Burning Man Tech 2007: The Hexayurt Report

[errantember]

After growing weary of being driven out of my tent at 9:30 AM by the relentless sun after a hard night of honest partying, I decided, two days before our Austin community truck left, to build a Hexayurt to take with me.



I decided that due to unknown space constrains on the community truck and my own cheapness, it would be good to start with a 6" hexyurt. Due to difficulties in acquiring the proper 3" tape, I ended up using commodity duct tape for my pre-construction, which turned out to be a mistake. As a result, the 'yurt was on the community truck before the hexyurt support staff, noticing my tags on LiveJournal, informed me that there was a good chance the 'yurt would blow apart due to melting glue at Burning Man. To remedy this, I speed ordered JVCC 761 Industrial Grade Strapping Tape (3 in. x 60 yds./Natural) from FindTape.com to spot-fix at the event as needed. The tape arrived just in time with three-day shipping, and although I still spent more money on shipping and handling than I did on the tape, I was glad to have it.

Note to prospective builders: The main expense of a any hexayurt is the tape, not the panels. This can be misleading when trying to estimate construction costs, especially if you try to cheap-out on the tape initially and have to re-do it.

I pre-spliced the top 6 and bottom 6 sections into a fanfold using a taping method I probably need to photograph to describe correctly. The result is that the yurt ends up being only two pieces, and needs only three (or, as I recommend, 4) seams to be taped and then later cut to put it up. This reduces both labor and tape costs, although there is a slight cost in rigidity. This cost didn't cause any problems at a fairly windy Burning Man this year, and I'd recommend it as an improvement on the basic design. Next year I'm interested in making at least the non-tension-ring seams out of very strong velcro.

The Setup:

Upon arriving at Poly Paradise at 9:00 and G, I had about 6 hours until dawn to try to fix the tape problem and get the yurt assembled before significant winds could complicate things. Being both optimistic and lazy, I opted to simply use the good tape to do the seams and re-enforce as needed. Even with the fan-folds, it ended up taking two people to quickly assemble the yurt, as the roof becomes ungainly without someone to help hold it in place. The incredibly annoying sound of strapping tape being deployed in quantity at 5 AM scored me quick assistance from desperate camp mates. It's certainly possible to assemble it with only one person, and with two the entire operation can be accomplished by beginners in under 30 minutes including staking. This is competitive with most tent setups.

I chose to tape the roof seam, the wall seam, and the tension ring around the top. In retrospect, especially considering the problem of duct tape glue letting loose in the heat and the dust-prevention angle, it would also have been good to tape the yurt to the tarp underneath. This could be done from the inside. I chose not to do this because I wanted to verify my sun-facing before committing to a deployment angle, and it's very easy to simply lift up the yurt and rotate it when it's not strapped down. Next year, however, I will be taping the yurt to the tarp to prevent the entry of dust, increase rigidity, and prevent bottom spreading at the panel joins, which I'll go into detail about shortly.

I chose the rope-loop tie down method, where a 20' loop of rope is placed evenly over the top cone of the yurt, and then tied down in six places. This method isn't quite as secure as using tape to integrate the tie downs into the structure itself, and it makes the structure more vulnerable to bottom spreading at the panel joins. However, it make it *much* easier to adjust the facing after deployment, and even with my crappy duct tape on 90% of the structure, it still held up well for the week of Burning Man with minimal maintenance. Using this method of tie-down places downward and therefore outward pressure on the panels of the yurt, particularly the sides. Over time and combined with my shitty duct tape, this caused as much as 2" of spacing to slowly develop about 4 days into the burn at the bottom of the floor panels. This made the entire structure less stable, and also caused the tension in the tie-downs to loosen, resulting in both extensive dust infiltration and about 6" of scootage during the second 6-hour dust storm. However, if I had tape the yurt to the tarp this wouldn't have happened, as there would have been counter-pressure from the bottom tension ring. As it stood, I simply re-enforced the bottom seams with the strapping tape from the inside, then re-tensioned the tie down lines using an adjustable knot I should also diagram, and the yurt stood fast for the duration of the burn. It was taken down before the final monster dust storm during Exodus.

Thermal Performance:

Thermally the hexayurt was a monster success. I was able to reliably sleep inside a sleeping bag until noon or later every day before becoming slightly uncomfortable, beating most tents by about three hours. A mister dropped the temperature down fairly quickly, though this operation had to be repeated at least every 20-30 minutes to keep things cool. Even so, the maximum temperature inside the yurt without active cooling rarely became stifling, and several other innovations helped lower the average temperature throughout the burn. With an even half-decent solar-powered swamp-cooler setup, and possibly with only a wind turbine, it could provide a cool resting place in the day and a warm snuggle space at night. Next year I'm planning on a solar fan on each window, one input and one output, with the input having a swamp cooler layer inside the furnace dust screen to cool things off and trap incoming dust.

On Site Innovations:

This year I brought out one of those crappy solar-powered doodads thats supposed to sit on your car's window and cool it down by moving air out. It has a small solar panel and fan (too small to be the only one on even a 6' hexayurt) and costs about $20 retail. I reversed the airflow (I wanted to pull air in, not take it out) and placed a water reservoir made out of a cut-up plastic bottle at the intake. I also put some orange peels into the water for scent. I cut up a cloth (not fiberglass! Don't cut fiberglass over your bed!) furnace filter to place over the intake. This created a tiny little swamp cooler that ran continuously though weakly exactly when it was needed -- when the sun was beating down on the yurt. I can't say it made much difference that I noticed, but that's only because it was underpowered.

Next I added the furnace filters over the windows. Piggy-backing on the swamp cooler idea, I added reservoirs to the bottom of both windows, dipping the fabric into the water for a wicking effect. When I discovered that the fabric didn't wick vertically well, I added a second reservoir on TOP of the window on the sunnier side, then primed it with a mister. This added significantly to the cooling, much more so than the powered swamp cooler. It continued to work well for several days until it got thoroughly dusted during a major storm, after which it was too clogged to work properly. Next year there will be an initial dust filter before the swamp cooler, which should help considerably. This year my windows were 10" square, which seemed functional.

After seeing a wind turbine on a similarly constructed geodesic dome, I cut a small triangle out of one the roof panels at the apex to encourage the escape of hot air and increase airflow. This helped considerably and could still be closed for rain or dust storms.

Size-wise the 6' was very tall but small. I use a minimum of a full-sized mattress in case of guests, and this size mattress stretches from wall-to-wall in the 6'. This left very little room for All My Crap, even considering my two outdoor 20-gallon bins. I had to close my suitcases and place them vertically against the wall, then fold them down onto the mattress when needed. During the day I deflated my mattress and used it as a floor covering, which meant it got somewhat dirty. Unless someone builds in a closet (which would violate the thermal integrity) I would recommend using the 6' stretch as the minimum size for even one person. Integration of some kind of shelves or hanging bins could also make the 6' tolerable, as there is a lot of unused vertical space. It was very nice to be able to almost stand up inside my yurt, which is 6' at it's apex. Next year I will buy the extra panels necessary to make the 6' stretch version.

Overall I consider the Hexayurt a success. It accomplished it's main goal of protecting my lazy ass from the sun until I *wanted* to get up with flying colors. Dust infiltration was nearly non-existent until the lower panels started to spread, which won't happen in a properly built 'yurt. The 6' was cramped as advertised, I would consider the 6' stretch to be the minimum comfortable size. When determining facing, I would recommend a loose initial setup with the rope-over tie-down, then actually test the movement of the sun with a fucking stick stuck into the ground, marking the shadow at different times. I tried several methods including using GPS to determine the path of the sun, and not only was I completely wrong on the first try, I was also completely wrong on the second try, which was 180 degrees rotated from the first. We'll note that this is physically impossible, but it happened anyway. The stick method should be about as foolproof as they come.

Good: Keeps you cool until at least noon. Keeps out dust. Impresses friends and potential dates. Easy to retrofit with any number of handy upgrades with playa scraps and elbow grease. Rigid and better isolated from harsh playa conditions day and night.

Bad: Hard to set up in windy conditions. The 6' is very small. Takes up a lot of space in transit compared to a geodesic dome or tent. Must be babied in transit lest it get crushed.

To-do: Diagram fanfold taping method, diagram adjustable tie-down knots, reduce wordiness of report

Comments

[eposia.livejournal.com]

This, with or without the edits you mention, would make a great entry for the Voluptuaries any month you're low on inspiration. Good essay!

Thanks!

[errantember.livejournal.com]

I'll definitely be writing more of these type of things in the future, so it's a delivery method I'd like to improve.

This month I'm thinking of submitting the story of my escape from Burning Man this year.