OT ceiling fan blades- better efficiency?

If you make the blades with an RG15 airfoil it will work better at higher speeds. Use a semetrical airfoil and you can run it inverted. If you want to thermal it I would use a 7037 airfoil thinned 20% so it will penetrate better.

If you really want some performance I would install a .91 4 stroke and convert it to a taildragger.

Craig

patrick mitchel wrote:

Day-um, Craig!! Before you put your tongue into your cheek, warn us, so we can keep the coffee out of our nose.... 'Scuse me, got some clean-up to do..... DC3

Most ceiling fans I see aren't worth the paint on them. They are way too close to the ceiling to be anywhere near even 10% efficient. Fooling with blade airfoils might help if the fan was at least one diameter away from the ceiling to let it draw properly. But how many folks have a ceiling that high?

Dan

So that's why my ceiling fan keeps clobbering me in the chest every time I go through the living room?

Patrick I've installed a "few" ceiling fans in the past, working new construction for several years, and the FIRST rule of getting any effectiveness from a ceiling fan is that the highest edge of the blades must be at least 6 inches from the ceilng, or they'll just spin and waste electricity...

You can manually adjust the pitch of the blades, but I've personally never seen it done where the balance wasn't severely affected.

Some models come with a "floating blade" feature, whereas the blades are loose on a track, utilizing centrifigal force when on to automatically balance the unit.

Ceiling fans were never designed to blow air on you, rather displace and circulate in order to maximize ventilation. I, of course, have my bedroom fan switched to "level 3 hurricane" and enjoy the effects of the intense downdraft