producing too much heat and noise

OK, I'll nitpick. I'm not saying that the vast majority of power consumed is not converted to heat, but I will contend that it is not exactly 100%. How do we apply the law of conservation of energy if exactly 100% is converted to heat?

If (100% of power) - (power converted to heat) = 0

Then where does the power come from to do work (not disorganized heat)? How about the power to create light (LEDs), sound (from fans, HD, speakers), other mechanical (movement of fan blades, HD platters, CD trays)?

So this would mean:
(100% of power) - (power converted to heat, 100%) - (power converted to other) = a negative number.

You have gotten more energy out of the system than you put in. I'd love to own the patent to that machine!!!

These ''other forms'' may eventually be converted to heat, but well after they leave the computer case. (As an example, photons emitted from LED's may heat an object outside the computer system.)

creates the heat. The sound made by the fan blades only occurs because the electrically enrgy was all used spinning the fan. Do you think that LED's don't get warm??? The movement of charge in every bit of a semiconductor ends up as heat.

Something such as a Radio Transmitter does in fact radiate some power at terribly low efficiency, thus, in that case not 100%.

Not Volt-Amps. For the situation of a power factor less than 1, when the voltage wave is positive while the current wave is negative, or vice versa, the power is being sent back to the power grid and not consumed. Your wattmeter only measures the + times + or - times - component, thus the power companies are very happy when you buy power supplies with power factor correction. LOL It doesn't make your power supply any better, but the power companies like it. LOL

Power and energy are interchangable when you account for time. Power = Energy/time. Just multiply by time, right?

If there is energy that is converted to do some work (linear work, rotational work), and there is energy that is converted into photons, how can all the energy used by the computer be converted to heat inside the computer?

Work and electromagnetic radiation are not heat. The energy for those has to come from somewhere.

Maybe I am thinking about this the wrong way. Makes sense to me, though.

Not to turn this into a physics discussion, but you're overthinking this matter.

Assuming the PSU is 65% efficient, then you've got an automatic 35% being "lost" and making up the heat generated by the PSU. The remaining 65% is converted to DC electricity and sent to various components where it will also eventually become heat.

Every last mW of energy from the PSU will eventually be turned to heat. Maybe not at the PSU itself, but somewhere along the line, it will all be accounted for.

Energy is converted to work. Work is not heat.
Energy is converted to light. Light is not heat.

So "Exactly 100%" of power can't be converted to heat.


I am thinking that the statement should be something like:

A great deal of power...
The vast majority of power...
etc., is converted to heat.

But not "Exactly 100%" of power is converted to heat.

Work is a force applied over a distance. Most of what electronics do, doesn't fit the strict definition of work.

But again, you're making this far more complex than it needs be. The final stage of ANY type of energy (that we're aware of at least) is heat. Your argument is about the number of stages that energy must go through to reach the state of heat, Ray's statement makes no mention of the number of stages, so it would be folly to read into that that it is all converted directly to heat.

With that, seeing is how we've strayed quite a ways from the subject, and are quibbling over inconsequential details for the sake of the previous discussion, I recommend we all just leave this discussion be and move on to other things. Otherwise, you and Ray can continue the debate in a more private forum, such as email.

As I stated in my original post, I realized that some will see it as nitpicking, but to me, it is an important point to be made when an absolute statement like ''exactly 100%'' is used.

''Most of what electronics do, doesn't fit the strict definition of work.'' You used the word ''most,'' which I agree with, and you didn't say ''exactly 100%,'' which would be terribly worong. That work which I stated does indeed fit the strict definition of work. That is why it saves energy to power down your HD when computer is not being used. It doesn't just save heat energy, it saves the work energy of moving the platters. Work energy can subsequently be converted to heat, but it is not necessarily done inside the ccomputer system where the heat matters.

A good example is the sound and light produeced. Sound waves and light can travel very far before being completely absorbed and subsequently converted to heat. What doees this far away heat have to do with heating computers?

My understanding has always been that the power is eventually converted to heat, but the amount that is eventually converted to heat inside the computer system is definitely not ''exactly 100%.'' If it were, then we never would hear any sound or see any light from any computer.

I think we are saying the same thing, but we are using different definitions of theremodynamic systems and surroundings. The thermo. system I had in mind is more limited--just the computer box.

Apologies for beating this to death.

I am not debating the intent of the original statement about 100% of the energy used by the computer getting converted to heat. I will say that to be very nitpicking - and another poster mentioned this maybe in a different way - but, even the work done to a fan in the PC case for example is not heat. The fan moving thru the air and causing friction in the air and parts moving will eventually become heat.

If some noise is given off, the vibrations with heat the air (a very small amount) and the wall too. The photons as light emitted could leave the PC and hit the wall and heat the wall in the room. Maybe a few photons escape out the window and some of the sound makes it outside the room. That very small amount I guess you could argue is turned to heat outside of the room. But still it will all go to heat at it's final stage. And to answer your other question, heat is simply atoms moving. The hotter, the faster.

Intel Pentium 4 3.0G-E (800Mhz FSB) Prescott
Asus P4P800-E Deluxe Motherboard
Seagate 80Gb 7200RPM SATA-150 8Mb cache
Geil 1gb DDR4000 Ram 2x512mb (HeatSpreader)
MSI 256MB FX5500-TD Video Card

running on windows xp

power consuming system, but still fairly high. The fan noise is likely because, as others have said, due to needing to clean the dust out of the interior fans etc [or a fan going bad]. The fan speed is automatically adjusted to run faster if the interior temperature of the CPU rises.

Keep in mind though, that even if the interior temperature has risen, the system has not created any more heat, just higher temoeratures in some interior locations/hotter components becaus the heat isn't being removed fast enough.

The system probably consumes around 400 to 425 watts.

Realize that a simple room plug in heater running from a normal 120 Volt outlet [15 amp fuse] at maximum heat setting probably puts out 1500 Watts.

Thus your computer is a room heater that is simply set to a lower heat setting [about one-third of the room heater.

Your only real issue is to improve the airflow through your system to reduce fan noise. The heat situation, however, will not go away.

Your room must be small or very well insulated.

thats the thing the room isnt small
its like 3.5m x 3.5m (12 feet x 12 feet)
and ive had the noise and heat problem pretty much since ive got the system

You have received a lot of good info on heat and fans from the other posters in this thread. I'll just add a litte.

Some cases just have noisy fans.
Some have too many fans.
Some cases are quieter than others.
Some PSU's are quieter.
Some CPU's heatsinks have little screaming fans (yuck).

Many builders have had success in using fewer large fans to cool computer components. In general, a 120mm fan moving at the same speed (rpm) as an 80mm fan will move more air (higher cfm) and usually do it with less noise (lower db). You can learn these qualities about a particular fan model before you purchase it.

I have seen some computers with a bunch of 80mm fans, which makes it outrageously loud. A good quieter solution for your system could be accomplished with just 3 fans. It is possible to cool your components in a good mid-tower case with one 120mm fan for rear exhaust, a quieter PSU with one 120mm fan, and a large fan on the CPU (whatever fits (90-120mm).

There is much more info on this and other noise solutions on the Web.
Google: QUIET COMPUTERS

so what, maybe get a better case will help my cause.
my current case is nothing flash

I'd look into your fans first. Clean them. Listen (with the case opened) to hear which are making the most noise. You might even discover that you have a malfunctioning fan. Replace the culprits.

How many case fans do you have and what size (diameter ususlly measured mm or cm)?

What's the max size fan your case can fit? If you can provide the case model name, then the answer is easy.

TIPS: 120mm is the diameter of a CD-ROM disc.

What heatsink/fan is on your CPU?