On the subject of pumps.....

[BrianW]

Here is an overview of my system:

3 blocks. CPU,GPU,Video. All will have 3/8 NPT Female threads to accept the barbs. The CPU will have 1/2" barb to accept 12" ID tubing. The other blocks will have 3/8" barbs to accept 3/8" ID tubing.

I will be using two Distribution blocks to get the water to the chips. Here's a pic.

<img border="0" src="http://thengc.net/images/watercooled/guide.jpg" alt="QuickView">

The block on the right will attach directly to the Pump/Res/BleedLine mod I made. Similiar to one on here earlier.

All tubing and fittings will be 1/2" id except for the individual runs to the two smaller blocks. The max head is 24". I have a full tower case, and the rad is in the top and the pump is on the bottom.

My question: What pump should I use? I want good flow, but not excessive as the heat from an overactive pump will probably heat up case. I will be venting the hot air around the pump via a low flow panaflow 92 mm fan. I will have two holes, one on each side of the case, directly next to the pump. The fan will suck air across the pump out the side of the case.

I know the Eheim's are highly recomended, but I've been looking at "The Quiet One" at www.overclock-watercool.com . A super quiet direct drive pump that pumps over 1100 GPH Here's a pic.

<img border="0" src="http://thengc.net/images/watercooled/quietone.jpg" alt="QuickView">

Thoughts, Ideas?

Thanks

[fugdong]

thats a big ass pump, both in size and power. And if i recall when i was at overclock watercool it wasnt cheap. That pump would definitly work in your system, but i think it would be too much, to much power and preasure. So there is no way you could fit it into your case, and 2 i would be afraid because that thing is going to maxing out the preasure your system can take, and if there is even 1 weakspot its going to cause a leak. A leak in a computer is bad. So if you do get the pump be weary

[BrianW]

So what brand and size would you all recomend? Thanks again for the input guys.

[Def]

A direct drive pump is not good in a computer application IMO. Those things have seals to wear out and some can leak oil or other stuff into your water.

I'd suggest a Danner MagDrive Model 7 - 700gph rating. You can get them from PetsMart.com, plus as a new customer you can get $10 off your purchase!

I've got a Danner MagDrive 5 which is rated at 500 gph and can pump over 10' high. Haven't put together my whole system, but with the Aquastealth Aquacoil radiator(similar to the Cooling Cube but with higher flow) and about 3 feet of 1/2" ID tubing the pump was really flowing alot of water. I'll put it this way, it was shooting a 1/2" diameter stream of water over a foot and a half out of the tube when held level, that's after going through the radiator.

I think the Model 7 would be perfect for your setup. They're extremely quiet, submersible or inline capable, and pretty affordable.

As for your design, have you thought about going to a 5/8" ID barb for the input/outlet barbs on the distribution blocks? Might really help the overall flow in your system.

[GuyBFF]

I'd go Danner Mag-Drive 350 or 500, or Eheim 1250 or 1048 if you got cash to burn (but you already know I'd say that).

One thing to consider with direct drive pumps is that the seals can fail without warning in time. A Mag-Drive will give off lots of noise before failure and keep going (unless it's a RIO).

Also the direct drives tend to be less efficient (adding more heat to the water) than the Mag-Drive variants.


Edit: changed danner sizes 500, 750 to 350, 500 (late here, getting tired I guess)

[BrianW]

So is a Eheim 1250 (317GPH on the same level as the Mag Drive 500 ( 500 GPH) I see them mentioned together, and yet they are different rated pumps.

Also is the Eheim threaded for npt? In other words can I screw a 1/2"NPT barb in the end of it?

Thanks

[GuyBFF]

The eheim 1250 is about the same level as the Danner Mag-Drive 350. The 1048 is between a 500 and a 750. Eheim rates there pumps in metric gallons (4.5 litres, rather than 3.78 litres), so there actually pushing a little more.

I'd normally say the 350 was enough, but I'd spec higher on either end due to the way you want to split flow to the three waterblocks.

Ideally I would say a Danner 500 or a Eheim 1048 would be more than enough with extra waterblocks (as any more will just contribute heat).

[gmat]

Danner pumps need some sealing work to prevent them from leaking. Try Hydor or Eheim pumps instead, they're OK out of the box and have threaded inlets on which you adapt any kind of fitting.

[BladeRunner]

arghhhhh Imperial Gallons rather than US Gallons! I think you'll find they show both on their site specs.

http://www.eheim.com/technik_pumpen.htm

I'm still at a loss as to why people require such huge flow rates. If you are using an air cooled rad with a smallish system coolant content you will push the coolant through it faster than it can release the heat properly if the rate is to much. Of course too much is better than not enough as you can always restrict the flow but I would think 250 GPH (imperial) should be enough for just about everything, as long as it is split in a manifold and you dont have any major pipe restrictions.

My cooling system works a little differently (no rad) so maybe that has something to do with it, but I noticed ZERO difference in CPU temps Before when the pump output just went through the CPU block, and after fitting when splitting the flow to a manifold and supplying CPU / VGA GPU & Ram, & mobo Chipset.

This indicates to me the original flow was in excess of what was required, and with the now slightly reduce flow rates it is still as good as it needs to be. This is using an Eheim 1250 pump which is also pumping up about 1.5 meters.

[Flash]

You've got to keep in mind that *none* of these pumps will come close to providing their rated flow when used in a water cooling setup--1/4 to 1/6 of the rated flow is, I think, a fair estimate. There's alot more restriction than you'd encounter in a pond or fish tank, which is what these things are designed for.

Still, you can have too much flow. I believe it depends on the surface area of the radiator, i.e., a smaller radiator benefits from lower flow, whereas a rad. with more surface area can handle increased flow.

[jimtbaker]

First time posting here. I have followed the threads here for awhile. I did some testing this past week-end on flow rates using a Quiet One Pump (it is silent). Hooked the pump up using various configurations I measured the following flow rates. Average flow with 3/8 tubing, 3 home-made copper HD coolers, Be-cooling water block, 5-way home-made copper splitter, home-made copper collector res and Aquastealth cube was 48 gph. With just 3/8 tubing and rad the flow was still only 64 gph. So I don't think the Quiet One is overkill, at least for my system (Dual OC'd Pent and 3 10,000 rpm SCSI drives to cool). My goal is silence. The pump and rad will be mounted outside in their own case.

[GuyBFF]

I've had two Danners (a 250 and a 350) and my good friend at a fish store has sold many to people who use them for hydroponics in inline configurations, and neither of use has heard of one leaking unless it was POORLY mounted. I tried to make mine leak by pulling on the hoses severly, and it wuoldn't. Even eheim's will sometimes leak at all there o-rings. Eheims deffinetely are a great pump, but I think this Danner Mag-Drive leakage thing is blown out of proportion.

I have to admit before I got mine I too was warning everyone to silicon it up to as I read this somewhere.

[BrianW]

Well I was all ready to get an Eheim, until I went to their site and saw how big it is. I was wondering if someone knows how bog the Magdrive 5 is compared to the magdrive 3. The three fits with room to spare. I want to get the 7 and i've read the 7 is the same size as the 5, with a diff impeller. Any ideas?

Thanks

BTW the Eheim 1048 is 158 gph not 500-700. The 1260 is 600, and the 1250 is 317.

[Def]

The Danner MagDrive pumps models 2-7 all have the same housing. So if a 3 fits, so will a 7.

IMO, you probably won't reach that level of "too much flow" with one of these centrifugal pumps. They just can't pump well against pressure, and that's the only way you're ever going to get say 100 gph in a standard WC system.

I'd still recommend a Model 7 over a 5 for your application. I've been messing around with my MagDrive 5 for a few days now, and with just the radiator hooked up it easily drops to about 1/3 of the flow without it. This is a BE Aquacoil radiator. I'd also estimate that just putting the 1/2" ID barbs cuts the flow almost in half from no barbs on it.

[BrianW]

Thanks Def.

As for your design, have you thought about going to a 5/8" ID barb for the input/outlet barbs on the distribution blocks? Might really help the overall flow in your system.

What if the barbs on the radiator will be accepting 1/2 id tubing? Will not that counteract having the larger tubing?

Did you have to superglue the impeller to the impeller shaaft? I've read that the impeller head can rotate 180 on w/o moving the shaft. I suppose it created vibration and noise. Did you seal yours?

Thanks

[gmat]

Just to make sure you dont fall in this common trap: "lower flow rate means more time to exchange heat", this is totally wrong.
Heat exchange rate depends on exchange surface. More flow rate, more surface. In theory you can get better heat transfer by have the highest possible flow rate.
In reality very powerful pumps tend to build lots of heat, due to their own motor power (Joule effect here). But those pumps are so expensive and so big... it's not the point here in computer watercooling. Just make sure your pump aint crap. What you want is *decent* flow rate and yet a silent pump. thats it

[Def]

My MagDrive 5 is nearly silent when all the air is out of the system. I can hear a nice purring sound if I put my ear right up to it, but when I get just 2 feet away I really cannot hear the pump at all. This is in a silent room btw. The vibration will make noise if you don't isolate it, so get some rubber to set it on.

I did seal my pump with Blue RTV Sealant, but the first time didn't do so well. I just got my waterblock today and I've been messing with my system some. I kept getting air into the lines, and I'm pretty sure it was the housing. So I just cleaned it off with alcohol this time and redid the RTV and it looks like it'll be sealed up nicely.

Not sure if it leaked when I first got it. I did some preliminary testing with it and it didn't, but I figured why take a chance if I can seal it really well now.

The impeller does in fact rotate on the shaft, but it doesn't really cause any noise(that I can tell). I have heard of some people having trouble to get their pumps to initially turn over when attaching the impeller to the shaft. I think these little motors don't develop much torque so they need that extra 180 degrees to get "wound up".

[Def]

If the radiator is 1/2" ID you might want to keep your current design. I was thinking it was a heatercore and you could change the barbs and it could cope with the flow.

You can still get some good flow coming out of 1/2" ID barbs, so don't worry about starving any components of waterflow.