questions about phase cooling

grvydude18 · 12-08-2003, 10:54 AM

ok, well everyone says that a refrigerator, especially minis won't work, well how small are we talking? and how much are you overclocking? i mean if regular water cooling is working then why won't a small refrigerator kick it up a notch? now i am new to cooling systems, and deff new to phase cooling... just wanting to understand what the problems are? what the limits are and everything like that... thanks all

grvydude18 · 12-08-2003, 10:55 AM

oh yeah, and then for waterproofing like your mother board? couldn't you just like seal it with some sort of sealing and then foam it to seal it from outside temps? would this work or could it melt/burn something? im talking not only cpu cooling but chipset too? just throwing ideas out there.

jaydee · 12-08-2003, 11:17 AM

Depends on the fridge I would assume. Most small ones only use TEC's. While some more expensive one's actually use phase change. I imagine the phase change would work better as the TEC's are not really made to handle a heat load. Stuff you put in a fridge doesn't generate heat so it doesn't need extream power to cool things off. Take a mini fridge and put a 100watt hologen flood light in it and see if it can keep up. It will not. Put a bottle of Soda in there and it will keep it cool because the Soda doesn't create heat.

grvydude18 · 12-08-2003, 02:59 PM

k, yeah i understand the heat deal, frigs not attacking something thats constantly warm, but to what temps will the frige still take it? and then also my question above about waterproofing?

jaydee · 12-08-2003, 03:08 PM

Quote:

Originally posted by grvydude18
k, yeah i understand the heat deal, frigs not attacking something thats constantly warm, but to what temps will the frige still take it? and then also my question above about waterproofing?

Depends on the fridge. :shrug: Look at the specs on some.

Don't know about water proofing. I doubt you would have to worry about it with a fridge. Won't get cold enough to cause condensation. Also you need to leave anything on the mobo that gets warm open, like the mosfets, coils, caps, etc...

You would probably be better off getting one of theose $100 window air conditioners and making a chiller with it.

grvydude18 · 12-08-2003, 03:31 PM

Well since im not quite ready, or need to do some serious overclocking yet, im just trying things out, cheap ways too. Basically im getting info, so that when i start building my computer this coming year i know exactly what i want to do, and for the most part i do, but yeah, thanks for the help, if anyone else has any info post please, thanks.

Tempus · 12-08-2003, 07:34 PM

You WILL get condensation in a mini-fridge. Typical compressor-based refridgeration has a low temp evaporator.

Look at a mini-fridge w/ ice box part. That heat exchanger plate gets ice all over it. Same thing will happen to the mobo.

jaydee · 12-08-2003, 07:51 PM

Quote:

Originally posted by Tempus
You WILL get condensation in a mini-fridge. Typical compressor-based refridgeration has a low temp evaporator.

Look at a mini-fridge w/ ice box part. That heat exchanger plate gets ice all over it. Same thing will happen to the mobo.

Like I said, put a 100watt light inside the fridge and see if it still freeze's.

Also as I said again most mini fridges do not use phase change, they use TEC's. At least the cheap one's. If your going to spend the cash on a mini fridge that is capable of cooling over 100watts then just buy TEC and power supply and do it right.

MadHacker · 12-08-2003, 11:12 PM

Quote:

Originally posted by jaydee116
....If your going to spend the cash on a mini fridge that is capable of cooling over 100watts then just buy TEC and power supply and do it right.

then there is the hydro bill to factor in as well...
what would be more expensive to run? Phase change or TEC?

jaydee · 12-08-2003, 11:18 PM

Quote:

Originally posted by MadHacker
then there is the hydro bill to factor in as well...
what would be more expensive to run? Phase change or TEC?

Flip a coin? They both will need to run as long as the comp is on. Will depend on the specs of the units aswell.

Groth · 12-09-2003, 01:43 AM

Phase change will use less power. The Coefficient of Productivity (COP - defined as heat removed / input power) for phase runs 2.5 to 3, a bit less if you want super low temps. TECs generally have a COP of 0.4 or so.

Tempus · 12-09-2003, 08:13 AM

There is a hell of alot more to this discusion than "TEC good phase bad."

Personally, I've never seen a mini-fridge using a TEC for cooling. I have seen a single or dual beer cooler using TECs but not a fridge.

Why?

Simple, TECs have a hot and cold side. If you stick a TEC in the fridge cool it then you have to move the heat somewhere. Its kinda hard to insulate it properly to prevent hot side thermal migration. TECs are just not suitable for something the is 1 cu ft or larger.

I *assume* you are talking about getting a reasonably large mini-fridge and sticking a computer in it.

If you are talking about the other option -- that is, pulling the refridgeration system off of the mini-fridge and mounting it on the computer as a cpu cool -- then thats a whole different issue.

Thats basically what a prometia does. You need 4 pieces: a compressor, a condensor, an expansion valve, and an evaporator. If you want to take a mini-fridge and adapt it for this, then you need to replace the evaporator with something thats more like a standard heatsink / waterblock so that you can mount it on the cpu.

Thats all a huge pain and I don't recommend it. Working with refridge tubing SUCKS. And you need special tools to play correctly. All and all its better to not delve unless you have plenty of time and money -- of you know a bunch of HVAC technicians. =)

One nice thing about using refidgeration is that the heat from the whole system exits the condensor coil. With a TEC you have local heat still and it will require fans (or a water system) to move it all away.

Theres alot of other issues but thats a good start.

12-08-2003, 10:54 AM	#1
grvydude18 Cooling Neophyte Join Date: Dec 2003 Location: virginia Posts: 17	questions about phase cooling ok, well everyone says that a refrigerator, especially minis won't work, well how small are we talking? and how much are you overclocking? i mean if regular water cooling is working then why won't a small refrigerator kick it up a notch? now i am new to cooling systems, and deff new to phase cooling... just wanting to understand what the problems are? what the limits are and everything like that... thanks all

12-08-2003, 07:34 PM	#7
Tempus Cooling Savant Join Date: Jul 2003 Location: Michigan, USA Posts: 456	You WILL get condensation in a mini-fridge. Typical compressor-based refridgeration has a low temp evaporator. Look at a mini-fridge w/ ice box part. That heat exchanger plate gets ice all over it. Same thing will happen to the mobo. __________________ Thou art God.

12-09-2003, 08:13 AM	#12
Tempus Cooling Savant Join Date: Jul 2003 Location: Michigan, USA Posts: 456	There is a hell of alot more to this discusion than "TEC good phase bad." Personally, I've never seen a mini-fridge using a TEC for cooling. I have seen a single or dual beer cooler using TECs but not a fridge. Why? Simple, TECs have a hot and cold side. If you stick a TEC in the fridge cool it then you have to move the heat somewhere. Its kinda hard to insulate it properly to prevent hot side thermal migration. TECs are just not suitable for something the is 1 cu ft or larger. I assume you are talking about getting a reasonably large mini-fridge and sticking a computer in it. If you are talking about the other option -- that is, pulling the refridgeration system off of the mini-fridge and mounting it on the computer as a cpu cool -- then thats a whole different issue. Thats basically what a prometia does. You need 4 pieces: a compressor, a condensor, an expansion valve, and an evaporator. If you want to take a mini-fridge and adapt it for this, then you need to replace the evaporator with something thats more like a standard heatsink / waterblock so that you can mount it on the cpu. Thats all a huge pain and I don't recommend it. Working with refridge tubing SUCKS. And you need special tools to play correctly. All and all its better to not delve unless you have plenty of time and money -- of you know a bunch of HVAC technicians. =) One nice thing about using refidgeration is that the heat from the whole system exits the condensor coil. With a TEC you have local heat still and it will require fans (or a water system) to move it all away. Theres alot of other issues but thats a good start. __________________ Thou art God.

12-08-2003, 10:55 AM	#2
grvydude18 Cooling Neophyte Join Date: Dec 2003 Location: virginia Posts: 17	oh yeah, and then for waterproofing like your mother board? couldn't you just like seal it with some sort of sealing and then foam it to seal it from outside temps? would this work or could it melt/burn something? im talking not only cpu cooling but chipset too? just throwing ideas out there.

12-08-2003, 11:17 AM	#3
jaydee Put up or Shut Up Join Date: Dec 2001 Location: Spokane WA Posts: 6,506	Depends on the fridge I would assume. Most small ones only use TEC's. While some more expensive one's actually use phase change. I imagine the phase change would work better as the TEC's are not really made to handle a heat load. Stuff you put in a fridge doesn't generate heat so it doesn't need extream power to cool things off. Take a mini fridge and put a 100watt hologen flood light in it and see if it can keep up. It will not. Put a bottle of Soda in there and it will keep it cool because the Soda doesn't create heat.

12-08-2003, 02:59 PM	#4
grvydude18 Cooling Neophyte Join Date: Dec 2003 Location: virginia Posts: 17	k, yeah i understand the heat deal, frigs not attacking something thats constantly warm, but to what temps will the frige still take it? and then also my question above about waterproofing?

12-08-2003, 03:31 PM	#6
grvydude18 Cooling Neophyte Join Date: Dec 2003 Location: virginia Posts: 17	Well since im not quite ready, or need to do some serious overclocking yet, im just trying things out, cheap ways too. Basically im getting info, so that when i start building my computer this coming year i know exactly what i want to do, and for the most part i do, but yeah, thanks for the help, if anyone else has any info post please, thanks.

12-09-2003, 01:43 AM	#11
Groth Cooling Savant Join Date: Mar 2003 Location: MO Posts: 781	Phase change will use less power. The Coefficient of Productivity (COP - defined as heat removed / input power) for phase runs 2.5 to 3, a bit less if you want super low temps. TECs generally have a COP of 0.4 or so.

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