Badgirs--Windcatchers

July 10, 2003 10:42 AM

Badgirs (Farsi) or barjeels (Arabic) are windcatchers that work as low-tech air conditioners. The city of Yazd, Iran is probably best known for them. Badgirs are built so that they can be opened to catch the wind from different directions, the air is then cooled as it travels down the tower, and in turn cools the rooms below. When there is no wind, air in the tower is heated and rises, which draws cooler air from the courtyard into the house. (There is no URL to link to for the search result for “badgir” on Encyclopaedia Iranica, but I recommend checking out their definition and diagrams even though you’ll have to go through three different PDF pages.) Badgirs have been around in some form “since the New Kingdom (1500- 300 BC) in Egypt”, but global warming might make them ineffective.(scroll down to #16-#18) Variations, such as malqafs, can be found from Egypt to Pakistan. You can get a modern one for your own house. You can win an award shaped like one for advancements in sustainable development. Or you could just stay in the Fairmont Dubai Hotel which is shaped like a huge badgir. So even after all this, I still don't know what those sticks sticking out of the sides are for.
posted by lobakgo (28 comments total)

Would an advancing ice age increase their effectiveness?
posted by alumshubby at 11:05 AM on July 10, 2003

(This is good)
posted by trharlan at 11:14 AM on July 10, 2003

Fascinating. Thanks.
posted by pjgulliver at 11:20 AM on July 10, 2003

wonderful, lobakgo!

I also wonder about the sticks, though from the third image it appears that their function is unrelated to the actual process of capturing the wind. In fact, from that photo it almost appears as if they were installed for the purpose of scaling the outside of the badjir (perhaps useful when it comes time for painting?). The other images, though don't really seem to indicate this.

Very interesting. Thanks!
posted by taz at 11:37 AM on July 10, 2003

Very interesting. I had noticed that type of architectural feature in photos, but never knew that it had such a purpose. Thanks!

Great first post lobakgo - you're a pretty smart turnip ;-)
posted by madamjujujive at 11:54 AM on July 10, 2003

I am constantly fascinated by passive methods of doing things we typically expend energy to accomplish. Things like this passive cooling food storage chamber or this pot-within-a-pot passive refrigerator, or hydraulic ram pumps.
posted by Cerebus at 11:57 AM on July 10, 2003

The visitor center at Zion National Park has towers that sound like this, among other features.
posted by ROU_Xenophobe at 11:59 AM on July 10, 2003

taz--
That was the only thing--maintenance-- that I could come up with for the sticks. I don't think I'd want to be the one who had to do the painting.
posted by lobakgo at 12:00 PM on July 10, 2003

Hassan Fathy is a name I came across while looking at badgirs. He looked at employing vernacular building techniques to provide improved housing for people.
posted by lobakgo at 12:07 PM on July 10, 2003

Terrific post, many thanks lobakgo. Plenty of research material here for me as I plan my dream low energy house ...
posted by carter at 12:11 PM on July 10, 2003

lobakgo, I just saw your latest addition before adding the following, but Hassan Fathy is the author of this:

Just in case some of you are more particularly interested, I found the online text of Natural Energy and Vernacular Architecture: Principles and Examples with Reference to Hot Arid Climates, a book published for The United Nations University. It has a section on The wind factor in air movement with lots of information on malqafs, in particular. Also many illustrations.

sorry if this duplicates any of the pdf stuff, but acrobat reader makes my baby computer cry...
posted by taz at 12:16 PM on July 10, 2003

taz--
Great links! The sticks are for maintenance.
posted by lobakgo at 12:20 PM on July 10, 2003

Badjirs? We don't need no stinkin' badjirs!

(I couldn't resist)

Nifty concept, great post!
posted by infinity-bound at 12:47 PM on July 10, 2003 [1 favorite]

Very nifty. Though this line threw me in the Egyptian history link:
"in Baghdad where the air temperature of up to 500C is too hot to provide cooling"

...until I realized it should read "up to 50^oC", an important distinction I think.
posted by GhostintheMachine at 12:52 PM on July 10, 2003

taz--
That was the only thing--maintenance-- that I could come up with for the sticks. I don't think I'd want to be the one who had to do the painting.

First thought, would I stand on sticks, especially as they became weathered? Ladder seems better and thought, maybe for the birds, so they won't land on the towers vent's edges, but then thought why would a bird land there and not the edge so back to maintenance use.

During colder & rainy times in the year do they close off these tower's vents and have a use there?
posted by thomcatspike at 1:18 PM on July 10, 2003

looks like maintenance is correct.

scroll down about halfway.


posted by goddam at 1:33 PM on July 10, 2003

But I agree with you thomcat, I wouldn't want to be balancing on those wooden sticks after they've been baking in the 500^oC heat!
posted by taz at 1:37 PM on July 10, 2003

Ignorant people. Everyone knows freon-based electric air conditioning is the best thing going! Viva America!

PS, can you pass the hydroflourocarbon hairspray canister?
posted by PigAlien at 1:41 PM on July 10, 2003

goddam good link.
"built around an armature of wooden poles, which stabilize and reinforce the structure, and whose projecting ends were usually left to serve as scaffolding for cleaning and maintenance."
posted by car_bomb at 2:01 PM on July 10, 2003

I'm not sure how much global warming will effect them just as long as there's not global humidifying! The sticks appear on all tall Iranian structures, minarets too, I always thought they had a strengthening effect somehow to keep the mud brick walls from falling outwards like the stars you see on the sides of old brick buildings in the US (they are connected to rods that go all the way through the building and keep the walls from falling outwards) but maintenance would be a good explanation too, although, I don't think I'd want to balance up there on a 1000 year old stick!
posted by Pollomacho at 2:01 PM on July 10, 2003

Great post, great thread. Yay, lobakgo! Hope your sophomore effort is even half as good.

(no pressure, or anything)
posted by iconomy at 2:10 PM on July 10, 2003

Starting to have flash backs to all the old homes throughout the US with towers. Thought they were for veiwing purposes only.
posted by thomcatspike at 2:18 PM on July 10, 2003

Wanted to add, looking at US's history of the wild wild west, the older civilizations made them look like cave men.(pruposely made the gender male)
posted by thomcatspike at 2:21 PM on July 10, 2003

Of course, not like these things actually get used anymore. Most Gulfies I know consider modern AC to be a necessity of life. Which is a shame because the couple I have seen at historical sites made intolerable (110 f) weather quite manageable.
posted by ednopantz at 6:31 AM on July 11, 2003

Of course, not like these things actually get used anymore.

What? Of course they use them, they build new ones!

I asked my dad about this one, a crusty old Isfahani, this opened the inevitable fountain of "knowledge"...

The sticks, according to him may serve a structural purpose, but, he says, they are left sticking out to give places for storks to roost. No, I'm not joking, this is what he said. Apparently storks roosting on your house is a good thing in Iran. He also gave me my daily Pharsi lesson (think My B-F Greek Wedding, everything is Pharsi, they invented everything of course!) bad - means wind and gir - is old persian for catcher, as in Giri-gury (Persian for Gregory) - catcher of onagers (giri-catcher, gury - onager), mistakenly translated to "tamer of wild asses" something my brother, Greg, used to use as a terrible pick up line before he got married.
posted by Pollomacho at 1:57 PM on July 11, 2003

Pollomacho--
Thank your dad for me! The stork info. really rounds out the whole thing.
posted by lobakgo at 3:40 PM on July 11, 2003

Starting to have flash backs to all the old homes throughout the US with towers. Thought they were for veiwing purposes only.

thomcatspike, bingo. Any building dating from before roughly 1900 for commercial buildings and somewhat later for residential, would have had to use a variety of passive systems to circulate air. For instance, the door transom permitted hot air near the ceiling to escape into a hallway or stairwell, which itself would be vented at the top (often lighted passively as well via skylight), and the ground floor would also have to include ways for air to get into the building, such as gated casements built into the sidewalk (generally now sealed or covered). The typical Victorian house was just as cutting-edge for its day in the thinking that architects would apply to ensure that air would properly move through the building. (In addition to being comfortable, this was thought to be "healthy". Indeed, bad housing was thought to contribute to poverty and other social ills.) In apartment buildings, cities such as New York mandated in code that central air shafts or stairwells bring light and air to otherwise-dark apartments, creating many well-known features of the city's architecture.

The familiar double-hung sash window wasn't just a way of dividing the glass in half so part would open, with the upper sash being a curious "appendix": indeed, both sashes would move toward the center, allowing cooler air in at the bottom and warmer air out at the top. The invention of the modern metal storm window, which usually included three sashes, only one of them a screen, frustrates this natural air movement and may have -- for example -- contributed to the heat deaths in Chicago in 1995. Other window styles that contribute to ventilation are the bay window and the Chicago window. Additionally, the ceiling fan was an early and obvious use for electricity (replacing models that used hydraulic and other propulsion methods), but went out of style for a long time, only returning recently.

The vogue of the round barn was in part due to its superior passive ventilation out the central air shaft (all parts of the ceiling would channel heat in one direction). Factories were traditionally built with a clerestory, a small structure extending the length of the peak of the roof with windows on both sides -- for light as well as ventilation.

In short, most of those towers you see -- they're usually called cupolas -- are too small to do much viewing. Open the windows, though, and they allow air to circulate.
posted by dhartung at 11:00 PM on July 11, 2003

The badgir goes beyond just good ventilation however. Air is channeled down the shaft to a basement where it is directed over a fountain, the water evaporates, cooling the air which is forced up vents into the main body of the home and as it heats back up out upper vents near the roof line, ancient central air!
posted by Pollomacho at 8:19 AM on July 14, 2003