Fan Wattage

[SpuD]

Just wondering the difference between the wattage used between 2x 12v DC fan 0.19Amp each with 1xAC fan with 0.12Amp. Which has a higher wattage?

2 x dc fan wattage calculation will be W=VxA
that means
0.19x2x12v=4.56W

What about the AC fan?
240vx0.12=28.8W???

Please advice..

[Goondoo]

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On 6/1/2003 12:37:56 AM

Just wondering the difference between the wattage used between 2x 12v DC fan 0.19Amp each with 1xAC fan with 0.12Amp. Which has a higher wattage?

2 x dc fan wattage calculation will be W=VxA
that means
0.19x2x12v=4.56W

What about the AC fan?
240vx0.12=28.8W???

Please advice..

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Hi,
I can't really remember much about this. As far as I know, when using any equipment DC, you should no longer based on the power consumption by the equipment itself. You have to calculate the power equation using the power consumption of the AC/DC converter and power loss through heat. Hope I could help you further but I had really forgotten majority of the stuff.

[David]

Hi Spud

What is the concern regarding power?.....consumption or cooling effectiveness?...whichever the case, the AC Fan will be at the advantage as it can accept our local voltage while the DC fan has alot of wastage through a stepdown transformer.

[SpuD]

Hi david,
i think my concern is the consumption. If the fan can cool down the water for 2 or 3 degrees, it's good enough. Don't really need such a powerful fan (AC fan). Been using the 2 dc fans and it had served me well. Managed to lower the voltage from 12v to 8v consumption using the adjustable knob at the adaptor. Less noisy and lower consumption.

[David]

Hey SpuD

I am no electrician ...but I think the consumption of the DC whether 12 or 8 volts is still the same....the current is just being absorbed by the stepdown transformer.....

[sherchoo]

David,
Nope, power consumed depends on load. However, there is some power loss in the convertor thus consuming into your electrical bill.

Lowering the voltage will reduce the speed of the fan which in turn reduce the power consumption. But bear in mind that the fan is designed to run at 12V. Reducing it may not damage the fan but effieciency might reduce.

[jacian]

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On 6/1/2003 12:37:56 AM

What about the AC fan?
240vx0.12=28.8W???
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So, does anyone know what is the watts of the AC fan we commonly used?

[sherchoo]

Jacian,
So far I've quite a few fans but non mentioned of the power consumption.

But you can assume that the power = 230 X 0.12 X 0.9 = 24.84W

[SpuD]

Hi Sherchoo,

to conclude
the old AC fan i'm using is
240v x 0.12A= 28.8W

the new 2 x DC fans i'm using is
8v x 2(0.19A)= 3.04W

i'm i correct?