Water cooling SPLIT FROM Re: Eligius

[TodaysGandalf]

Hey everybody!  Seems like things have settled down for the pool.

As irritating as all the little speed bumps of "Failsafe Mode", unreliable stats, DDOS attacks and the lack of NMC payouts have been; there is a much bigger bogeyman on the horizon... summer.  It is now hitting 70 degrees here in Minnesota.  70 in Minnesota!  That means, for most of the audience, unless you've made special arrangements (or you live someplace with almost free cooling and power, like Iceland), your profits from mining are, or will soon be, "tempered" by air conditioning costs.

I know, I will probably be pounced on by people saying "You posted that in the wrong forum topic", but I think this forum topic is read by enough people to at least get an indication of the level of interest in my idea.

Being an engineer, I decided I wasn't going to take summer's impact on my mining (and my wallet) "laying down."  So, I started thinking about ways to I dispose of the heat generated by my miners without dumping it into the air inside the house, or, more accurately, paying for more electricity to pump it into the air outside.

My friends are telling me things like "immerse your miners in oil" and crap like that, but, in the end, the heat still has to be sent outside of the house somehow.  The only solution I could devise is the same one the nuclear power generators use... heat up water and dump it outside.  Unfortunately, I do not have access to a river to use water from there, not to mention what the DNR would say, so tap water is what I will use.

I know, I know.  I can hear people gasping and saying something like "Waste water!  Isn't that, like, a Cardinal Sin or something!  In California that's a flogging offense!"  True, it is wasteful; but no more wasteful then the additional carbon footprint resulting from generating the electricity to do the mining and the extra electricity it takes to remove the resulting heat from the house (or data center, ahem Ghash).  Since I don't have the finances (or the land-use variance from the condo association) to create a deep-earth-based heat-pump cooling system, wasting tap water will have to do.  In Minnesota (sorry California), water is cheaper than electricity.  Also, I'm using a 340 gallon tank of water for thermal mass, but it wouldn't have to be that large.  So, the water wasted will be slowed to a trickle in and out of it to keep the water in the tank reasonably cool.

I've done considerable research, design and prototyping, and I've come up with a viable, cost effective water cooling solution.  I've found a source that manufactures waterblocks (that don't cost a right arm) sized to fit the Antminer S1 and ASICMiner Cube, since those are the miner models I own.  I couldn't sell the cubes now that summer is coming and the Bitcoin difficulty level is out near Pluto.  The waterblocks from that same source could also be tailored to fit the other larger miners as well.

If you've read this far you must find the idea intriguing or angering.

If you find it angering, please forget you read this.

Those of you that find it intriguing, I'm looking for some feedback.

I'm thinking of offering pre-designed complete water cooling products for the larger miner hardware.  Do you see a market?

I'll create a forum topic as appropriate as the implementation nears completion and I can offer some pictures.

Thoughts?  Feedback?  Interest?  Please PM me.

[1715381691]

1715381691

[AbiTxGroup]

I think you are worrying to much about the heat.  You realize that 70F is only 21C.  Here in Texas last summer I was running a bunch of GPU miners.  They run at 70C which is 158F.  The hot Texas summer day of 115F (46.1) air was enough to cool the miners down.

This year I have a bunch of S1 Antminers and we have already had high 95+F days so far.  The S1's did fine with just some outside air being blown into the room with the miners and the hot air leaving the room.  In the main mining room with the building closed up, the room was at 115F (46.1C).  I opened the doors and windows to get the air circulating and the room dropped to near outside ambient temp in no time.  

I don't see that much of a problem here when it gets to summer temps at 115F (46.1C), just keep the air moving with outside air and have several replacement miner fans on hand as fans fail when you don't want them to.  If you cannot create the air exchange from outside with the inside, then you need to rethink you setup.  You need air flow from outside to inside to outside.

This reminds me of the late 80's and early 90's when small and medium businesses where having their computers networked.  I could not count how many times I was called in to troubleshoot network problems only to find a server or router closet.  That was the dumbest idea I seen done over and over by inexperienced so called "tech's".  Putting electronic equipment that produces heat into a closed off, normally not air cooled, closet. You have to have air exchanging to keep the equipment running.  Same with the miners.

[tranzsport]

I think you are worrying to much about the heat.  You realize that 70F is only 21C.  Here in Texas last summer I was running a bunch of GPU miners.  They run at 70C which is 158F.  The hot Texas summer day of 115F (46.1) air was enough to cool the miners down.

This year I have a bunch of S1 Antminers and we have already had high 95+F days so far.  The S1's did fine with just some outside air being blown into the room with the miners and the hot air leaving the room.  In the main mining room with the building closed up, the room was at 115F (46.1C).  I opened the doors and windows to get the air circulating and the room dropped to near outside ambient temp in no time.  

I don't see that much of a problem here when it gets to summer temps at 115F (46.1C), just keep the air moving with outside air and have several replacement miner fans on hand as fans fail when you don't want them to.  If you cannot create the air exchange from outside with the inside, then you need to rethink you setup.  You need air flow from outside to inside to outside.

This reminds me of the late 80's and early 90's when small and medium businesses where having their computers networked.  I could not count how many times I was called in to troubleshoot network problems only to find a server or router closet.  That was the dumbest idea I seen done over and over by inexperienced so called "tech's".  Putting electronic equipment that produces heat into a closed off, normally not air cooled, closet. You have to have air exchanging to keep the equipment running.  Same with the miners.

+1

I have 21 S1 Antminers sitting in a plastic bench/rack in a small room .. I just installed 4 of these fans http://www.walmart.com/ip/Powermax-High-Velocity-Fan-20/17134033 from walmart
two in the front and two the rear to create a massive tunnel effect and it works like a charm. They cool down the miners down to outside temp in no time given the room door iand windows are open.
Today it was 90F outside and my miners read 38C

[TodaysGandalf]

I think you are worrying to much about the heat.  You realize that 70F is only 21C.  Here in Texas last summer I was running a bunch of GPU miners.  They run at 70C which is 158F.  The hot Texas summer day of 115F (46.1) air was enough to cool the miners down.

This year I have a bunch of S1 Antminers and we have already had high 95+F days so far.  The S1's did fine with just some outside air being blown into the room with the miners and the hot air leaving the room.  In the main mining room with the building closed up, the room was at 115F (46.1C).  I opened the doors and windows to get the air circulating and the room dropped to near outside ambient temp in no time.  

I don't see that much of a problem here when it gets to summer temps at 115F (46.1C), just keep the air moving with outside air and have several replacement miner fans on hand as fans fail when you don't want them to.  If you cannot create the air exchange from outside with the inside, then you need to rethink you setup.  You need air flow from outside to inside to outside.

This reminds me of the late 80's and early 90's when small and medium businesses where having their computers networked.  I could not count how many times I was called in to troubleshoot network problems only to find a server or router closet.  That was the dumbest idea I seen done over and over by inexperienced so called "tech's".  Putting electronic equipment that produces heat into a closed off, normally not air cooled, closet. You have to have air exchanging to keep the equipment running.  Same with the miners.

Yes, 70F outside is far from a crisis for the miners, it's just a harbinger of what is to come.  Perhaps you like your house at 85 to 95F; I, and especially my wife, do not.  We are Minnesotans.  We are used to temps of 10F outside, not 100F.

I keep my miners in the garage.  The garage doesn't have any windows.  I prefer not to advertise the fact that I have lots of nice electronics in there.  With the door closed and it's upwards of 70F outside, my miners (Ten S1s and six Cubes) bring the garage to 85F in under a half hour and the miners' temp sensors quickly head north of 75C.  The cubes drop 10GH apiece at the high clock rate.  They don't have temp gauges that I can see via the web interface.  When the Cubes go over whatever is their maximum temp, they drop down to the low clock rate.  The error rate of the S1s increases from under 100 per hour to several ten thousand per hour.  The number of invalid/discarded/rejected shares jumps from tens to tens of thousands.  Then the chips on all the miners randomly start getting flagged with X's a few at a time.  So no, the miners are not happy at 50C or higher ambient temps.  When it hits 80F and 90F outside, forget it, the garage turns into an oven.

Secondly, I doubt your miners are doing "just fine."  I'd be interested what temp the S1s are reporting on their miner status web page.  If the room is already 50+C, I'd bet they are running at 70 to 80+C.  At those temps you can look forward to cumulatively degrading hashing rates and/or chips failing.  Me, being an electrical design engineer, I want my miners to perform as best they can for as long as they can.  Right now, when they are operating below 50C, they get hashing rates around 220GH consistently, with no permanent X's on any chips.

Lastly, again, being an electronics design engineer, I tend to be a little anal about keeping my electronics running in the "low to mid" temp range stated on a devices data sheet, if I can, and stay far away from the "absolute maximum" temp range.

So, all those who like to bake their miners and shorten their useful life, you can line up with AbiTxGroup.

I'll keep it cool thank you.

[baddw]

I think you are worrying to much about the heat.  You realize that 70F is only 21C.  Here in Texas last summer I was running a bunch of GPU miners.  They run at 70C which is 158F.  The hot Texas summer day of 115F (46.1) air was enough to cool the miners down.

This year I have a bunch of S1 Antminers and we have already had high 95+F days so far.  The S1's did fine with just some outside air being blown into the room with the miners and the hot air leaving the room.  In the main mining room with the building closed up, the room was at 115F (46.1C).  I opened the doors and windows to get the air circulating and the room dropped to near outside ambient temp in no time.  

I don't see that much of a problem here when it gets to summer temps at 115F (46.1C), just keep the air moving with outside air and have several replacement miner fans on hand as fans fail when you don't want them to.  If you cannot create the air exchange from outside with the inside, then you need to rethink you setup.  You need air flow from outside to inside to outside.

This reminds me of the late 80's and early 90's when small and medium businesses where having their computers networked.  I could not count how many times I was called in to troubleshoot network problems only to find a server or router closet.  That was the dumbest idea I seen done over and over by inexperienced so called "tech's".  Putting electronic equipment that produces heat into a closed off, normally not air cooled, closet. You have to have air exchanging to keep the equipment running.  Same with the miners.

Yes, 70F outside is far from a crisis for the miners, it's just a harbinger of what is to come.  Perhaps you like your house at 85 to 95F; I, and especially my wife, do not.  We are Minnesotans.  We are used to temps of 10F outside, not 100F.

I keep my miners in the garage.  The garage doesn't have any windows.  I prefer not to advertise the fact that I have lots of nice electronics in there.  With the door closed and it's upwards of 70F outside, my miners (Ten S1s and six Cubes) bring the garage to 85F in under a half hour and the miners' temp sensors quickly head north of 75C.  The cubes drop 10GH apiece at the high clock rate.  They don't have temp gauges that I can see via the web interface.  When the Cubes go over whatever is their maximum temp, they drop down to the low clock rate.  The error rate of the S1s increases from under 100 per hour to several ten thousand per hour.  The number of invalid/discarded/rejected shares jumps from tens to tens of thousands.  Then the chips on all the miners randomly start getting flagged with X's a few at a time.  So no, the miners are not happy at 50C or higher ambient temps.  When it hits 80F and 90F outside, forget it, the garage turns into an oven.

Secondly, I doubt your miners are doing "just fine."  I'd be interested what temp the S1s are reporting on their miner status web page.  If the room is already 50+C, I'd bet they are running at 70 to 80+C.  At those temps you can look forward to cumulatively degrading hashing rates and/or chips failing.  Me, being an electrical design engineer, I want my miners to perform as best they can for as long as they can.  Right now, when they are operating below 50C, they get hashing rates around 220GH consistently, with no permanent X's on any chips.

Lastly, again, being an electronics design engineer, I tend to be a little anal about keeping my electronics running in the "low to mid" temp range stated on a devices data sheet, if I can, and stay far away from the "absolute maximum" temp range.

So, all those who like to bake their miners and shorten their useful life, you can line up with AbiTxGroup.

I'll keep it cool thank you.

It's also about airflow, not just temps.  In many ways, 20k CFM of -10 degree air = 10k CFM of -20 degree air.  Cut a hole and mount an exhaust fan high up in your garage.  Cut another one and mount an intake fan low on the far side (north/shaded side is best for intake).  With the right capacity fans, you can make it so that your garage never rises more than a couple degrees above the exterior temps.  This will be much cheaper and less trouble-prone than your proposed water-cooling design.

Speaking of which, the "thermal mass" of a 340Gal tank isn't going to do jack.  (Although of course it's a good idea to have a reservoir in case something goes wrong with your plumbing.)  If you've got cool water coming in from your tap, running through your system, and then running down the drain, the system is going to use so many GPM of cool water regardless of whether it's initially stored in a tank.

The stagnant air in your garage hits 85F in half an hour, with exterior temps of 70F.  Your miners are putting X BTU's into the garage at a constant rate.  The rate of heat exchange is related to the temperature differential.  At 15F differential, there is enough heat exchange going on between the garage and the exterior to maintain equilibrium.

This is how all cooling systems work.  All you're doing is moving heat from one place to another via a medium.  The "thermal mass" of the medium of heat exchange doesn't matter.  What matters is the overall heat exchange rate. 

The amount of water stored in my car's cooling system doesn't make a difference.  Once it hits the minimum level required to fill the radiator, engine block, and all connecting lines, having an extra gallon or two in there won't make a difference.  (It will take a bit longer to reach equilibrium temps from a cold start, but other than that, no difference.)  What WILL make a difference is if my water pump goes out and the flow of water through the engine stops.  In that case, it won't matter how many gallons of coolant I have in my reservoir; the engine will overheat.  Same with the radiator being blocked.  If air is not flowing over the radiator at a sufficient rate, the engine will overheat.  (Dependent upon the air temps, of course -- I know you northerners sometimes block your radiators with cardboard in the winter when the temps hit the negatives.  In this case, there is sufficient heat exchange even without any airflow, due to extreme temperature differential.)

I apologize for the continued derailment of the thread.

[AbiTxGroup]

I think you are worrying to much about the heat.  You realize that 70F is only 21C.  Here in Texas last summer I was running a bunch of GPU miners.  They run at 70C which is 158F.  The hot Texas summer day of 115F (46.1) air was enough to cool the miners down.

This year I have a bunch of S1 Antminers and we have already had high 95+F days so far.  The S1's did fine with just some outside air being blown into the room with the miners and the hot air leaving the room.  In the main mining room with the building closed up, the room was at 115F (46.1C).  I opened the doors and windows to get the air circulating and the room dropped to near outside ambient temp in no time.  

I don't see that much of a problem here when it gets to summer temps at 115F (46.1C), just keep the air moving with outside air and have several replacement miner fans on hand as fans fail when you don't want them to.  If you cannot create the air exchange from outside with the inside, then you need to rethink you setup.  You need air flow from outside to inside to outside.

This reminds me of the late 80's and early 90's when small and medium businesses where having their computers networked.  I could not count how many times I was called in to troubleshoot network problems only to find a server or router closet.  That was the dumbest idea I seen done over and over by inexperienced so called "tech's".  Putting electronic equipment that produces heat into a closed off, normally not air cooled, closet. You have to have air exchanging to keep the equipment running.  Same with the miners.

Yes, 70F outside is far from a crisis for the miners, it's just a harbinger of what is to come.  Perhaps you like your house at 85 to 95F; I, and especially my wife, do not.  We are Minnesotans.  We are used to temps of 10F outside, not 100F.

I keep my miners in the garage.  The garage doesn't have any windows.  I prefer not to advertise the fact that I have lots of nice electronics in there.  With the door closed and it's upwards of 70F outside, my miners (Ten S1s and six Cubes) bring the garage to 85F in under a half hour and the miners' temp sensors quickly head north of 75C.  The cubes drop 10GH apiece at the high clock rate.  They don't have temp gauges that I can see via the web interface.  When the Cubes go over whatever is their maximum temp, they drop down to the low clock rate.  The error rate of the S1s increases from under 100 per hour to several ten thousand per hour.  The number of invalid/discarded/rejected shares jumps from tens to tens of thousands.  Then the chips on all the miners randomly start getting flagged with X's a few at a time.  So no, the miners are not happy at 50C or higher ambient temps.  When it hits 80F and 90F outside, forget it, the garage turns into an oven.

Secondly, I doubt your miners are doing "just fine."  I'd be interested what temp the S1s are reporting on their miner status web page.  If the room is already 50+C, I'd bet they are running at 70 to 80+C.  At those temps you can look forward to cumulatively degrading hashing rates and/or chips failing.  Me, being an electrical design engineer, I want my miners to perform as best they can for as long as they can.  Right now, when they are operating below 50C, they get hashing rates around 220GH consistently, with no permanent X's on any chips.

Lastly, again, being an electronics design engineer, I tend to be a little anal about keeping my electronics running in the "low to mid" temp range stated on a devices data sheet, if I can, and stay far away from the "absolute maximum" temp range.

So, all those who like to bake their miners and shorten their useful life, you can line up with AbiTxGroup.

I'll keep it cool thank you.

WOW!!!

First off, its back to what I first posted, here I will quote it again:

If you cannot create the air exchange from outside with the inside, then you need to rethink you setup.

That should cover it.

As far as my equipment being to hot, not even close.  You need air flow.  Our hottest days here in the continental US will still cool down our mining equipment as long as you have air flow and exchanging the air from the outside.  If you cannot do that, then it is your setup, meaning your garage with no windows or the server/router closet (now a closed garage).  

As for you being an electronics design engineer, sure, whatever you want to be.  It's the internet after all.

You can spend all the money you want to keep your electronics running in whatever low to mid temp you want, but we are mining here.  Use standard air flow to cool them.  Hell, these miners are not going to be running for years and years, the difficulty will prevent that.  As soon as the cost of running them is more than they will mine, its time to unplug them. In the mean time, my miners are running smoothly and within "manufacturers specs".

[TodaysGandalf]

I think you are worrying to much about the heat.  You realize that 70F is only 21C.  Here in Texas last summer I was running a bunch of GPU miners.  They run at 70C which is 158F.  The hot Texas summer day of 115F (46.1) air was enough to cool the miners down.

This year I have a bunch of S1 Antminers and we have already had high 95+F days so far.  The S1's did fine with just some outside air being blown into the room with the miners and the hot air leaving the room.  In the main mining room with the building closed up, the room was at 115F (46.1C).  I opened the doors and windows to get the air circulating and the room dropped to near outside ambient temp in no time.  

I don't see that much of a problem here when it gets to summer temps at 115F (46.1C), just keep the air moving with outside air and have several replacement miner fans on hand as fans fail when you don't want them to.  If you cannot create the air exchange from outside with the inside, then you need to rethink you setup.  You need air flow from outside to inside to outside.

This reminds me of the late 80's and early 90's when small and medium businesses where having their computers networked.  I could not count how many times I was called in to troubleshoot network problems only to find a server or router closet.  That was the dumbest idea I seen done over and over by inexperienced so called "tech's".  Putting electronic equipment that produces heat into a closed off, normally not air cooled, closet. You have to have air exchanging to keep the equipment running.  Same with the miners.

Yes, 70F outside is far from a crisis for the miners, it's just a harbinger of what is to come.  Perhaps you like your house at 85 to 95F; I, and especially my wife, do not.  We are Minnesotans.  We are used to temps of 10F outside, not 100F.

I keep my miners in the garage.  The garage doesn't have any windows.  I prefer not to advertise the fact that I have lots of nice electronics in there.  With the door closed and it's upwards of 70F outside, my miners (Ten S1s and six Cubes) bring the garage to 85F in under a half hour and the miners' temp sensors quickly head north of 75C.  The cubes drop 10GH apiece at the high clock rate.  They don't have temp gauges that I can see via the web interface.  When the Cubes go over whatever is their maximum temp, they drop down to the low clock rate.  The error rate of the S1s increases from under 100 per hour to several ten thousand per hour.  The number of invalid/discarded/rejected shares jumps from tens to tens of thousands.  Then the chips on all the miners randomly start getting flagged with X's a few at a time.  So no, the miners are not happy at 50C or higher ambient temps.  When it hits 80F and 90F outside, forget it, the garage turns into an oven.

Secondly, I doubt your miners are doing "just fine."  I'd be interested what temp the S1s are reporting on their miner status web page.  If the room is already 50+C, I'd bet they are running at 70 to 80+C.  At those temps you can look forward to cumulatively degrading hashing rates and/or chips failing.  Me, being an electrical design engineer, I want my miners to perform as best they can for as long as they can.  Right now, when they are operating below 50C, they get hashing rates around 220GH consistently, with no permanent X's on any chips.

Lastly, again, being an electronics design engineer, I tend to be a little anal about keeping my electronics running in the "low to mid" temp range stated on a devices data sheet, if I can, and stay far away from the "absolute maximum" temp range.

So, all those who like to bake their miners and shorten their useful life, you can line up with AbiTxGroup.

I'll keep it cool thank you.

It's also about airflow, not just temps.  In many ways, 20k CFM of -10 degree air = 10k CFM of -20 degree air.  Cut a hole and mount an exhaust fan high up in your garage.  Cut another one and mount an intake fan low on the far side (north/shaded side is best for intake).  With the right capacity fans, you can make it so that your garage never rises more than a couple degrees above the exterior temps.  This will be much cheaper and less trouble-prone than your proposed water-cooling design.

Speaking of which, the "thermal mass" of a 340Gal tank isn't going to do jack.  (Although of course it's a good idea to have a reservoir in case something goes wrong with your plumbing.)  If you've got cool water coming in from your tap, running through your system, and then running down the drain, the system is going to use so many GPM of cool water regardless of whether it's initially stored in a tank.

The stagnant air in your garage hits 85F in half an hour, with exterior temps of 70F.  Your miners are putting X BTU's into the garage at a constant rate.  The rate of heat exchange is related to the temperature differential.  At 15F differential, there is enough heat exchange going on between the garage and the exterior to maintain equilibrium.

This is how all cooling systems work.  All you're doing is moving heat from one place to another via a medium.  The "thermal mass" of the medium of heat exchange doesn't matter.  What matters is the overall heat exchange rate. 

The amount of water stored in my car's cooling system doesn't make a difference.  Once it hits the minimum level required to fill the radiator, engine block, and all connecting lines, having an extra gallon or two in there won't make a difference.  (It will take a bit longer to reach equilibrium temps from a cold start, but other than that, no difference.)  What WILL make a difference is if my water pump goes out and the flow of water through the engine stops.  In that case, it won't matter how many gallons of coolant I have in my reservoir; the engine will overheat.  Same with the radiator being blocked.  If air is not flowing over the radiator at a sufficient rate, the engine will overheat.  (Dependent upon the air temps, of course -- I know you northerners sometimes block your radiators with cardboard in the winter when the temps hit the negatives.  In this case, there is sufficient heat exchange even without any airflow, due to extreme temperature differential.)

I apologize for the continued derailment of the thread.

I'll keep the reply shorter this time.  You have a substantial misunderstanding of the system I am designing and using.

I am currently using this method of water cooling.  It works as designed.  NO airflow AT ALL is required.  NO garage modifications are required, short of adding some plumbing.  The heat is transferred to the water by waterblocks.  The heated water is then returned to the tank.  When the water in the tank is too hot to keep the miners at optimal temperature, the hot water is DISPOSED down a drain.  The heat leaves with the water.

The purpose of the thermal mass water tank is to recirculate the water until it reaches the temperature where disposal is warranted.  The disposed water is replaced by fresh cold water from the water main at a much slower rate due to recirculation of the tank of water.  This is not a closed system like a cars water cooling system which has to dispose of the heat to the air.

When I was running the miners with just fans, I just opened the bottom of the garage door to exchange air.  That worked fine, but I know worse is coming.  That was when I started designing this water cooling system.  The garage only heated up so severely when the garage was closed up AND the miners are running with fans only.  That is not the way I run the miners.  It was an experiment to see how fast the heat accumulated.

The 70F degree air outside right now is NOT the concern.  It is the 85+F temps that are coming that are the problem.  When starting with such temps no amount of air exchange between indoors and outdoors will cool the miners below the ambient temperature.  In fact, considering the 570+ watts of heat dissipation by the miners, the chips have little chance to get below 70C (158F).  As I noted above, I have observed significant performance degradation, malfunctions and even chip failures begin when the S1 web interface is reporting temps of 60C (140F) or higher.

End of thread derailment.

[ronin4bits]

I think you are worrying to much about the heat.  You realize that 70F is only 21C.  Here in Texas last summer I was running a bunch of GPU miners.  They run at 70C which is 158F.  The hot Texas summer day of 115F (46.1) air was enough to cool the miners down.

This year I have a bunch of S1 Antminers and we have already had high 95+F days so far.  The S1's did fine with just some outside air being blown into the room with the miners and the hot air leaving the room.  In the main mining room with the building closed up, the room was at 115F (46.1C).  I opened the doors and windows to get the air circulating and the room dropped to near outside ambient temp in no time.  

I don't see that much of a problem here when it gets to summer temps at 115F (46.1C), just keep the air moving with outside air and have several replacement miner fans on hand as fans fail when you don't want them to.  If you cannot create the air exchange from outside with the inside, then you need to rethink you setup.  You need air flow from outside to inside to outside.

This reminds me of the late 80's and early 90's when small and medium businesses where having their computers networked.  I could not count how many times I was called in to troubleshoot network problems only to find a server or router closet.  That was the dumbest idea I seen done over and over by inexperienced so called "tech's".  Putting electronic equipment that produces heat into a closed off, normally not air cooled, closet. You have to have air exchanging to keep the equipment running.  Same with the miners.

Yes, 70F outside is far from a crisis for the miners, it's just a harbinger of what is to come.  Perhaps you like your house at 85 to 95F; I, and especially my wife, do not.  We are Minnesotans.  We are used to temps of 10F outside, not 100F.

I keep my miners in the garage.  The garage doesn't have any windows.  I prefer not to advertise the fact that I have lots of nice electronics in there.  With the door closed and it's upwards of 70F outside, my miners (Ten S1s and six Cubes) bring the garage to 85F in under a half hour and the miners' temp sensors quickly head north of 75C.  The cubes drop 10GH apiece at the high clock rate.  They don't have temp gauges that I can see via the web interface.  When the Cubes go over whatever is their maximum temp, they drop down to the low clock rate.  The error rate of the S1s increases from under 100 per hour to several ten thousand per hour.  The number of invalid/discarded/rejected shares jumps from tens to tens of thousands.  Then the chips on all the miners randomly start getting flagged with X's a few at a time.  So no, the miners are not happy at 50C or higher ambient temps.  When it hits 80F and 90F outside, forget it, the garage turns into an oven.

Secondly, I doubt your miners are doing "just fine."  I'd be interested what temp the S1s are reporting on their miner status web page.  If the room is already 50+C, I'd bet they are running at 70 to 80+C.  At those temps you can look forward to cumulatively degrading hashing rates and/or chips failing.  Me, being an electrical design engineer, I want my miners to perform as best they can for as long as they can.  Right now, when they are operating below 50C, they get hashing rates around 220GH consistently, with no permanent X's on any chips.

Lastly, again, being an electronics design engineer, I tend to be a little anal about keeping my electronics running in the "low to mid" temp range stated on a devices data sheet, if I can, and stay far away from the "absolute maximum" temp range.

So, all those who like to bake their miners and shorten their useful life, you can line up with AbiTxGroup.

I'll keep it cool thank you.

It's also about airflow, not just temps.  In many ways, 20k CFM of -10 degree air = 10k CFM of -20 degree air.  Cut a hole and mount an exhaust fan high up in your garage.  Cut another one and mount an intake fan low on the far side (north/shaded side is best for intake).  With the right capacity fans, you can make it so that your garage never rises more than a couple degrees above the exterior temps.  This will be much cheaper and less trouble-prone than your proposed water-cooling design.

Speaking of which, the "thermal mass" of a 340Gal tank isn't going to do jack.  (Although of course it's a good idea to have a reservoir in case something goes wrong with your plumbing.)  If you've got cool water coming in from your tap, running through your system, and then running down the drain, the system is going to use so many GPM of cool water regardless of whether it's initially stored in a tank.

The stagnant air in your garage hits 85F in half an hour, with exterior temps of 70F.  Your miners are putting X BTU's into the garage at a constant rate.  The rate of heat exchange is related to the temperature differential.  At 15F differential, there is enough heat exchange going on between the garage and the exterior to maintain equilibrium.

This is how all cooling systems work.  All you're doing is moving heat from one place to another via a medium.  The "thermal mass" of the medium of heat exchange doesn't matter.  What matters is the overall heat exchange rate. 

The amount of water stored in my car's cooling system doesn't make a difference.  Once it hits the minimum level required to fill the radiator, engine block, and all connecting lines, having an extra gallon or two in there won't make a difference.  (It will take a bit longer to reach equilibrium temps from a cold start, but other than that, no difference.)  What WILL make a difference is if my water pump goes out and the flow of water through the engine stops.  In that case, it won't matter how many gallons of coolant I have in my reservoir; the engine will overheat.  Same with the radiator being blocked.  If air is not flowing over the radiator at a sufficient rate, the engine will overheat.  (Dependent upon the air temps, of course -- I know you northerners sometimes block your radiators with cardboard in the winter when the temps hit the negatives.  In this case, there is sufficient heat exchange even without any airflow, due to extreme temperature differential.)

I apologize for the continued derailment of the thread.

I'll keep the reply shorter this time.  You have a substantial misunderstanding of the system I am designing and using.

I am currently using this method of water cooling.  It works as designed.  NO airflow AT ALL is required.  NO garage modifications are required, short of adding some plumbing.  The heat is transferred to the water by waterblocks.  The heated water is then returned to the tank.  When the water in the tank is too hot to keep the miners at optimal temperature, the hot water is DISPOSED down a drain.  The heat leaves with the water.

The purpose of the thermal mass water tank is to recirculate the water until it reaches the temperature where disposal is warranted.  The disposed water is replaced by fresh cold water from the water main at a much slower rate due to recirculation of the tank of water.  This is not a closed system like a cars water cooling system which has to dispose of the heat to the air.

When I was running the miners with just fans, I just opened the bottom of the garage door to exchange air.  That worked fine, but I know worse is coming.  That was when I started designing this water cooling system.  The garage only heated up so severely when the garage was closed up AND the miners are running with fans only.  That is not the way I run the miners.  It was an experiment to see how fast the heat accumulated.

The 70F degree air outside right now is NOT the concern.  It is the 85+F temps that are coming that are the problem.  When starting with such temps no amount of air exchange between indoors and outdoors will cool the miners below the ambient temperature.  In fact, considering the 570+ watts of heat dissipation by the miners, the chips have little chance to get below 70C (158F).  As I noted above, I have observed significant performance degradation, malfunctions and even chip failures begin when the S1 web interface is reporting temps of 60C (140F) or higher.

End of thread derailment.

Everyone here knows how water cooling systems work. Please get a blog for this stuff - or visit the hardware topics...