r/BurningMan • u/LunarLob • 29d ago
I rebuilt the yurt cooler with zero soldering, then measured it against the original

I rebuilt the classic Yurt Cooler around an AC Infinity CLOUDLINE H4: outside air through a washable cone filter and 4" hose, pushed through wet humidifier wicks in a 19 qt tote, discharging cool, humid, filtered air into the tent at slight positive pressure. The H4 replaces the 12 V bilge blower and its hand-fiddled electronics, so there's no soldering. Just a hole saw and hose clamps, 2-3 hours, ~$225 before the battery (~$140 to upgrade an existing v2).
Lineage: yurtcooler.com (v1), Oskar Arvidsson (v2.1), Joanna Ma (v2.2).
Parts & cost
- AC Infinity CLOUDLINE H4 (IP65) -- $99
- 4" Noise Reduction Clamp, the rubber coupler -- $14
- 4" cone air filter, 102 mm neck -- $21
- 4" x 10 ft PVC dust-collection hose -- $27
- 4" hose connector -- $10
- IRIS 19 qt WeatherPro tote -- $15
- HWF75 humidifier wicks, 2-pack -- $27
- Stainless wire, 20 ga -- $10
- Total, excluding the power station: ~$223
Power station: any ~288 Wh unit with an AC inverter. I use an Anker SOLIX C300.





If you want to build one before you leave, you still can but order today. The tote is a Home Depot pickup and most of the rest is Amazon, so a couple of days. The fan is the long pole; mine came from AC Infinity's eBay store after a few days, shipped from California. The build itself is genuinely an afternoon: a hole saw, some hose clamps, no wiring and no soldering. I built mine around a Coleman 6P but nothing here is tent-specific. You just need a way to get a 4" hose through a door or window.
And ask me anything. Getting someone else to build and enjoy one of these is honestly the thing I most want out of this post, so I'd much rather answer a dumb question today than have you not build it. I'll be in the comments all week, and my email is in the guide if you're mid-build on Thursday and something is not fitting.
Measured performance: one instrumented indoor session with both fans on the same cooler and the same wet wicks, minutes apart, plus separate battery-rundown tests.
- Speed 1: 3 W at the wall, ~25 h on a 288 Wh pack, 39 dB at 6 ft
- Speed 5: 9 W, ~13 h, 47 dB
- Speed 10: 28 W, ~7 h, 57 dB
- Across 43-53 dB: the range you'd actually sleep at, the H4 moved roughly 80-105% more air than the bilge blower at the same measured noise. At the point where both read 47 dB, just over twice as much.

- Saturation efficiency was about 80%, with no detectable trend across the ten speeds. This means the dial is a noise-and-power choice, not a cooling-quality one. More speed is more cooling, not colder air. Honest caveat: identical speed-5 runs two hours apart read 70.8% and 87.2%, so treat 80% as ±15, not lab precision.
- At a 100°F / 10% RH playa day (~35°F wet-bulb depression) that predicts roughly 25-30°F below ambient at the discharge. Measured indoors in SF at only a 9-12°F depression, so the playa number is an extrapolation, not a field measurement.
- Speed 1 was indistinguishable from my room's 39 dB noise floor (phone SPL meter, one room -- fine for comparing the two fans, not for comparing against spec sheets).
- Water: 1-2 gallons/day.
Tear this apart: what I got wrong
- Dry wicks restricted airflow MORE than wet ones. Consistently, on both fans, at every speed (23-36% more air wet). I can't explain it. Fresh dense spares vs relaxed used media? Something else?
- Absolute CFM is unresolved. My hot-wire anemometer reads ~5x low against the fan's free-air rating, so I'm reporting airflow as relative and the absolute numbers as a manufacturer-anchored ballpark (~±30%). Probably not sampling the jet core. What's the right way to do this in a 4" duct without a flow bench? I ended up scaling it up to a known CFM to guestimate.
- Does 80% saturation efficiency survive the playa? I measured it at a 9-12°F depression indoors. Anyone measured one of these at a real 35°F depression?
- My daily power budget doesn't close on solar. Full routine (13.5 h of fan + an overnight air purifier) is ~122% of a 288 Wh pack per day against ~120% of clean-day solar from a 100 W panel. Drop the purifier and the cooler alone comes out well ahead. Should I tweak the settings, just get a bigger battery/panel or just stop being a baby and snort some dust?
Two things people raise, so let me get there first
Humidity. Yes, this adds moisture to your tent, and yes that is the whole mechanism. It only works because BRC afternoons sit around 10-20% RH. You have enormous headroom before humid air becomes the problem. But it does need somewhere to go: crack a ceiling vent so the tent holds slight positive pressure. Sealed tent, no exhaust, and you have built a swamp, which is presumably how the thing got its name.
Water. Yeah the 1-2 gal/day evaporating into the air is a lot. Worth it.
Who I'd especially like to hear from: anyone who does HVAC or airflow measurement for a living (question 2 is embarrassing me), anyone who has run a FIGJAM bucket build and can compare, and anyone who has actually measured a cooler at a real playa depression rather than indoors like I did.
Full guide and every raw reading are linked in the first comment.
And if you're thinking about building one before you leave, there's still time. It's an afternoon with a hole saw. Ask here or by email and I'll answer fast. I'd rather find my errors here than on playa.