Can Someone Settle This Argument?

[elkangorito]

Sorry but your logic escapes me.

[zorro1]

ceiling fan on low and air on low on hot days is a winner. This combo would be best bet however if you don't have air then ceiling fan is the go for sure, larger volume of air with less load on the blade due to gravity.

[trogers]

We use different types of fan for different purposes, and not because one type has a smaller or larger motor than the other.

The choice of fan will depend on how we want to circulate air in a room. I use a table fan blowing on to me and my desktop. That's all I need.

But I use a ceiling fan over the dining table because there will be 6-8 people sitting around a floor space of 3x5m, and we do not like to have a strong wind blowing at our faces some of the time as we eat.

But if we only buy a fan based on the least amount of electric power it consumes, I suggest a plastic fan with 4" blades that runs of batteries.

[elkangorito]

We use different types of fan for different purposes, and not because one type has a smaller or larger motor than the other.

The choice of fan will depend on how we want to circulate air in a room. I use a table fan blowing on to me and my desktop. That's all I need.

But I use a ceiling fan over the dining table because there will be 6-8 people sitting around a floor space of 3x5m, and we do not like to have a strong wind blowing at our faces some of the time as we eat.

But if we only buy a fan based on the least amount of electric power it consumes, I suggest a plastic fan with 4" blades that runs of batteries.

Why would you suggest this? Has it got something to do with thew size of the motor?

[trogers]

We use different types of fan for different purposes, and not because one type has a smaller or larger motor than the other.

The choice of fan will depend on how we want to circulate air in a room. I use a table fan blowing on to me and my desktop. That's all I need.

But I use a ceiling fan over the dining table because there will be 6-8 people sitting around a floor space of 3x5m, and we do not like to have a strong wind blowing at our faces some of the time as we eat.

But if we only buy a fan based on the least amount of electric power it consumes, I suggest a plastic fan with 4" blades that runs of batteries.

Why would you suggest this? Has it got something to do with thew size of the motor?

Yes. The size of motor in this plastic fan is the same one used to run a kid's toy car.

[elkangorito]

Take the following scenario into consideration:

What about if a ceiling fan with a 100W motor with tiny tiny blades on it was compared to a floor fan with a 50W motor on it with huge blades on it.

Surely? the ceiling fan is going to pull practically no current due to almost no load on it. Against the smaller motor with a huge load on it. Less current = Less consumed power = Less used electricity.

I would guess in this case the ceiling fan would use less kWHr than the floor fan even though the floor fan has a smaller rated motor.

So the size of the attached load also has to factor into the calculation, and not only the size of the motor. However ceiling fans more often than not have longer blades than a floor fan (hence the need for a larger motor in the first place).

Make Sense?

This is not the case.

A motor with a minimal load, will draw current according to its iron & copper losses. The bigger the motor, the more iron & copper losses. This means that a motor, no matter the load, will draw a minimum current. This current will never be less than 50% of the full load current (assuming that the load is always connected i.e. fan blades). Please bear in mind that its the same type of load for either ceiling or floor fan. That is, the load increases by a cubed value as rotational speed increases.

Also, the type of speed control will affect the amount of power used.

If the speed control is purely resistive (not used in fans these days), the fan in question will use the full amount of power to which the motor is rated. The lost energy (power) is converted to heat by the resistor.

In a choke controlled unit (still very common), less energy is wasted by resistance, so this arrangement is slightly more efficient than a resistive speed controller.

Electronic control is by far the most efficient.

Disregarding the method of speed control, the larger motor will always use more energy (power) than a smaller motor (due to internal copper & iron losses), under similar operating conditions.

Conclusion.

A 50W floor fan will use less power than a 120W ceiling fan.

Edited August 1, 2009 by elkangorito

[robertsonmartin]

Conclusion.

A 50W floor fan will use less power than a 120W ceiling fan.

Really?

[elkangorito]

Conclusion.

A 50W floor fan will use less power than a 120W ceiling fan.

Really?

I'm only kidding.

What moron would design a fan & use a 120W motor when a 50W motor would do?

Edited August 1, 2009 by elkangorito

[ronswelters2]

In practice I don't think there's actually a great deal of difference if you compare cooling effect (it's not actual cooling).

Floor fans tend to be smaller (except Gungadins turbo-props) and move a fairly small air column at a fairly high speed, ceiling fans move a much larger air column but tend to move it more slowly. The actual effect is very similar.

Our 14" Hatari floor fans (rated at 60W) pull 50W at speed 2 (measured with my handy-dandy Kill-A-Watt), the ceiling fans are rated at 80W but are only ever run on speed 1 for a similar feeling of cooling. I can't conveniently measure the power used but I'd reckon it's as near 50W as makes no odds.

Personally I like the feel of a ceiling fan (less draughty), but each to his own.

Moved to DIY for more opinions

EDIT For the energy-misers here, check out the Sycamore fan http://www.treehugger.com/files/2007/06/sycamore_ceilin.php

Finally after 15 minutes of windy bar talk, a real answer. My question, Crossy, can you buy a device to measure amp flow here in BKK?

Ron

[Crossy]

Finally after 15 minutes of windy bar talk, a real answer. My question, Crossy, can you buy a device to measure amp flow here in BKK?

Just measuring the current isn't enough, you need to measure True Power (which is not necessarily the same as Volts x Amps).

You need a WattMeter, I couldn't find one locally (doesn't mean they're not available), so I got this on Ebay UK (via my parents' address), about 12 Quid plus the adaptors from HomePro. Dead handy for looking at the vampire load of all that kit on standby

Measures:-

Volts...........Supply Voltage

Amps..........Supply Current

Watts..........True Power consumption (what your electricity meter measures)

VA..............Apparent Power consumption (Volts x Amps)

Hz...............Supply Frequency

PF...............Power Factor (True Power / Apparent Power)

kWH............KiloWatt hours consumed over a timed period

If you do only want to measure Amps there are clamp-on meters which will do the trick safely (normal ammeters need you to break into the circuit, not a safe pastime). They usually have the facility to measure voltage too via test probes.

[Lancashirelad]

Celing v floor? Different horses for different courses.