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80mm Zalman vs 80mm Panaflo L1A

Posted: Thu May 08, 2003 3:22 am
by JEN
Which shifts more air?

80mm Zalman @ 5.5v (noisy!!!)

or

80mm Panaflo @ 7v (haven't tried yet)

[edit]

I found out that the Zalman can shift 20.6 CFM @ 5.5v.

Does anyone know how much the Panaflo 80mm L1A can shift at 7v?

[/edit]

Posted: Thu May 08, 2003 6:54 am
by Ralf Hutter
Information taken from this chart on the SPCR main site claims that a 7-volted L1A puts out about 14cfm.

Posted: Thu May 08, 2003 7:30 am
by JEN
Will 14CFM be enough to cool the PSU??? Currently its beening cooled by Zalman 80mm @ 5.5V which is 20CFM.

The temp of the PSU is 40C after 1/2 HR of 100% CPU load????

Posted: Thu May 08, 2003 9:32 am
by L4177312
i have my generic 400 watt psu fan running with a 7v panaflo L1A. so far there have been no problems. i usually leave my computer on 24/7 and switched fans about 4 months ago. the only difference i notice is the air coming out of the psu is a bit warmer. i have no way of monitoring psu temps.

Posted: Thu May 08, 2003 9:42 am
by JEN
That has given me a bit more confidence! Thanks :)

Posted: Thu May 08, 2003 11:18 am
by rpc180
If you're into mathematics, which I suspect Jen, you might be with all the tinker you've been up to in the past few weeks, this thread has got some info on heat output by wattage of PSUs and CFM calculations of fans to make them stable.

http://forums.silentpcreview.com/viewtopic.php?t=4442

I've also fan modded a PSU. Its been fine 24/7 for the past month.

Posted: Thu May 08, 2003 12:12 pm
by GamingGod
Ive said in an earlier thread I had an old power supply that was 200W??? i think, and was running my old pentium 200 system. Anyways the fan died in it and I didnt replace it and it ran fine for a about 3-4 months (during this time I would run it for like 6-10 hours a day then turn if off at night.) The power supply felt warm to the touch after about 2-3 hours of having the computer on. When It died I opened it up and their was smoke residue all inside the power supply, and the pcb had scortch marks on it. Moral, if your power supply casing feels hot or even too warm to the touch then your reducing its life by quite a bit. Also a little bit of airflow is a HELL of alot better than no airflow at all.

Posted: Thu May 08, 2003 2:25 pm
by ez2remember
The better the quality of the PSU the more unlikely it will burn or cause damage to it. I have a chieftec PSU (possibly a fortron, channel well etc.) I modded with Panaflo @7v and the temps seems fine, but I would not modify my brothers PSU which has two fans and it just looks like a very cheap generic type. It makes so much noise, and the fact that it blows so much air with the two fans, I think it would be unwise for me to mod his PSU.

So really what I am saying it is a matter of judgement on the quality of the PSU. Watch out for weedy heatsinks! That certainly does not help..

Also try to help the PSU cool itself, rather than let it suck up the hot air inside the case.

Posted: Thu May 08, 2003 2:34 pm
by Riffer
My PC Power & Cooling PSU (originally a Silencer 400) has been running 24/7 for a couple of weeks with a L1A at about 6 volts. No problems or instability - rails still push out the same volts as they did before.

The better the PSU, and the less the load, the lower the CFM you need.

Posted: Fri May 09, 2003 8:13 am
by jafb2000
Try to keep Panaflo L1A at or above 7V re fan start,
or use the NMB 15dB(A) fans which are as-quiet/quieter.

The ATX 2.03 right back to original PC spec:
o PCs co-locate the case/CPU/PSU cooling to the 1 PSU fan
---- reason is misers re cost/margins & 1-field-replaceable-unit
---- plus arguably similar obsolescence & failure curves
o So PSU fans must supply cfm *beyond* their own needs
---- generally this is 35cfm for continuous full-load under 40oC ambient
---- clearly ambient will be even higher after dragged thro a case
---- and continuous load is beyond most PSU components anyway *smile*

So if you distribute load across several quieter fans external to the PSU,
then you can reduce the PSU fan speed beyond normal quiet-fan fitment.

The dB(A) figures are not accumulate, but weighted.
o You have 1x 37dB(A) fan & 1x 21dB(A) fan (typical PC PSU & L1A)
---- your gross dB(A) is now 37.10dB(A)
o You change to 2x 21dB(A) fans (L1A)
---- your gross dB(A) is now 24dB(A)
o You change to 1x 21dB(A) fan & 1x 15dB(A) fan (L1A & NMB)
---- your gross dB(A) is now 22dB(A)
o You change to 2x 15dB(A) fans (NMB)
---- your gross dB(A) is now 18dB(A)

So if a typical 400W modern PSU with once 37dB(A) and 35cfm has
a L1A fitted of 21dB(A) & 24cfm and a case fan of 21dB(A) & 24cfm,
the system airflow has gone up to 48cfm & noise level down to 24dB(A).

The reason some ATX specs suggested drawing cool air INTO the PSU
rather than exhausting it FROM the PSU, was to allow cooler air to be
brought in - so allowing quieter fans to be used and very importantly
to get away with a design which still used just the PSU fan in most cases.
You could make it work with P3/P4, but AMD aren't suited to this idea.
--
Dorothy Bradbury
www.stores.ebay.co.uk/panaflofan
Panaflo L1A in stock at 5.89ukp
NMB 15dB(A) & 18cfm in stock at 4.99ukp; 60, 92mm & 120mm fans in stock