling breezes and exclude hot, dry
and dusty winds.
Two storey solution for hot and dry climate
• Topography, to enhance the efficiency of passive
• Orientation, to reduce the sun exposure in
• Air movement, to provide ample ventilation in
summer and protect from winds in winter.
Form, to design compact settlements for mutual
• Hazards, to avoid dangerous sites
Typical settlement for hot-dry regions
• As most day-to-day activities take place
outside,it is important totreat the external
spaces just as carefully as the indoors.
• Adjacent buildings,pavements,roads heat up
quickly and cause aglare onto the building
during the day and at night,they reradiatethe
heat stored during the day.
• One way to avoid this is to place walls
protecting external spaces,tokeep out dust
• Also,landscaping like trees,plants and water in
enclosed spaces willcool the air by
• But the best solution is courtyards. In these,a
pool of night air isretained,as this is heavier
than surrounding warm air
• A small courtyard is excellent as a thermal
Courtyard design with evaporative cooling
•curtain wall systems but this usually provides poor external
views, lack of optimal natural light and introduces excessive shine
•Alternatively, shading fixed devices, the "mashrabiya" in Al Bahar
Towers has a number of components transparent umbrella that
open and close in response to the sun's path.
•Each of the two towers comprising more than 1,000 individual
sunscreens are controlled via the building management system,
creating a smart facade.
Al bahar- Cool building in Abu Dhabi’s heat
Mashrabiya’s opening sequence
• Courtyard or Patio
• White Colored walls (“cool” colours reduce heat
• Arrangement of the houses in is very closely packed
to each other.
• Vegetation (reduces the temperature, filter’s the dust
• and around the house, elevates the humidity level may
reduce as well as increase the wind speed)
• small openings
• double roof or white single roof
• thick walls
• big basin to collect rainwater
• louvered windows
• a water body
OVERVIEW OF DESIGN PRINCIPLES..
1. A text book of climate and design for the built-form designers –Bijon b. Sarma , Falguni Mallick
2. Manual of tropical housing and building -koenigberger