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Safe fan swap on Zalman ST300BLP?

Posted: Sat Jan 04, 2003 2:02 pm
by schnee
I bought this PS a while ago, and have found the 'accelerate quickly to a high speed and stay there' behavior annoying.

I want to swap fans. Which fans would anyone recommend? Would a PapstNGL be enough, or should I put in another thermally-controlled fan instead? Any specific makes/models?

Also, I was contemplating modding the PS to have more airflow. I saw an article a while back where they used one of those wire mesh letter trays you can get at an office supply store as a replacement for the stamped metal grill... I was thinking if I opened up the back ventilation slots, epoxied/screwed on that mesh instead, it would let in a lot more airflow while keeping the structural integrity of the cover a bit more intact. Opinions?

I plan on cutting out the back finger guard too, and might do the mesh trick there too, or might do the typical chrome guard. Any reason *not* to do the fine mesh? It'll have more surface area, but the wires are very small... not sure if it's the best idea for the PS.

Thanks... :)

Posted: Sat Jan 04, 2003 2:56 pm
by Gandalf
If I were you I'd play it safely and just put the PAPST in there. It will probably move more air then the standard fan and is pretty darn certainly a lot more quiet. I can't think of any reason why not to do the mesh, but I can't think of any reason why *to* do it either!

Posted: Sat Jan 04, 2003 3:44 pm
by MikeC
My experience with typical stamped fan / air grills:

1) Even with a Panaflo at 7V, there is more turbulence noise with than without. The effect is small but audible & gets more so with higher airflow. The stamped fan grill on the orig Zalman is particularly obstructive (in contrast to that on the Nexus, which is nowhere as bad) -- I'd cut it out completely. Don't use a wire grill either, unless you feel you have to for safety of kids, pets, whatever.

2) On the other side, if you might cut it up anyway, before you do it, try taking a pair of needle noise pliers and simply twist the metal strips 90 degrees so that they offer less air resistance. Because of its distance from the fan, this may be enough to reduce the noise substantially -- it will certainly improve the airflow.

BTW, your fan swap will do nothing to change the speed-up-and-stay-there behavior.

Posted: Sun Jan 05, 2003 11:22 am
by schnee
Huh, I guess my reply got eaten. Here goes again...
your fan swap will do nothing to change the speed-up-and-stay-there behavior
I was either going to use a fan with it's own thermal control (i.e. a Verax or those Papst w/thermal control on Silicon Acoustics) or just use a fixed-speed fan. My dilemma is I don't want to use a fan that's too little CFM and fry the PS prematurely; it's a great PS otherwise.
If I were you I'd play it safely and just put the PAPST in there. It will probably move more air then the standard fan and is pretty darn certainly a lot more quiet.
Is it enough CFM? A Papst NGL is 19CFM. I guess I'll have to look up the specs and see.

I have a coolermaster 110, and the air coming out of the top blowhole feels really cool, so I was considering just taking that fan and putting it in the PS, and leaving the top vent sans fan. I have access to some tools and a workspace now, so I was going to duct the CPU to the back fan hole just below the PS, making the PS the main vent for system heat. Since the CPU is the hottest thing in there, it shouldn't affect ambient too much.
I can't think of any reason why not to do the mesh, but I can't think of any reason why *to* do it either!
I'll do it because I can. :D

No, really, I've already twisted the vent fins 90 degrees to increase airflow, but it looks ghetto and doesn't look like it opened it up much. If I use some bolts and a bit of epoxy I can open up that entire back area to allow more airflow and stilll keep it more structurally sound.

Posted: Sun Jan 05, 2003 3:02 pm
by loply
I think PSUs as stock usually have like ~30cfm fans. So your average "silent" fan which shifts 27cfm will probably do, when combined with a better grill.