I have used 2 of the 5″ 02-Cool fans for the past two summers. The smaller fans pack easier than the 10″ fan. Also, you have a breeze from two directions. Batteries have lasted the whole week but if they don’t there a plenty of places to buy replacements.
One of the 5 inch O2′s does fine for me. I run it on high for about a half-hour to cool off as the sun goes down, then switch to low. Do yourself a favor and (i) use lithium batteries – they are worth the extra few bucks and (ii) switch the batteries as you start the fifth night whether you think you need to or not.
This will come up sooner or later. Use the older batteries in one of those AA battery device chargers. I use them to charge my Garmin GPS (500) since I hate having to go over to my charter’s juice thingy. And although I don’t need to charge my Iphone more than once during the week (I keep it off during the day), the used AA batteries probably can be used one last time in one of those emergency power devices (cost about $4 on ebay) if you just have to do it.
I have a O2 five inch fan that I used the first four Ragbrai I rode. Last year my family was worried about the heat and bought me a larger fan that was not an O2 that was a piece of junk. I relplaced it with a O2 10 inch fan and it works great.
I use a Coleman fan also. I do not remember which model. It has a 2 speed fan and a light. I hang it from the ceiling loop of the tent with a short lenght of cord. I adjust it so that it is about a foot above my shoulders. It always cools me enough so I can sleep.
I’m with the majority here: my wife and I both used the O2 Cool 10″ fans last year and they were great. I think I’m fairly safe in saying it was pretty hot (especially early in the week) and we ran them a lot at night. The batteries lasted all week. Can’t imagine RAGBRAI without them!
For the last two Ragrai’s I used two of the 5 inch O2 Cool fans available for $9.99 each from Walmart. The batteries lasted all week with fans running all night. I just set one up on each side of me and I was comfy. These were recommended on this forum, so I tried them – never had a problem.
The O2 Cool 10″ pushes alot of air and you can hang from the loop at the top of the tent. I really like mine. The downside is packing up the fan so it doesn’t get crushed in your bag and the battery pack can be a bit finicky. Never used the 5″ model but I’m sure it would work great, particularly if you have 2 of them.