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 Post subject: How much energy is converted into heat?
PostPosted: Wed Nov 07, 2007 5:54 am 
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Hello,
Folding once again in the winter months to try to keep my apartment warm. I was just wondering: how efficient is it to use my computer like this to heat up my room? Say I have 1kW of energy. How much heat would my computer make with this 1kW when compared to, say, a conventional heater?
I don't need exact figures, just wondering about how efficient is it, because I really can't afford a larger electricity bill...


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 Post subject:
PostPosted: Wed Nov 07, 2007 6:38 am 
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Typical resistance heaters are said to be 100% efficient, but what exactly does that mean?

A conventional lightbulb is said to give off about 400BTU, which in the winter is not much.

A pc ps with 75% efficency will create 40 watts worth of heat, 160 watts in and 120 watts out. The resistance heater is probably 1500 watts, so 40 watts worth of heat is not much. Sure there's heat coming off the CPU, NB, etc, but while they are very hot they are also very small.

A simpler way to look at it would be the exhaust temp of your pc. If the air coming out is say 7 degrees warmer than the intake and then factor in the amount of air it's heating up. Then look at the exterior walls and how much heat you're losing.

There's a reason in the northeast a home furnace or boiler may be much more than 80,000 BTU.

You give off a few BTUs yourself.

I realize my post is worthless, its all I have to offer. :)

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 Post subject:
PostPosted: Wed Nov 07, 2007 6:40 am 
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AFAIAA (AIANAP) >99% of the energy going into a PC is eventually converted to heat.


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 Post subject:
PostPosted: Wed Nov 07, 2007 7:11 am 
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I thought everything in the end was %100 converted to heat.

sound in itself is converted to heat as it touches walls, as is soaked into to enviroment.

Since heat is just the vibration of atoms.


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 Post subject:
PostPosted: Wed Nov 07, 2007 7:35 am 
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you have some electro-magnetic radiations ... at least from the coils in the psu so I think some (insignificant) amount of energy is EM emission.


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 Post subject:
PostPosted: Wed Nov 07, 2007 7:38 am 
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But those electro-magnetic emissions are probably caught by the case.
In theory the case acts as a faraday cage.


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 Post subject:
PostPosted: Wed Nov 07, 2007 9:29 am 
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Quote:
In theory the case acts as a faraday cage.


yes, in theory. but any case with side windows will be a very poor faraday cage, as well as all plastic cases. any radio ham can tell you the problems caused by RF emissions from computers.


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 Post subject:
PostPosted: Wed Nov 07, 2007 11:04 am 
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Thanks for your posts. My case is neither windowed nor plastic, so I doubt any EM is gonna be getting out.

Just as has been stated a few times, I think that all energy is eventually converted into heat. If not at the power supply, then at the VRMs, and if not there, then at the actual chips. So I'm glad that virtually none of the energy that I'm using to power my computer is not going to heat production.

So basically since all the energy going into my computer comes out as heat, it doesn't matter if that heat is being generated at my heater or at the computer. This post really doesn't make much sense, but if everything I've read is correct, 40W being used for folding creates just as much heat as 40W being used by the heater, so (in theory) 40W of folding energy will mean that the heater can spend 40W less energy.


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 Post subject:
PostPosted: Wed Nov 07, 2007 2:03 pm 
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tehfire wrote:
if everything I've read is correct, 40W being used for folding creates just as much heat as 40W being used by the heater, so (in theory) 40W of folding energy will mean that the heater can spend 40W less energy.


You should also consider the cost of generating these 40 W with the PC and the heater.

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 Post subject:
PostPosted: Fri Nov 09, 2007 12:46 pm 
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I think what tehfire and myself need is a good watercooled system with the radiator and a quiet fan positioned under the bed, so that the heat moves upwards into the mattress and keeps us warmer.

Now to get a reasonable amount of heat out of would of course require at least a 67% OC on the processor. 8)

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 Post subject:
PostPosted: Fri Nov 09, 2007 5:06 pm 
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Yeah, basically all energy that you pull from the wall socket, turns into heat in the pc, so if you have direct electric heating, it's the same to run a 1kW heater as to run 1kW worth of PCs.

But you could be running an air pump that pulls energy from cold air outside and pumps it in. It can pump 3x the amount of energy from outside the house, that it needs for running itself. So basically you would get 4kW worth of heating with 1kW load showing in your energy bill.

The efficiency gets smaller as outside air gets colder, so you still need alternate heating system for very cold weather.

There is also the cost of running a 1kW heater for 1 year vs. the cost of running 1kW worth of PCs for 1 year. The electricity cost is the same, but the cost of the parts is much higher for PCs especially if you take into account that you need to replace them more often than your heater.

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 Post subject:
PostPosted: Fri Nov 09, 2007 6:38 pm 
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Fans convert most of their energy to moving the air, but they use so little power that I image it is pretty much the same. I guess I should start getting my new PS3 folding to keep the room warm. Too bad it is the new 65nm version that only uses 130W of power :D


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 Post subject:
PostPosted: Mon Jun 28, 2010 8:05 am 
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Very nearly 100% of the power your PC consumes will be released as heat to the room. However, this is less efficient than a typical home heating system, which works by pumping heat into the house from outdoors. By doing this, your home heating achieves over 100% apparent efficiency.

Edit: oh bleh, I just realized this is a very old thread bumped by a spammer. Oh well.


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 Post subject:
PostPosted: Sun Jul 11, 2010 4:06 pm 
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It's OK, actually I turned a PC off recently as the room was much too hot and the PC made it worse. Some of my GPU temps were 97C. And they were still running well. But I gave them a vacation.

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 Post subject: not alone
PostPosted: Sun Jul 11, 2010 9:23 pm 
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Location: San Jose
Yeah, I don't think you're alone with that, it looks like everybody on the team is down. With the notable exception of jhimanka nipping at my heels. I've dropped down to around 66k ppd, although I've actually had to turn on some extra gpus to compensate for the loss of bigadvs on my linux machines. With the 670* smp WUS, my ppd is randomly up and down. It's been cool enough here that I can keep it all under control with the AC, but I know it's been hot as hell back east, so it seems like that's probably killing production. Hope it cools down sometime soon!


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