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India's lattice buildings cool without air con

bbc.com

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Re: India's lattice buildings cool without air con

#11

Post by Retric »

refactor_master wrote: post #7
vivegi wrote: post #5

Earlier quoted context omitted.

Using an airconditioner and lattice structures/jaali are not mutually exclusive. As an example, if you consider large buildings like hotels that have an open central courtyard, the open spaces could use the lattice structures for cooling/circulation while the rooms, banquet/conference halls and other closed spaces can use airconditioners. Since the lattices offer passive cooling, they can lower the overall energy bil…

Given the amount of traffic, street level noise, and air pollution in many Asian countries I don’t see this being implemented any time soon, in places where it matters. Ceiling fans would also work really well, but similarly require openings in buildings. Now you only see them in traditional buildings (read: museums most often) because they were made with airflow in mind, before the age of AC. People will prefer a he…

A shell within a shell also works. It’s common for tall building to have air gapped external cladding to reduce the need for cooling. There are significant trade offs around construction costs, views, and the need for cooling. However, the savings can be very significant for more extreme designs.

Re: India's lattice buildings cool without air con

#13

Post by spaceman_2020 »

Modern Indian housing in major Indian cities has done a complete 180 from these tried-and-tested architectural practices. The materials used seem to be deliberately chosen to maximize human misery. There's glass everywhere which, besides being impossible to keep clean in India's dusty summers, also retains heat and makes most housing unbearable without AC.

Then there are the designs themselves. Faux wood is everywhere, as are laser-carved patterns that collect dust. Spaces are designed to maximize square footage, ventillation and sunlight be damned.

The "builder floors" that dot cities like Delhi are an exercise in public ugliness and bad design.

Edit: An example of the kind of housing I'm talking about. Superficially "modern", but absolutely the wrong design for Indian weather:

https://newprojects.99acres.com/projects/findahouse/findahou...

Re: India's lattice buildings cool without air con

#14

Post by mellavora »

refactor_master wrote: post #7
vivegi wrote: post #5

Earlier quoted context omitted.

Using an airconditioner and lattice structures/jaali are not mutually exclusive. As an example, if you consider large buildings like hotels that have an open central courtyard, the open spaces could use the lattice structures for cooling/circulation while the rooms, banquet/conference halls and other closed spaces can use airconditioners. Since the lattices offer passive cooling, they can lower the overall energy bil…

Given the amount of traffic, street level noise, and air pollution in many Asian countries I don’t see this being implemented any time soon, in places where it matters. Ceiling fans would also work really well, but similarly require openings in buildings. Now you only see them in traditional buildings (read: museums most often) because they were made with airflow in mind, before the age of AC. People will prefer a he…

> People will prefer a hermetically sealed building....

where along with being isolated from the natural environment they can be isolated from everyone else and only interact over social media.

Sounds a bit like being in a tomb to me, but then again, I was never fully domesticated.

Re: India's lattice buildings cool without air con

#15

Post by wil421 »

b1ue64 wrote: post #3
guywithahat wrote: post #2

They also make it impossible to add air conditioning if I'm reading this right and can only really cool things down to the surrounding temperature (basically attempts to keep buildings from turning into greenhouses). Very cool but I don't see this being implemented anywhere where someone can afford AC

From the article: "Jaali’s cooling feature relies on the Venturi effect in a similar way to an air conditioning unit. 'When air passes through holes, it picks up velocity and penetrates afar. Due to the small apertures, air gets compressed and when released it gets cooler,' says Pandya."

There’s no way holes are going to cool a building down like AC. The building is going to be similar to the outside it will just cut down on the greenhouse affect.

Re: India's lattice buildings cool without air con

#16

Post by dageshi »

guywithahat wrote: post #2

They also make it impossible to add air conditioning if I'm reading this right and can only really cool things down to the surrounding temperature (basically attempts to keep buildings from turning into greenhouses). Very cool but I don't see this being implemented anywhere where someone can afford AC

In Thailand it seemed more common to have small spaces indoors that could be sealed and air conditioned very efficiently, typically a bedroom.

You might have a semi open plan apartment with the bedroom inside a smaller room with a sliding door you could use to seal it.

Quite an efficient approach I thought, doesn't waste energy cooling the entire space but offers somewhere cool if you need it.

Re: India's lattice buildings cool without air con

#17

Post by trabant00 »

I don't think this is correct at all:

> Jaali’s cooling feature relies on the Venturi effect in a similar way to an air conditioning unit. "When air passes through holes, it picks up velocity and penetrates afar. Due to the small apertures, air gets compressed and when released it gets cooler," says Pandya.

When the air passes through the holes, yes, it picks up velocity, but that velocity is lost immediately upon exiting so it can't penetrate further than if the restriction wasn't there. In fact it must lose some energy due to the restrictions so it will penetrate less and you can easily observe this when using a mosquito net in window.

Secondly the air is not compressed through the holes, the pressure actually drops as the speed increases. Unless I completely misunderstand the Venturi effect, in which case please correct me.

The purpose of the lattices is to let in air and light while restricting direct sunlight. That is important enough especially since it's passive, but shades are being used in modern buildings, it's not some lost art, and it is clearly nothing like AC. It's not even like modern ventilation or mobile shades which can let air only during the cool nights.

Re: India's lattice buildings cool without air con

#18

Post by gattilorenz »

eb0la wrote: post #9

Really interesting! It reminds me of Majorcan shutters (in spanish persianas mallorquinas). In Majorca/Minorca you cannot shut the windows when theres hot outside: humidity will make interiors as hot as the outside; but you can open the window while you have the shutter closed... and survive. Probably in California there are some Majorcan shutters, too (Juniper Serra was from Majorca after all) ???

I think they're popular all across the Mediterranean, I've certainly seen them in Italy and Croatia. Shutters are noticeably missing in areas in Northern Europe due to "never being hot enough", except... now they would be welcome.

Re: India's lattice buildings cool without air con

#19

Post by pembrook »

spaceman_2020 wrote: post #13

Modern Indian housing in major Indian cities has done a complete 180 from these tried-and-tested architectural practices. The materials used seem to be deliberately chosen to maximize human misery. There's glass everywhere which, besides being impossible to keep clean in India's dusty summers, also retains heat and makes most housing unbearable without AC. Then there are the designs themselves. Faux wood is everywher…

In the example you give, there’s no way of knowing if it’s been properly designed for Indian climate per given budget constraints.

There appears to be windows on only 2 sides of the building, 1 of which is far enough inset to create significant shade.

Depending on what direction the building faces, this could in fact be optimal design for staying cool while still having windows.

Now, of course, the best design for staying cool would be an underground cave carved out of rock with no windows—-but is that really how we want to live?

There is no scalable home design that works without AC when temperatures regularly get to 100-120F with high humidity.

Re: India's lattice buildings cool without air con

#20

Post by smcl »

gattilorenz wrote: post #18
eb0la wrote: post #9

Really interesting! It reminds me of Majorcan shutters (in spanish persianas mallorquinas). In Majorca/Minorca you cannot shut the windows when theres hot outside: humidity will make interiors as hot as the outside; but you can open the window while you have the shutter closed... and survive. Probably in California there are some Majorcan shutters, too (Juniper Serra was from Majorca after all) ???

I think they're popular all across the Mediterranean, I've certainly seen them in Italy and Croatia. Shutters are noticeably missing in areas in Northern Europe due to "never being hot enough", except... now they would be welcome.

I remember seeing them a fair amount in the old quarter in Hanoi, quick search shows my memory isn't failing me: https://www.indochinavoyages.com/travel-blog/hanoi-old-quart...
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