MGB: Ceiling fan direction argument...need final answer

My wife and I disagree on a lot of things, but the one that bugs me the most is our different opinion on which way the ceiling fans should rotate.

Here's my take on this:

House does not have central air. Heat is oil fired, hot water, baseboard throughout.

Summer
1). cooler air stays closer to the floor.
2). hotter air rises toward the ceiling.
3). on a hot day, it makes sense to me to have the fans pulling cool air up instead of blowing hot air down.

(now, mind you, when I pop out of the shower on a hot day, I'll have the fan blowing down at full speed to cool off)

Winter
1). cooler air stays closer to the floor.
2). hotter air rises toward the ceiling.
3). on a cold day, it makes sense to me to have the fan pushing the warmer air down into the room instead of pulling up cold air.

I will tally the responses from this forum and live with the results. Heck, I might even apologise if I've been mistaken all these years.

My fan instructions say up for winter, down for summer

Instructions!?!

Damn it, I think I'm already in trouble here...........

We have a couple of ceiling fans in the dining room and living room (high ceilings) and I agree with Summer --> UP and Winter --> Down.

(I'm thinking your wife will feel we ganged up on her. Sorry about that.)

My instructions show summer down and winter up as well.

Summer down because it blows the wind on you making you feel cooler.

Winter up because it forces the warm air down along the walls, but doesn't blow the air directly on you making you feel cooler.

http://www.hansenwholesale.com/ceilingfans/fanfaqs.asp#ceilingfandirection

We leave ours on "up" because I figure that the air mixes up quickly anyway, but the consensus here and instructions both make sense because of the physics.

In the summer the fan provides cooling blast (like any fan) when blowing down.
The temp is pretty much the same in the room and the air is just being forced down to the floor, up the walls and along to the ceiling back to the fan anyway.

In the winter you don't want airblast for cooling. It does become advantageous to blow any warm air, as produced by the heating units, along the ceiling down the walls and back to the center of the room, thus distributing the air evenly. This is done by forcing the air up.

Besides, the instructions say up in the winter and down in the summer. Make up your own reasons why that is.

Bob

Smirkinwill wrote:

Instructions!?!

Damn it, I think I'm already in trouble here...........



I know I am! Down? Up? It's a ceiling fan. It blows. Now I find out it sucks!? Wonders never cease.

a thermometer might help....and then a blind taste test of Vichyssoise soup to be the final arbiter.

wyatt Wrote:

Down= summer

Up= winter

Down at the wall, up at the centre OR down at the centre and up at the wall???
A conumdrum for sure. I think ours is pushing air down at the centre all the time.

Up, 2 weeks in January.

Down, the rest of the time.:)

In my house, the living room fan stays on blowing down. In my bedroom the fan stays on blowing up, the wife doesn't like the breeze blowing on her and I like air circulation.

In the summer, we like the air blowing down on us because it feels cooler. In the winter, we just want to mix the air and not feel the breeze so it blows up.

... I could be persuaded to change my answer...

And the paper goes over the top of the roll!

Wayne

Britpit Wrote:

The one on porch is always down, cool breeze and it keeps the bugs away. The one over the bed is always clockwise because the mirrored blades would show the movie bass acqwards if it ran counter clockwise. Living room always UP!

Dave

I Like the air moving flowing past the sweat, so summer down, winter up, Do a test, On a very hot day have the "misses" stand under the fan totally without clothing. turn the fan on up and then down. Make your choice after watching the results.

........thats not gonna happen..........

olparatrooper Wrote:

http://www.wonderquest.com/Fans.htm

Down in summer, up in winter. How are you going to get out of this one?

The only reason I ask is I haven't yet told the wife how much I have actually spent on the MGB in the last 7 weeks! I might need a couple of "Get me out of the doghouse" tips soon

Jim

Down in summer, up in winter, for two reasons.

#2. Because you want to feel it more in the summer when you are hot, and you feel it more when it is blowing down.

#1. Because that is the direction of the natural convection. The outside walls heat the air up and cause it to rise along the walls and sink in the center.

During the winter, the outside walls cool the air, causing it to sink on the walls and rise in the center.

So operating the fan in the direction of the natural convection will give you more efficient airflow.

Summer down, Winter up unless you live in Australia.

"Summer down, Winter up unless you live in Australia." Now that's funny.
I thought fans naturally turned the opposite way in Australia like water going down the drain. :)

We naturally turn our fans the opposite to you in the north. When you switch to up we switch to down then when you switch to down we switch to up. I think its best exlpained like this...At about sixty degrees latitude in both hemispheres, the prevailing westerlies join with polar easterlies to reduce upward motion. The polar easterlies form when the atmosphere over the poles cools. This cool air then sinks and spreads over the surface. As the air flows away from the poles, it is turned to the west by the Coriolis effect. You see it all relates to the Coriolis effect.

Yep, you're doing it backwards, William.

Unless your ceilings are 12 foot or more, the ceiling fan isn't really contributing to efficiency in terms of total energy used with the heating/cooling system.

The real benefit of a ceiling fan for most folks is the breeze effect of the fan allowing you to raise the thermostat a couple of degrees (in summer) and still feel comfortable.

Fans are better at pushing than pulling in terms of people the breeze effect near them. So, that is the best reason for summer down, you'll feel the breeze better.

And in winter you generally don't want to feel a breeze from the fan. What I do in winter, one those occasions you it's cold in central Texas, is to just leave fans off.

if over the dining table, it depends on whetehr you want to blow the bug onto your food (extra protein, ya know) or away from it. Or cool it or not.

most of these units I've had have a reverse switch.

hpmowog Wrote:

They change directions!?

Pete