Great thread! My young camp Oontz Pouch uses 3 hexayurts for sleeping, and this year I'm doing A/C for them following your design. Planning to add a 15W solar panel to the system to slow the drain on the battery, though maybe I should just assume I will charge it when the generators are running at night.
I think I found a promising source of pumps, targeted at computer cooling. It isn't self-priming, but maybe that's a good thing--when it runs out of water (a distinct possibility with my camp's occasional responsibility lapses), it should lock up and stop running. From Amazon reviews, would take some poking/prodding with a paper clip to free it up again and re-prime it.
Sold for $11.50 before shipping via Amazon.com:http://www.amazon.com/Brushless-Submers ... d_sbs_sg_1
3.6L/min Mini DC Brushless Submersible Water. Ideal for CPU cooling
This is a compact size submersible water pump(none self-prime). It can be used inline or submersed for water pumping. It's built by a brushless motor providing smooth and quiet operation than a non-brushless water pump. Plus,it will not generate 'electric spark' like what a brush type does so it's more safe. It can be used to pump dilute oil as well (no gasoline*)
Output: 3.6L/m or 68GPM @12V
Vertical lift: 3m (10ft)
Current: 320mA@ DC12V
Intake: 8mm ID/10mm OD Dia.
Outlet: 5 mm ID/8mm OD Dia.
Life span: > 20,000hrs @ 1600rpm~4200rpm
Noise: << 38dB
Working Temp: 55'C (non-submersed)
Size(L*W*D): 2.0"x1.7"x1.36" (52mm X 42.7mm X 34mm)
Weight (net): 5.0oz