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I have made a few posting discussion cooling of mining rigs and have gotten many good responses from you guys. The progress I have made so far would not have been possible without the advice. I have made some great progress but am still fighting with temps.

With an intake air temp of 38C or 100F I am not able to keep card temps around 70C as I am aiming for. Should I allow temps to go higher? Are those box fans not able to push enough air through the cards? Would I be better with the small high speed PC type fans?


https://i.imgur.com/aYXDz23.jpg
https://i.imgur.com/tXQxcmf.jpg
https://i.imgur.com/Cy1RrTX.png

With all those rigs your going to need to pull out the hot air using a squirrel cage fan so that cooler intake air can replace it. Otherwise your just circulating the hot air in the room. It's also more efficient to pull hot air out than push cool air in.

When I say intake air I am talking about the air it is pulling from outside. I cant get any cooler air than what ambient is outside without AC. So I either need to figure out how to pass enough 100F air over them to cool them or start undervolting them to lower the heatload.

The temperature in the room is able to maintain whatever the outside temp is leading me to believe maybe not enough air is passing over the GPU's.

I use my basement as a heat sink. I pull air out of the room with all my rigs. The air travels through the rest of the basement and cools and then exhausts through the rig room.

The rigs were initially in the basement but there is no good way for me to exhaust in the basement. It was impossible to control the heat down there.

What electrical modifications you have made to be able to run all those rigs?

So far I have added 4 20A breakers and run 2 rigs per 20A breaker

I'm also curious as to what mods to electric you have made as well as where did you get that shelving unit - it's nice and looks EXTREMELY sturdy!

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The power electrical modifications are mentioned above. The shelf is just a cheap shelving unit from home depot.

Thanks for the info! Did you add the breakers yourself?

As for heat w/100 ambient you're kind of in a hard place - I would say swamp cooler but humidity and rigs don't mix well - A/C expensive but might be last resort needed.

Yes I added my own breakers, I am an EE so it doesnt bother me any. It does seem like 100F would be too much and difficult but i know there are others that do it.

http://www.homedepot.com/p/Square-D-QO-20-Amp-Single-Pole-Circuit-Breaker-QO120CP/100028706

Something like this is what you added? Did you add the breaker to your box directly?

Yes though I would not recommend messing with it without doing your homework.

As long as your wires are the correct guage to handle the new breaker you can add it, but don't just go popping in a higher rated breaker on a lower rated wire or you're going to have a fire Mister305. OP said he's an EE I'm sure he did it all correct.

I'm definitely going to follow this heat is an issue for me too but I'm only running 1 rig in my garage until an electrician comes out and I find out if I can run a sub or if I can upgrade to a 200A panel.

how close to the wall is your fans?

What other ventilation is there in the room?  Are you pulling air from the outside?  Are you exhausting air from the room into an attic or outside?

The biggest thing you need to do is remove the hot air with exhaust in order to allow fresh air to come in.  During this cycle, you need to position your rigs so that the fresh air is forced to go through your rigs in order to exhaust.  This may require setting up tarps or other barriers to keep the fresh air and exhaust air from mixing.  This increases the efficiency of the system, even with higher intake temps.  An additional step would be to position your intake vents in an area with little to no direct sunlight, which should help cool the inlet air.

the top rig should move to the bottom empty shelf.

the air is cooler and the rig will pull in cooler air.

cost 0 dollar

next get a roll of this from amazon

https://www.amazon.com/Car-Insulation-Deadener-Automotive-Lightweight/dp/B016QUSBRQ/ref=sr_1_9?ie=UTF8&qid=1496086347&sr=8-9&keywords=carinsulation.com

now the top shelf is empty since you moved the top rig to the bottom.  so drape the insulation from the  fan end go behind the rack where the white wall is cover the side of the fan on the wall pull it over the empty top shelf. over the top of the fans. and down the side of the fans.


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now I can tell you  you have to pull the air out of the room

below will feed air into the rig and work well
https://i.imgur.com/xFyGyMF.png

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Is there an exterior wall that you could put an exhaust fan in? Something like this would do wonders for sucking that hot air out.  You can get them in smaller sizes too, just with lower CFM of course.

https://www.amazon.com/dp/B00CMZZ0E2?tag=amz-mkt-chr-us-20&ascsubtag=1ba00-01000-org00-def00-other-nomod-us000-pcomp-feature-scomp-wm-4

I had actually thought about the wind tunnel thing, there is a sheet of cardboard over that side now. I cant tell if it has helped much or not.

Hello,

I have a somewhat similar setup in my 2 car garage as well.  I have 46 x 400/500 GPUS all mining.  I also have a set of those exact fans behind my rigs.  I keep both garage doors opened about 4 - 5" and have a couple box fans trying to pull some cooler air in, and not enough clearance for someone to crawl in.  I have considered buying a couple carpet drying fans to see if they help pull cooler air in, but I haven't done that yet.  I don't have the same issues that you do with the heat being 100 deg F (I'm closer to mid 80 - mid 90)

A couple of additional thoughts:
   - I would rotate the PSUs 90 deg so they are more flat.  This may help with the air flow
   - I would push the rigs back so that the GPUs are closer to the fans.  On my setup, I created alternating shelves and have the PSU/MB on one shelf and the GPUs on another shelf.  I used 2 sets of the inexpensive $40 Home Depot shelving, but cut the vertical tubes in half.  It created a pretty nice, dense setup and because the posts are 1/2 length, it's really rigid too.  On your setup, rotating everything 90 degrees and having the fans behind the GPUs and nor passing through the PSU/MBs may field similar results?
   - I would also look at how the fans line up with each rig.  The middle of the fan behind the plastic disk moves less air then the outsides.  From top to bottom, I am thinking rigs 2 & 4 may be having additional issue for this reason?

Hope this helps,
Erasmus (was MashRinx)

Good idea in the PSU's I could get more air past them to the cards behind them by doing this.

Also a good call on the shelves, it may not be a bad idea to look at putting the OTHER stuff on a shelf below allowing airflow straight to the cards

Oddly enough rigs 2 and 4 run the coolest of the whole bunch. I could move the rigs back or a also considered using the fans in a pull configuration as opposed to a push

Well I bought a 12" inline exhaust fan today, plan to create duct on the exhaust side of the GPU's to suck that heat right outside. Will see how much of a difference that makes. The fan is able to move around 1000CFM

https://www.amazon.com/gp/product/B007ZU69DU/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1