2007-06-17 03:21:13 · 4 answers · asked by avinash007 1 in Science & Mathematics ➔ Engineering
I dug out my Kill-a-Watt device and my 16" oscillating fan. Here are the loads on each speed:
Low: 44 watts
Med: 53 watts
High: 58 watts
It didn't make any difference if the fan was locked in position or allowed to oscillate.
My old 20" box fan uses:
Low: 83 watts
Med: 138 watts
High: 180 watts
Nearly every applicance has the power requirements stamped on a nameplate or in the instruction manual.
For the relative accuracy needed in your calculations, you can use the approximation of volts x amps = watts.
For larger motors, if you can't find nameplate voltage and amperage information, convert horsepower to watts with the formula 1 HP = 746 watts.
If you want to measure your own appliances, check out the Kill-a-Watt device at the link below. It is available online or at home improvement stores and Radio Shack. I've seen it for around $25 US.
2007-06-17 05:11:53 · answer #1 · answered by Thomas C 6 · 1⤊ 0⤋
Fans come in different sizes. One web site lists table fans at 10 to 25 watts.
(note they give watts/hour simply because some devices are typically cycled on and off but for a fan the watts/hour should equal watts). A fan uses little power and the cost of running one is low.
http://www.absak.com/design/powercon.html
Further notes (added)
one can not just take current x voltage to get power in watts when the load is an induction motor (as is the case with a fan) because the current and voltage are not in phase.
power = I V pf
I is current (RMS amps)
V is voltage (RMS volts)
pf is power factor which is cos(phase angle)
see http://en.wikipedia.org/wiki/Wattmeter#Digital
http://en.wikipedia.org/wiki/Power_factor
Watt meters are available to make the measurement.
also
I just looked at my fan and it is marked with a voltage rating and a current rating. There is not wattage rating given.
2007-06-17 05:33:29 · answer #2 · answered by Dan Peirce 5 · 0⤊ 0⤋
Often the max power is printed on the fan somewhere.
If you want to take a given fan and measure how much power it actually uses, a Kill-a-Watt will tell you. It's basically just a device that you plug in to a wall outlet and you plug what your measuring into it. It will give you volts, amps, watts, VA, Hz power factor, KWH, and hours.
2007-06-17 04:53:21 · answer #3 · answered by Anonymous · 0⤊ 0⤋
it should say on the box. They all are different, due to size or functions they carry out.
2007-06-17 03:25:24 · answer #4 · answered by thenz0 1 · 1⤊ 0⤋