The spin of a ceiling fan.

I was just on a road trip and read this in a paper on the way:

We are running this fact again because so many wanted to see it explained again. If you want to maximize the cooling of your ceiling fan, before making the blades turn faster, make sure they are going in the right direction.
The paddles on a fan should be turning counterclockwise to keep a cool breeze circulating. Even if you have more than one fan, side by side, make sure ALL of the fans are spinning in the same direction. Clockwise rotation (as you are looking up at it) will heat the area below.
So remember, counterclockwise means cool, clockwise means warm.

Is this acurate? I can see this working if the fan blades are angled in to the direction of the motion, but what about a ceiling fan where the blades are horizontal?

You mean no angle of attack? That isn’t a fan, that would be a useless (and expensive) decoration. Ceiling fans have angled blades just like any other fan. The article was talking about whether to blow warm air down from the ceiling, or pull cool air up from the floor (the undesired temp going up or down the walls where the people usually aren’t).

My ceiling fans does not have angled blades and I can’t tell a difference when it spins clockwise or counter clockwise.

Adam - are you sure it’s not a circular saw?

You’re either not looking at it right, or you got robbed. The fan has to have some angle of attack to the blades, or it won’t move air at all (well, not any usefull amount anyway). Looking at my ceiling fan, I see roughly 5 degrees angle, which means that when viewed ‘on edge’ from the end of a blade, the right edge is about 3/4" lower than the left edge. When I stand directly under the fan and it is rotating counter clockwise (as viewed looking up), I feel the air blowing directly at me. When I reverse the rotation, it takes longer, but I feel a general motion of the air, no longer blowing directly on me (because it is first deflected off the ceiling and down the walls).

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I’ve always felt that the sole reason for reversing ceiling fan rotation to aid in heating, as opposed to cooling, was to avoid a noticeable breeze in winter. I do not see how it makes any difference otherwise: both directions homogenize the air in the room.

Christ, what an imagination I’ve got…

In summer you want the fan rotating so that the blades push the air down. This produces a draft which makes you feel cooler.

In winter you want the fan rotating so that the blades pull the air up. This circulates the air in the room (pulling the warm air off the ceiling) without producing an obvious draft.

“You can’t run away forever; but there’s nothing wrong with getting a good head start.” — Jim Steinman

Dennis Matheson —
Hike, Dive, Ski, Climb —

It might eventually homogenize the room, but in general, the warmer air is going to be near the ceiling, while the cooler air is near the floor. By changing the rotation of the fan, you can determine which of those two temps is moving around the center of the room where the people are and which is moving up, or down, the walls.

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I wanna hear more about Adams odd fan. :slight_smile:

Work like you don’t need the money…
Love like you’ve never been hurt…
Dance like nobody’s watching! …(Paraphrased)

I see no reason why a fan with blades angled in one particular direction and rotating in one particular direction wouldn’t be exactly equivalent to each of these parameters being reversed.

In Berkeley here, you don’t need fans (unless maybe you dance with them).


But this is probably another one of those right-hand rule threads in disguise.


Nano, you’re quite right. Whoever wrote that fans should alway spin “counterclockwise” was assuming that all fans have their blades angled in the same direction.

NEVER EVER have your fan turning clockwise! it will go right through the ceiling.
nano, i have been avoiding that thread like a right wing nut avoids the ACLU,and you bring it in here.
You wanta hear odd fan? Back when I was playing with the Bensley Trio Two,we had a real odd fan. She used to jump up on the stage and…oh sorry, wrong news group again.

“Pardon me while I have a strange interlude.”-Marx

Actually, I would think which way you turn the blades would depend on your goal in having the fan on in the first place.

For example:

In my old house, in the bedroom I used, the main reason for the fan was to cool me while I was in bed. The bed being near the wall, and my head being there as well, it made way more sense to create a breeze down the wall than down into the center of the room. But in the computer room where I am now, the fan sits almost directly above me, making a downflow most delightful on hot, summer days.

as for the clockwise, counter-clockwise, right-handed thing… Nope, not gonna touch it.