Xtreme Xterior Cooler

[ColonelCain]

Ah, I love winter. Makes the heat produced from F@H not that noticable!

[CyberDruid]

Agreed!

[Kimjor]

How cold would it have to be before condensations begins to be a problem? sub 0 degrees?

I have the posibility of doing about the same, but here in Denmark winter tends to be pretty cold.. (well not canada like.. but still :-) )

[CyberDruid]

All you need to do is pack the socket with dielectric grease and line the tubes in and out of the case with foam sleeve. Piece of cake. Considering the benefits I hardly see condensation as a factor to hold you back.

[SiGfever]

What percentage of glycol will you have to run and what performance hit will it create?

[CyberDruid]

That's a good question. Right now I have added about 2 0Z on Pentosin to 1 quart of water. It rarely dips into subfreezing here in the Winter...and I run the rig 24/7 (currently running BOINC ) so I doubt it would slush up on me...

[CyberDruid]

Thanks for reminding me...sometimes I overlook the simple stuff...lol.

I just checked the Pentosin bottle and it appears that I have used less than 1/4 of a 4 OZ bottle...so it's probably more like Sherlock Holmes would prefer: 7%

[Real Genius]

You know, the ultimate solution would be some type of earth radiator buried about 10' - 20' underground. At that depth, the surrounding earth temperature = the average annual air temperature - about 50 degrees F for a temperate zone. The temperature is constant from season to season. You would have to design some type of system to conduct (not radiate) the heat to the surrounding earth without corroding. A cement tank might be a good option to circulate coolant through if you can figure out how to prevent cracks.

It would definitely be going to an extreme length to cool a PC but it would be killer! The heat capacity of the surrounding earth is infinite for all practical purposes. You could cool ANY system that way, silently.

[The Lone Wolf]

your talking about something along the lines of a septic tank there real genius plus your trying to remove heat the trick is to use something that wont degrade like plastic. something along the lines of what they use for raidant heat. do note if you did that you would need something like a 1/2 hp circulator pump. that alone requires a transformer though im not too sure on that.

[Nate P.]

Awesome idea man!

[Jedda]

It has been done and you don't need to go down anything like 20'.

[CyberDruid]

yip its called Geo-cooling just below frostline is enough

Thanks for the link. That notion had crossed my mind in the past. I might still get around to trying that out one day. I was thinking about using a pony keg...but an oxygen bottle looks to be a good size.

[Real Genius]

The best vessel would be an aluminum scuba tank. The oxygen bottle is probably steel - a poor choice. Steel cylinders have thinner walls than aluminum and are very susceptible to corrosion. A typical 80CF @ 3000 PSI scuba cylinder will have a wall thickness of of something like 3/8" and are very corrosion resistant. Furthermore, aluminum oxide actually inhibits further corrosion while rust on on teel tank begats more rust. It's best to use a bare cylinder. All paint does is trap moisture underneath - encouraging corrosion.

I''ve worked full-time in the recreational dive industry for 12 years by the way and I can't BELIEVE I didn't think of using a scuba tank!

[SiGfever]

The best vessel would be an aluminum scuba tank. The oxygen bottle is probably steel - a poor choice. Steel cylinders have thinner walls than aluminum and are very susceptible to corrosion. A typical 80CF @ 3000 PSI scuba cylinder will have a wall thickness of of something like 3/8" and are very corrosion resistant. Furthermore, aluminum oxide actually inhibits further corrosion while rust on on teel tank begats more rust. It's best to use a bare cylinder. All paint does is trap moisture underneath - encouraging corrosion.

I''ve worked full-time in the recreational dive industry for 12 years by the way and I can't BELIEVE I didn't think of using a scuba tank!

Mixed metals is not a good thing.

[Real Genius]

Stainless Steel is not used in pressure vessels because it's not strong enough. It's corrosion resistance is also over-stated.

SIGFever, as I pointed out in another thread, two conditions have to be met for galvanic corrosion to occur:

1. Two or more dissimilar metals must be submerged in the same electrolytic fluid and,

2. The metals must be electrically connected.

The tank would be at earth-ground potential, obviously. I haven't built a water cooling system yet but I don't see why the copper blocks would be connected to anything. They're mounted to non-conductive chip housings, right? I notice there is usually a screwed-down clamp over the block. If the screws contact the case or the pcb ground plane anywhere, the clamp should be insulated from the block.

You CAN have aluminum and copper in the same loop as long as they are not electrically connected to each other.

[CyberDruid]

Stainless Steel is not used in pressure vessels because it's not strong enough. It's corrosion resistance is also over-stated.

SIGFever, as I pointed out in another thread, two conditions have to be met for galvanic corrosion to occur:

1. Two or more dissimilar metals must be submerged in the same electrolytic fluid and,

2. The metals must be electrically connected.

The tank would be at earth-ground potential, obviously. I haven't built a water cooling system yet but I don't see why the copper blocks would be connected to anything. They're mounted to non-conductive chip housings, right? I notice there is usually a screwed-down clamp over the block. If the screws contact the case or the pcb ground plane anywhere, the clamp should be insulated from the block.

You CAN have aluminum and copper in the same loop as long as they are not electrically connected to each other.

Galvanic reactions or electrolysis as I know it from the yachting industry are present any time two dis-similar metal are in electrical contact. In the case of a PC cooling loop that would be the fluid--which is usually conductive to some degree.

Although mixed metals can be prevented from reacting by using chemicals in the cooling loop there is still a slight chance of corrosion from any air that might be in the loop too.

I too have used mixed metals in loops and have an extant example of this in service. After 2 years I see no sign of corrosion..but I also used a 25% mixture of Zerex with the distilled.

For those of us looking for maximum efficacy from the medium the use of chemicals is a no no as anything added to the distilled will reduce it's ability to transfer heat.

I like the idea of a large copper tube sunk into the earth--but not sure how it holds up to the acids present in most soil.

Interesting stuff...

[Real Genius]

Galvanic reactions or electrolysis as I know it from the yachting industry are present any time two dis-similar metal are in electrical contact. In the case of a PC cooling loop that would be the fluid--which is usually conductive to some degree.

Yeah, I'm a dive boat captain so I'm well familiar with it too. I don't think the fluid can be the connector AND the electrolyte. You need a complete circuit. Current will flow from the cathode to the anode (aluminum to copper in this case) through the fluid and return via the electrical connection. The electrical connection is usually physical contact between the two metals such as when a bronze prop is mounted to a steel shaft. I suspect a lot of pc cooling installations inadvertently ground the physically-separated metals like the blocks and radiators when it could be easily prevented. If they are both grounded, we have a return path and electrolysis can occur.

[CyberDruid]

Yeah, I'm a dive boat captain so I'm well familiar with it too. I don't think the fluid can be the connector AND the electrolyte. You need a complete circuit. Current will flow from the cathode to the anode (aluminum to copper in this case) through the fluid and return via the electrical connection. The electrical connection is usually physical contact between the two metals such as when a bronze prop is mounted to a steel shaft. I suspect a lot of pc cooling installations inadvertently ground the physically-separated metals like the blocks and radiators when it could be easily prevented. If they are both grounded, we have a return path and electrolysis can occur.

Not to argue but the field given off by most yachts even at anchor is strong enough to corrode the zincs on boats up to 150 yards away. This is a fact. The salt in the water makes it highly conductive--and the EM fields thrown off by charging equipment and the general wiring of the boat (as everything is bonded) is very powerful. That is why keeping the sacrificial zincs up to snuff is so critical--especially in harbor or when docked for long periods.

An improperly bonded or wired vessel can rapidly corrode the zincs on surrounding boats and lead to damage unless the situation is noted and remedied.

In a PC loop it is not exactly the same deal..but indeed the water acts as the electrolyte in that it makes the transfer of ions possible due to it's conductivity...this effect is independent of pump action or any other EM effect from the PC. It's like a battery.

Any easy proof. Dip a chunk of aluminum and a chunk of copper in some water and make sure they do not touch and take a voltage reading. To really make the point thow in a pich of table salt.

[crash5s]

nice, but living in NOVA as well it hasn't been that cool lately

[CyberDruid]

My ambient tonight is 18.6C outside and 25.2C inside...that's 6.6C lower than I might other wise be getting

But yeah it has been annoyingly UN Fall-like--and today got up in the high 70F range which is NOT what I want right now...

[Real Genius]

Not to argue but the field given off by most yachts even at anchor is strong enough to corrode the zincs on boats up to 150 yards away. This is a fact. The salt in the water makes it highly conductive--and the EM fields thrown off by charging equipment and the general wiring of the boat (as everything is bonded) is very powerful. That is why keeping the sacrificial zincs up to snuff is so critical--especially in harbor or when docked for long periods.

An improperly bonded or wired vessel can rapidly corrode the zincs on surrounding boats and lead to damage unless the situation is noted and remedied.

In a PC loop it is not exactly the same deal..but indeed the water acts as the electrolyte in that it makes the transfer of ions possible due to it's conductivity...this effect is independent of pump action or any other EM effect from the PC. It's like a battery.

Any easy proof. Dip a chunk of aluminum and a chunk of copper in some water and make sure they do not touch and take a voltage reading. To really make the point thow in a pich of table salt.

Google, "galvanic corrosion" and you'll get a plethora of artlicles telling you the same thing: There has to be an electrical connection between the two metals in question. You'll have that in your anchored yachts if they are both using all-chain rodes - they are both close to ground potential. It's certainly true in separated boats both plugged into shore power. Plus, the huge surface area of an aluminum-hulled boat is going to generate a large concentrated current on a tiny zinc 150 yards away - IF they are at the same electrical potential or anywhere close to it.

You are correct when you say that there is a voltage potential between un-bonded pieces of aluminum and copper in a glass of water but that doesn't result in any corrosion. You need a current flow between them for that. There is NO current flow between the two because it is an open circuit. You have to connect the two to get current flow. It doesn't have to be a perfect connection but the more resistance (ohms), the less the flow. Two pieces of metal which are in total isolation from each other CANNOT interact galvanically.

Is it possible to electrically isolate a copper block from an aluminum radiator (resistance beyond the range of a good digital multimeter)? As I said earlier, I haven't built a water-cooled rig yet but I don't see any reason why you cant.

[CyberDruid]

To steer more directly to what is going on in a PC cooling loop:

It is not glavanic corrosion but the subtle process of electrolysis that pits the aluminum and sludges the brass and copper. The electrical impulse is generated by the disimilar metals difference in ionic potential just like a battery--because of the neutral ph of the water the current is minute...but over time it will pull pieces of aluminum toward the brass.

To veer back to the similar issue at play with yachts:

Salt water forms the electrical connection between the disimilar metals and the effect is much more pronounced. If you put a piece of copper and a piece of zinc in a glass of salt water where they do not touch the zinc will eventually dissolve and copper will form a residue. If you add voltage the effect is rapid.

[Real Genius]

Salt water forms the electrical connection between the disimilar metals and the effect is much more pronounced. If you put a piece of copper and a piece of zinc in a glass of salt water where they do not touch the zinc will eventually dissolve and copper will form a residue.

Do you have a link to a study which confirms this? I'd be interested as I will be using an aluminum radiator with copper blocks in the system I will be building.

[CyberDruid]

I will see what I can dig up for you. My knowledge of the yachting end of this is first hand. I have spent about 18 years beating the docks and have read many articles on the subject.

I simply applied that to what I see first hand happening to stuff in my loop.

The very first LCS I concocted used a Rev. 1 Storm and an aluminum universal transmission cooler from NAPA. I went heavy on the Zerex and still years later the block and cooler are in perfect condition. The Tygon is still supple

I buy a lot of used stuff and I have found that alumunum watercooling parts are absolute junk. I have thrown away quite a few GFX card waterblocks that were part of bundles of LC gear I was getting because they were riddled with corrosion and no longer trustworthy due to the porosity of the metal.

A recent example of something you might not expect but that does happen.

Despite using Primochill PC Ice non conductive coolant I still found a greenish accumulation on a Danger Den aluminum filport I was using...the effect might have been attributable to condensation but it was starting to effect the nickle-plated barb/aluminum body connection. Having a number of rigs with the same type Filport I started making sure they wer topped off...this elimnated the problem. But is still stood out to me that reactive metals in a loop are not a good thing.

I'll see what I can find for you on the subject.

I no longer will purchase anything aluminum to use in a PC, despite having my first LC rig operating troublefree all this time. Gotta love that AquaXtreme 50Z DC-12...what a great pump.

[CyberDruid]

This pretty much some up what I just said. But now feel very ignorant because it's Improper to call the process elctrolysis. What can I say...that's what they call it on the docks

http://www.ocean.udel.edu/seagrant/p...corrosion.html