The ratio should be 8::1 in air volume. I don't know if two large vents would be adequate or better than six or seven smaller ones.
My own design uses one on each wall panel. Am not sure what effect these low exhaust vents will have on swamp cooler efficiency. With a swamp cooler, you want a steady source of dry incoming air (to evaporate the moisture produced by the swamp-cooled air) and constant exhausting of the damper air (so that you maintain a cooled, dry environment inside). You want the cooler, damp air to circulate as widely as possible before the moisture completely evaporates or is exhausted. Being heavy, cooler and damp, it naturally wants to drop and in a swamp-cooled house, if you crawl around on your hands and knees, you find that level more humid than higher off the floor. This is why in the southwest, in large buildings, swamp coolers traditionally were roof-mounted. Which allowed the greatest dispersal of the ceiling vented incoming cooled, humid air. Using floor level exhaust vents and creating convection for them is, it seems to me, going to draw the swamp-cooled air downward (floorward) more quickly than otherwise. The ceiling chimney (air intake) is going to be drawing in a constant flow of dry air, which will help with the evaporative efficiency -- assuming your design actually invokes the Bucky "cooling effect(s)." Be interesting to find out how it works and what effect it has on the efficiency of the swamp cooling. Really glad to see so much interest and thinking going into this! --kenwinston ----- Original Message ----- From: "Shannon" <[email protected]> To: <[email protected]> Sent: Saturday, July 31, 2010 4:00 PM Subject: Re: [hexayurt] Buckminster Fuller's Passive Cooling Effect I am willing to give this a shot. However, this will be my first hexayurt so I will not have anything to compare it to. I will also have a swamp cooler. How many vents should I cut along the bottom you think? Maybe 2? On Jul 31, 2010, at 12:02 PM, ken winston caine wrote: > Has anyone experimented with Buckminster Fuller's repeatedly demonstrated > passive "chilling effect?" (Sometimes also written about as the "cooling > effect.") > > He accomplished this with a chimney in the center of the roof (with a vent > flap which could be opened and closed), and with a series of wall vents > just > inches to a foot above the floor all around the building -- those vents, > too, could be opened and closed. > > As the sun rises, all the vents are opened. Heat reflecting off the ground > and off the building create an updraft all around the building. This > updraft > draws air OUT of the vents just above floor level. (It appears to me that > these vents often were about 1 foot off the floor -- and that in total, > they > exceeded the volume, by at least 8::1 or greater of the volume of the > chimney vent.) > > As air is sucked out of the bottom vents by the updraft around the > building, > air is drawn in through the chimney. > > Fuller said the chimney downdraft effect extends hundreds of feet upward > into the air and draws down a much cooler air than is found closer to the > ground. > > He demonstrated this effect in equatorial desert regions with domes > equipped > as described above. But, the dome shape was not a significant factor in > the > "chilling effect," he said. > > This "chilling effect" was also implemented in Fuller's "Dymaxian Home," > which somewhat resembled a hexayurt. (Do believe that it may work best in > quasi-round buildings -- which the hexahurt is.) While Fuller promoted the > cooling effect in hot climates, he also promoted the same process as a > "self-cleaning" effect. > > Because this effect creates a cool downdraft and floor-level exhaust, it > tended to draw out most of the ambient dust from the house, reducing the > need for frequent cleaning/dusting. > > In Fuller's demonstrations -- in both humid Kansas summers and in > equatorial > deserts -- indoor temperature was lowered by about 15% after opening the > events and setting up the "chilling effect." > > People reporting on the experiments frequently noted with amazement the > sensation of cool air falling on them when they walked into one of the > demonstration buildings. > > Fuller wrote, in what may be his last book, "Critical Path," on page 212 > that the " pressure differential between the small air entry and large > exhaust openings produces the Bernoulli chilling effect, which in hot > weather will swiftly cool the ... interior." > > On that page he also provides a drawing of how it works with a geodesic > dome. > > Here's a Google Books link to that page: > http://books.google.com/books?id=2rPqFvn3nocC&pg=PA211&lpg=PA211&dq=buckminster+fuller+chilling+effect&source=bl&ots=refmEA3ApA&sig=3MMsUUMp4QPWIhFAdLciDRULC4w&hl=en&ei=SGxUTPamF4G78gbO19SpBA&sa=X&oi=book_result&ct=result&resnum=1&ved=0CBYQ6AEwAA#v=onepage&q&f=false > > You can read more about the effect in these two books also: > > Air Cooling Tendency > Buckminster Fuller's Universe pp 208-09 > And Chilling Effect > BuckyWorks pp 114, 116 > > > This is all counter-intuitive, I know. We all "know" that heat rises and > that you need to vent it via an updraft at the highest point in your > building. But not if you want to enjoy Buckminster Fuller's "chilling > effect." > > In that case, you want to out-vent via convection at a low point all > around > the exterior of the building, and actually draw in a downdraft cool column > of air from much higher in the atmosphere through a chimney at the peak of > the roof. > > Fuller explained somewhere -- and I can't find my old notes at the > moment -- > that a column of hot air rising from around a circular building actually > creates a downward vacuum in its center that pulls cool air down through > its > middle. > > I asked a couple years back if anyone would demonstrate / experiment with > this at Burning Man and report here their experience, but found no takers > then. > > How about this year? > > I would think that for the Playa, you would want to cover the vents with a > filter material, such as the cheap blue synthetic stuff used for swamp > cooler filters now that they rarely use straw any more (because of its > tendency to grow mold). That way, during dust storms, it would be unlikely > that you would experience much dust intrusion. Or, you might set up > another > simplie way to block the vents during periods of extreme blowing dust. > > In my original experimental designing with this, I found located some > dollar > store air-filled plastic balls (bouncy balls) that would perfectly fit > inside 3-inch pvc pipe. So I created a design using pvc pipe for the > floor > vents and the balls to seal them closed. I also drew into the design > pieces > of fiberglass insect screen crudely tied around the outside openings of > the > pipes. (The pipes fit through the wall panels and extend a couple inches > beyond the wall on both inside and outside -- though could be cut to mount > flush for a neater install.) > > And for the roof vent, you can use a capped stovepipe and a damper flap > section. The damper flap can be used to close (and open) the roof vent. Or > just use another piece of pvc pipe and plastic ball and buy a $2 > sewer-vent > cover at an > RV supply joint for a rain cap. > > Or, you could go even lower tech and just cut vent holes and save the > cut-out material and stuff it back in and tape it in place to close the > vents. > > I remain astounded with how this "chilling effect" works and, even more, > that about 70 years after Fuller first began demonstrating effective, > passive air conditioning drawing cool air from hundreds of feet above > ground > that it is NOT being designed into buildings in warm and hot areas > worldwide. > > This MAY be because it works best in quasi-circular buildings (if that is > true), and conventional design does not use round buildings. > > Do believe that it was engineered into the early sports domes. > > And I know that there is an emphasis since the late '70s on airtight, > sealed, stale-indoor-air-filled, atmosphere-controlled buildings (which > this > is the opposite of) for energy efficiency. > > Anybody up to testing / demonstrating this at Burning Man this year? > > If you do, would you report on it here? Maybe shoot a video with a > thermometer demonstrating temperature with vents closed, after an hour > with > vents open, and of the outside air temp? Then, for all time, everyone > could > *see* the results in action. > > Best, > ken winston caine > > > > > ----- Original Message ----- > From: William Ozier > To: [email protected] > Sent: Friday, July 30, 2010 3:53 PM > Subject: Re: [hexayurt] Insulation Thickness > > > I am going to try and create a solar chimney on mine to help keep it cool. > You put a black tube coming out the top. The sun heats the tube which > heats > the air and causes an updraft, which vents out the hot air and pulls in > cool > air...of course finding cool air to bring in on the playa maybe difficult, > so there are a few more details to be worked out. > > > On Fri, Jul 30, 2010 at 2:45 PM, Spiral Syzygy <[email protected]> > wrote: > > -- > You received this message because you are subscribed to the Google Groups > "hexayurt" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/hexayurt?hl=en. > -- You received this message because you are subscribed to the Google Groups "hexayurt" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/hexayurt?hl=en. -- You received this message because you are subscribed to the Google Groups "hexayurt" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/hexayurt?hl=en.
