2007-05-26 10:02:46 · 7 answers · asked by dashingskamal 1 in Science & Mathematics ➔ Engineering
Nope, it's the same consumption at all speeds, just as a car's gas mileage is the same no matter how slow or fast you drive it.
/sarcasm off/
2007-05-26 10:06:12 · answer #1 · answered by Anonymous · 0⤊ 2⤋
Its all a matter of Ohm's law. Voltage = Current x Resistance. In order to get the fan to blow harder, you turn down the resistance (The knob). In order to do that and voltage to maintain 120 volts, current has to go up. Current and resistance are inversely proportional.
The standard voltage coming out of your outlet in your house is 120 volts. That is a constant.
So at low speed lets say that the resistance is 10 ohms.
replace the formula with the numbers.
120volts=12ampsx10ohms
at high speed the resistance is 5 ohms.
This means that current drawn is doubled because resistance is halved.
120volts=24ampsx5ohms
Power is calculated by this formula and measured in watts
power=current x voltage
At low speed:
1440watts = 12amps x 120 volts
At high speed:
2880 = 24amps x 120 volts
I hope this answers your question.
2007-05-26 14:28:38 · answer #2 · answered by Ace 1 · 0⤊ 1⤋
yes!
it matters a lot. and its not a linear equation even.
this is how its calculated.
(speed 2/ speed 1) to the power 4 = (KW 2/ KW 1)
so if u have a 1 KW motor on full speed, running it on 90%
will result in
0.9*0.9*0.9*0.9= 1* new KW
new kw = 0.656
so u r saving 34% of energy by just running the fan by 10% less.
2007-05-26 18:47:08 · answer #3 · answered by lord 3 · 0⤊ 0⤋
Yes.
The horsepower required to operate the fan varies directly in proportion to the total pressure produced and by the cfm or amount of air moved by the fan.
As the fan speed is increased or decreased, both the static pressure and cfm change
Air HP = Ht(total pressure in inches of water) x cfm/6350.
2007-05-26 10:38:57 · answer #4 · answered by gatorbait 7 · 1⤊ 1⤋
Well, looks like all the bases are covered. At least one person got the right answer, but no one yet has the right explanation if its an alternating current (120v) fan.
;)
2007-05-26 15:59:56 · answer #5 · answered by eric.s 3 · 0⤊ 0⤋
Yes, increase speed, increase the load..consumption increases..and vice versa.
2007-05-26 12:43:56 · answer #6 · answered by Norrie 7 · 0⤊ 1⤋
yes - the faster the fan turns - the more juice you pay for
2007-05-26 10:06:15 · answer #7 · answered by tom4bucs 7 · 0⤊ 1⤋