They do not cool the air. They give an effect that is rather similar which impact is commonly labeled "wind chill".
Wind chill is not a specific science and there are numerous formulas that aim to provide it some sort of conventional but they are all different - so I take that to indicate there's no requirement. But it works something like this plumber clapham :
The body - your body - has its own internal heating system that is always burning away. As it burns, it warms up a thin layer of air that's in contact with your skin. It's that temperature your skin feels.
When the ceiling fan blows that warmer air far from your body, you feel as if the air is cooler. It is cooler than the heated air you were feeling however it is no cooler than the large bulk of air that was currently around you.
Once again your body starts to heat up the recently blown in air, perspiration evaporates and your temperature reduces.
Your sensation of cooling is dependent on the wind speed of the ceiling fan.
Wind speed is the result of the wind speed straight underneath the fan as it blows air across your body. This wind speed is effected by the size of the blade span compared with the number of cubic feet per minute (CFM) the fan can push.
The fan with the wider blade period is pressing the exact same volume of air as the smaller fan - but over a bigger location. The smaller sized fan is much faster because it presses the exact same volume over a smaller area.
Although they have the same CFM step, in this example, the smaller sized fan will cool you more because it is pressing the exact same volume of air over you at a much faster rate than the larger fan.
OK. It may not be right away apparent to you how that works. It certainly took me some thinking time. Attempt this twisted example and see if it makes it a bit clearer. I call it "twisted" because you still need to do a bit of work to obtain it.
That's your volume of air. The bigger fan is represented by a larger hole in its bucket than the smaller sized fan, er, bucket.
In this twisted example, we have 2 motors that will clear the 2 buckets at the precise very same time. The water is going to squirt out of the smaller sized hole much quicker than it does out of the bigger hole if both pails empty at the exact same time (CFM).
I did call it "twisted" however I still hope it got the idea across so you might comprehend it better.
CFM is the most vital element you need to think about. An average ceiling fan moves about 5,000 CFM which's probably less than you will need to cool an average size room ... it will need about 6,000 CFM.
Why would you require a bigger fan? Back to the smaller sized bucket/fan. The speed of airflow is quicker, the area it covers is smaller so you may be well cooled under the smaller fan, other individuals in the space are likely not well cooled. That's why you need a bigger fan -or another small fan- depending upon the shapes and size of the room.
Is Ceiling Fan Blade Pitch Important For Cooling?
Most ceiling fans run at a top speed of 200 RPMs. Motor strength, speed and blade pitch are the combinations that determine CFM.
Blade pitch is determined in degrees and it is the angle at which blades are slanted from the horizontal. In basic, provided the exact same RPM, then blades that have a bigger pitch will allow the fan to move more air.
You don't truly have to fret about the pitch, as long as you bear in mind of the CFM.
On the other hand, if you see a fan with virtually horizontal blades you will understand that it's not putting much load on the motor and there's most likely a negative reason for that.
It is often an indicator that the motor is not strong enough to push a big volume of air. There are manufacturers of low-cost fans who do not use real ceiling fan motors. They use motors from other devices such as vacuum cleaners and mixers to power their ceiling fans.
Motors that are designed for short durations of use are not going to be great enough for a ceiling fan that is likely to run non-stop for numerous hours and in very hot conditions.