JAISALMERTHE GOLDEN CITY

  Rawal Jaisel, the sixth in succession from Deoraj,

founded the fort and city of Jaisalmer, in 1156. Built on a hill top. Lies in the heart of the Thar desert and has a

population of about 58,000. Covers an area of 5.1 sqkm.

Construction material – yellow Sandstone. Jaisalmer was positioned strategically and was a

halting point along a traditional trade route traversed by the camel caravans of Indian and Asian merchants. The route linked India to Central Asia, Egypt, Arabia, Persia, Africa and the West.

Jaisalmer Fort still houses some 2,000 residents, which makes it India's last “living fort”.

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HISTORY

A 5 to 6m high wall surrounds Jaisalmer town.

The fort wall has 99 bastions around its circumference.

Number of gates called Prols, define the entry points of the

town.  In summer the day-time

temperature can reach up to 45°C and down to 25°C at night, in winter the temperatures vary between 25°C and 5°C. 

Average annual rainfall is 150 millimetres.

Severe dust storms during May and June. Average depth of the wells is said to be about 250 feet.  

TOWN LAYOUT The layout of the town is the first

defense against the harsh climate.

The dense compact settlement planning generates a large

thermal mass attenuating the external

ambient conditions.. For hot arid climates, thermal

design principles call for:1) a building form that

intercepts least possible solar radiation,

2) a low surface area to volume ratio, and

3) a building design that promotes ventilation when needed. The town was planned with major streets

oriented along E-W(opposite to the direction of sand strom) and minor streets at right angles to these.

At the town scale the buildings are of unequal heights with wind pavilions and high parapet walls creating an uneven skyline and shading each other in the process.

At the second level, the building facades have a large number of projections like sunshades and balconies

At the smallest level, The flat parts of the building facades are deeply carved creating finned surfaces. Such uneven structures and surfaces can be considered extended surfaces. The use of such surfaces always results in increased convective heat transfer to air . An important aspect of these structures was arrangement of

activities in space and time - lower floors and shaded courts used for daytime activities and upper floors and terraces for nighttime sleeping.

The street maximum daytime temperatures in summers are 1.5 to 2.5 oC lower than metrological data while in winter this difference was less than 1 oC.

The night street temperatures are elevated by 3 to 5 oC in winters, while in summers the corresponding elevation was only 0.5 to 3.5 oC. This shows the positive impact of urban form on microclimate.

The problem of wind-blown sand is effectively settled by the 5 to 6 metre high wall around the town. Within the town most surfaces are paved, reducing the

chance of dust being raised. The heights of the buildings are 1 to 2 times street width of main

street and 4 times the street width for N-S streets.

The street orientation of WNW-ESE ensures that the building facades are either shaded by the balcony and sunshade projections or by the buildings opposite to it.

For street oriented N-S the building opposite shades the northern facade even if the street is relatively wide.

The only way to achieve thermal comfort is to increase ventilation. This is effectively done by the combined effect of courtyard andthermal vertical shafts.

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A – Approach rampB – Entrance gateC – Royal squarek – Queens palacej – King’s palaceM – Stables for camelD – Royal seatH – TempleF – Residential streetE – SquareN -- Granary

KINGS PALACE

QUEENS PALACE

ROYAL SEAT

SECTION

For streets oriented N-S, the summer sun shines on the east facade till 10.30am and the west facade after 1.30pm. Solar altitude varies from 0° to 79°, With a narrow street, the building facades would be shaded before 10.30am and after 1.30pm.

An E-W street orientation, in summer the sun would be shining on the south facade from 9.30am to 2.30pm. The corresponding solar altitudes are 54° to 86° and even small horizontal projections are sufficient to shade the south-facing building.

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