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Too much gph ?????

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Budzman

Registered
Joined
Feb 14, 2001
I just picked up a new pump for my cooler form a garden store. The pump is for water fountains and is rated at 384gph. Got a good deal on this bad boy too, it was regularly priced at $75 but they had a 50% off sale so i lucked out on that.
Just wondering, could it be possbblle to have too powerful of a pump in your system? I'm using a HW Black ice radiator, and its got small tubing and i'm thinking that the water could be going to fast through there. Just a thought, my temps are pretty good, with my DD Maze2 block (new design) my temps are about 36*c under full load and my water is about 28.5 +/-.5*c, room temp is 27*c.
Well now that i think about it, it does a good job. Guess i just wanted to talk about my new pump. I needs to stop smokin that reefer.
 

Diablo

Registered
Joined
Apr 17, 2001
if you pump the water to fast it wont have time to dissipate the heat in the radiator. the water has to have enough time to dissipate its heat otherwise youll notice an increase in temperature after the system runs for awhile.
 

Richard

Senior Member
Joined
Jan 15, 2001
I doubt that he'll see an increase in temperatures. He'll just pass the point of dimishing returns is all. Like putting a 90 cfm fan on a heatsink. Eventually, you're going to be limited by the thermal conductivity of the waterblock.

Diablo (Jul 30, 2001 05:05 p.m.):
if you pump the water to fast it wont have time to dissipate the heat in the radiator. the water has to have enough time to dissipate its heat otherwise youll notice an increase in temperature after the system runs for awhile.
 

Thelemac

Administratively Deficient
Joined
Mar 15, 2001
Diablo (Jul 30, 2001 05:05 p.m.):
if you pump the water to fast it wont have time to dissipate the heat in the radiator. the water has to have enough time to dissipate its heat otherwise youll notice an increase in temperature after the system runs for awhile.

But there will be much less heat to dissipate as the water will have picked up less from the waterblock...

Like Richard999 said, it just comes to diminishing returns like air.
 

LordSmack

Registered
Joined
May 3, 2001
I cant find the article but the faster the flow rate the more heat is released. the way the guy explained is he compared it to dumptrucks. 10 dumptrucks hauling a full load of heat. It hakes them one hour to make a complete loop(10 heat units lost/10x1), now take 20 dumptrucks hauling half the load but they complete the loop in a half hour(40 heat units/20x2). here's the way it works :slow moving water (smaller volume)stays in the water block longer picking up more heat(10btu), it then spends as long in the rad releasing the heat(10btu).so you get 10btu an hour. the faster moving water picks up less heat(5btu) while in the water block but it moves say three times as fast(greater volume), so you have in theory three times the water and it releases it's heat in the rad (5btu x three passes =15 btu) now here's the kicker someone is going to say "hey wait a minute! If it picks up less heat why doesn't it release less of the heat it is carrying?!) well here is where thermal dynamics comes into play: turbulent(fast) water releases energy much faster than stagnant(slow) water. Ever see a running river freeze or boil over? Even though it picks up less heat in the block it can release more heat as it travels through the rad and if you don't believe this,I didn't, go buy a flow meter their around $80.00,a restrictor around $20.00 and test this theory your self. When I did the test I found that after a certain point my temps didn't change any more. This was because I had hit the limit of my cooling gear, but until I hit that limit my temps went DOWN as my flow went UP. Please make sure you don't try to go to high because most water cooling rigs especially the hose clamps won't hold under pressure so don't buy some pool pump rated at 1000 gph at 70psi or your going to get in trouble. remember normal pumps don't exert pressure. That is why they loose gph as you add hose. PSI pumps hold the same flow rate by FORCING the water to flow.
 

Colin

Arctic Silver Senior
Joined
Dec 19, 2000
Most fountain pumps don't generate enough pressure to worry about blowing a hose. If you think you have too much flow, put a hose clamp on the output of the pump and restrict the flow. If you temps go down, continue to tighten the clamp until they go up. Then set the clamp at the sweet spot. My guess is if you restrict the flow, your temps will go up. 384 GPH necked down to fit the Maze 2 is not that much flow.
 

Diablo

Registered
Joined
Apr 17, 2001
Flowing the water to fast as far as I am aware after testing Automobile engines which in theory here is the same will not kool the the source cpu or engine as compared to flow where the water has more time to dissipate the heat. Your cooling system reaches a certain point where the water cant kool fast enough in the heat exchanger so it carries heat back to the source. At a certain point. In testing cooling systems in race engines increasing the waterpump volume aided in kooling until a certain point each system is different where the temperatures over 20min rose higher than with a slower pump. Electric water pumps for race engines are controlled by a shogun tic toc,a device which starts the water pump so the water picks up the heat from the source than enters the heat exchanger, than the tic toc shuts off the waterpump allows the heat to dessipate in the exchanger for a few seconds than repeats the cycle. average temps are over ten degrees lower. If you pull a thermostat out of a chevy or ford which is a restrictor you cant keep the engine warm enough. Do it with a mopar which has better cooling and the engine will overheat. You have to put a restrictor in place of the thermostat. My point is there is a point where you will go backwards after optimal flow is reached. Heres one for you ever wonder why radiators are black? General motors conducted countless hours of testing thickness of paint on radiators and engine blocks and remember its dark in the engine bay. A thin layer of black paint on the engine block and radiator reduces the temperature by helping to dessipate the heat off the radiating surface. Just like smooth polished peices hold more heat compared to rough castings. and im not talking about contact points between cpu and waterblocks where smooth surfaces have more surface area contact.
 

SteenkyBastage

Member
Joined
Jul 9, 2001
Location
Land of OZ
woah...that sounded like dennis leary on a rant! one of those non-stop, never take a breath raving lunatic rants! LOL

no offense, not saying you're a raving lunatic...just the whole 15 sentances into one thing always makes me think of dennis leary. heh
 

Def

New Member
Joined
Jun 23, 2001
My experience in using high rated pumps is that your water temp will go up, but your core temp will drop or stay about the same.

Reason being is that you are removing less heat from a given volume of water(faster flow, less time in radiator). Conversely, the faster flow through the waterblock allows the water to pick up more heat energy over a given time period(more water volume going through the block).

So you basically increase water temps and keep about the same temps or maybe go down a bit.

I've also seen evidence in automotive applications that point to faster flow = hotter temps in your heat source. But I don't think we're anywhere near that point with centrifugal type aquarium pumps. Maybe if you hooked up a 2 hp sewer pump in your system with 1" ID hose, but not with our little dinky pumps.