Stacking radiators? Will it work?

D

DeGrey

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Nov 26, 2006
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Ok, I'm going to throw an idea out there and get some opinions from the pros.

Background: I am new to water cooling, this will be my first build. I currently have a Q6600 CPU and a 8800 GTS GPU. I plan on over-clocking both and water cooling both. I'm trying to get the entire system to fit cleanly inside of a TT Armor full tower case.

Now, originally I was thinking of using a ThermoChill PA120.2 for my rad with 2 low RPM fans pulling air through (I want this setup to be quiet as well as efficient). However, after doing some more research, I am wondering if a single 2x120mm radiator will be enough to handle an over-clocked quad core and the 8800 GTS.

So, I got to thinking, what if purchased a pair of SwifTech MCR-220 radiators and made a sandwich of sorts.

Something like this:

||Fan|| |||RAD 1||| ||Fan|| |||RAD 2||| |Front of case

Radiator 1 (the back radiator) would be the first radiator in the cooling sequence. Once the water passed through radiator 1, it would then loop through radiator 2 (in the front). Theoretically the progressively cooler radiator.

The reason for this little idea was so I could double up my radiators BUT still be able to fit them in the case. This little radiator sandwich should fit nicely in the lower 5.25 bays where fresh air can easily be pulled through the front of the case.

So what do you think? 2 radiators and 4 fans. The back radiator would be a push/pull config and the front, a simple pull config. Granted the warm air from the front radiator will pass through the back radiator but I'm not sure how adverse that effect would be.

Oh yeah, other components in the system will be:

CPU block: Fuzion
GPU block: EK full coverage block (still not sure on this as full coverage is expensive)
Pump: Swiftech MCP655
Tubing: Masterkleer Tubing 7/16" ID
Reservoir: Swiftech MCRES-Micro

Any and all recommendations are welcomed. Feel free to tell me I'm crazy... I don't get offended easily ;)
 
Well as long as you have fans inbetween the rads it will work but you would get much better performance having the 2nd rad by itself.
 
Don't know too much BUT I'd venture to guess that there are (at least) two things wrong with this picture -
1. The amount of heat exchanged between the radiator and the air depends on the difference in the temperature between the two. Heated air from rad 1 wouldn't play nicely with rad 2.
2. The amount of cooling also depends on the volume and pressure of air which is pushed through the fins of the radiator. With two rads, you're probably looking at a setup which is very restrictive, which would require some fast and loud fans to properly cool.

on a side note, wouldn't this make the space issue even worse in terms of tubing and clearance with other components...two rads and two fans is a pretty thick slab.

I'm sure that like all things, this is a compromise - it will work to a degree but by separating the rads you will be able to get lower temps or a higher OC with slower and quieter fans. Poke around the watercooled case galleries of [H] and xtremesystems for ideas on how to fit everything nicely.
 
In another thread somewhere, a poster called this arrangement a "counter-current heat exchanger", which, as heat exchangers go, is quite efficient. As long as your flow goes Rad 1 -> Rad 2 like you say (that is, counter to the airflow) it should work fine.

I would expect that two MCR220 rads in counter-current-exchange setup would indeed be more effective than a single PA120.2. Probably not by a large extent, though, and the question is if it will be enough of an improvement to justify the added expense, space, setup hassle, etc. A ThermoChill PA120.2 already is essentially two radiators sandwiched together---the "dual-row" part of its description, and why the PAs are so freakin' thick.

Regards the video waterblock: The full-coverage blocks look awesome, and many are single-slot, but you will get lower temps with a GPU-only block and RAM heatsinks. There's a comparison at Madshrimps. (As an owner of a BFG 8800GTX "Water Cooled Edition" that came with a Danger Den waterblock preinstalled I was less than thrilled to have discovered that comparison.)
 
One of my first builds was with a setup like this and it doesn't work very well at all. A rad can only cool the water down to the temp of the air that is passing through it. So your second rad will only be able to cool things down to the temp of the air exiting the first rad which will not be very cool at all. Rads work best with fresh cool air.
 
rsquared said:
I would expect that two MCR220 rads in counter-current-exchange setup would indeed be more effective than a single PA120.2. Probably not by a large extent, though, and the question is if it will be enough of an improvement to justify the added expense, space, setup hassle, etc.
Click to expand...
There is no added expense, but space, setup and flow rate would be better with the Thermochill. I personally don't think the Thermochill PA120.2 is worth it.

rsquared said:
Regards the video waterblock: The full-coverage blocks look awesome, and many are single-slot, but you will get lower temps with a GPU-only block and RAM heatsinks. There's a comparison at Madshrimps. (As an owner of a BFG 8800GTX "Water Cooled Edition" that came with a Danger Den waterblock preinstalled I was less than thrilled to have discovered that comparison.)
Click to expand...
Thanks for linking that. I recently lost my bookmarks and forgot about it.

vsboxerboy said:
Don't know too much BUT I'd venture to guess that there are (at least) two things wrong with this picture -
1. The amount of heat exchanged between the radiator and the air depends on the difference in the temperature between the two. Heated air from rad 1 wouldn't play nicely with rad 2.
Click to expand...
You drastically exaggerate the amount that the air will heat up. Thermochill radiators are thick, as rsquared mentioned.

vsboxerboy said:
2. The amount of cooling also depends on the volume and pressure of air which is pushed through the fins of the radiator. With two rads, you're probably looking at a setup which is very restrictive, which would require some fast and loud fans to properly cool.
Click to expand...
Any radiator performs better with faster, more powerful fans. The MCR series are designed to perform well with little air flow - performance shouldn't suffer much with a little added air restriction.

Sideroxylon said:
One of my first builds was with a setup like this and it doesn't work very well at all. A rad can only cool the water down to the temp of the air that is passing through it. So your second rad will only be able to cool things down to the temp of the air exiting the first rad which will not be very cool at all. Rads work best with fresh cool air.
Click to expand...
Again, Thermochill radiators are over two inches thick and are the best performers on the market. I don't know why your first setup performed badly, but it wasn't because the first radiator heated the air too much - unless you used two 2" thick radiators.

The one thing no one's mentioned yet is air turbulence. With all those fans that close together, you may create more noise from air turbulence, and your fans may actually get louder as well. Try holding two fans close together while running and you'll see what I mean. I'd imagine that high speed fans would be something you'd want to avoid here, and you may want to have both radiators separating the fans, like FAN || RAD || RAD || FAN.

Since this is your first setup, I'd have to suggest using a single radiator though. The added surface area helps cool, but the added restriction reduces flow. I don't think that the cooling benefits are worth the hassle of what you're trying to do - you can't bolt all the way through those radiators, so you're going to need to get very creative when it comes time to fasten everything together.
 
I would think the cooling would be better if you set it up this way...

res>>pump>>rad1>>cpu>>rad2>>gpu>>res
 
Thanks for all of the tips. Great information here! I appreciate all of the insight and experience. I may bite the bullet and go for the ThermoChill. I think it may be the quietest and most straight forward solution. I just hope the 2x120 rad will be enough to cool everything.

If it doesn't work out as well I would like, I'm going to do build my other idea which consists of a aluminum box the exact dimensions of the bottom of my case. I'll attach this to my existing case and build all of my radiators and fans into the extended area. The custom build would look seamless and it would be fun project to tackle. Tinkering is half the fun of computers ;)

Again, thanks for all of the information. I won't be adding water cooling for a couple of weeks yet so I'll keep the gears going on ways to get this to fit and perform quietly.
 
Keep us posted Ive been thinking going water but just on my videocards.. This CM 830 is not the most WC friendly case..
 
Yes, it would work. The 2nd radiator's efficiency would be reduced by anywhere between 30-50% depending on total heat load.
 
Its not really worth it, you hurt the cooling about as much as you help it in this case. Not only is the second radiator getting hotter air, but you are increasing the back pressure by having two rads in series like this. That means less airflow and therefore less cooling. Your better off just sticking to one and trying to find another place to put the second one.
 
Nicepants42 said:
Again, Thermochill radiators are over two inches thick and are the best performers on the market. I don't know why your first setup performed badly, but it wasn't because the first radiator heated the air too much - unless you used two 2" thick radiators.
Click to expand...

You are obviously confused on how radiators work. They do not magically wisk heat away. They simply transfer it to the air being passed through it. Their performance is directly related to the air temp passing through them.

Arcygenical said:
Yes, it would work. The 2nd radiator's efficiency would be reduced by anywhere between 30-50% depending on total heat load.
Click to expand...

As usual Arcy is the voice of reason here. I would think his estimate is very close to the actual performance you could expect from the "sandwich" setup.

And just for the record. A single 2X120mm rad will not be sufficient to cool a quad core and a GTS vid card. Actually, let me rephrase that a bit. It will work if you aren't expecting very low temps and your not oc'ing. I'd be willing to bet that your temps with that setup will be very close to high-end air cooling. Consider using a 3X120mm rad at minimum or figure out a dual loop setup without the rad sandwich.
 
Sideroxylon said:
You are obviously confused on how radiators work. They do not magically wisk heat away. They simply transfer it to the air being passed through it. Their performance is directly related to the air temp passing through them.



As usual Arcy is the voice of reason here. I would think his estimate is very close to the actual performance you could expect from the "sandwich" setup.

And just for the record. A single 2X120mm rad will not be sufficient to cool a quad core and a GTS vid card. Actually, let me rephrase that a bit. It will work if you aren't expecting very low temps and your not oc'ing. I'd be willing to bet that your temps with that setup will be very close to high-end air cooling. Consider using a 3X120mm rad at minimum or figure out a dual loop setup without the rad sandwich.
Click to expand...

A rough estimate is that a 2x120 can dissipate 300W while maintaining about a 10C coolant to air delta. I think a GTS and Quad is right around 300W or less, so a 2x120 is fine.
 
Erasmus354 said:
A rough estimate is that a 2x120 can dissipate 300W while maintaining about a 10C coolant to air delta. I think a GTS and Quad is right around 300W or less, so a 2x120 is fine.
Click to expand...

But it isn't [H]ard. ;) If he leaves it stock he'll be fine. If he oc's, like he says he wants to, he will not be happy with the temps he ends up with.
 
Yes, I am planning to overclock at least the quad. Actually, I am now on my new system as I type this. Just got it all up and running tonight with all stock coolers. Can't wait to pry those off and water cool this thing.

I was looking at the ThermoChill PA120.3 and I *could* fit that in this case if only use two of the 5.25" bays. I currently have the power switch in the top bay and a DVD drive in the 2nd bay. If I donate the rest to a radiator, there would be room for a 3x120.

I was mis-informed (elsewhere) that the PA120.2 would be plenty for an overclocked quad and a 8800 GTS. The more I read, the more I regret taking that advise as it was the basis for my decision to go with this case.

Oh well, I'll figure something out. I hate to do it, but I may have to go external :(
 
Erasmus354 said:
A rough estimate is that a 2x120 can dissipate 300W while maintaining about a 10C coolant to air delta. I think a GTS and Quad is right around 300W or less, so a 2x120 is fine.
Click to expand...

A gts is around 140 at stock. 180 overclocked to the max. :)

A Q6600 is around 90 at stock. But by 3000mhz (1.35v) you're looking at 140w :) At 3500mhz 1.4v, 202w.

The 150w per 120mm radiator figure is a tad overzealous of a recommendation. A good figure to start with (hell, I generally say it myself) but not when the user is *right* on the cusp of heat saturation... Said figure is generally only true with a 1.5gpm coolant flow, and around 55-75 cfm per fan... Not very quiet setup! 104w is the figure I was able to dissipate to air (10c coolant over air delta) while using a single BIP radiator with a single yate loon fan at 12v. That figure rose to 119w at 1400rpm (medium speed yate at 10v) and later 140e (2200rpm screamer).

A BIP2 yielded almost exactly double this figure. Add in 10% for Thermochill superiority (estimate with the odds against you for protection) and you're around 120w with a yate per 120mm fan.

DeGrey said:
Yes, I am planning to overclock at least the quad. Actually, I am now on my new system as I type this. Just got it all up and running tonight with all stock coolers. Can't wait to pry those off and water cool this thing.

I was looking at the ThermoChill PA120.3 and I *could* fit that in this case if only use two of the 5.25" bays. I currently have the power switch in the top bay and a DVD drive in the 2nd bay. If I donate the rest to a radiator, there would be room for a 3x120.

I was mis-informed (elsewhere) that the PA120.2 would be plenty for an overclocked quad and a 8800 GTS. The more I read, the more I regret taking that advise as it was the basis for my decision to go with this case.

Oh well, I'll figure something out. I hate to do it, but I may have to go external :(
Click to expand...

Going for a triple radiator would make a world of difference. How? Well... Your temperatures might not change all that much, but your noise level could drop anywhere 33-50% while maintaining the same loop to air heat dump!

What's with the power swich as a front bay? Personally, I'd just get a slimline CD rom drive and an all in one bay-panel.
 
At this point I am thinking about just going external. I'm going to build an aluminum cage that will hold a pair of radiators (probably Swiftechs 3x120 or 2x120 for cost considerations).

I may even put the radiators in a crawl space underneath this room where they can run cool and quiet. That would put them about 18" below the pump which I would keep in the case along with the MicroRes.

Would a MCP655 pump be able to handle pushing the water through a loop with two rads 18" below? I would also like to find some nice quick disconnects to make things a little easier if I ever need to move the case and radiator box. What's the best to use for that?
 
My external set up is somewhat what you originally described.

Rad-->1/2" spacer--> Fan --> about a 6" gap--> Rad--> 1/2" spacer-->fan.

As far as the second rad getting notionally warmer air, as long as you are using the setup as a single loop this is easily remedied (if it has any effect at all), have the warmer water enter the second rad first, then go to the first rad (the one getting the "fresher" air), then back onto the blocks, etc.... The water will be as cool as it can get with ambient temps.

Testing...
DSCF0333.jpg


....and the finished product.
DSCF0462.jpg
 
zacrobmer said:
My external set up is somewhat what you originally described.
Click to expand...

Dude! That's exactly what I had in mind to build for an external system. That looks great by the way! Very nicely done. I love the clean, finished look of it all. That's it, I'm going external like that. My mind has been made up after seeing your pics.

Do you have any more pics / tips / instructions for putting something like that together?
 
Yeah hind-sight is 20/20..... Unfortunately I didn't leave room for swapping the fans/rads.

The original idea was to not have the vent on the side (top?), but I had an issue with the box being too air tight and the fans not being able to move any air. When the top was off it would hum along great, so I added the vent to equalize pressure a bit.

Thanks for the comments.

Here's how I did it.

I used 1/4" acrylic, doubled up for the supports, super-glue to hold the pieces together (with a few screws for added support) and a little weather stripping to seal it up. Before painting I sanded the edges round, filled any gaps and holes and plumbed for the inlets/outlets.

I used Panaflo L1's at 9v (home made resisted leads). They still push a lot of air but are very quiet.

Making the fan/rad supports
DSCF0328.jpg


Main structure complete.
DSCF0329.jpg
 
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