Similar to the membrane in speakers, except much slower and much larger, if you have a large curtain set to slowly viberate, in and out, it would create a nice "breeze" in the room without the noise of fan propellers.
If a sail can move a ship, then a motor attached to a "sail" can probably move a large volume of air around the room.-- pashute, Apr 14 2008 (?) Nukik Fan http://www.geus.dk/ghexis/play-typ.htmAn example of a hanging wall fan [mylodon, Apr 14 2008] similar effect for pc cooler https://youtu.be/C3GKe7eXbPE [pashute, Mar 23 2022] Quieter, yes, but like you said, large.-- Texticle, Apr 14 2008 I thought the way a fan worked, from a human-cooling point of view, was this: that it increased the rate at which (a) sweat could evaporate from the skin and (b) body heat could pass directly into the air by conduction ... because ... the movement of the fan carried away from the body air which was (a) already moistened and/or (b) already warmed to body temperature.
Would a vibration do these jobs as well as a more-or-less continous movement of air in one direction, (as generated by a spinning fan)?-- pertinax, Apr 14 2008 From what I understand, this would create huge, slow-mo "sound" waves. And in my understanding, sound is generated by periodic pressure waves in the medium, not by the medium travelling across. Would that really increase convective heat loss from a human body? If any of my train of thought is faulty, please correct me, I am intrigued yet sceptical.-- Ratwoman, Apr 14 2008 What Ratwoman said.-- DrCurry, Apr 14 2008 Ratwoman has a valid point if the fan is part of the wall, sealed at the edges. The air in the room would alternately pressurize and equalize.
But I read the idea as a curtain separate from the wall itself. If the Wall Sail-Fan is nearly the size of the wall, but has a gap behind it, moving the curtain back and forth will cause air to move along the adjacent walls, ceiling, and floor. The bulk of the “cooling” is from air moving around the edges of the “fan”. It's slightly more effective to place another of these, synchronized, on the opposite wall.-- Amos Kito, Apr 14 2008 perhaps my choice of the term vibrate was not the best. It alternatively is tightened and released inaudibly. Competely silent. Pushing the air in the room. a slight angle of the curtain at the top or bottom or one of the sides would send the air circulating in the room. coming back from the push when loosened does not pull the air back but rather from the sides so a fow of air is created. You can simulate this with the palm of your hand.-- pashute, Mar 23 2022 Kind of overkill, rather than moving a 10 ounce fan blade you're moving a comparatively heavy curtain.
Might be pretty though so [+]
Also, great link so [+] for that too.-- doctorremulac3, Mar 23 2022 Bun, although I don't think this will be as effective at cooling people. You're moving much more air, but at a much slower speed. cfm only helps when the air is moving across the surface to be cooled.-- Voice, Mar 25 2022 Look up "punkahwallah fan".-- xenzag, Mar 25 2022 I think that's a bit harsh. I'm sure there's a hand operated punkawallah version under development?-- xenzag, Mar 25 2022 random, halfbakery