My family is going to Burning Man this year! I've been twice in the past and there have been a few things about my experience that were less than comfortable. The biggest problem I had on the playa was sleeping during the hot days in a tent. Once the sun rose over the RV I pitched my tent next to the heat became unbearable and I had to get up.
So for this year I have built a Hexayurt to stay in and a "swamp cooler" to keep it cool during the hot days. A swamp cooler is essentially identical to what we know as a humidifier, its a fan that blows air over some sort of absorbent material. In environments that are very dry, like the Black Rock Desert where Burning Man is held, the air exits the swamp cooler significantly cooler that when it entered. Or at least that's the plan! I'll take data and report back after the Burn.
I found a set of brand new replacement humidifier "filters" at our town dump, and these seemed to be about the size I wanted so I started there. Very similar filters are available online as well as all of the other components needed for this build..
I cut some frames from Coroplast sheet stock and glued together a frame with silicone seal to hold the filters in the center of the plastic shipping crate I decided to use for the body of the swamp cooler.
The 200 mm fans are made for cooling PC cases. They are very quiet and quite efficient, using a few tenths of an amp each and pushing 120 CFM of air.
On the side of the filters facing the fans is a loop of hose with several holes in it. There is a pump at the bottom of the crate that circulates water over the filters, keeping them wet. There is also a float switch to turn the pump off if the water level get too low. The pump switch I used switched the reverse of what I needed so I added a relay to the circuit to achieve the desired action.
The fans and pump together use about 6.5 watts which means I should have plenty of power from the 30 watt solar panel to run the cooler all day long.
The whole unit backs up against the air vent in the hexayurt so that it draws in the dry outside air. Our cooler chest will sit on top of the unit and feed melt-water to it throughout the day.
The 30 watt solar panel should provide plenty of power for the swamp cooler, LED interior and decorative lighting, as well as charge batteries for cameras and phones.
I re-purposed an old A/C computer load center for the solar system. Mounted on top is the charge controller, batteries, and a 110 watt inverter for charging things like my electric shaver.
I'll take temperature and humidity readings both inside and outside the hexayurt and report back as to how well the swamp cooler worked.
The Man burns in 23 days.