Computer heater

[rh77]

Originally Posted by 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.

That estimator deal is WAY off for some reason, until you let it run a few Frames. For me it does the same. Now, I'm halfway through one now, and it estimated to complete Thursday. It's like a trip computer calculating average speed from the start. 15 mph average before you hit the highway, and you'll get to your destination in 24-hours instead of 3.

Originally Posted by SVOboy

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

Yup -- you can set the checkpoint save from 3- to 30-minutes.

Originally Posted by 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.

I'll look into it, but I've been crunching for Stanford for a few years now. Medical Research is an important adjunct in my life, but the Environment is also at the top of "my platform".

Originally Posted by Erdrick

I think we are kind of heading in the wrong direction with this thread.

My fault -- I inadvertently hijacked the thread with what creates a lot of heat in my computer. When I had a small, well-insulated room in an apartment, the PC (and monitor) would often warm up the place to a comfortable level with the door shut. Conversely, the door needed to open in the summer to improve airflow (and I'm sure the A/C worked harder as a result).

My point is, if your computer is left on all the time, put it to work. The power supply is generally going to create the most heat, second to a CRT monitor. Processor and auxiliary device heat should be negligible (except for some vid-cards).

So, if you look at it this way, the step-down transformer in the power supply is taking 120-volts AC and stepping it down to ~5VDC -- so you have some heat generated in the transfer.

[DracoFelis]

Originally Posted by Erdrick

I think we are kind of heading in the wrong direction with this thread.

I disagree. This site is about energy efficiency. And if you find that you "need" some extra heat in the winter, why not get that heat + get something else useful (even if it's just "SETI at home" or some other "common good calculations") done?

i.e. If (and only if) you are going to pay for electric heat anyway (to heat your house), than why not do it with some appliance (that you can get something else "useful" out of), vs just using something that only produces heat? And even if that "something useful" is just helping with some community computation project ("SETI at home", or something similar), you have still gotten something useful "for the community" done along with producing the heat you desire.

Of course, the above assumes that you need to heat your house, and that you were planning to use electricity to do it. If either of those assumptions are incorrect, than the conclusion is also incorrect. For example, if you don't need the heat right now (i.e. it's not winter, or you get enough heat from other sources), than running more appliances just generates more "waste heat" that you don't need. Likewise, even when you do need the heat, you may have a source of heat that is cheaper to use than electric heating (in which case it may be more "efficient" to use that other source of heat). But if you really do need the heat, and your main viable option is simple electric heating, I think it's at least worth considering getting that heat from an appliance that you also get some useful "work" out of...

NOTE:
As another poster (correctly) mentioned, during the warm months you actually get bit twice, when you run an electric appliance. i.e. You pay for the electric to run the appliance, and again for the AC to remove the heat generated by running the appliance.

But the point I was making, is that it works both ways. In the cold months, you actually get a "free bonus" of sorts, in that while you pay the electric to run your appliance, you also get very useful (useful ONLY when it is cold out) "waste heat" off that appliance. This essentially gives you two useful properties (whatever the appliance is designed to do + the "bonus" of the "waste heat") while only paying for the electric (to run the appliance) once (essentially giving you a 2-for-1 with your electric energy dollar).

[trebuchet03]

I disagree. This site is about energy efficiency. And if you find that you "need" some extra heat in the winter, why not get that heat + get something else useful (even if it's just "SETI at home" or some other "common good calculations") done?

I agree Otherwise, it would be like using an outdoor BBQ to cook food in 30 degree weather because you have a central heating system

[landspeed]

Regarding the computer issue.......

Almost all of the power that goes in is dissipated as heat!.

A little bit goes to the cooling fans. These move the air round, which heats it up. Also, the noise you hear from a computer ends up making things is the room vibrate (how your ears work). This heats the things up!.

Even if the noise didn't make heat, it is probably less than 1 watt of noise on a 300w or so computer!. I would say 99+% ends up as useable heat, which heats your room! It is the same with light bulbs - say 84% of their output is heat, 16% is light - but the majority of the light bounces around the room, ending up as heat.

Heat is the lowest 'grade' of energy, which is why it is quite strange to use electrical energy to make heat (except in NZ, where apparently 70% of electricity is from hydroelectric, and they have 'heat pumps' so you get 3000W of heat out, from maybe 1000W or less of electricity in!

[rh77]

Originally Posted by landspeed

Heat is the lowest 'grade' of energy, which is why it is quite strange to use electrical energy to make heat (except in NZ, where apparently 70% of electricity is from hydroelectric, and they have 'heat pumps' so you get 3000W of heat out, from maybe 1000W or less of electricity in!

Many of us in the 'States have Heat Pumps, which are on the higher-end of efficiency scale for the mass market. The problem is, the "Heat" part only works at 40F+ -- otherwise, the system freezes. So, it kicks-on a backup. It's not practical in colder parts of North America.

Backup or "Emergency" heat as the thermostat is quoted to call it, is generally either gas or electric. My old apartment had electric coils as backup, which was REALLY costly. My house now has a natural gas backup, which would be OK, but the darn unit that came with the place is very inefficient. So, for those rare occasions it's 40-50F and heat is required, it works great, but the other 98% of the time is burns a bunch of gas

RH77

[Gearshredder]

actually, since it has been getting colder here, the oven has been used ALOT more than the summer. basically the oven was never used at all.

One thing i don't get (a lil off topic, not subject), Why is it that you can create heat by using energy but you ALSO have to use energy when you cool. (acctually ur just using energy for moving heat). But what im saying is, why isnt there a way to capture heat and turn it into power (yes, yes, sterling engine, but you need a difference of temperature to make it run) but using solid state tech. i.e. plate that absorbs heat and use to power other things.
Or is there, but we haven't found it yet?

[skewbe]

There are passive cooling systems, i.e. a large heat sink, that do not require additional energy. It relies extensively on a difference in temperature though as do most conventional energy converters.

Imagine you were in a sealed room, the observers increase the pressure to 5 psi, and then say to you "ok, turn that extra pressure into a continuous source of energy". Where would you start?

[trebuchet03]

But what im saying is, why isnt there a way to capture heat and turn it into power (yes, yes, sterling engine, but you need a difference of temperature to make it run) but using solid state tech. i.e. plate that absorbs heat and use to power other things.
Or is there, but we haven't found it yet?

There is Use a Peltier effect plate backwards and you get a current -- this is called a thermocouple

But remember, entropy will win and defeat us all! Entropy, if you didn't know, is (in a very basic sense) a quantity of heat that can never EVER be used for useful work or recaptured. Every time you do work, entropy is created. Bugger Entropy is the reason why 100% efficiency is not possible (unless you assume reversible conditions - which are not possible in the real world)

[skewbe]

Originally Posted by trebuchet03

this is called a thermocouple

It still needs a temperature differential to work.

So is there anything special about a solar cell in this regard? What if you could make one that responded to infrared radiation, would it care if it was bathed in heat?

[Gearshredder]

blah.. ok haven't gotten to that part in science yet (still in hs)
what i have learned: Entropy = stupid