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Hi all, I did a quick search and I don't think that this has been suggested here before so, here goes.

If you want to mine, it makes sense to cram as much processing power into every computer you build, so as to minimize overhead and cost of components that don't actively contribute to the mining process. So one automatically turns to multi-GPU cards that spew out almost half a kilowatt each when overclocked, which obviously means that we will quickly run into thermal limitations. The only way to resolve this is to use water-cooling.

But then there is the added cost of such set-ups: You need cool-blocks for the cards, hoses, a circulation pump, reservoir and big radiators. By the time you're done, it was probably cheaper just to build an extra computer and just skip the water-cooling idea, one might think. Ok, let's eliminate the radiators from the equation, instead let's reroute that waste heat to a heat sink with virtually unlimited capacity. You should be able to find one in your home, where you can put the energy to good use instead of venting it (or worse, A/C'ing it out).

I don't know how you fix your domestic hot water, perhaps you have a boiler? Perhaps you have a central under-floor heating system that works at low temperatures (35 degrees Celsius). Or perhaps you have a swimming pool that requires heating? Are you starting to see the bigger picture? Special boilers for green energy use have multiple internal heat exchangers. Get yourself one of those (or DIY), route your water cooling through one of the heat exchangers, and hook up the boiler between your cold water feed and the cold water inlet of your domestic hot water system... Presto!

You'll now get a couple of hundred Watts to multiple kW of heating power basically "for free", since it would have been wasted otherwise, you might even have struggled to rid yourself of it. I hear some of you saying, but I use my rigs for space heating. Well that's great when you live in Antarctica, but not so efficient when summer comes around and your air conditioner is working overtime to remove your "miner heat". As an added bonus, your cards will run cooler than you ever thought would be possible and you will be able to overclock like mad (don't fry them though, they still have limits), knowing that the power is being put to good use and saving you money elsewhere - though it will still cost you, as long as fuel is burned to produce electricity, electric heating will remain the least efficient form of heating.

Wont work with boiler unless you constantly have water draining out of it to make room for the water coming form your water cooler kit. Not to mention the rusting problem from using tap water.

Swimming pool water wouldn't last too long in a water cooler kit before it causes problems with corrosion and clogs the system.

But good idea's anyway.

putting your mining rigs to good use
Stop running your cloths drier,
buy a laundry drying rack
....... 2 hours later 1 full load of dried cloths.

+1 lowers temp a great deal due to evaporative cooling

Been doing this for 2 weeks now, works like a charm. Buy some liquid fabric softener, you'll need it!

heh it reminds me of pugetsystems submerged aquarium pc.

You don't circulate the actual boiler water or pool water through the water cooling system, are you nuts? ;) Renewable energy boilers have heat exchangers, basically a copper coil inside the boiler, to which you hook up your water-cooling circuit on the outside. Heat from water-cooling gets exchanged with the (still cold) water in the boiler, and nothing more but thermal energy is exchanged. They are both closed, separate circuits, only in connection with each other via a thermal route. Hence there are no issues with rust, corrosion, clogging,... Same principle can be applied for a pool, a copper coil in the filter housing will give off heat to the water flowing past it.

This way you are only limited by the flow-rate and size of your boiler or swimming pool, in the case of a boiler it might get a little hot if you're out on vacation. :)

I was thinking of something similar to this but on a smaller scale. I was thinking some sort o small urn. So that I dont need to boil a kettle every time i go make coffee. If anyone has any ideas please post them. I'm in a building mood.

if Ends are ≤ Means
then its not worth it imo.

Think about the following
idea formation
research time
risk in long term devaluation of your structural investment
expenses
loss of interest generating revenue in the interim
general upkeep...

Granted, if you're small-scale then this is of little use to you, if you have a single rig with a few 5870's, don't go there. But from time to time you see clusters filling up one or multiple racks. You can imagine that there are some serious kilowatts being pumped out there (and hence being consumed and paid for), in such a case it would definitely make sense to recuperate the heat. Still, an average solar boiler will cost some $$$, so it's up to the end user to figure out if it's worth the initial investment.

However, one can still DIY for a cheaper solution: Pick up an old electric boiler (discarding the electric parts), cut a hole in the top, run your own copper coil heat exchanger down into the bottom and close up the hole again with expanding PUR insulation foam. There's your cheap heat-dump that can be implemented for a much lower cost than a new solar boiler, fun project!

If you're really opposed to green energy or energy recycling: You can always spend the money for that old electric boiler on a few bags of cement and more copper pipe instead. Lay your copper heat exchanger over a greater surface area such as a basement floor, then poor a layer of concrete over it. Make sure the concrete slab can exchange heat with the ground, this would be the inefficient version of the heat dump load. Or one can run pex tubing (underfloor heating) underground in a long trench dug outside in the ground, that would also work well to distribute the heat.

I wouldn't go there, you will not be able to keep the hardware temperature under control if your aim is to boil water. ;D

You're right!
But i'm still gonna come up with some idea to use this heat!

In fact, I'm seriously considering setting up a heat recuperation system like this myself. I am very much obsessed with money and when I first found out about bitcoin and how you can "be the bank" and create money (up to certain extent), I felt like I had found a little golden egg and instantly considered halting my monthly investments to redirect them into hardware purchases. The only things that really hold me back are the uncertainty (but as we know, risk = return potential) and declining yields (denominated in BTC), and lastly: potential cooling issues. Well, if I do go through with it, I'll be sure to post some pics of the process.

Here (http://bitcointalk.org/index.php?topic=3707.msg53879#msg53879) is one.

I have connected my boiler as well.  An old boiler is used for temporary heat storage, and water is circulated through a heat exchanger mounted on the input to the boiler in my house.  When there is a temperature difference between cooling water going in to the heat exchanger and coming out of it, indicating that heat is consumed (hot water used), a pump switches on to force more water through the heat exchanger.  The water is pre heated by my miner before it enters the boiler.  I'm installing floor heating in my living room as well now.  The old floor is almost out, and I expect to build the new floor next week.

I'd love to see pictures of your setup, but the link is just to 'here' ;-)

In my personal case, I have excess heat I'd love to re-use to heat up water, but I don't like the idea of running a liquid into my servers, especially long term, a leak would cause damage (one side: the flooding, next: all systems overheating). And right now I can just move them around, no hoses attached. Two of them are in the
bathroom and dry laundry ;-)

Wouldn't it be far cheaper to keep the machines as they are: pumping out hot air and getting a heat pump water boiler that takes this hot air and that way recover the energy?

Perhaps the energy balance is better with water as a direct energy exchanger than with air? With water cooling, you have a pump running all the time. With a heat pump, you need to pump in 1 kW of electricity to get 3 kW of hot water. Pro's and cons all around...

But as this is all a temporary setup (good for one or two years), an air heat exchanger could find another life after the servers are switched off...

From past experience in a "green" hobby I had as a younger man and still smoked the green.... We kept our hydro water cool in Texas by digging a 6 foot hole and buried the inside core of a water heater in the hole and it would keep 80 gallons of nutrient water in the low 60s in the summer and in the low 50s in the winter.... I dont see why you could not use this concept for GPU cooling

NowI agree I think I might build a new comp for more hashin power rather than water cooling untill GPU blocks get under 100$... for my idea of a miner thats 300$ in waterblocks alone when I could build another budget 3x 6870 miner for 750$

It is also worth investigating using castor oil or mineral oils with immersion circulators for cooling. It has been proven (messy) albeit successful in the cooling communities due to its' non-conductive nature.

Ooops.  Fixed the link, and here it is again: http://bitcointalk.org/index.php?topic=3707.msg53879#msg53879
It's not much water in a normal water cooling system.  My system, as pictured there, has only 3l in total.  Floor included.  More now, but the computer is placed above the water line.  No water will leak out inside the computer.  In case of a leak, only air will leak in.
No.  Water has 1400 times the heat capacity than air, and is a much better heat conductor.  You need to pump a lot of air through your system and the heat pump, and this costs energy.  And the heat pump uses energy as well, of course.
The water pump use less energy than the fans which used to cool my system, and the system itself uses less energy because it runs cooler.  A heat pump is much less efficient, as you have discovered.  It will take 2 kW from the air and 1 kW of power to supply 3 kW to the water, and when the water is hot enough, your air temperature will rise quickly unless you have a temporary heat storage to put it in.

if you want something that are near unlimited, put it in space, not occupied space are extremely good at cooling :)

Not really.  Space is extremely good at being hot and cold at the same time.  Heat can only leave as radiation, and if you are in the path of the sun's rays, your thing in space will become very hot because there is no air or fluids to lead the heat away.

Even in total darkness in space, radiation is limited at our temperatures.  A perfect 10cm x 10cm black-body surface will only radiate about 8W at 80°C.  Enough to cool one of Art's ASICs, if it can stay out of sunlight (may have a slight power supply problem there) but not any modern GPU.  A GPU will not last long in the radiation in space anyway..

Glad someone liked my new laundry dryer!!! I'm currently involved in a informal contest w/ a friend of  mine ( who is invested in the rigs that I run ) to see who can make the best gpu water-block and would love to extend the contest to a few forum members.

I'm also looking for additional criteria for defining the "best" ( for this application ) GPU water block

So far the design merits are

- Cheapest
- Lowest production time
- Highest thermal delta
- Easy of implementation
- Reliability assessment
- Highest flow rate

any suggestions?

IMO -Watercooling seems pointless unless you are getting your heat outside, until then your just heating a room in a different way. Best solution is find an abandoned home and liberate this home of its a/c condenser, ( please properly evac. the freon LEGALLY! ). After that remove the dryer canister and braze a set of barbs ( or use flared compression nuts ) on the lines. you wont even need a fan thanks to the ridiculous amount of cooling capacity you've just gained. Just be sure to feed the hot line to top to assist natural convection.

What about an inverter deep freeze frost free freezer as a starter.  Drill, fan, wizbang at that

well unless you plan on heat-sinking the inside of this deep freezer ( not cost effective ) your freezer will be unable to evacuate the heat fast enough ( even w/ a hole and fan ). This is mainly due the fact that a freezer is by design and extremely efficient insulated container.

I hope there is no mention peltier junctions!!!

No, it isn't.  A water cooled system with a decent radiator can be almost inaudible.

Waaay back in the day I earned my machinist/mechanic cert by mostly working on industrial pumps and heat exchangers and here's how I see it.

You guys are absolutely on the right track with many great ideas, the ones that pop out to me are:

1) Use Vacum pumps, that way any leaks suck air into the hoses/tubes instead of squirting liquid on your circuit boards.

2) Use automotive hoses, radiators and coolants. cheap, easy to get and efficient in the temperature ranges we are fiddling with.

3) Have the output from the GPU's as close to and then wrap around your hot water heater

4) Liquid filled (water) tank in the ground is an excellent heat exchanger, but you have to work out the engineering of how big the tank is and how many feet of coiled tube inside it you have. Interesting week long test project.

5) Big industrial fan blowing on automotive radiators will probably be almost as efficient as the tank in ground but will chew up more electricity.

Biggest design headache, how to produce cheap/efficient connectors to the GPU's, I'm thinking J-B Weld. I've molded some really strange stuff out of it and it never breaks.

Love this thread guys!

Plus, it keeps your room cooler so you use less A/C.

I think you may be missing my point.

Granted the act of quickly removing heat from a gpu has its benefits, however those beninfits are just as quickly lost by raising the temperature of the air in the room containing the radiator, so as the room temp climbs the air that you're blowing over the radiator also rises causing the delta to decrease. To me having the a/c kick on a few extra times is not a very good solution.

I am aware of the audible benefits of water cooling, my htpc is water cooled, thus silent

wait what??

That is assuming your plumbing your radiator outside the house correct? B/c last I check all logical cooling methods involves some sort of medium to convey heat away from the point of origin, be it standard heat sink or fluid ( air being a fluid of course ).

so if your gpu runs at 147 F and its 100 F on a bad day shedding 47 deg really isn't much of a stretch w/ enough decent radiator.

That's an excellant setup. Thanks for the pics. I'll be scrounging materials for my setup. Thanks, Bikerbum

Why would anyone who use A/C place the radiator indoors?  That would be incredibly stupid.  You can get a lot of tubing for a few dollars.  A crane to switch between an indoor and outdoor radiator doesn't cost much either, in case you need heating on cold days.

Electronics use less power when it runs colder, btw.  My computer use about 5% less power on water cooling than it did on fans due to lower chip temperatures.  That's 5% less heat.

I myself have two of my three Mining rigs watercooled with the radiator outside the house. I have a total of 8 Radeon HD 6950's in the loop, and they are currently running at 57c (134f) when it is 38c (100f) outside. I use far less electricity to cool the room they are in now, and as a bonus, I am now able to run the cards at 1,000mhz instead of the max of about 880mhz I was able to do on air. The watercooling equipment pays for itself in a little over a month and a half in my situation because of the increased hashrate, and the reduced A/C cost. Basically each waterblock costs me $50, and I spent maybe $100 more on plumbing, pump, and radiator. Price to watercool 8 GPU's: $500; Savings in elec: $200/mo (I live in a high $ and hot area); Additional hashrate= $70/mo;

So in 1.8 months, it has paid for itself, *and* made my office a whole lot quieter and comfortable.

BTW, I am using the swiftech mcw82 waterblocks. Not the Best out there, but definitely great when you consider it's price.

I also have a pool and have considered using the pool water with a water-water heat exchanger instead of the air-water radiator, but currently it does not seem worth it to run all the extra plumbing, and the larger pump required to move water through that long of a pipe run.

I can't afford water blocks for my mining GPU, but my CPU has been water cooled for more than a year. I used to use a submersible fountain pump and run hoses out to the pool... Virtually unlimited heat capacity.

I keep my PC next to the windows so it gets the proper cooling.