ceiling fans and cetral A/C

[kevnan]

Since hot air rises is it a bad idea to use ceiling fans; seeing that they will push down the hot at the ceiling. when using central A/C.

[Toolpusher]

No,
I run fans alot,summer and winter. Don't forget to reverse the rotation.

It will move the air, and that air will then be sent back to the coil and be de-humidified.

[RoBoTeq]

Air movement evaporates moisture on the skin surface which cools the skin surface. Ceiling fans enhance mechanical cooling.

[kevnan]

Thank you much! I over looked the dehumidification part. the fans go on.

[mizearella]

Heat rises and cold air drops. In summer months select the fan rotation that sucks the cooler air from floor area and throws air out above fan (umbrella effect) where the cool air drops back to the floor again & again. In winter reverse rotation so warm air at ceiling is being forced down into the room. I suggest a low speed for winter months.

[red]

I disagree with the direction of air from the ceiling fans for summer and winter use. You want the air to blow directly on you in the summer, but not in the winter. The following paragraph describes the correct blade rotations.

In the summer you want the fan to blow air directly downward. This position has a cooling effect on those beneath. During the winter you want air to blow upward toward the ceiling. This causes the hot air above to blow across the ceiling and down the walls. Warm air circulates throughout the room and absorbs condensation from windows and glass doors.

[bubbacake]

Here is a good link--- http://www.fsec.ucf.edu/bldg/pubs/pf306/index.htm

[mizearella]

An excerpt from a ceil fan company.

Blade Direction,
Ceiling fans are designed to operate in two directions – clockwise and counterclockwise. This is not just a coincidence, but also a design that will provide benefit in both summer and winter. During the summer months, the blades will rotate counterclockwise to help create movement in the air, which helps to cool the room. Then in the winter, you can switch the blades to rotate clockwise, which push warm air down into the room from the ceiling, helping to make the room warmer.

[2hot2coolme]

Originally posted by mizearella
An excerpt from a ceil fan company.

Blade Direction,
Ceiling fans are designed to operate in two directions – clockwise and counterclockwise. This is not just a coincidence, but also a design that will provide benefit in both summer and winter. During the summer months, the blades will rotate counterclockwise to help create movement in the air, which helps to cool the room. Then in the winter, you can switch the blades to rotate clockwise, which push warm air down into the room from the ceiling, helping to make the room warmer.



That's exactly how it is, Period!
Put this baby to rest!
BTW this OP is a BOZO anyhow...

[mark beiser]

Having a cieling fan on in the room will circulate the air in the room, eliminating stratification and making the room heat/cool more evenly, regradless of wich direction the blades are turning.

Having the fan blow air down in the summer will make it feal better in the room due because of increased evaperation from your skin.

Having the fan blowing air down in the winter is a bad idea because, even at low speeds, it will make it feal drafty in the room. Reverse the fan blades in the winter to pull air up. The air will still get circulated in the room, but without it fealing drafty.

As for the quote from a cieling fan company, whoever wrote it obviously lacks an understanding of the factors involved in human comfort...

[RoBoTeq]

Ceiling fans in rooms with flat ceilings should drive air towards the ceiling at a very, very....very slow rate in the winter. This passively pushes warm air on the ceiling down the outside walls of the room.

For cathedral or even very high ceilings the fan should drive air straigt down, again very, very....very slowely.

In the winter you should be able to easily follow any fan blade with your eyes.

[t527ed]

don't like ceiling fans to run with a/c if high ceilings. leave the hot air up by the ceiling instead of mixing it in and adding to the cooling load.

[robnjr]

Originally posted by mark beiser
Having a cieling fan on in the room will circulate the air in the room, eliminating stratification and making the room heat/cool more evenly, regradless of wich direction the blades are turning.

Having the fan blow air down in the summer will make it feal better in the room due because of increased evaperation from your skin.

Having the fan blowing air down in the winter is a bad idea because, even at low speeds, it will make it feal drafty in the room. Reverse the fan blades in the winter to pull air up. The air will still get circulated in the room, but without it fealing drafty.

As for the quote from a cieling fan company, whoever wrote it obviously lacks an understanding of the factors involved in human comfort...

I agree, Mark...maybe another lost in translation "made in China" product instruction???? BTW, I have 7 ceiling fans in my home....

[mizearella]

Your right ceiling fan companies know nothing about the product they design and manufacture. Kinda like HVAC manufactures,Auto manufactures & the like. Why know anything about the product you sling.

[alinnova]

Go by what works in your room, both summer and winter. Try things out for yourselves. The business of pushing air down in summer and up in winter is just a starting point.

In our house with vaulted ceilings in kitchen and dining/living room/upper foyer area and with registers low in the walls, I have ceiling fans usually running at medium speeds in the summer and low speeds in the winter. In our case, it is best to push the air up in both summer and winter. Our living activities are more near the walls than directly under the fans. We like the air to be moving softly down near the walls, both summer and winter, rather than with higher force down under the fans.

To the point that it is better to leave the warm air near the ceiling undisturbed in summer, we find that it is better to draw the cool air up from the floor and mix it thoughout the room. Better to have the cool air up around the face than having it stay down by the knees.
Al

[mark beiser]

I think it is safe to say that, like many things, there is no one way that is correct in all situations and applications. ;)

[mizearella]

I agree with every home is different. My last home I had to blow the air down to stay cool. (R-19 attic,R-11 walls loosely constructed piece of crap) The new house freezes me out if I blow the air down.(super insulated)