Designing my house! Looking @ wierd alternative way for CPU cooling.

[Evadman]

Hey guys. I am actually going to start a topic that belongs here

This is the story. I will be building my house sometime next year. I am currently designing it. This is something I want to do to cool the huge wattage that my fleet puts out.

Currently, I have 11 computers running in a 14 x 16 room. It gets extremely hot in here. In the beginnin of the year I touched on 120 degrees or so. I ened up adding a though the wall 5000 btu AC unit to help cool the room down. It did make a huge difference, but it never turns off. Sucking up the power

This is my plan. I want to water cool this fleet. I want to cool it using the naturaly cool ground. The water circuit I have in my head goes like this:

Water is held in a tank 4' or so undergound. From there, it is gravity fed into my basement, where the cooling water would be directed to each computer. From the computer, it would go into a water pit like a sump pump has, but much larger. In that pit will be 3 pumps that will raise the water up to 18" below ground level, and though a long series of pipes. Those pipes would be in a grid like patern ( smallest possable area wise )

After flowing though the grid patern ( where it gives up its heat to the gound ) it would return to the tank about 4' below ground.

I am looking to disapate somewhere in the area of 10,000 watts. ( I disapate somewhere in the area of 3k now, and I have to plan for the future )

I was looking for some imput on pipe diameter, location, and area of the "field" that would be needed. Remember to think 3d as I can go up ( within 18" of gorund level ) with no real depth limit, but 10' I would like to be max as that is the same height the basement will be excavated to.

I was assuming black or galvinized pipe for the pipe in the gound, and PVC for interior runs. ( not sure yet, as I may get a voltage difference )

Oh, and the pumps I have selected will pump about 1200 GPH @ a 10' head.

 

[Turkey]

Well first of all you are crazy. What the hell do you need 11 computers running all the time for?!?!?

So here's what I would recommend... find a way to put that heat to use. Pump it to your water heater as preheated water, or have some duct work that would allow you to use your PC room as the furnace for your heat in the winter. Install a hot tub. Put in a filtration system and wash your dishes/clothes/self with it. Disguise your PCs as rocks and make a deal with the local zoo to keep desert animals in your office.

Or maybe just turn off about 9 of those computers!

Or, if you are dedicated to heating the ground, it'd be cool if you put the cooling grid under your driveway/porch so you didn't have to shovel snow in the winter. Also, you only need one tank/pit. The water can go directly from the end of the cooling grid to your PCs, it doesn't have to go to a tank then to the PCs.

Sorry I have only philosophical and not technical advice!

 

[JustinLerner]

How good is the ground for dissipating heat away from the heat source while absorbing heat from the same heat source? (A directional heat pump.)

After some time wouldn't the naturally cool ground become unnaturally hotter and approach the temperature of the water warming it? Isn't air used because the heat transfer is faster at even smaller temperature differences than could ever be achieved using the ground?

Why not make a smaller scale test setup with pipes, pumps, water, and heat transfer capabilities. Fine tune your concept before building one, which has good merit.

 

[blahblah99]

Well, since no one ever actually needs the coldness of the cold water coming from the main plumbing pipe, what about using that to feed into that storage tank, which then goes through the computers and finallay up to your home for regular use?

 

[Evadman]

Turkey: Wow, never thought of putting it under my driveway! Sweet idea! Thanks. And the reason I have so many computers, is that 8 of them are servers for a buisness along with game servers that I run, the others are personal. ( like this one, and a laptop that will not be cooled anyway )

JustinLerner: That is the info I am looking for. I have no idea how well the ground will wick away heat. I am assuming decently, baised on the fact that the water from my tap is about 50 degrees f year round. The tanks in this area are all above ground, so I would assume the water temp in the tanks is closer to ambient. I was assuming the solid ground would move heat relitively well because of the water content of the soil and clay. Building a test rig is one way to find out, but the excavation for even a small one would be prohibitive. I may do a real small one by hand If I can not get any more info tho.

Blahblah: I do not want to use the water out of the tap for 2 reasons. #1 the water is not always flowing. #2, I would get scale and lime buildup inside the small pipes running to each CPU. In a 1" pipe in the house it is not a problem, but a 1/4" it would be. I could do a water to water heat exchanger, but that would be mroe $$ and be less efficent. As for the 2 tanks, I want to pump the hot water ( warm maybe ) out of the house as soon as possable so it can not heat the room.
The 2nd tank outside was added as a type of "heat resovoir" ( cold in this instance ) and as a pressure breaker. I wanted to gravity feed the CPU coolers so I do not blow the hoses. The Pumps I was looking at will put out up to 500 PSI which would blow most flexable lines. Max I would want for pressure would be 25-30 PSI. i have not done any calculations to find out the PSI of the water with 4' of drop, but my guess would be around 15 PSI or so.

 

[rbhawcroft]

you could use a convection cooler, have a cold rod ie a steel joist as the heat disperser, or simply have a tube that collects the hot air from the rear of the computers and pumps it outside.

 

[Sahakiel]

My inexpert opinion: build a pool as a massive swamp cooler.

 

[PowerMacG5]

First of all, you have to look at what the freezing depth of the ground is. From their you can drtermine what depth everything needs to be. Say the ground freezes up to 48" down. Then the ground under that is always at a constant temperature. What you should do is run the pipes down as far as you are allowed by your town or as far as you want, then pump it back up. It should remove the heat as it goes down, and replace the heat, with the coolness of the ground. You shoould not need a tank to store the water, as long as you put nough water in to go through the entire pipe system. One wuestion though, were you going to have all the computers linked on one pipe, or have one pipe branch off, go to each computer, the recombine at the end? My reccomendation would be to branch the pipe when it comes up from the ground, it will cool each computer evenly, and not transfer the heat from one computer to the next.

 

[Shalmanese]

As said before, your just wasting your money trying to cool 10,000W when you spend more money on heating stuff by that amount. Use it as a hot water heater.

 

[Armitage]

There are heat pumps that work on this principle (ground source heat pumps). You want to dump heat to the ground instead of extracting it, but some of the calculations to figure out the size of your field, etc.. should be similar. It will depend on your soil type as well, so you'll probably need to get a soils report for the area you want to use. It's a place to start at least. Local HVAC pros can probably help.

As somebody else suggested, you'll want to be sure you're below the frost depth for your area. 36" is pretty safe for much of the country, but you need to go deeper in some areas. I'm building an addition on my home in Colorado, and code requires underground water lines to be down 5'!

Are you sure you want to do this though?
It sounds like a maintenance nightmare?
Every time you get a new system, you'll have to outfit it for water cooling. A leak in one system couldput a few inches of water into the room and overheat all the other boxes. You'll have to have cutoff valves for each box, and then bleed the air out of the lines when you hook them up again.

Not to be critical, but I'd seriously consider a heat pump. If it's for a business, consider getting a seperate meter so that you could write off the power costs as a business expense.

 

[Demon-Xanth]

Consider using a central water cooled system w/ a water-water heat exchanger on the water pipe that is immediately before your water heater. The pipes will act as a heatsink themselves when the water isn't flowing, and when it is it'll act as a pre-heater for the water heater.

 

[bizmark]

There have been some cool ideas here. I like the heating the driveway thing. But others bring up a good point: how feasible is this, really? Is this even close to being an optimal solution, or is this the "10-times-harder-than-it-needs-to-be-just-because-it's-cool" solution? I mean, before you go any further with this, you should probably price electricity to run the pumps 24/7 vs. the electricity for a dedicated A/C for that room. My 5000BTU window A/C is rated to cost $35/year in electricity. That's pretty reasonable IMO. You're in Chicago, where it's cool for a lot of the year (hell, I need a jacket today, in friggin June), so just a system for ducting outside air into the room during the cold months (and dedicated, well-designed A/C the rest of the time) would probably be a helluva lot cheaper to build and maintain than this network of underground pipes and pumps. Plus, what happens when your cable or phone wire screws up, and they send out crews with backhoes? What if you want to plant a tree? What if you decide you want an in-ground pool? I don't mean to crap but these are issues you should consider.

edit: oops, I was wrong about the electricity my A/C takes. But $35/year still isn't much IMO.

 

[rgwalt]

CYPM buddy.

Ryan

 

[rgwalt]

Those of you suggesting to use it as a water heater have to understand that he plans to run distilled water through the system to avoid scaling. Even if he ran two water loops, the amount of heat transfered to the water heater wouldn't be that much, and it would fluctuate with the outside temperature over the summer. The CPUs aren't going to run much hotter than 35C, so the best you could hope for is 30C hot water, which is tepid at best.

Running outside air in isn't a very good option. A 5000 BTU AC unit runninng constantly is VERY expensive. Pumps running constantly aren't. Pumps typically don't take much power, especially when compared to a compressor.

This idea is certainly feasible. The hardest part is going to be building and burrying a sufficiently large heat exchanger in the ground.

Ryan

 

[capybara]

you dont wanna dig this by hand, or rent a backhoe either. a ditchwitch cuts a 3' deep
by 6'" wide trench. what about the frost line busting pipes? Ive lived in cgo, and i doubut theres a 3' deep solid freeze.
but lets assume ther is. wouldnt plastic pipes (abs or pvc or .....)flex enough to handle the
freeze w/o breaking?
i think this idea has real merit, it deserves a small demo b4 going full scale. for ex, rent
a ditchwitch for 1 hour only = about $35. i also respect alot your thinking out of the box
here.

 

[Evadman]

I am actualy going to be doing all the digging myself. I know how to drive a bobcat, and will just dig out an area to 42" deep ( the frost line in this area) when I dig the hole for my basement.

As for the power my AC unit draws..... I pull 12 amps when the unit is on. And it NEVER shuts off. Usual room tempeature is between 70 and 79 with it on. 12 amps @ 120v is some serious wattage. The 3 pumps together will be pulling 5 or so, and they will not always be on. I figure a 70-80% duty cycle. Still pretty high. The 3 pumps are only for redundancy. 1 pump should be more than enough.

And some of this is for a "cool" factor. I am not going to say it is not. but is mostly for saving me some money.

I may do a water to water heat excanger on the inlet side of my water heater, but that is going to be an instant water heater, and not a tank system rated at a 70 degree tempeature rise, so not too sure on how much it would help.

PM and maintnance should not be that bad. I was planning on running a 50/50 auto anti freeze ( wow, look @ me spell! ) water mix, so freezing and corrsion will be kept to a minimum.

<edit>
And for those wondering I was thinking of the heat excanger being a size of around 25 x 25 feet. 625 sq feet or so. I hold no dilusions that this will be small.

 

[RSMemphis]

Here's my idea:

Water cooling is just a huge hassle, so:

Have the rear fans of the computer blow out, the front fans blow in (that's easy enough).

Connect good air ducts to all of your computers, and run the final air duct outside to where you cannot hear a largish fan (near the driveway? to defrost it) and then use the fan to suck all the air and blow it out outside.

It a) should not be loud inside b) you can more easily remove and add computers (get something to plug up empty air ducts), and no need to worry about freezing or anything.

 

[Ilmater]

First of all, WOW! What an amazingly cool idea. I don't think it would be impossible, but there are many things to consider. I've had pipes freezing and bursting before and let me tell you, it's a b!%ch. So, before I say any more, I want to stress that in Chi-town, I have no idea, but I would make this my top priority as far as planning for problems after this system gets up and working. The other thing I want to say before I get into it is that the whole driveway thing would be flat-out the best thing to use the heat for. I could imagine that actually working somehow. however - and this is a big however - isn't the whole point to run cooler??? Unless you have some type of exhaust system, you're wasting your time thinking about this option.

Alright, with that out of the way, I want to say that this completely ruined my day at work today because all I could think about was how to do this. The following is what I've come up with. I'm sure that I haven't thought of everything, but I tried. OK, start with a tank in the ground. Obviously copper or aluminum would actually be able to give off the heat better than anything else, but clearly it will have to be some type of metal. I'd think about making this as large as possible, mainly because the more water you have in there that's cool to start with, the easier it will be to keep the water cycling through the system cool (duh, simple thermodynamics). Make sure that the liquid comes from the bottom of the tank. Obviously, this would have the benefit of getting the coldest water out of the system (again, duh). You don't need 50/50 water/anti-freeze. You can use 70/30 and it would work just as good. Depending on how much total liquid you're using, it may make a noticable cost difference ($50 is $50). Use the pump(s) (redundancy is good) to pump water to a basin somewhere above the computers. I would say that you'd like the basin inside the "structure" (or house, whatever you call it) in order for the liquid not to get hot in the summer, but someone else might think of a better place to put this. Now, drain the basin into a big tube that would eventually feed the tubes going to the water blocks. Or, maybe you have the smaller tubes hooked directly to it, it depends on where you put the basin. The tubes would put the liquid through the CPU waterblock and the hard drive waterblocks. I was surprised that nobody mentioned this, but hard drives put off a good amount of heat (I've got five in my one PC, so I know). Heck, you may want to even run this through a VGA waterblock. I know you can get hard drive waterblocks from Koolance, but I'm sure somebody else makes them. The only thing that I don't know what to do with would be the power supply and the removable media drives, but that was not in the assignment. Now, once it's gone through the system, the tubes would come out the back of the computers (which would have to be on top of desks, or at least off the ground a foot or two) and drain. I don't care what they drain into or how they do it. They should go directly down from the cases, though, and should be free flowing in a downward slope; the steeper the slope the better. It's the same principle as syphoning gas; the draining liquid will help pull the rest of the liquid through the system, rather than just hoping that falling liquid from the basin will push itself through. In order to add the cool factor, you could have the tubes seep the liquid into a bowl (probably metallic, but you can be creative with this) with a pipe at the bottom that leads into the tank. You could have more than one - even all - of the tubes drain into one bowl, with its pipe leading to the tank. How hard would this be to do? I don't know. But, in my head, this is feasible. I don't think that you would be able to actually flip a switch and have the pump turned off though. However, as your pump will probably be putting more water in the basin than is flowing out of it, you might be able to time it to run for a few minutes and then shut off for a minute, and then refill and repeat.

The problem with this (and any water-cooling system in general) is right there: how do you have the right amount of liquid going in to the basin and coming out of it? You'd have to do some seriously good calculations as to how much water will be pushing through the system on a consistant basis. Otherwise, you'll overfill/underfill your basin, both of which would be serious problems. The only way to correct this would be to actually have the pump feeding directly into the system. However, this COULD put some serious pressure on the tubes, specifically their connections with the waterblocks. However, I'm not an engineering genius, so I don't know for sure. The only way (I can think of) to alleviate this would be to make sure that the amount of liquid it's putting into the system is exactly the same as the amount pouring out. That would take some careful calculations, though, and might be impossible, depending on the range of water pumps out there (maybe one's too slow and the next one up is too fast). If you do rely on that many calculations, you have a higher chance of not carrying the 2 or not moving a decimal place and making the whole system fail. With a system that's putting water into your computer, you really don't want that type of thing to happen.

Well, I'm sure that there's someone that will tear my system apart, but that's the best I could come up with in 1 day's work (hey, now you know how my employer feels!). Best of luck and I hope whatever you decide on works. BTW, regardless of how you do it, if you do do something that's anywhere near as complicated as you're trying to go with it, please let me know what you decide on and how it turns out. Post on this forum later.

 

[Armitage]

Evadman, what the BTU/hr rating on that AC?
Any specs on the computers?

The AC running constantly and still only managing high 70's just doesn't seem kosher. Are you sure the AC is working properly?

 

[Evadman]

Ilmater: You do the same thing that I do @ work You have some great ideas as well. Man I love HT!

ergeorge: I have some serous power running here. I installed a 60 amp sub breaker for this room, as I kept blowing the 20 amp that feeds it. If you seriously want to know what my setup looks like, then cool. I will link it. hold on.

<Current computer setup>
Here ya go. I cleaned up a little, so you can see the floor in most places. The Magnaserver is empty, untill I find a cheap Nightshade board. Everything else is running hot.

Rack wall top From left to right... 600 Duron @ 800 - 1.0 @ 1.3duron - 1.0 duron @1.2 - dual 1600+ - dual 1600+ (7 Cpu's on that row )
Rack wall middle
Rack wall bottom

Then my workstation on the other side of the room: The toolbox looking thing is my Lancase. (1700+) The one under it is a 233 amd k6. ( 2 Cpu's)

workstation The small one under the desk is a dual 1900+, the other is a 1700+. One of the boxes on the far right is a 286, the other 2 are osbornes. ( Remember the first portable computer? Only weighs like 80 lb's. Both still work )
workstation 1 x 2 Look, you can see my lunch. Since the pic was taken I have added a k6/2 500 to the mix. (4 more CPU's )

13 Cpu's with a total of 13,400 MHZ ( counting the XP's @ their PR rating. Kinda cheating I know


Workstation Downstairs ( the 2 boxes are 1.4 thunderbirds, and the lappy is a 633. I hate walking up a flight of stairs just to use a computer. why do that, when you can just build another room?

the bold stuff will be links to pics I took. My DNS record is being updated for my entire computer setup tonight, so I will linkify them tommorow.

<edit>
Cool, My DNS propigated to me ion less than an hour. Sweet! May take 24 hours or so for entire net.

 

[networkman]

For those who are curious, Evadman is NOT crazy.

Okay, granted that being said by me probably doesn't re-assure you much, but he isn't the only one with double-digit numbers of computers in his house(I have 14, half are duals and all CPUs are 900+ MHz each). :Q On second thought, maybe we are both crazy!

It's okay though - it's a GOOD kind of crazy.

 

[Confused]

Ilmater: Thinking about what you said about having enough water in the basin above the computers, how about some sort of setup like they have in a WC, where as the water level drops the water flows back into the cistern, and fills it up, and shuts off when it gets to a certain level. Getting a float from the cistern hooked up to some sort of sensor to turn the pump(s) on/off would eliminate the problem of having too much or not enough water in the basin.

And no, Evadman (and networkman) isn't mad I have 4 CPUs in my house (Duron 850@935, Athlon 1.0@1.33, Dual Celeron 400) , and only 2 people living here, and they give out quite a bit of heat too! I've not had to have the heating on in the room where these are for the past 2 years!

Confused

 

[dEvio]

The pipes will probably not freeze, because the water is always moving (and warm).

 

[Plugers]

check out THIS site. He only has one computer ( I think ), but he is using a cooling system similar to what you are looking to build

 

[Plugers]

Also check out THIS. This thread shows some quick disconnects you may find usefull. I was thinking maybe 2 manifolds made from 2-4" pvc, copper,....? 10' or 15' long on your wall or shelving with 20 connects on each one. One manifold for water inlet and one for water outlet so you can connect and disconnect your computers rather easily