Yakhchal: Ancient Refrigerators (2009)(eartharchitecture.org)
eartharchitecture.org
Yakhchal: Ancient Refrigerators (2009)
http://eartharchitecture.org/?p=570
51 comments
Agreed. Similarly, when I learned of the Indian technique of stepwall evaporative cooling, I was shocked that something so misleadingly simple could have been derived so long ago.
https://www.treehugger.com/green-architecture/architect-uses...
But, of course people back then weren't any less intelligent, they simply didn't have as much knowledge, probably due to the inefficiency of transmitting knowledge from one generation to another without the use of digital technologies.
If anyone is at all interested in ancient (or even just modestly old) cooling techniques, 99 Percent Invisible had a particularly great episode in "Thermal Delight"
https://99percentinvisible.org/episode/thermal-delight/
https://www.treehugger.com/green-architecture/architect-uses...
But, of course people back then weren't any less intelligent, they simply didn't have as much knowledge, probably due to the inefficiency of transmitting knowledge from one generation to another without the use of digital technologies.
If anyone is at all interested in ancient (or even just modestly old) cooling techniques, 99 Percent Invisible had a particularly great episode in "Thermal Delight"
https://99percentinvisible.org/episode/thermal-delight/
It's more shocking to realise how much we've needlessly thrown away.
There's a vast selection of old architectural techniques for controlling environment that we've thrown away, preferring to bolt an AC unit to a hugely inefficient building instead. Many are free, relying on natural convection and material properties etc, others rely on movement of water like the Yakchal.
Some, but far from all, are coming back to be seen in things like passive houses, but that remains an extremely small niche.
There's a vast selection of old architectural techniques for controlling environment that we've thrown away, preferring to bolt an AC unit to a hugely inefficient building instead. Many are free, relying on natural convection and material properties etc, others rely on movement of water like the Yakchal.
Some, but far from all, are coming back to be seen in things like passive houses, but that remains an extremely small niche.
A lot of these forgotten technologies are revived in various contemporary green movements - such as Permaculture and Earthship, for example.
Permaculture attempts to learn as much forgotten technology as possible and re-apply it in a modern context for agriculture - the Earthship movement, same but for architecture.
I think the biggest barrier to these forgotten technologies is the stigma around the cultures they attract, as well as the hubris around the technologies they supplant. Its very difficult to get someone who has grown up with the Monsanto mindset to consider Permaculture concepts as a viable means of agricultural production - likewise with Earthship.
Stigma and Hubris seem to be the number one causes of lost technology, imho.
https://en.wikipedia.org/wiki/Permaculture
https://en.wikipedia.org/wiki/Earthship
Permaculture attempts to learn as much forgotten technology as possible and re-apply it in a modern context for agriculture - the Earthship movement, same but for architecture.
I think the biggest barrier to these forgotten technologies is the stigma around the cultures they attract, as well as the hubris around the technologies they supplant. Its very difficult to get someone who has grown up with the Monsanto mindset to consider Permaculture concepts as a viable means of agricultural production - likewise with Earthship.
Stigma and Hubris seem to be the number one causes of lost technology, imho.
https://en.wikipedia.org/wiki/Permaculture
https://en.wikipedia.org/wiki/Earthship
A very good point. After reading the linked 99% piece linked above I'd perhaps extend that to "stigma, hubris and marketing".
It's not very "modern" either is it? Hmm. I wonder if that's why we got the post-war modernism school of architecture. :)
Someone used to monoculture and pesticides presumes dishonesty when hearing about the productivity of permaculture - or even traditional mixed farming as it's comparing mono yields against dozens of crops and livestock at the same time from the acre.
It's a disappointment realising, after visiting a selection of old buildings, just how much nicer the old solutions are for humans to inhabit. You get none of the harsh drying that you do with heating and AC, but you do get small temperature variations and air movement that make it far better.
I haven't come across Earthship before, surprisingly, so thanks for that.
It's not very "modern" either is it? Hmm. I wonder if that's why we got the post-war modernism school of architecture. :)
Someone used to monoculture and pesticides presumes dishonesty when hearing about the productivity of permaculture - or even traditional mixed farming as it's comparing mono yields against dozens of crops and livestock at the same time from the acre.
It's a disappointment realising, after visiting a selection of old buildings, just how much nicer the old solutions are for humans to inhabit. You get none of the harsh drying that you do with heating and AC, but you do get small temperature variations and air movement that make it far better.
I haven't come across Earthship before, surprisingly, so thanks for that.
Regarding old buildings - it also applies to cities.
I once seen somewhere that Wrocław was designed to have air flow through the streets freely to take out coal hearing induced smog.
Now, after the war, Polish architects unaware of that redesigned some of these airways and even though coal burning is almost non-existent smog levels are rising.
Cars and loss of greenery contribute to it but one can only wonder how good air would have been if they would follow the original plan.
I once seen somewhere that Wrocław was designed to have air flow through the streets freely to take out coal hearing induced smog.
Now, after the war, Polish architects unaware of that redesigned some of these airways and even though coal burning is almost non-existent smog levels are rising.
Cars and loss of greenery contribute to it but one can only wonder how good air would have been if they would follow the original plan.
> inefficiency of transmitting knowledge from one generation to another without the use of digital technologies.
Digital technologies haven’t transmitted information between very many generations at all. I don’t think this was the problem.
Digital technologies haven’t transmitted information between very many generations at all. I don’t think this was the problem.
Lack of writing was the problem (and paper). The most effective innovation was the printing press - what followed was an explosion of technological progress.
printing press was an improvement, not the invention of information transfer.
They were doing just fine with papyrus(paper), leather(letters), tablets, and bark
They were doing just fine with papyrus(paper), leather(letters), tablets, and bark
The movable type and printing press combination was introduced by Gutenberg in 1455 and in a single generation spread to hundreds of European cities. By 1500, there were 20 million printed books in Europe for a population of 70 million, mostly illiterate.
It was a cultural revolution, in half a century the price of books dropped by an order or two of magnitude. They were transformed from a luxury item only the wealthiest could afford to something any middle class, literate citizen could own.
It was a cultural revolution, in half a century the price of books dropped by an order or two of magnitude. They were transformed from a luxury item only the wealthiest could afford to something any middle class, literate citizen could own.
Interestingly, in Korea, they had movable metal type some decades earlier (in 1377). Check out the image and text about Jikji, "from Korea, the earliest known book printed with movable metal type, 1377" (from the Wikipedia article about Printing) at the bottom of this blog post:
https://jugad2.blogspot.com/2014/10/print-selected-text-page...
https://jugad2.blogspot.com/2014/10/print-selected-text-page...
Cunei form also had moveable type. Afaik most was still handwritten though.
There are hundreds of thousands yet untranslated cunei form tablets in museums and maybe many more that never made it through time.
From "Moveable type" wikipedia:
"Seals and stamps may have been precursors to movable type. The uneven spacing of the impressions on brick stamps found in the Mesopotamian cities of Uruk and Larsa, dating from the 2nd millennium BC, has been conjectured by some archaeologists as evidence that the stamps were made using movable type."
Just to provide some perspective
From "Moveable type" wikipedia:
"Seals and stamps may have been precursors to movable type. The uneven spacing of the impressions on brick stamps found in the Mesopotamian cities of Uruk and Larsa, dating from the 2nd millennium BC, has been conjectured by some archaeologists as evidence that the stamps were made using movable type."
Just to provide some perspective
It was one heluva invention.
> They were doing just fine with ...
Writing books by hand, letter by letter? Not really.
I sometimes wonder what the romans could have achieved if they had a printing press.
> They were doing just fine with ...
Writing books by hand, letter by letter? Not really.
I sometimes wonder what the romans could have achieved if they had a printing press.
To mangle a masterpiece: What have the Romans ever done for us?
They invented modern roads.
>annoying about pop archaeology
"HOW COULD THEY POSSIBLY HAVE MOVED THIS!?!?!"
Many paragraphs or commercials later:
"Ok they just put it on top of some logs and rolled it..."
"HOW COULD THEY POSSIBLY HAVE MOVED THIS!?!?!"
Many paragraphs or commercials later:
"Ok they just put it on top of some logs and rolled it..."
Evaporative cooling plus the fact it freezes at night, and they have a system for transferring melted run off to the outside to refreeze.
Being originally from a hot, HUMID climate, I find these articles so exasperating. It can get to 85 degrees at night where I was born. So thanks, thanks for the mystic knowledge of the ancients, but it's central and a fridgedair for me.
Half the articles are trying to stop people from using cooling compressors, and discuss the limitations in passing.
Being originally from a hot, HUMID climate, I find these articles so exasperating. It can get to 85 degrees at night where I was born. So thanks, thanks for the mystic knowledge of the ancients, but it's central and a fridgedair for me.
Half the articles are trying to stop people from using cooling compressors, and discuss the limitations in passing.
From building a mostly mud building in a hot humid climate, it seems that the best you can usually do is "not less comfortable than outside". Basically a large reflective (say straw) roof/shade without walls is the ideal dwelling type, open to prevailing south breezes. Humidity can be regulated a bit using appropriate partitions, but nothing too much as far as I have found.
In the end as long as there is enough of a breeze conditions can be kept "moderately comfortable" without AC for most of the year in our location. Though, it does really ask for there to be a nap in the middle of the day.
I feel great jealousy for all the creative solutions that can be used in dry climates, including convective and evaporative!
In the end as long as there is enough of a breeze conditions can be kept "moderately comfortable" without AC for most of the year in our location. Though, it does really ask for there to be a nap in the middle of the day.
I feel great jealousy for all the creative solutions that can be used in dry climates, including convective and evaporative!
Sadly, where I lived summers usually brought the mother of all high pressure zones, which meant WHAT BREEZE?!!!! Much of the American south has the hottest, most humid type of the year matched with only the dream of wind.
The first time I went to the desert I was amazed at how much you can change the climate without a hermetically enclosed environment. Fans work! Shade works! Blowing air over water works! Ice wrapped in a towel works!
You can make 115 feel tolerable with very little electricity or effort. THAT'S CHEATING!
I solved it by moving away.
The first time I went to the desert I was amazed at how much you can change the climate without a hermetically enclosed environment. Fans work! Shade works! Blowing air over water works! Ice wrapped in a towel works!
You can make 115 feel tolerable with very little electricity or effort. THAT'S CHEATING!
I solved it by moving away.
For a very well written and detailed description of the principle of evaporative cooling, you can’t beat Feynman.
Section 1-3
http://www.feynmanlectures.caltech.edu/I_01.html
Section 1-3
http://www.feynmanlectures.caltech.edu/I_01.html
While he may very well be both, I will take an average scientist/engineer with a talent for communication over the inverse any day.
Then I can have the opposite case all to myself. Excellent! :-)
Most of the article is pulled word for word from the Wiki you linked.
Thank you. Came to comments to find this out.
Evaporative cooling is a very powerful technique, but does not work quite well at small scales.
Evaporative cooling is a very powerful technique, but does not work quite well at small scales.
Yes, but with this method, items can be kept at 4.5 Deg Celcius, they cannot hold ice.
There's no link I think, but I'm fascinated by the windcatcher: https://en.wikipedia.org/wiki/Windcatcher
The specific trick here appears to be that you connect a qanat (underground canal, which routes water from the water table at a higher elevation to the surface at a lower elevation) to the bottom of the structure, and a wind catcher to the top, with its opening facing away from the prevailing direction of wind. Wind blowing past the tower causes a pressure drop near the opening, which draws in air from the other end of the qanat, which is cooler because it's underground / next to water.
The specific trick here appears to be that you connect a qanat (underground canal, which routes water from the water table at a higher elevation to the surface at a lower elevation) to the bottom of the structure, and a wind catcher to the top, with its opening facing away from the prevailing direction of wind. Wind blowing past the tower causes a pressure drop near the opening, which draws in air from the other end of the qanat, which is cooler because it's underground / next to water.
I'm also fascinated by this. I've read about a similar setup where instead of a windcatcher driving the airflow it's wood being burnt near the top of the air channel. I can't recall who used this though. If anyone has some keywords or links, I would appreciate it.
I was recently reading about solar chimneys, which is a somewhat similar idea, but driven by heat from the sun rather than wind: https://en.wikipedia.org/wiki/Solar_chimney
Thank you, I could not find an intuitive explanation anywhere.
Got to see a bunch of these when I visited Yazd last summer (which in general is just an amazing city, seems straight out of the Arabian Nights). The fun you realize when you’re there is that they’re just one part of a massive infrastructure of ancient technology that also includes the qanat system and the amazingly beautiful wind towers. One theory for the origin of windmills is that they were invented in Sassanid era Persia as well. Really impressive stuff.
This semi-related TED talk also describes Yakhchal and describes a different, local technique of ice production (as opposed to faraway mountains):
"How we can turn the cold of outer space into a renewable resource"
https://www.youtube.com/watch?v=7a5NyUITbyk
"How we can turn the cold of outer space into a renewable resource"
https://www.youtube.com/watch?v=7a5NyUITbyk
Thanks! I've been playing with science education content around temperature. 'The universe was once as bright hot as the Sun, but it's been expanding, and is now dark cold. So very cold. The Sun is still bright hot. So very hot. In between, the Earth spins, mixing too hot and too cold. The atmosphere shades us from the hot Sun, and insulates us from the dark cold. Ground and water [buffer the night]. If Earth was much further from the Sun [atmosphere becomes a few feet of snow].' And so on [closer to Sun; non-spinning and Mercury; no atmosphere and lunar temps; more atmosphere and Venus; less buffered desert; etc]. Sort of using a story frame of Sun vs space for teaching temperature in primary school. Raman's work ties in nicely.
Ever since I learned that Persian is related to English (with near identical words for mother,father,daughter,brother…) I enjoy thinking of direct word-correspondences (similar to most English-German pairs):
yakh chāl ~ ice hollow / Eis Kuhle/Halde <> hall ~ Höhle
yakh meaning "ice" chāl meaning "pit"
chāl <> cool@Kuhle
yakh chāl ~ ice hollow / Eis Kuhle/Halde <> hall ~ Höhle
yakh meaning "ice" chāl meaning "pit"
chāl <> cool@Kuhle
At risk of sounding like a ludite or troll, why aren't these used in modern times? Earth architecture is so efficient and cost effective, it seems.
I read an article on this topic about a month ago, but I can't find it now.
In short, cheap energy in the post-war US meant that mechanical heating and cooling were affordable. Builders moved away from a vernacular architecture style, which had adapted to the local environment, to a more standardized style that was cheaper to make.
While it didn't cover this detail, I think another aspect was that many people decided to move to other parts of the country, and wanted the architecture of where they came from. For example, people from the NE who moved to the desert SW and wanted a Cape Cod bungalow-style house.
The vernacular architecture in the SW is for thick adobe walls and small windows. The walls are thick enough that it takes 12 hours for the heat of the day to reach the interior, and help keep it warm during the cold nights. While it's a better fit to the local weather, it's also more expensive to build than a stick-built home + insulation + A/C and heating systems. (Traditional adobe can be built using local mud, but that needs yearly maintenance, because the rains will wash it away.)
In short, cheap energy in the post-war US meant that mechanical heating and cooling were affordable. Builders moved away from a vernacular architecture style, which had adapted to the local environment, to a more standardized style that was cheaper to make.
While it didn't cover this detail, I think another aspect was that many people decided to move to other parts of the country, and wanted the architecture of where they came from. For example, people from the NE who moved to the desert SW and wanted a Cape Cod bungalow-style house.
The vernacular architecture in the SW is for thick adobe walls and small windows. The walls are thick enough that it takes 12 hours for the heat of the day to reach the interior, and help keep it warm during the cold nights. While it's a better fit to the local weather, it's also more expensive to build than a stick-built home + insulation + A/C and heating systems. (Traditional adobe can be built using local mud, but that needs yearly maintenance, because the rains will wash it away.)
Thanks for your perspective. I think cost is interesting, because the cost of conventional building with air conditioning and heating doesn't seem to factor the long term earth or environmental cost. My suspicion is that these actually cost a lot more to maintain if cost to the earth and long term natural resources is accounted for. But I'm just speculating so far.
Yes, the price of fossil fuel use does not include the full impact costs.
The IMF report at http://www.imf.org/external/pubs/ft/wp/2015/wp15105.pdf estimates:
> Post-tax energy subsidies are dramatically higher than previously estimated—$4.9 trillion (6.5 percent of global GDP) in 2013, and projected to reach $5.3 trillion (6.5 percent of global GDP) in 2015.
Secondary articles on the topic at https://www.pri.org/stories/2015-06-07/imf-true-cost-fossil-... and http://priceofoil.org/fossil-fuel-subsidies/ .
That's about $800/person for the world's population.
The IMF report at http://www.imf.org/external/pubs/ft/wp/2015/wp15105.pdf estimates:
> Post-tax energy subsidies are dramatically higher than previously estimated—$4.9 trillion (6.5 percent of global GDP) in 2013, and projected to reach $5.3 trillion (6.5 percent of global GDP) in 2015.
Secondary articles on the topic at https://www.pri.org/stories/2015-06-07/imf-true-cost-fossil-... and http://priceofoil.org/fossil-fuel-subsidies/ .
That's about $800/person for the world's population.
Well evaporative cooling, and ground-source energy similar to this does get used in modern architecture. Cooling towers are used to evaporatively cool waste heat from the circulating water in HVAC systems. Thermal labryinths, or earth ducts directly transfer heat to and from the earth, ground source heat pumps do as well through refrigerant loops.
They work much better in dry climates that cool down massively at night, and require that digging that far into the ground doesn't make you hit the water table.
[deleted]
Very cool! ;)
It's amazing what's possible with evaporative cooling in dry climates. If you have enough water, anyway.
It's amazing what's possible with evaporative cooling in dry climates. If you have enough water, anyway.
https://news.ycombinator.com/item?id=11719441 - Here is a good HN read/thread from two years back about Qanats. Yakhchals was mentioned there.
This is available in India: https://mitticool.com/product-category/earthern-refrigerator...
In Dari any normal electrical household fridge is also called a Yakhchal.
They also had climatized buildings, the „badgir“s.
Repost from 2012 :)
https://news.ycombinator.com/from?site=eartharchitecture.org
In short, the WikiPedia article about yakhchals is much more satisfying: https://en.wikipedia.org/wiki/Yakhch%C4%81l