Calculating power consumption
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Nishant Sivakumar wrote:
Now using those bits of data, is there some formula to calculate the power consumption?
Not really. You can calculate the VA rating (voltage * current), but the actual power consumption depends on the power factor of the equipment (1.0 for a perfectly noninductive circuit, but in practice is almost always less than 1.0). However, given the figures you quoted, I'd expect the power consumption to be somewhere around 150W.
Ryan
"Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"
You could go out and look at your meter, leave the thing on for a whole day and write down what you used, then turn it off for a whole day and compare the usage. The effeciency of your line and other factors may make it use more power than the actual rating. If you average your 'normal' usage over 24 hours, you may be able to get a good estimate of the difference in cost - I suspect it's the cost difference you want to know, not the power usage. If it costs you 100 bucks a month to run, it may not be worth it, but if it only costs you 2 dollars to run it all month, then it's probably worth it. Depending on the brand, some of the air purifiers actually are pretty good, but something often overlooked is that homes with a central air conditioner and heater already have a method of filtering the air. It won't make it smell like ozone in your house, but changing your furnace filter can help a lot with the general air pollution. For emergent conditions like cooking odors, you need to address that problem while the situation is happening, like with a good stove hood that empties to the outside air. Air purifiers aren't designed for that.
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Ravi Bhavnani wrote:
Power = Volts x Amps (132W)
That would be for DC. For AC you have to integrate the absolute value of the voltage times the current over a full sinusoidal cycle. If I remember right, that gives you a factor of 0.707 of the DC value.
The evolution of the human genome is too important to be left to chance.
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Ravi Bhavnani wrote:
Power = Volts x Amps (132W)
That would be for DC. For AC you have to integrate the absolute value of the voltage times the current over a full sinusoidal cycle. If I remember right, that gives you a factor of 0.707 of the DC value.
The evolution of the human genome is too important to be left to chance.
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Holy crap! That *is* expensive! Not sure if Smitha's gonna let me buy that one - and I myself don't want to spend that much on this. But they claim that their filter does not need changing. So maybe in the long run it may be cheaper.
Regards, Nish
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Rama Krishna Vavilala wrote:
I never knew that those things actally work.
They don't :-(
Regards, Nish
Nish’s thoughts on MFC, C++/CLI and .NET (my blog)
Currently working on C++/CLI in Action for Manning Publications. (*Sample chapter available online*)They cycle the air through a small filter which makes them ok for dust. But stuff that smells can get stuck to the walls via humidity so its not going to be filtered at all.
Todd Smith
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Use the range hood. And open a window. Or just open a window. Or just cook things that smell nice...
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Ravi Bhavnani wrote:
Power = Volts x Amps (132W)
That would be for DC. For AC you have to integrate the absolute value of the voltage times the current over a full sinusoidal cycle. If I remember right, that gives you a factor of 0.707 of the DC value.
The evolution of the human genome is too important to be left to chance.
<geek mode>Assuming the power supply is a clean sinusoid with no excessive harmonics.</geek mode>
Anna :rose: Linting the day away :cool: Anna's Place | Tears and Laughter "If mushy peas are the food of the devil, the stotty cake is the frisbee of God"
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<geek mode>Assuming the power supply is a clean sinusoid with no excessive harmonics.</geek mode>
Anna :rose: Linting the day away :cool: Anna's Place | Tears and Laughter "If mushy peas are the food of the devil, the stotty cake is the frisbee of God"
:) I'll even add: also assuming the phase is set properly
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Ravi Bhavnani wrote:
Power = Volts x Amps (132W)
That would be for DC. For AC you have to integrate the absolute value of the voltage times the current over a full sinusoidal cycle. If I remember right, that gives you a factor of 0.707 of the DC value.
The evolution of the human genome is too important to be left to chance.
These are RMS figures so it's still P=V*I.
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Ravi Bhavnani wrote:
Power = Volts x Amps (132W)
That would be for DC. For AC you have to integrate the absolute value of the voltage times the current over a full sinusoidal cycle. If I remember right, that gives you a factor of 0.707 of the DC value.
The evolution of the human genome is too important to be left to chance.
As Elaine says, the quoted AC line voltage is the RMS value. UK 240Vrms AC peaks at nearly 340V.
Stability. What an interesting concept. -- Chris Maunder
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Use the range hood. And open a window. Or just open a window. Or just cook things that smell nice...
Shog9 wrote:
Use the range hood. And open a window. Or just open a window.
The kitchen doesn't have a window - the nearest window is the one in the living room - which we keep open. But it still takes a while for the odors to vanish.
Shog9 wrote:
Or just cook things that smell nice...
We are Indian, remember? :-)
Regards, Nish
Nish’s thoughts on MFC, C++/CLI and .NET (my blog)
Currently working on C++/CLI in Action for Manning Publications. (*Sample chapter available online*) -
They cycle the air through a small filter which makes them ok for dust. But stuff that smells can get stuck to the walls via humidity so its not going to be filtered at all.
Todd Smith
Todd Smith wrote:
They cycle the air through a small filter which makes them ok for dust. But stuff that smells can get stuck to the walls via humidity so its not going to be filtered at all.
Yeah, these things seem to be meant for visible dust particles and not for odor.
Regards, Nish
Nish’s thoughts on MFC, C++/CLI and .NET (my blog)
Currently working on C++/CLI in Action for Manning Publications. (*Sample chapter available online*) -
We bought an Air Purifier (Holmes) yesterday, and its manual says it can be left on permanently. But I am a little concerned about its power consumption - I mean if it's 400W or something I don't want to leave it on 24 hours a day. Unfortunately it doesn't mention power consumption anywhere on it :-( I checked the manual, the specifications, searched their website, searched the body of the equipment etc. I did find the following info : 120 V, 60 Hz, 1.1 Amps AC only Now using those bits of data, is there some formula to calculate the power consumption? Or is that indeterminate? Thanks in advance.
Regards, Nish
Nish’s thoughts on MFC, C++/CLI and .NET (my blog)
Currently working on C++/CLI in Action for Manning Publications. (*Sample chapter available online*)Something else to keep in mind is that stated power consumption is not always equal to actual power consumption. Many products will list power consumption at full load, which is almost never reached. I'm not an expert on air purifiers, but I would expect your actual power consumption to be less than listed. Also, some devices cycle themselves through states where they may be fully on for a while, then in idle state for a while. I guess what this really boils down to is this: you have an air purifier, you obviously thought it was important enough to pay to purchase it, now you need to pay to use it. Either you want it, or you don't. Is that harsh? I don't mean for it to be. Rick.
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132 Watts * 24 Hours = 3.17 KWh. If you pay $0.10 per KWh, then your device costs you about $0.32 per day which is a bit less than $10 per month.
danmorin wrote:
132 Watts * 24 Hours = 3.17 KWh. If you pay $0.10 per KWh, then your device costs you about $0.32 per day which is a bit less than $10 per month.
Thanks - that's lower than I had imagined then. Though I don't know my rate - it's in therms (whatever that means).
Regards, Nish
Nish’s thoughts on MFC, C++/CLI and .NET (my blog)
Currently working on C++/CLI in Action for Manning Publications. (*Sample chapter available online*) -
danmorin wrote:
132 Watts * 24 Hours = 3.17 KWh. If you pay $0.10 per KWh, then your device costs you about $0.32 per day which is a bit less than $10 per month.
Thanks - that's lower than I had imagined then. Though I don't know my rate - it's in therms (whatever that means).
Regards, Nish
Nish’s thoughts on MFC, C++/CLI and .NET (my blog)
Currently working on C++/CLI in Action for Manning Publications. (*Sample chapter available online*) -
Nishant Sivakumar wrote:
Though I don't know my rate
The cost per KWh is written on your utility bill. On my last bill, I has to pay $0.0522 per KWh, which would cost about $5 per month for operating your device.
danmorin wrote:
The cost per KWh is written on your utility bill. On my last bill, I has to pay $0.0522 per KWh, which would cost about $5 per month for operating your device.
Okay I checked now and found that I had to pay $ 0.122 per KWh (I wonder why my rate is twice yours). But yeah - about $10 then.
Regards, Nish
Nish’s thoughts on MFC, C++/CLI and .NET (my blog)
Currently working on C++/CLI in Action for Manning Publications. (*Sample chapter available online*) -
Nishant Sivakumar wrote:
Though I don't know my rate
The cost per KWh is written on your utility bill. On my last bill, I has to pay $0.0522 per KWh, which would cost about $5 per month for operating your device.
Plus, your device wont be drawing 1.1 amps continuously.
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danmorin wrote:
The cost per KWh is written on your utility bill. On my last bill, I has to pay $0.0522 per KWh, which would cost about $5 per month for operating your device.
Okay I checked now and found that I had to pay $ 0.122 per KWh (I wonder why my rate is twice yours). But yeah - about $10 then.
Regards, Nish
Nish’s thoughts on MFC, C++/CLI and .NET (my blog)
Currently working on C++/CLI in Action for Manning Publications. (*Sample chapter available online*)Nishant Sivakumar wrote:
I wonder why my rate is twice yours
The answer is Government Regulation, the same as telecoms used to be regulated. The government passes a law preventing competition of production and/or distribution of electricity, thus granting the power utility a monopoly over a geographical area. The corporation can charge almost as much as they want - there is no price cap. This is analogous to telecom regulations. In the 80's we used to pay long distances $0.35 per minute. Since the telecommunications have been de-regulated, there is more competition which drives prices down. Bell Canada no longer has the monopoly.
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Nishant Sivakumar wrote:
I wonder why my rate is twice yours
The answer is Government Regulation, the same as telecoms used to be regulated. The government passes a law preventing competition of production and/or distribution of electricity, thus granting the power utility a monopoly over a geographical area. The corporation can charge almost as much as they want - there is no price cap. This is analogous to telecom regulations. In the 80's we used to pay long distances $0.35 per minute. Since the telecommunications have been de-regulated, there is more competition which drives prices down. Bell Canada no longer has the monopoly.
danmorin wrote:
The government passes a law preventing competition of production and/or distribution of electricity, thus granting the power utility a monopoly over a geographical area. The corporation can charge almost as much as they want - there is no price cap.
:omg: Why would any government pass such a law?
Regards, Nish
Nish’s thoughts on MFC, C++/CLI and .NET (my blog)
Currently working on C++/CLI in Action for Manning Publications. (*Sample chapter available online*)