How bad is 30C-35C water for my tec?

[charlie]

( probably more like 40C-45C) It's just an open resevoir (no radiator) I change the water every 4 hours or so...it's not my everyday computer. I have it on a lot now to download 3dmk03...on 56k...15hrs!! It's a benching rig, thus the lack of longterm cooling solution.
So I just remove 80% of the resevoir water and replace it with tap water (15C) Hope the fast temp change doesn't hurt anything too.
C

[docah]

When the temps get up that high you aren't necicarily hurting anything. I've run tec's in water that warm and never had trouble. Sudden water temp change also never caused me trouble. snag an old heater core and rig it up with another pump ... should keep water temps near ambient with some good airflow.

[KS1]

At water temp 45C, What is your CPU temp then?
I guess it was no different than using a good air cooling.

If my memory serves me right, 4800W is needed to heat up 1 Ltr (Kg) of water 1C in 1 second.

Try to extrapolate: 2400W 1C in 2 seconds. 1200W ... 4 sec. 600W ... 8 sec. 300W ... 16 sec. 150W in 32 sec. 75W... in 64 seconds. Your P4 should heat up 1 Ltr of water 1C in 1 minute.
So if you have 10 Ltr in the reservior, it should take 10 minutes to heat up 1C.

[charlie]

KS1,
It's my 80-w gpu cooler, my cpu is still on air. While benching I'll add ice, but was just curious if it was ok to have warm water when the system is just idling.
C

[KS1]

What I tried to say is that with temp on hotside of peltier going up, temp on cold side also going up accordingly. So you might end up with no better than a good air cooling without lowering water temp.

It's good that you kept on adding ice to the water and top up with new water. Or you should have a very big reservior.

[Marci]

My water runs at around 45 degrees, cpu when overclocked upto 2.5Ghz ful load temp is 15 (even after about 8 hours), idles at 5. At stock 2ghz it runs at -6ish. That's cooling 226w TEC on CPU, GPU, NB with 1250 pump and 3x120 radiator....