Computer heater

[omgwtfbyobbq]

If yer leaving it on crunching distributed stuff, maybe climateprediction.net is the most suitable, since the computer is likely powered by some form of FF electricity generation.

[SVOboy]

Get a macbook,

I need to close my laptop to move around between classes and such, can folding accommodate being stopped and restarted all the time?

[DracoFelis]

Originally Posted by Gearshredder

well does a computer acctually put out 100% heat of the power it uses to process?

My understanding is that virtually all electric devices (not just computers, virtually ALL of them) have so close to 100% of their power ultimately end up as "waste heat", that it's not worth worrying about the difference!

i.e. use a 100 watt bulb, and you not only get light but also essentially 100 watts of heat as well. Replace a 100 watt light with a 17 watt compact florescent, and you have also lowered the heat by 83 watts of power savings. Etc.

Now, in the summer this effectively works AGAINST you, as any power you use in the house (even fans to move the air around) ultimately is extra heat you are fighting against for cooling! But in the winter, this can actually work in your favor, because the "waste heat" will actually heat things up pretty much as effectively as an electric "space heater" would. i.e. If you would otherwise have to run a space heater at 700 watts of power (to heat up a room you are in), you might as well run "appliances" (TV, lights, computer, etc) that use 700 watts of power between them instead, because it should add about the same level of heat to the room (as the "space heater"), while also giving you other benefits (assuming you actually get some benefit from the electric devices you turned on). So this is one place were "energy efficiency" can actually work against you, as the less efficient the appliances, the more "waste heat" they produce (not just the more electricity they use)!

However, the above analysis assumes that you are comparing running electric devices (including, but far from limited to, computers) against getting your heat from basic electric heating elements (i.e. the laws of physics mean that "waste heat" from electric appliances is almost exactly as effective/efficient as almost all electric "heating elements" on the market).

But when comparing electric to other "heating sources" the results can be different. For example, electric "heat pumps" can often heat up a building at greater than 100% efficiency (i.e. with a heat pump you often get more heat than just converting the electric to heat could give you), because the heat pump (unlike the waste heat, or the electric space heater) isn't actually creating heat from the electricity, but is instead moving heat from the outside (effectively making the outside a little bit colder in the process). Furthermore, there are many other sources of heat (with varying "costs") on the market. And when dealing with those other heating sources, you pretty much have to "run the numbers" to see which is less costly to you. For example, the cost per "therm" for gas is (in many areas) cheaper than the equivalent amount of electric power needed to produce a therm of heat (which is why it is usually "cheaper" to have a gas furnace, than an electric one). And there are even somewhat "free" sources of heat (for example, some solar heating designs).

But when you are just dealing with "electric heat" anyway, its useful to remember that electric devices produce "waste heat" for almost exactly the same amount of input power as an electric heating device (a space heater, an electric stove, etc) would (given the same amount of input electric usage). So in the winter, consider turning on some useful electric appliance BEFORE turning on the electric space heater. It won't save you any power vs the space heater, but you will get two functions (the heat and whatever the device supposedly does) out of the power you do use...

[SVOboy]

A slight correction on the lightbulb thing that I recently heard from an ENVS professor is that incandescent bulbs are 5% efficient at creating light, and 95% at creating heat, whereas flourescents are 20% efficient at creating light and the rest goes to hear (and sometimes a little bit to noise).

*shrug*

[trebuchet03]

My understanding is that virtually all electric devices (not just computers, virtually ALL of them) have so close to 100% of their power ultimately end up as "waste heat", that it's not worth worrying about the difference!

This really isn't the case - especially when you consider how much work is being done. I've been trying to find actual % efficiency numbers for processors - but I think the actual numbers are kept secret. BUT, a great experiment for comparison can be found here:

http://www.tomshardware.com/2007/09/...ls/page15.html

The Final chip completed/survived all benchmarking tests while having a higher wattage rating than another chip that was not able to complete the tests due to heat/temperatures.

All that said -- IF efficiency for all electronics were to be 5% - the size of a power supply to run a 50 watt processor would be 1000 watts. This clearly isn't the case. Power supply efficiency typically runs in excess of 80%

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Now, after saying all that.... You can say exactly what you said for ANYTHING given that the device is in a completely closed system. A car, for example, is say 30% efficient (comparing energy in to useful work). BUT, if you look at total waste heat emitted to the universe -- it's 0% efficient as brake heat, heat generated from air friction, etc. all generates heat.

What I'm getting at is - it's easily interpreted that all electronics have very low efficiency as stated (especially when compared to a heater @ 100% efficiency)

[88HF]

If you lost 100% the energy from electricity as heat then their would be no visible light from a bulb, no buzzing from a transformer, no signals to be picked up by radios, or sound to be heard from a speaker. Energy is manifested in numerous ways which are not heat.

[DracoFelis]

Originally Posted by trebuchet03

Now, after saying all that.... You can say exactly what you said for ANYTHING given that the device is in a completely closed system. A car, for example, is say 30% efficient (comparing energy in to useful work). BUT, if you look at total waste heat emitted to the universe -- it's 0% efficient as brake heat, heat generated from air friction, etc. all generates heat.

That's what I was thinking.

For example, you not only have waste heat from the power supply, but you also have waste heat generated from the electronics (CPU, RAM, etc) as a by-product of them doing their job. And when you add up all of those waste heat factors, I was under the impression that the total "waste heat" from the entire electric system was very close to the electric energy put in (with only a very small percentage of the input energy ultimately, after all steps/conversions are accounted for, ending up as anything other than heat energy).

And while I could be wrong, I thought that the with the vast majority of electric devices around the home, the energy (after doing any desired "work") eventually transforms into heat energy. As you pointed out, many times it will take multiple steps (for example, in a computer you move electrons around tiny electric "gates" to do "computations" before a lot of the energy ends up as heat), but ultimately "heat" is usually the form that the energy eventually ends up as. And as we all know, we don't create/destroy energy, we just convert it from one form to another (raising "entropy" in the process).

Of course, another poster on this thread pointed out that there are other possibilities. For example, the energy could be released into the environment as some other form of radiation (i.e. for example, a radio transmitter releases energy as radio waves). And it's also possible to pipe the energy out of the area in some form. But for appliances in an enclosed space, the used energy has to radiate into the area somehow. And I was under the (possibly mistaken) impression that (with the exception of various RF "transmitters") almost all such energy eventually (often after several intermediate steps) becomes thermal radiation (i.e. "waste heat") into the local vicinity.

[Erdrick]

I think we are kind of heading in the wrong direction with this thread. We are talking about maxing out computers' CPU usage and whatnot... kind of the opposite of what this site stands for. Rather than talking about ways to use (or abuse in this case) technologies to make our lives better, why not think of ways to passively let nature help make our existence a more pleasant one? Better sun exposure and things like this are infinitely better than electricity.

[GasSavers_Ryland]

If you are running A/C in the same building as you have a device that gives off heat like your computer does, then you are paying to creat that heat, and you are paying to remove that heat, so you are paying twice for your computer being on, dirrect venting your computer to the outdoors could help if it was cool enough out side, keeping the door of the room closed will help, but unless you have no insulation in the walls, or a window open, it still has an affect on the load of the A/C, a LCD moniter will help cut power used, letting the computer go in to a sleep mode will help, but biggest of all is turning off the computer, I highly recomend getting a watt hour meter that you can plug your computer in to, I suspect that your electrical savings over the course of a year will off set the cost of the meter.

[Gearshredder]

yes.. i definately have to go find one of those meters.. idk why i didnt already..
I tried the folding@home program to max it out and found i wouldnt get a WU done until jan 10 2008.. lol
I will though try to get a more efficient computer cpu such as the core2duo and definitely buying an lcd monitor will help. Except today, those graphic cards are energy hogs.. and produce alot of heat.