Computers in Boxes

I have a need to put servers in boxes and am trying to determine the heat load in the box so I can size my cooling unit.

If a computer has a 400W power supply, how much of this 400W should I take into consideration as heat?

Thanks,

We have covered this topic before

http://www.plctalk.net/qanda/showthread.php?t=23557&highlight=heat

All of it. Where else does it go?

Peter Nachtwey said:

http://www.plctalk.net/qanda/showthread.php?t=23557&highlight=heat
All of it. Where else does it go?

Click to expand...

My thinking is more along the lines of the fact that the power supply rating is listed as high as the manufacturer can make it in ideal lab conditions because a bigger number here looks better.

But, it can't be rated on the edge or else it would trip out all the time and people get mad enough when the operating system crashes let along their power supply.

So, my guess is that a computer server with a 400W power supply can't possibly use 400W continuously.

I guess the real question is how are computer server power supplies rated and how much head room do the manufacturers leave in the rating.

Does 75% sound reasonable? How about 50%?

You are asking everyone to guess at what the load on the power supply will be.

A 400 watt power supply better be able to supply 400 watts continously.