The black pipe concept is similar to what is known in passive-solar building as a "solar chimney." Google that term for some more inspiration. Solar chimneys do work.
-- ken winston caine On Fri, Aug 26, 2011 at 4:30 PM, William Ozier <[email protected]> wrote: > First off I am also a skeptic on this version of the cooling > effect...though the conditions set in the video did not match the > description of how the effect works. Anyway, I had an idea for a > hexayurt passive cooling system that I designed, and started but did > not get to try last year (and won't this year either). > > Here's the idea: > Put a black plastic PVC pipe in the center of the roof. The sun will > heat the pipe causing the hot air inside the pipe to rise, > consequently drafting cooler air in the bottom, through the spaces > around the door flap. To further cool the air coming in, you could > build the hexayurt directly next to an evap pond you are using to deal > with your shower water. To further cool you could place a length of > copper tubing into the evap pond, with one open end just pointing into > the air and the other open end inside the hexayurt. > The sun heats the black PVC which causes a strong updraft. The updraft > pulls air in through the copper pipe. The air moving through the pipe > cools down. The copper pipe is laying in the evap pond so the evap > effect is further cooling the air. > > Does this system sound like it would work? > > On Fri, Aug 26, 2011 at 12:15 PM, The Distinguished ... > <[email protected]> wrote: > > Greetings, > > > > Sorry I'm behind again, catching up from being at Pennsic (and living in > > a collection of connected traditional ger (yurt)) cooled in the > > traditional style (open roof vent hole, raise the sides a little, and > > get a pleasant breeze) quite pleasantly. > > > > A few questions, if I may, > > > > On Tue, 2011-08-09 at 19:04 -0700, KK wrote: > >> Ok...part 2 of the video test is up. > >> > >> http://youtu.be/bJXd71ZaWls > >> > >> Foam board covering. Model on ground. > >> > >> Outside Temp - 100 deg. F > > > > What was the inside temp? > > > >> Windspeed - 7mph > >> Sun Intensity - Off the chart! > >> > >> Same result. No difference. No reverse air flow downwards. > >> So, if you are one of the "wee people" living in a tiny hexayurt, > >> Bucky Fuller is not your friend. > >> Prepare to sweat. > > > > What is the temperature of the smoke? That might effect things, if we > > are expecting it to rise or fall. > > > > What was the expected difference in the vent-size for the roof-vent and > > the side vents? > > > > From my read of the quote, the top vent should be much smaller than the > > side vents, not that I think it would make much difference, unless the > > air in the structure started cooler, or the whole system started cooler, > > and the outside heated up quite a bit faster than the inside, which > > might (might, mind you, not would) bring the inside air out, but you > > would be "cooling" with moving warmer air, pulled in from the top, > > because the coolest air would be being pulled out of the bottom vents. > > > > So, even if the reverse flow worked, you would be moving warmer air, and > > perceiving the moving warmer air as cooler than the static cooler air, > > simply because of evaporation, and "any breeze is better than none." > > > > I'm still much more enamored at the vacuum pull of heated air up a black > > pipe, you are still moving warmer air than cooler air, but it is > > probably much easier to arrange for, and still used the Joule-Thompson > > effect to "cool" or at least speed the air up in its movement similar to > > the Venturi effect. The Coanda effect could be used for the redirection > > of the flow, due to the shape of the pipe, causing more suction up > > through the pipe. > > > > Of course, as a side note, the Bernoulli Principal applies to a liquid > > or a gas, for it's a fluid, and both follow the rules, see also: > > http://mitchellscience.com/bernoulli_principle_animation > > > > Percy > > > > > > > > -- > > 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. > > > > > > > > -- > William Ozier, > Director of the Camassia Institute at Lost Valley > www.lostvalley.org > (541) 937-3351 > > -- > 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.
