while looking through my collection of adapters and power plugs (from the other thread).... I spied my single D Coleman tent fan with a magnetic base... it served me in the 04 hurricane season, and prompted larger fans for 05...an idea hit me...I have an old design 4 bladed ceiling fan above my bed...I used a nylon strap over the end of a blade, and slipped the free end under the magnetic base.... although it ended up pointed at less than an ideal 90degree angle, it provides enough thrust to rotate the ceiling fan....it was necessary to add a counter weight to the opposite blade, but it actually works quite well... about 21 rpm

Wow. Very interesting. Not sure I'd ever buy a fan for camping, But I can't find flaw in your need or ingenuity!

This needs pictures, b/c I don't think I'm imagining it correctly.

MDinana...don't know how to post pictures...Coleman has a small tent fan (Campmor.com #85229)that has a small plastic blade, and powered by a single D cell... it is held in place on the tent with a magnetic base...the tent is sandwiched between the magnet and a metal plate on the exterior...I had purchased one of these to provide a little air movement for power outages, primarily for hurricane season... after 04, I obtained a larger 9v fan, and the small one was relegated to a back up...I've had a slow moving ceiling fan over my bed for a lot of years, and in the back of my mind have been wondering how to get more air moving when the power is out...the thought occurred to me to use the small tent fan as a thrust engine to turn the larger fan blades (eg. airplane propeller)...optimally you would want to mount the thrust at a right angle to the plane of the moving ceiling fan blade ...I'll probably make a metal bracket I can clamp on the blade, but with my preliminary trial, it provides enough thrust even at a non 90degree angle to move the fan blade (a slight upward angle, provides a little oscillating breeze when it rotates)...my initial trial mount was a piece of nylon webbing looped over one blade, and the end sandwiched between the magnet and the metal base plate... added a counter weight to the opposite blade to balance the fan blade..

thought I would pass this on to others that might have a similar ceiling fan... if you market it, send me a little royalty...

Ceiling fans, needing to be light and well balanced for optimum operation, are actually quite efficient. It's why their use helps lower power bills during the hotter parts of the summer; they use so little power, but are able to help so much.

I never would have thought about attaching a battery fan to one. I'll have to remember that tip!

I gotcha ... and the pic helps. Would you mind if I steal it from your email and post it in my first post of the thread?

MDinana...please do... I posted to another forum, and the discussion came up concerning the laws of conservation of energy...that the small high velocity flow would would become less efficient powering the larger fan lower flow, as opposed to using it directly...for me it is a perciption of the cooling effect of the lower flow...and the larger area cooled by the ceiling fan vs. practical mounting of the smaller fan...am currently running a run time test with a new alkaline D cell...

Very clever, LesSnyder!

Yes, you can't get around the laws of conservation of energy. If only...

You may want to consider a larger battery powered fan like this:

10" Battery powered fan

They also come in a smaller 6" personal size.

I have one of the 10" fans and I love it. It moves a lot of air and is pretty quiet. In addition to the 110V AC adapter that it came with, I have a 12V DC adapter that I use in my RV. It can also be run with 8 D cells. Great to have during a power outage.

Oh, and I also have a 10ft cigarette lighter extension cord so I can use the fan outside the RV without using D cells.

I've plugged an inverter into a rechargeable jumpstarter, and plugged a fan into that successfully. Best for short-term power outages. Since then I've bought D-cell powered camping fans.

Treeseeker....after 04, my second fan purchase was very similar to the one pictured, except that it has a 6 D cell battery pack (9v)..I tried it with a 12v cigarette plug and didn't seem to mind the added voltage, so added a female tubular cigarette adapter ending in terminal clips for a 12v auto battery ...powered it off a partially charged Harley Davidson and auto battery for 05...I've been on the fan quest for several years, as my bedroom window is an old Florida design called an awning crank out and won't hold a window AC to use with the generator...

follow up comment...I ran the fan continuously for 8h 55min on a new alkaline D cell, and at the end of the test, the fan rotation had slowed from 21 to 19 rpm... easily enough for one night or so...

I bought 2 of those at Wally World for the pop-up camper. I think they were $14 each. The 8 D-cell batteries cost more than the fan! I agree with all your statements above.

Not exactly the same subject but within the area of cooling yourself. In you tube some guys made battery powered "A/C units". They used disposable ice chests , full of ice, and made two holes . One hole (inlet) has a small battery powered fan. The other hole (exit) directed towards you.

Pics he sent:

MDinana... thanks for hosting the picture

last beating of a dying horse... attached a model airplane propeller to the shaft of the fan with a pinch collar propeller hub... 9 x 6 model propeller, running reversed... attached mid fan blade... 32 rpm (highest yet)