Page 1 of 2

water or oil cooling??

Posted: Sun Jul 11, 2010 8:47 am
by POLAND_SPUD
I concluded that air cooling just isn't the right solution... adding some fins/radiators might help a bit but I want to build the ultimate cooling system

I think that liquid cooled system would be the best idea. The idea is simple: get a bucket put the compressor in it and fill it with liquid. Oil would be ideal as it isn't conductive. However it is also fairly expensive and I am going to need about 15 litres of it

However, because the compressors are perfectly sealed I concluded that I might as well use tap water... The only problem is to seal perfectly the 3 pin connector but I think I might be able to do that

so... do you have any thoughts, ideas, opinions etc. ?

Posted: Sun Jul 11, 2010 8:52 am
by jackssmirkingrevenge
How come you changed your mind? And I suppose you could use vegetable oil to save money...

Posted: Sun Jul 11, 2010 9:21 am
by POLAND_SPUD
well I concluded that an 80W fan is an overkill... and if it can't keep the damn thing cold on hotter days or when I use it for more than 2 hours then it might be a good idea to try something else
vegetable oil
AFAIK vegetable oil deteriorates with time... I am leanign towards using water as it has higher heat capacity than oil... I might as well use 50 L or more

Posted: Sun Jul 11, 2010 9:44 am
by Ragnarok
POLAND_SPUD wrote:...then it might be a good idea to try something else
The daemonic kettle! (It's a weird project of mine - basically a high powered automotive intercooler)

In the less oddly named department, have you tried just something simple, like filling the space around the compressor with steel wool?
If you then blow air through it, that would basically act as a very high surface area heat sink.

A kilo of grade 1 steel wool has a surface area of about 10 square metres.
Although you might need a coarser grade (and thus less surface area) to be able to get air blowing through it easily, compare that to a 1 kilo steel sphere, with a surface area of 1/80th of a square metre.

Posted: Sun Jul 11, 2010 10:23 am
by jackssmirkingrevenge
Ragnarok wrote:In the less oddly named department, have you tried just something simple, like filling the space around the compressor with steel wool?
Interesting thought, instant radiator...

Posted: Sun Jul 11, 2010 10:30 am
by Insomniac
Could work, but I can't help thinking that the heat transmission from the compressor case to the steel wool itself would be less than ideal.

Posted: Sun Jul 11, 2010 10:37 am
by jackssmirkingrevenge
Insomniac wrote:Could work, but I can't help thinking that the heat transmission from the compressor case to the steel wool itself would be less than ideal.
Indeed... perhaps a 5-6" inch wide strip of sheet metal welded to the case, wrapped around the case in a spiral, with steel wool packed in between.

Posted: Sun Jul 11, 2010 10:40 am
by spudamine
I can't believe air cooling isn't enough for you :) It keeps my compressor running a few degrees above ambient for as long as I can be bothered to run it for, increasing my surface area with fins or otherwise would be fairly pointless.
if you really want to use oil cooling it would be most efficient to use the oil already in the compressor, just add a reservoir, pump and fan cooled radiator. Some larger compressors even come with the plumbing for this but you'd probably have to braze an extra connection or two into the shell.
I wouldn't piss around with water and mains power unless the water was in a selaed loop.

Posted: Sun Jul 11, 2010 10:56 am
by Ragnarok
Insomniac wrote:I can't help thinking that the heat transmission from the compressor case to the steel wool itself would be less than ideal.
It might take some thought, but it should be better than to air alone. Other than what Jack suggests, thermally conductive paste might help - although don't do the trick someone I know did, mixing up the insulating paste and the conductive paste when putting their computer together...

Provided you're not letting the wool stagnate the air around the compressor (in other words, keep air moving through it), it at least shouldn't worsen anything.

Posted: Sun Jul 11, 2010 5:42 pm
by jimmy101
Remember that just dropping the compressor into a bucket of water will keep the thing at or below the BP of water. That may or may not be cool enough for you.

If the temperature of the compressor is more than a few degrees below the BP of water than all the water really does is increase the heat capacity of the system, it does fairly little to the ability of the system to dissipate heat. In other words, it'll take longer to get to say 180F if the compressor is in water but it will eventually get there. You need some way to actively room heat from the system, like a radiator.

If cooling is really needed, and assuming you don't want to use a second reefer to cool the first compressor ( :D ), and water is ok...
wrap the compressor in a towel, dribble water onto the towel, blow across the setup with a small fan (like 4" computer case fan). Basically a swamp chiller. They are generally very effective and use minimal power, but do require a slow stream of running water.

Edit: You might be able to skip the fan and the running water by wrapping the compressor in cloth then setting it into an inch or so deep pan of water. Capillary action will draw water up into the cloth and simple air convection may give enough evaporation of the water for effective cooling.

Posted: Mon Jul 12, 2010 12:54 am
by Crna Legija
just put it in a fridge :D

Posted: Mon Jul 12, 2010 9:02 am
by psycix
-_- wrote:just put it in a fridge :D
Are you insane? Nobody does that!

Image
:D


Poland, the ultimate fridgy cooling system is as follows:
Pump the oil that the compressor bathes in through a radiator. This way you are directly cooling the electric motor and the compressor instead of cooling the shell around it.
I'm sure it could pump 24/7 on a hot summer without overheating, as long as the radiator is big enough (with an optional fan) and the pump pumps enough oil.

You could take it out of the shell and put it in a new one or make two holes in the shell to pump the oil in and out.

Posted: Mon Jul 12, 2010 9:04 am
by POLAND_SPUD
Could work, but I can't help thinking that the heat transmission from the compressor case to the steel wool itself would be less than ideal.
yeah, I agree
It keeps my compressor running a few degrees above ambient for as long as I can be bothered to run it for
well it isn't that bad but what if I add another compressor ?

hmm I've got to test something then I'll report back

EDIT
Yeap... It gets waay too hot... especially whne running at 400 psi for an hour or so

ohh BTW my face just got a few ricochets :? damn that was stupid

Posted: Sat Jul 17, 2010 10:37 am
by POLAND_SPUD
I filled the bucket with a couple of litres of water...

Posted: Sat Jul 17, 2010 11:39 am
by jackssmirkingrevenge
Doesn't look very safe...