Many of us like to believe that Jharokhas are a unique feature of the Havelis that dot dry, dusty Rajasthan. They offer the purdah bound ladies private entertainment of the goings on of the outside world, the streets outside the havelis and the acitivities in the courtyards inside.
Plus, the perforated sculpture of the jharokhas filters the harsh glare of the desert sun, offers shade and therefore cool too.
These styles are common to most of the Arab world, again desert. Popularly called Mashrabiya, those are less of sculpture and more wood and glass lightweight, serving the same purpose: private viewing for purdah bound ladies; since most are on street homes of the wealthier people, the cool shade is free for both the ladies and the pedestrians on the streets below.
The designs of the latticework have smaller openings at the bottom and larger ones higher up to allow for efficient movement of drafts.
What of the hoi polio? The ones with no access to ACs, coolers, fridges etc, summer staples of middle and upper middle class India -- residents of societies and premium condominiums that draw their labor from the roasted slums next door.
For them life is even more difficult as their tin sheds get ultra heated, even though they are tightly enough packed to minimize the sun’s rays. Placing wet gunny bags on the roof is a great cooling device ---- but for the fact that every summer, water is at such a premium that we who live in comfort will never realize.
Many innovations have been floated for ‘low cost’ cooling, everyone of them requiring considerable investment. Recently one has come from Grameen in Bangladesh, as simple to put together as low cost.
A simple sturdy sheet, may be thick cardboard sheets (like those our ACs, fridges and coolers come in) pasted together or a plywood/ metal /tin sheet, anything that can support a couple dozen large empty water/cold drink bottles. The sheet is perforated and the holes protected with rubber rings to allow inserting the bottles with all the necks in on direction, after the bottoms have been sliced off.
The bottle laden sheet is placed into an inset in the wall of the hutment; hot air from outside enters the bigger end of the bottles and is cooled as it passes through the narrow segment to come out at least 5 degrees cooler inside the house. Viola, a low cost, no electricity, home made air cooler for a hutment.
Let us see how many of our elite and not-so-elite societies will cotton on to this idea, start a collection drive for empty bottles from the dozens they guzzle at home and in their clubs and pubs and plus may be, apart from may be hundred ruppes per home to help out the people who come to make their lives comfortable with their labor.
check out the homemade cooler at Youtube : https://youtu.be/jPuh8IFbIzQ