Water Chilling

natedog

natedog

natedog

Associate
Joined
19 Jul 2009
Posts
8
Morn'in everybody,

I have been doing a lot of research of late on a design to help chill my 3 mac mini servers I currently run for different things, they are all intel base core duo machines. Right now I am having to run them in a closed cabinet due to space. An idea I have had to use use the following

1. aquarium chiller
2. 4 x Radiators with fans on them
3. Pump and 1ltr tank

I plan to mount a small Radiator under each Mac Mini and have another in front of my synology NAS box. The idea is to chill the water using the chiller, and then pump the water into the radiators were the warm air will be chilled down when it is forced through the radiators. bit like a small split unit A/C unit

So my question is does anybody know of a good small water chiller I can use?, or have any other idea's on how to chill the water that I can investigate.

I have already tried using just fans in the unit which did not work, the last thing I have tried was putting in an extractor fan but nothing seems to reduce the temp of the equipement
 
What budget are you allocating, and how good are you at making things?

Cheapest option for a water chiller is a bong, which would be entirely hand made. It relies on water evaporating to chill the water.

Beyond that you have phase and peltiers. Both are generally home made, neither are simple. It rather depends on how much effort you're prepared to put into this project.


Besides the means of chilling water (I don't think the aquarium will keep it below ambient) the idea is fairly sound. You'd need fans on the radiators, but you'd blow air through the radiator, it cools down as it passes the fins, and blows cold air towards the air intake of the computers. It's not exactly amazing from an efficiency point of view, but it's probably serviceable.

Does the cabinet have to be sealed? Cutting holes in the bottom and top, and mounting a large exhaust fan horizontally above the servers would be a lot simpler. You just need a means to get the hot air out.
 
Sorry should have said budget wise I have got abotu £200 - £250

Not going to be able to cut holes top and bottom as the bottom is sitting on the floor and the top is mad out of glass. I know the idea is not very effective but it will keep them cooler than what they are right now. My diy skills are on the plus side of good so am open to trying most things. I have checked an the water chillers and they seem to be ok. I did find a new peltiers block that was released that had 2 water systems on it one for chilling the water an one to take the heat away from the peltiers, it looked like a sandwich. I am currently sealing the cabinet up so when the equipement goes in an gets chilled it will stay cool

I found this on ebay which I was thinking could be a start

http://cgi.ebay.co.uk/Aquarium-Base...ksid=p3286.m63.l1177&_trkparms=|293:1|294:200
 
I think that chiller's probably crap, sadly. Heat exchanger (the sandwich) is the way to go if using peltiers, and is just about achievable at that budget. Your electricity bill won't like it mind. You'd run tubes from the cold side into the bottom of the cabinet, through a 240 or 360 radiator with low speed fans on it. This will then keep the inside of the cabinet cool. The other side of the sandwich would need a 360 radiator, possibly with high speed fans. Both sides need their own pump, and the peltiers need a power supply.

If you overspec the peltiers and/or the hot loop, it'll pull the inside of the cabinet below dew point and you won't like that as the servers will expire. There are a few design issues, such as choosing which pelts and what voltage to run them at, getting the correct clamping force applied to the pelts, and stopping condensation ruining everything. It's basically quite a difficult thing to do. Do you have access to a milling machine and copper stock? If so, the heat exchanger part will be rather easier/better/cheaper.



I still think that air cooling is the way to go here. For the top of the case, cut holes in the glass and mount some 120mm fans. You'll need a piece of copper tube that's about 110mm across, this will be the hole air moves through. Also a piece about 5mm accross, through which you'll pass bolts to fasten fan guard, glass, fan together. Don't overtighten said bolts.

Grip the tubing in a drill, dip it in water then in carborundum grit. On the slowest speed available you can now drill through glass, dipping in water & grit as and when needed. It would be a really good idea to do this on a pillar drill. Cut slowly. Alternatively buy some 4mm clear plastic sheet from a diy shop of your choice, cut it to the size of the glass and cut holes in that. Won't look as nice, doesn't matter if it goes wrong as you just get another sheet.

Then all you need is some form of holes near the bottom to let air in. I can't suggest how to do this without seeing the cabinet, you may well be fine without changing the base if there are gaps already present.
 
First question is, why do you need them cooler? Are they crashing or locking up as is? Are you exceeding any stated temperature limits?

Are these 24/7 servers? You ok with running a water chilling system full time which would probably be working flat out given if is effectively extracting heat from a heat source? You ok with the electricity bill that will generate? Would the ongoing electricy cost outweigh buying a new cabinet which you *can* modify for improved normal air flow? Fully sealing the box and hoping chilled water will extract *all* the heat, verus having a fan sucking air in/out is ambitious imo.
 
bubo,

The units in question are 3 servers and 2 NAS boxes that run 24/7 providing Email, Backups, file, print etc. They currently are running a little on the warm side, I have tried cutting a couple of holes in the back an this has made a little difference but the noise levels have gone up, this is were I thought about using a water chiller to reduce the temp in the unit, I am not expecting to reduce it loads just enough to make the equipement run in normal temps.

I would have used a another unit but the wife wanted this one, which means I now have no space to put anythign else, oh an I just asked if I could cut some holes in the glass top. I will not go into detail but have been informed that if I do then im sleeping on the sofa :confused::confused::confused:

As for the elec bill, im not worried too much about that as home business will be picking up the tab as this equipement is used for that.
 
A water chiller probably isn't the solution to keeping it quiet I'm afraid. How about holes cut in the back at the bottom, with 120mm fans running at 7V drawing air in, and another set of holes cut in the back at the top, with similar fans exhausting?

A refrigerated cabinet would certainly solve the problem, but would be an excellent example of over-engineering. if you don't have a mill available it'll also be difficult/impossible to assemble the heat exchanger. With regards noise, can you move it further away from the working environment? It is unfortunate that the missus objects to cutting holes in the top. How hot are they running? If its enough that lifespan and reliability are compromised, you may have to put your foot down on this one and replace/cut up the cabinet. Aesthetics has to come second to function, especially when it's a business relying on it.
 
this is all true, being into my gadgets an stuff I thought it a cool little project to work on in my spare time. Its a little hard as we are currently working from home so all the equipement was put in the front room in the TV unit which we just got. So changing or modding the top is going to be a no no.

I think its going to have to be more holes and fans then. Think I will need to get some mounting brackets sorted to stop some of the noise.. Thanks for the advice an stuff
 
Also, be aware that Aquarium Chillers actually belt out a lot of heat. Most Aquarium owners house their chillers outside (I do with mine). The other thing is the pressure that chillers are designed to be run at would likely blow the seals on a PC waterblock.
 
Its nice to have ideas for cool projects and that but bare in mind this is going to have an ongoing cost ascoiated with it. All very well if it is your only pheasable option, and if others are picking up your leccy bill, but I would be looking putting the server somewhere else in your house where it won't have to look nice if it was me, do you have a under stair cupboard or a spare room? Bascially, does it *have* to be housed in your TV unit, which presumably is also being used as your TV stand? What sort of business do you have if you don't mind me asking. I would still be asking myself if "a little on the warm side" was actually a problem though, if it wasn't causing things to crash.
 
ok had an afternoon to look over all the options. The only other one I have come up with is move all the equipement into the garage as I dont have any other space in the house. I will be investigating if this is possible. As to do that im going to need to make the garage a little more secure. I will keep you all updated on how things go
 
The way i've seen water chillers done before is just the cooling pipe taken from an old fridge and stuffed into a make shift reservoir. Though to then use that to cool air seems a bit pointless.
I'm sure you'ld get much better performance if you just directly attached the phase change cooling pipes to a couple fans.

Personally i think you should just look at AC units as cooling air is what they were designed to do after all and you don't have to mess about with highly toxic refrigerants.
 
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