Water pumps

By CMH ยท 45 replies
Apr 23, 2006
  1. I'm not yet buying one, but I'm building one for a friend.

    I heard that submerged pumps are alot quieter than unsubmerged ones. Is this true?

    If it is, why aren't there many submerged ones in the market? The majority I found are unsubmerged pumps. Going to the fish shop, I found plenty of submerged ones, but they're 240V....

    Any ideas?
  2. twite

    twite TechSpot Paladin Posts: 937

    i have the L30 unsubmerged pump and its completly silent..i wouldn't worry to much about getting it submerged
  3. KingCody

    KingCody TS Evangelist Posts: 992   +8

    what's wrong with 240V??

    I use a submerged pump for mine and it is 120VAC (US, obviously yours in AUS is 240VAC). 12V pumps are usually alot more expensive than 120/240V pumps.

    I modified my PSU and added an AC outlet inside my case for the pump, but I used to simply run the AC cord through an empty PCI slot and that worked fine.
  4. CMH

    CMH TechSpot Chancellor Topic Starter Posts: 2,039   +9

    running AC cords through a PCI slot seems kinda.... messy. Not to mention I lose the option of switching the pump automatically at startup.

    I get it that its pretty silent, but given that I've got 3 computers to deal with, the combined sound might still be irritating. As it is, my computer room sounds like a factory.

    Is it louder than a good PSU? If its softer, I won't worry about submerging pumps then.
  5. KingCody

    KingCody TS Evangelist Posts: 992   +8

    do you really care what the wires behind your puter look like? I could never see the wire on mine, but I'm anal so it still bothered me that it was there which is why I wired it into my PSU.

    you don't have to turn it off with your system, there's only 1 moving part in a submerged pump and it's lubricated by the water it's pumping, so they last a long time.

    But if you really want to turn it on and off with the PC you can buy a relay card. these cost about $10-$20 USD and will automatically switch the pump on and off with the PC. or you could simply add a switch to your case somewhere, just remember to turn it on before you turn on your PC.. lol
  6. CMH

    CMH TechSpot Chancellor Topic Starter Posts: 2,039   +9

    I should take a pic of what the wires behind my 3 puters look like now. Its not pretty, and whenever I go down there to remove/add something (USB thumb drives or something), usually another computer shuts down or something :p

    A relay ehh?? Kinda good idea, but it still doesn't solve the 240V stuff. I suppose I can mod the PSU to gimme a 240V supply. Not sure if I should be playing with those kinds of power, so far all my modding is restricted to the 12V and 5V lines...
  7. KingCody

    KingCody TS Evangelist Posts: 992   +8

    of corse it solves it.. lol, that's the whole point.

    you plug the pump into the relay card, the relay card has it's own 240V power cord, you also plug the PSU's 12V molex into it. The relay is a magnetic switch. when your psu is on and 12v is applied to the relay card, it "flips the 240VAC switch" and turns the 240V pump on. when you turn the PC off, the 12V is cut and the "240VAC switch is flipped back" to off.

    funny that with the way you described the tangled mess of wires behind your computer, you were worried about 1 wire making it messy?? haha :D :D :D
  8. CMH

    CMH TechSpot Chancellor Topic Starter Posts: 2,039   +9

    I'm worried given that there's no sound from the pump, I can accidentally disconnect it and blow my PC.

    And besides, I don't need extra wires. I would've gone wireless if I had confidence in the tech. Still on my trusty ole MX500, and standard logitech keyboard.

    Edit: My 400th post
  9. KingCody

    KingCody TS Evangelist Posts: 992   +8

    you wouldn't "blow" the PC, if for some reason you shut it off or disconnected it... your CPU would heat up and the mobo would shut the system down before any damage occurs.

    The same thing would happen if a fan on a heat sink stopped spinning, it wouldn't be the death of your PC, so don't worry about it.
  10. CMH

    CMH TechSpot Chancellor Topic Starter Posts: 2,039   +9

    Not too worried about it, but I'd like to have a fool proof system.
  11. KingCody

    KingCody TS Evangelist Posts: 992   +8

    it would be just as "foolproof" as a 12v pump. just tryin to give u some cheaper alternatives...

    it's really not worth water cooling unless you can build it cheaply, IMO.
  12. CMH

    CMH TechSpot Chancellor Topic Starter Posts: 2,039   +9

    I dunno, I went to an enthusiast shop's site, and the best watercooling stuff all up will cost me AUD$600. That doesn't even include TECs, but I'm sure I can add that in for an extra 100.

    But as I said, I was talking best. I don't think a 200+W TEC will be sufficient. I'm more comfortable with 300W or more, but this shop doesn't have them.

    But I configured this:
    CPU: Swiftech Storm (129)
    GPU: Swiftech MCW60 (99)
    NB: Swiftech MCW30 (49.5)
    Pump: Swiftech MCP655 (139)
    Coolant: CoolerMaster Thermal Conductivity Fluid (22)

    All up: 438.5.

    Of course I can save some money if I went for some cheaper parts, but when I looked up google for reviews, these are the best I can lay my hands on. Lowest temps I can find.

    If I wanted the Swiftech Apogee CPU block instead, I'll save myself some money, but CPU temp goes up 2C (according to one review article). But that one's still alot better than anything Tt comes up with.
  13. CMH

    CMH TechSpot Chancellor Topic Starter Posts: 2,039   +9

    Took some time reading up on DIY waterblocks.

    DIY waterblocks are the way to go if you're after high end performance. And don't forget, also if you're a handyman with a workshop filled with metalwork tools. Not to mention the performance comes with the waterblock design.

    Unfortunately, I have no such experience/equipment, so I think I'll have to forgo that even if I really wanted to do it.
  14. hadoud76

    hadoud76 TS Rookie Posts: 41

    So the only problem left is the submerged 240V???
  15. CMH

    CMH TechSpot Chancellor Topic Starter Posts: 2,039   +9

    Looks like its quiet enough being submerged (plus I read that output water temps actually rise more from submerged pumps) so I'll just go with the unsubmerged ones.
  16. KingCody

    KingCody TS Evangelist Posts: 992   +8

    true, but very little. it won't make a significant difference.

    all electric motors generate heat, an inline (un-submerged) pump will generate heat as well and the water going through the pump will carry some of that heat off in the same way that a submerged pump will.

    again, the heat generated by any pump is very minor compared to the heat generated by the CPU/GPU/etc.
  17. CMH

    CMH TechSpot Chancellor Topic Starter Posts: 2,039   +9

    Either way, it is so much harder to get my hands on a submerged pump, so I couldn't be bothered.

    Anyone with experience with aquarium pumps? How do they fare in relation to flow rate and water height (or whatever the technical jargon is for it)?
  18. AtK SpAdE

    AtK SpAdE TechSpot Chancellor Posts: 1,495

    I work with pumps quite often. We use 50-700gph pumps. I think the "water hight" youre reffering to is called head. Head is the length that the pump will have to push the water. A 700gph pump is pretty damn powerful.

    Most aquatic pumps are rated by model number. Model 2=200gph Model 7=700gph etc. There is not much size difference between MOdel 2 and Model 7.
  19. KingCody

    KingCody TS Evangelist Posts: 992   +8

    pretty much all water pumps used for PC water cooling are aquarium pumps (except for some pre-built kits)

    I find it just the opposite. i find it to be much harder to find small inline pumps than subermersible ones.

    I use this pump in my system. it can pump up to 156 G/h with a max head of 46 inches (much higher than my PC case goes... lol)
  20. AtK SpAdE

    AtK SpAdE TechSpot Chancellor Posts: 1,495

    Well if the pump is rated for 156gph, its most likely not going to put that out. Cheap pumps are rated a 0 head, so as soon as the head is increased the flow rate drops way down.

    The pumps we use can be both submersible and non. An example can be found here
    I think they may be a bit too expensive however.

    We have smaller ones, but i cant seem to find them on the site. If i do, i will repost.
  21. KingCody

    KingCody TS Evangelist Posts: 992   +8

    i know, but in my case it's only being used at about a 10 in head, so the water moves fast enough. i have run the system open, and the water is moving fast.

    i was trying to give some cheap solutions, because IMO it's not worth spending $60 on a pump. that money would be better invested towards a new CPU, etc.
  22. CMH

    CMH TechSpot Chancellor Topic Starter Posts: 2,039   +9

    I don't know too much about the physics of water, but don't all the loops and ups and downs in a system (especially in the radiator) count in measuring the total height the water has to move?

    For example, if the radiator is 25cm long, and the water goes up and down a couple of times, doesn't the total height the water moves become 50cm? (or 75 or whatever, you get my drift).
  23. CMH

    CMH TechSpot Chancellor Topic Starter Posts: 2,039   +9

    Also, I'm looking at some pumps available from eBay.au and I'm seeing alot of "interesting" pumps.

    Now I'm confused about how big a pump I should get.

    What would be a recommended Head and recommended LPH for computer watercooling? I'm not talking minimum, cos I'm willing to spend some here. I'm thinking of running a couple of X1900XT (not the XTX) overclocked, so I'm expecting some serious heat.

    I'm also thinking if its a good idea to run the water circuit in parallel, reduces flor resistance, and makes sure there's no heated water going through the GPU/CPU.

    I'm also wondering if cooling GDDR RAM is a good idea, I've read that its not really necessary, and the waterblocks for X1900s look crap. The same goes for the NB. ear in mind the overclocking I plan to do.

    Sorry for all the questions :D
  24. KingCody

    KingCody TS Evangelist Posts: 992   +8

    yes and no

    loops and ups and downs will not have a huge impact. it takes pressure to push the water up, but when gravity pulls the water back down, a vacuum is created and helps pull the water through.

    the biggest restrictor for proper flow is right angles. avoid right angles and 'T' splitters whenever possible, try to use straight barbs and 'V' splitters/combiners.
  25. twite

    twite TechSpot Paladin Posts: 937

    running water through 2 overclocked gpu's and a cpu will heat up the water alot...so running it through the memory to will probably heat up the memory rather then cool it.I would try to find a pump thats at least 700 LPH..you will also have to consiter what radiator you get. For your needs you will probably need a 2(120 mm) radiator.
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