Quote from: Chris_Sabian on October 30, 2014, 06:00:32 PM

Is there anyway to replace the fans with a quieter one? Do you happen to know the CFM of the fan used?

In reply to your first question, my answer would be "Sure, but you'd better make sure it's a damned good one." I don't know the CFM/Static Pressure info on these (I think the labels were removed -- kind of like filing the serial number off a handgun, lol) but I think if you go to Dogie's review of the ASICMiner Tubes, he has some info on the fan THEY use -- and I bet it's similar.

In that same Tube thread -- or it might be the main, ASICMiner/Friedcat announcement thread -- look for a post by phillipma1957. He went into great detail discussing some mods he'd made to the tube which worked well (and should work here, AFAIK). IIRC, he had quite a bit of luck replacing the super mega hyper loud one with a pair of slightly less super mega hyper loud fans. So that's an option, I suppose.

Personally, I found the noise *really* annoying not due to the volume but the *pitch* of the fans. They just have a loud, high-pitched ... well, literally the exact same sound as a hair dryer (there's a reason people keep using that comparison). Unlike the other fans which just all kind of fade into the background as a low-pitched "hum" they are absurdly loud and cut through walls and brain-tissue alike. lol I think the primary issue (Someone knowledgeable please correct me if I'm wrong) is that even though they're 3-pin fans, they're being run flat-out (100%). Seemingly no "throttling" like you have with Bitmain fans, for example. And almost any fan if you run it at 100% is going to be obnoxious.

I'm not sure if that's a mistake, or a design flaw, or if ASICMiner was just lazy...or if they did careful math and concluded that they needed exactly 100% of the fan 100% of the time to cool the chips (although that last one seems a bit unlikely). Others have hooked up fan controllers (in between the prisma and the fan). And if you felt like "60% of the fan was sufficient" (and you thought that was going to be the case 24/7) you could always just put a resistor in-line with the ... um... again, let me defer to other websites and/or people who can tell you exactly what kind of resistor and between which wires you want to put it. But the point is, you can *usually* slow fans down...either crudely (with the resistor method, though that might not work with PWM fans) or with a fan controller, or ideally by doing *something* with the blue wire to throttle the fans appropriately.

Oops. Sorry, I'm a bit longwinded -- now that I re-read your questions, apparently the normal human reply would have been:

1. Yes.
2. No, I don't know the CFM off-hand, but see Dogie's thread because it's not JUST CFM, but also static pressure you'll want to match.

PS, I should point out that I have an exhaust duct sucking hot air from the back of my shelf/rack/whatever and blowing some/most of it out the window. (Doing my part to destroy the planet...because I'm a complete dick, I guess, but that's beside the point.) Anyway, I had the Prismas sitting on a different shelf when i was first messing with them -- and the noise was terrible, I could hear it on the other side of my apartment, with two closed doors in-between! However, yesterday I finally made some room on the rack/shelf/thingy and moved all three Prismaux in there...and since it's partially enclosed (to funnel the hot air out the back vent/duct) the noise just magically vanished overnight.

Okay, it didn't *vanish* but I can sit here in the living room without clawing at my face and begging to die like previous days. So if you can enclose/muffle the units just a little bit, that helps a *lot*. I wouldn't recommend doing that unless you have a duct or fan evacuating that heat, of course--otherwise you'd be creating your own little Bitcoin Greenhouse, which IIRC is *not* a Best Practice if you want things to function longer than a few days.

Hope that helps and if you try something new, be sure to share with the group... I can still just *barely* hear those obnoxious fans (nothing like it was before, but the AC kicked off just now so I can barely make them out) and the more solutions the better, because I think more than a few people are going to be having to choose between "Mining" or "Divorce" if they can't get these bastards to run a bit quieter.