Topic: Brainstorming Mining room cooling - Need advice (Read 4130 times)

This is a small update but sorry no pics yet. I have built the sheet metal cabinet and am have to do a little more grinding and then I will be ready to add the a/c.

This will not be for everybody but I plan to hard wire everything except the a/c, the plugs for the psu's and the pcie cables to the miners.
When I need to turn miners off for maintenance they will be wired to light switches on a control box. This build will have a heavy focus on fire protection so I am avoiding plug type connections and blackened wires that tend to come with them.

Pics soon.

Most of the summer is very low humidity. But there is the odd stint where it will be over 35C and 80% humidity. That combination of heat and humidity will render any evaporative cooling useless and if I am off site at the time my miners could die very quickly.

You should simply get an evaporative cooling system.  They are relatively cheap and based on your high heat I'm assuming you have relatively low humidity.  Just get something like this and duct it into the intake and exhaust outside.  Don't recycle the air in an evaporative cooling system as the humidity will slowly climb and you'll have problems.

http://www.ebay.com/itm/ESSICK-AIR-N28W-Ducted-Evaporative-Cooler-2800-cfm-1-8-HP-/381023962944?hash=item58b6cc4740

Regards,
yan

Looks more like a "solar chimney" type setup. Bit expen$ive to build those for something as small as a bitcoin farm though, unless you're a really really BIG bitcoin farm.

giant watercooling system ?

Noiseless cooling 

If you mean storing the cold wallets as 2D barcodes, we do have a laser-marker in-house that does them. Hmmm...
But now we're way OT.

Thanks for sharing!  Very interesting indeed.   And those are some heavy duty lasers.   

You might look into goods sections.  People always seem to be buying coins or things to store cold storage print in.  You might be able to make one with one of your lasers.

Systems we build are mainly for micro-machining ceramic substrates that circuits are built on. eg. scribing/cutting to size and drilling 10's of thousands of holes in them for vias. Single biggest use is for high -power LED manufacturing where the ceramic chips are heat spreaders/connections for the actual LED die. Around 75% of all the LED's you see for lighting were born on our systems In-house we do metal cutting, welding and selective hardening. http://www.synchronlaser.com http://www.industrial-lasers.com/articles/2007/11/processing-ceramic-substrates.html

And what do these industrial lasers do?  With professional I think of all kinds of cool possible government work.

heh heh... I too up to a point have 'free power' at work. 15kW of it to be exact. Then again, I'm also a partner in our industrial laser business I set that limit to keep miner electric usage to just a very small part of our total energy usage so it is slushed into the general operating expenses Any more than that and yes I'd start reimbursing the company just to keep the accounting straight and IRS happy.

What type of job are you in? (I'm not calling you a lier) just curious.  I have never seen a job that has a bonus of power.

Since people seem to not want to let this thread die I might post some updates on my mining cabinet soon. I have gone with a all steel, non-flammable (albeit noisy) build. In part to stick it to people who claim I am stealing power, but more so that it's a more suitable and practical idea.

To the last few comments, I do have free power, but not unlimited power, and I can't just run 100 miners with a/c... I am provided free electricity as part of my salary package so within reason I can do what I want with it. But it only takes one jealous tool to potentially change that. Such is the workforce.

Depends on HOW cheap your electric is, but at a common EER (SEER or CEER) of appx. 13 you would have to spend about 26% of your miner power load on cooling if you use mechanical air conditioning (some central units are well over 20 CEER, but those tend to be expen$ive in their own right).
This cost might be "make or break" on attaining RoI on mining hardware, much less profit.
Do factor in that if you can keep your miners cool enough, you can probably clock them higher and make back a LITTLE of the "lost profits" to A/C power cost, but not likely more than 20-25% of your AC power cost.

 If evaporative cooling aka "swamp cooling" is viable in your area, THAT is a lot less power hungry and you might be able to pay for it with the increase in mining hashrate vs. no cooling.


 Personally, I hate the "tons" rating on AC units. Dunno why we're still stuck with a rating from back when actual ICE was used in cooling stuff instead of using BTU across the board.

This is correct, for every Megawatt of power consumption you are looking at about 285 tons of cooling to offset the heat generated.   or 28.5 tons for every 100 Kilowatts.  Not only do you need that much cooling, but you will need serious air movement to get that cool to where it needs to be and the hot away from where it shouldn't be.  This is why we install lots of actual HVAC and not rely on fans, also when you are talking about these massive loads, you can't cut corners here or you will damage miners, make them run slow or create a fire hazard. 

Folks.... Using conventional A/C is right out unless you have free power.
The math:
BTU/hr=Watts x 3.4129
1 Tonne=12,000 BTU/hr

So if your power load is 1kw you are pumping out 3412.9 BTU. That is how much cooling is needed just to balance out the heat from the miners! Throw in bringing the temps to below outside air temp and it gets worse... For most farms you're are talking insane amount of cooling needed.

Plug in your own load for the amount of cooling you need just to break even on the miners heat output.

 Doesn't quite match up with the observed appx. 4000 RPM on the S5 fans (I run mine with PWM disabled but RPM monitoring enabled, commonly 3960 RPM observed).

 I'm also curious which Delta fan model you're quoting specs from, the fans are definitely Delta as that flow-director design is patented.

Did you even read my post?

I am not going to keep wasting my time defending myself. I apologize for bringing up such a touchy subject and would now like to bring this thread to a close.

I have thought about the advice about a server rack type setup and think I might either go the dog kennel type box or a vertical type cabinet setup.

I thank everyone for their positive advice and apologize again for the way this thread has gone down. I wish I could explain my circumstances better because I am not "stealing" power, I just don't want to advertise that I am mining bitcoin with it in case someone tells me to stop doing it. The workforce is a bitchy place and people get jealous.

Thanks again all.

Bitcoin is not for commiting crime.

If you want to steal electricity then plan it your self, if i did that i would figure it out my self.

You are just greedy and besides not even clever to figure it by your self. good thiefs do it whit no need of secondary help.


Greedy thief i propose to the community to not help out this guy.

it's more than clear that you are stealing the electricity..

Let's keep the "free electricity" part out of the equation please people. I don't want us to get side tracked.

I only have 70A to use and when you are facing 45C plus days in a very big house that gets used up in A/C fast and I just don't people thinking I am growing pot or have my boss tell me to turn my miners off if the cost of electricity gets too high (and environmental policy is a big deal nowadays)  I have in my letter of offer that my house comes with free electricity, but MY policy is "If you have nothing to gain and everything to lose, then don't." So that means, I want to mine BTC and if someone tells me to stop, then I would have to go rent a place somewhere just to run my miners. It's just not feasible.

Now with that aside.

I have come up with a way to make a 'Dog kennel' to house an A/C and my miners.

It is a bit more complex than this but I have tried to simplify it so it doesn't appear too confusing. I apologise in advance if it is hard to get the picture.

if you are stealing electriticy just overlock your machines.


Build a big box metal.

Make it look like a Server just all the miners in a box.


And if boss ask, tell him that you are doing some research for the work.


Do not try to have some Big bitcoin stickers or anything just hide it on plain sight, maybe put it on the balconi.


either this sounds like you are just to greedy, i don't think that they will care if it's "free" so you are most likely stealing and just trying to get good ideas from the enginers  here..

Yeah, good point. Big fans and lots of air movement make cheap perfect sense.

Probably too much trouble.  Just focus on moving lots of air, that's the cheapest way.  There's a reason why you never see mega-farms doing this, they all have massive intake and exhaust fans and just stack the miners on shelves.  If you can exchange the entire airspace of the room in a few minutes it never has a chance to get too hot....

Look for something called a squirrel cage fan.  Mine does about 1000CFM and exhausts through a space that's 12X5.

Have around 3 sqm that work as a sound muffler on both the cold and hot zone of my mine, and they reduce the miners' noise to whisper-level noise.

Also, have an awning that works as a sound barrier to the upper levels of the building (my mine is on the floor level).

Have the neighbors not complained?   Normally even barely audible to neighbors I would think would be to loud for that location.

What about going to liquid immersion cooling?  I live in a hot/humid climate so I completely understand the dilemma!

I heard about these guys on a SovereignBTC podcast:

www.grcooling.com

Hi, just read the OP and part of the thread, i'm sleepy as hell and can't read it all, however, living on Venezuela with relative humidity points between 50% and 90%, i can tell you, this idea totally works.

I have a location with around 15 S5, have an outside inlet mixed with a 24k BTU a/c, two extractors doing some hard work, and have the temperatures below 60ºC on the miners (on a 30-31 ºC day).

So yeah, go for it, any advice just ask and i'll fire right away.

EDIT: Ohh, also forgot to say, this mine is on a very quiet zone, and it is barely audible to the neighbors.

Yes, that's how I did mine through winter and it worked well.

Now that I am considering a larger fan, it won't fit into the window frame :

I am kind of stuck for ideas at the moment, next to putting a fat A/C onto it like I mentioned above.

This is basically how I cool 10kw in my garage.  Which is sadly empty right now, all gear sold....

I have some really good 3000 cfm single phase fans I can use, but the more I think about it and the more complicated the design keeps getting, the more I am considering maybe throwing one of our 6kw A/C's  onto the side of the space panel box with the S7's inside it. The A/C and the heat from the miners should cancel each other out but I don't know if it will work that way and if I would need more than just equal parts heating to cooling.

That and having to make the house as insulated a possible as to not be thrown out of the house to sleep in the mining room if my family gets too hot inside.

Thank you for picking up on that. I am now going back to drawing board because of this and the right angles in the design.

It is an outside toilet attached the the side of the house. There is sufficient cover from rain etc, but if people ever come looking around, I don't want there to be anything suspicious. It is really just me being over cautious. I wouldn't get fired, just maybe told that I shouldn't do it... and I don't want to not mine BTC I would do it if I didn't have free electricity.

It is mostly very dry where I love but we do have some summer storms here.

[/quote] How are you connecting to the internet?
[/quote]

I have an etherent cable running from my switch in the mining room to my modem.


I sold off all of my S5's in anticipation for the S7. It's a bit LOL because I now have 2 S5 cooling kits sitting here to never be used. I was using the maximum amps I felt safe using and I want to be first on board with the next generation of miner as to stay on top.

I don't want to draw any more amps through my main switch because out of the 2 34A poles, one of them goes up to 40A whilst the hot water system runs after 12pm if we have all the A/C on. I don't want to tell my wife that she can't heat/cool the kids... Not a wise move

The S5 fans specs are: external dimension: 120*120*38mm Weight: 128.5g Qty Bearing: Electrical characteristics Rated voltage: DC12V Rated current: 1.8±10%A Rated input power: 21.6Watt Operating voltage: 7 - 13．8V Efficiency Rated speed (range) 4450±10%RPM Maximum air flow 186.2 CFM Characteristics Operating temperature: -10℃～+70℃ Life expectance: continuous operation 40,000Hrs

 Only NEW miners available?


 An AC unit REMOVES moisture from the air it blows out.
 Most modern window AC units have a specific "dehumidify" setting.

 There is also a tray under the condenser coils, intended to collect and direct the water to somewhere "safe" - just make sure the drain from that doesn't go back into the room.

 Mixing the output of the AC unit into the incomming air should help some with temps, but use a 30 degree or 45 degree "merge" duct design don't just blow it at a 90 degree angle as that will tend to mess up your airflow a lot more than merging it in.

 Also, try to avoid the pair of 90 degree angles your picture is showing on the OUTPUT side, that WILL reduce the airflow. In fact, you would be better off pointing the output of the S7s directly at a room air fan (common Lasko designs flow around 1700 CFM with low backpressure) that is in a cutout on the side of the room blowing out.


 The fans on the S7 are rated appx. 200 cfm, presuming they are the same fans used on most previous Antminer gear.
 More than 4 S7's WILL overload the capasity of that blower.

 Same for the S5, and probably worse for older units since they were LESS efficient than even the S5 was.

You can put one extra fan for S5.

If you use 2x the original S5 fan, the ambient temperature may be  50 degrees Celsius.

You are probably RIGHT!!!  I just looked up the specs on the S5 and see that the Operating Conditions were 0 °C to 35 °C:

S5 Specifications

Hash Rate: 1155 GH/s ±5%
Power Consumption: 590 W (at the wall)
Power Efficiency: 0.51 J/GH (at the wall)
Rated Voltage: 12V
Dimensions: 298 mm x 137 mm x 155 mm
Cooling: 1x 12038 fan
Operating Conditions: 0 °C to 35 °C
Certified By: FCC / CE
Network Connection: Ethernet

I am feeling Much better about this!!!

S7 Specifications:

Hash Rate: 4.86 TH/s ±5%
Power Consumption: 1210 W (at the wall, with AC/DC APW3, 93% efficiency, 25C ambient temp)
Power Efficiency: 0.25 J/GH (at the wall, with AC/DC APW3, 93% efficiency, 25°C ambient temp)
Rated Voltage: 12V+5%, should not be less than 12.0V
Chip quantity per unit: 162x BM1385
Dimensions: 301mm(L)*123mm(W)*155mm(H)
Cooling: 2x 12038 fan
Operating Temperature: 0 °C to 40 °C
Network Connection: Ethernet

By operating temp I assume they refer to ambient temp/input temp, not the operating temp of the chips.
Can anyone confirm this?

40C ambient is tho..

I have many concerns for keeping the S7 cool enough!!!!  I A/C my units right now and they run anywhere from 48-60 degrees Celsius while the required Operating Temperature for the S7 is 0 °C to 40 °C.  How in the world is this going to happen?  Air Volume alone cannot solve this and if you add A/C......there go your profits.

You're right! Any miner that gives you the best deal on TH/$, and can operate under those temps should be his choice I guess.
I bet the S5 are more silent as well?

No. I think the best way is used S5 . 
65 degrees Celsius is not some kind of a problem for them.  Tested with my Water Cooled S5-half years

This! S5+ is the way to go with free electricity atm, unless you have space issues?

I'm sure most of us have dreamed of hiding these at our work but be cautious in doing so.  A/C directly will contain moisture as I'm sure the nights will where you live which may damage your miners.  So this is outside?  How are you connecting to the internet?

You have not yet explained why you need the best efficiency factor miners, If your electricity is free of charge.

Is it because of greediness ?

Looks way better imho. Should help you when the heat outside is on and then you can switch it off when its not needed.

Thanks for your replies.

I think I need to clarify a bit. My employer provides me free electricity but I would rather not advertise that I am mining Bitcoin with it. So the original drawing takes into account the need for discretion by hiding the miners inside a very heavy sound deadening, insulated box which would be located inside a gutted out, outdoor toilet.

I should also add that the blower I am using is my old ducted air con blower which is rated at 24,000Lt/m or 848cf/m so there will be a load of air pulling over the miners.

I have updated my plan to incorporate some A/C into the mix. The A/C is 2550W which is 42.5% of what would be needed to cool the system alone but I thought that if I set the A/C away from the in supply of air (because I need the hot air from the back of the A/C away from air in) and used ducting to guide the cold air into the 45C air before the miners, I might be able to reduce that down to about 40C or 35C if I am lucky.

Because the volume of air going into the miners is so high, I am not sure of how much of a reduction in temp I can expect. I am aiming to create some decent negative pressure in order to "suck" a fair amount of the cold air into the mix.

While I think lots of ventilation is a good idea, I think you will still have trouble keeping the miners cool if the air entering the S7 is 45C. I don't think that an S7 will operate with only a 15C rise in temperature (i.e. from 45C to 60C) for the air moving through the machine. If it works, then I am mistaken. I think you only choice in the end will be to try and reduce the total power dissipated by each S7.

Get a bunch of industrial fans the rolling typecto redirect the air to your man exhaust

For your main exhaust chect Zorro.com or granier forget the spelling for Dayton type exhaust fans

The more cfm the better and they will run you far less in electricity use than ac.

I run a 4000 cfm reversible model 22 inches to exhaust my basement, its reversible so in the winter I flip the switch then it becomes supply.

In your case you probably need a couple of exhust fans and maybe some supply ones to pull air in

4000+ cfm will run you around $500

How about:



Pro edition:



Seriously tho, it sounds like you could benefit from evaporative cooling? I can't imagine it being worth running AC? Thinking of power consumption.

All very good points. Especially about the space for hot air as I haven't account for this. Thanks for you input everyone. I will get back to you sometime today after I have thought about it some more.

You will probably need some type of cooling or underclocking for this to work.

A lot of middle eastern countries have very cheap power, as well as parts of South America and Africa.

Where do you get cheap power with "normal" 113F days?

you really dont wanna run these miners at 45C inlet.. thats hot!

First off, fans will be running mad

second - specs says operating temp is 0-40c

thirs, im pretty sure u'll run into some temp issues with the chips - and prolly wont be good for them longterm

You might wanna add some sort of cold air to the mix when its that hot outside

you will need to under clock.  think  4000gh not 4800gh.

 the plus side it you will spend less power and be cooler.

you may be able to use 1 less psu per every 2 miners.

113f for your ambient....sheesh.  Is this in a garage?  The room/garage itself needs to be vented or box fan near your intake.  Otherwise cooling should be sufficient as long as the dead space behind the S7 fans is at least 1 1/2 ft.  Those fans need some space to output hot air.

I will have 5 Antminer S7's and they will already overheat due to the weather warming up here leading up to summer.

I have gone over a few methods of cooling, A/C, evaporative cooling etc. Evaporative cooling scares me because of the water in close proximity issue, drips getting sucked into miners as well as the odd 40C, 104F high humidity day. We get many storms here in summer and sometimes the humidity can get high for a day or two and I am concerned that there will be no cooling factor once that happens.

So this is my current scenario:

A insulated space panel box divided into 2 compartments (chambers on picture)

Outside air will get drawn in through both chambers separately as to draw cool air over the outside of the miners and the PSU's, and to draw the very hot air from the miners out and away from contact with electrical components.

My issue is that the summers get very hot here. Days over 45C, 113F are normal for periods of time, a week or more before a break in the weather.

Without knowing how well the S7 dissipates heat I have just estimated a reasonable amount of heat to be expected. If I could meet these numbers I would consider this a big success.  Obviously I would not want my miners to run above 60C, 140F but for this setup I may very well have to accept up to 70. Hopefully not.