what to look for when shopping for pumps

[kristos]

I'm planning on getting a watercooling and I'll be needing a pump offcourse.

Now I've noticed there are a lot of factor's that come into play like flowrate, pressure (how high they can yet water?), submerged or not, noise production, AC or DC, inlet, outlet, inner diameters, outer diameters and I don't know what else.

Most importantly, I need to know what factors play in getting a good overall flow because I've heard about 1000 l/h pumps outperforming 1200 l/h pumps because the 1000 l/h pump had more pressure.

So, if If you lot could share your knowlledge with me that would be great


PS: I'm from Belgium and we work with liters and cm instead of gallons and inches so if someone knows how they compare to eachother that would be great too

Thx in advance

[krazy]

Welcome to procooling, Kristos! I just went through the great pump search, after debating and researching a whole lot of properties about different pumps. i ended up with a Danner Mag 3, but your ideal pump could be just about anything.

The main things to look into strictly for performance reasons are head and flow. With these two criteria the same, pumps perform almost identically. Head seems to be a little more helpful than tons of flow these days because of the highly restrictive blocks coming into play.

Looking slightly more into the long-term, you'll also want to care about duty cycle of te pump. Is it designed to run continuously? A non-contunous rated pump is a very bad idea for a watercooling project. Stay away from sump pumps and bilge pumps, as they are usually designed to pump for short perods of time and then sit for a while and cool off.

Some pumps may be rated for continuous duty, but will wear out much sooner than other pumps. Be wary of pumps that use motor brushes. Every second the pump is running, the brushes are just wearing thinner and thinnner. Stick to pumps with brushless motors if at all possible unless you understand what you are getting into.

The criteria that pertain least to performance are things like how much noise the pump makes, how it looks, or what kind of power it runs off of. Generally, quieter pumps are preferred, but going with a louder pump seems to allow you to get more performance for less money.

AC pumps have the advantage that you don't have to drive them off of your power supply or have a dedicated transformer or separate power supply in the machine. AC pumps theoretically make more noise than an otherwise identical DC pump because of the alternating current pulling the impeller in 60cycle jogs instead of smoothly, like DC can. With an AC pump, you also have to find a way to get power to it. Some people just plug the pump in separately, and some people wire it into the power coming into their PSU with a relay, which can be triggered by the PSU coming on.

DC pumps can usually be hooked right onto your power supply, but be ready for the noise they can induce and the power they can draw. They should be a little quieter than AC pumps, but you need a separate power supply to run them when the computer is shut off. An AC pump could have a bypass switch wired in to keep the water circulating while the PSU is powered down or for testing purposes.

In the end, it all comes down to how much money you want to spend versus how well it needs to perform and how quiet it needs to be. I hope this is helpful.

Krazy Karl

[killernoodle]

The most reliable pumps are usually the mag drive pond/fountain pumps. They can run continuously for years on end and are relatively quiet. Most can be submerged or ran inline. They are almost always cheaper than 12v pumps with the same capacity. Mag drive pumps never contain brushes, so you dont have to worry about that part wearing out and usually have only one moving part. They may not create the flow or pressure of a Iwaki pump, but generally they are very quiet.

I would recommend the mag 3 for any watercooling system. It is quiet, powerful, rugged, and above all: cheap.

[Gooserider]

Unfortunately Killernoodle, I don't think the Danner Mag pumps are available in Belgium, as they have that weird 220V 50Hz stuff in the wall instead of nice normal 110V 60Hz. I could be wrong though. I know that Europe does have Eheim pumps, which are about the same quality, or maybe a bit better than the Danners.

I would add that Krazy's response was very good, except that I would probably put a bit more emphasis on head pressure than on flow rates. I would almost say to get the highest head pressure you can afford, and don't even worry about the flow rate since any good head pressure pump will have acceptable flow.

Gooserider

[kristos]

thx guys, I'll keep an eye out for those mag drive pumps around here.

another question though:

If you got a pump with insane head pressure (in pc watercooling terms that is ) does this worsen the chances for leaks or breaks in the water circuit?

I would think it would but then perhaps I'm just worrying over nothing


PS: 110V 60 Hz sounds just as odd in Europe

[killernoodle]

Eheim pumps are also mag drives, those work just as well but usually cost more.

[WAJ_UK]

In Europe the Eheims aren't too bad price wise. The 1250 is only about £10 ($18 ish or €15 ish) more than the L30. I haven't seen any danners over here though, could well be because of the power supply

[pauldenton]

Originally Posted by WAJ_UK

In Europe the Eheims aren't too bad price wise. The 1250 is only about £10 ($18 ish or €15 ish) more than the L30. I haven't seen any danners over here though, could well be because of the power supply

don't know where you're looking but afaik best UK price for a 1250 is £44.65 (inc VAT and shipping) and for an L30 £25.50 (inc VAT and shipping)......

no danners here (60hz only)

[AngryAlpaca]

I would suggest the Eheim 1250 if the Mag 3 is unavailable. There is not much (probably not measurable) difference between the standard pumps, due to the fact that they all fall into the 1-2 GPM range. And, Eheims are very high quality. By the way, blocks are actually becoming less resistant, but people have only just realized how important head pressure is, due to the testing done by pHaestus with the MCP 600.

[WAJ_UK]

don't know where you're looking but afaik best UK price for a 1250 is £44.65 (inc VAT and shipping) and for an L30 £25.50 (inc VAT and shipping)......

Sorry, I didn't realise the L30 could be had for that little, cheapest I had seen was about £35, with the L20 for £25.
Sorry for the dodgy info

[pauldenton]

Originally Posted by WAJ_UK

Sorry, I didn't realise the L30 could be had for that little, cheapest I had seen was about £35, with the L20 for £25.
Sorry for the dodgy info

no sweat - it's from somewhere that didn't used to sell them (the coolingshop) - L20 is just under £20...

[Gooserider]

kristos :
If you got a pump with insane head pressure (in pc watercooling terms that is ) does this worsen the chances for leaks or breaks in the water circuit?

I would think it would but then perhaps I'm just worrying over nothing

Not really. Keep in mind that AFAIK ALL the pumps normally used in PC cooling systems are some form of mag drive, as they are the easiest / lowest cost to make water tight and durable. Mag drives are inherently not very powerful, and even the high pressure Iwaki's max out at around 30' / 10m of head (approx - I'm working from memory so I'm probably off a wee bit) and most of the rest will be somewhere's between 8-15' (2.5-4m)

That is a MAXIMUM head pressure, that you would see only if you had *NO* flow at all. More typically you will have a head pressure *about* 1/2 the rated max or 4-8' (1.2-2.5m).

Head pressure translates at the rate of 32' = 14.7PSI = 1 atmosphere of pressure, so your actual pressure difference between the pump inlet and outlet will be on the order of about 2-4 PSI, which should be easily within the range of any hose or fittings you are likely to encounter. Even a big Iwaki will probably only get you up to 7-8 PSI, which is still not enough pressure to cause problems if your build technique is reasonable.

Arguably the biggest single point of failure is hoses blowing off of fittings, which is easily prevented by simply using appropriate clamping technology on the barbs. Next most common POF is poor construction techniques, such as overtightening fittings in plastic (causes cracks); lack of appropriate sealants on fittings; poor choices of glues and sealants; and poor application techniques (especially trying to seal leaks by globbing sealant onto the outside of the leaking part....)

Personally, I pressure test each component I will use to 90PSI (the max my air comressor will put out) or it's maximum safe pressure (whichever is less) before starting to build a system. Once the system is built, I will pressure test the entire system to the lowest pressure rated component's pressure (typically the radiator at ~25PSI) This will find any problems, and prove that the build is OK.

Gooserider

[bigben2k]

I had to dig this up, just for you! This is what I go by, when selecting a pump:

1-make sure that it's a centrifugal pump.
2-if it's a "self priming" pump, don't get it: it'll be noisier than you can handle.
3-Magnetically driven, centrifugal pumps are usually the quietest
4-The pump should have a max pressure (a.k.a "dead head") rating of at least 1.5 meters, the more the better.
5-The flow rating is pretty much irrelevant, but you'd be shooting for at least 300 gph (~1200 L/H) at zero height.
6-Don't even think about using a massive pool pump: there's a limit to the efficiency of these things.
7-Keep in mind the power source: mains (110 or 220 V AC) is easy to deal with. 12 V DC is a bit trickier.

I personally have a Little Giant model 2-MDQ-SC (max flow > 550 gph, max head: 14.6 feet) ( www.convert-me.com ) and also have two Johnson pumps (linked in my sig). Both of these are phenomenal pumps, but each have their advantages and disadvantages.

The Little Giant draws a lot of power, and is quite large, because it's a true mag drive. The Johnson pump is a direct drive, so it draws a lot less power, but has been known to leak.

I know that in europe you might be able to get your hands on a fabulous pump, relatively cheap, depending where you live: Grundfoss. They're used in water heaters.

[RoboTech]

Hi kristos,

Welcome to ProCooling...

I generally select a pump based on the waterblock (and other water-cooling system components) I plan to use. Head pressure is what drives flow. Too low a head pressure and you may not get the flow you want, especially if using a restrictive waterblock design (some microchannel and/or jet impingement blocks). Selecting a pump with uber head pressure may be overkill and dump excess heat into the water and increase the chance for leaks.

You might look at both Eheim and Hydor pumps, especially since you are in Europe. The Eheim 1250 and 1048 are very popular as is the Hydor L30. I recently reviewed the L30, which you might find helpful.

Good luck with your project!

[BillA]

dig deeper fellows, as in market research

it is my understanding that the US market Hydor has a ceramic shaft,
and that the European still has a ss shaft
- this will affect the longevity, no ?

[RoboTech]

The US market Hydor L30 II (115 VAC, 60 Hz) I received two weeks ago has a SS shaft (see picture in link above). I was "expecting" a ceramic shaft and was surprised to see SS.

[pauldenton]

Originally Posted by RoboTech

The US market Hydor L30 II (115 VAC, 60 Hz) I received two weeks ago has a SS shaft (see picture in link above). I was "expecting" a ceramic shaft and was surprised to see SS.

pardon my ignorance, but which is preferable?

according to this aussie site the australian (240V, 50Hz) model has a ceramic shaft...(and a 3 year guarantee...) i'd be surprised if they did a special 240V model for the aussie market rather than using the same one as europe (since it's made in italy)

[BillA]

Originally Posted by RoboTech

The US market Hydor L30 II (115 VAC, 60 Hz) I received two weeks ago has a SS shaft (see picture in link above). I was "expecting" a ceramic shaft and was surprised to see SS.

uuh ?
tilt, perhaps someone knows 'what's really goin' on' ?
(clearly I do not, looking at my broken ceramic shaft - 43dbA ??)
BTW, the L20 has a ss shaft

Bruce is due to pay a visit today, I'll ask (he'll post)

[RoboTech]

The pump I received is a Hydor (Seltz) L30 II (note the II). I was unable to find out any information about what makes the new "II" version different from the original L30. I checked the Hydor website, talked to the US supplier and I also called Hydor USA - none had any info. I e-mailed Hydor, Italy but have not received a response. My first reaction after opening the pump was that maybe the "II" has a SS shaft instead of ceramic... ???