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Fantastic, cheers Martin, though i must admit that did get a bit heavy for what few grey cells i got left.
Anyway, my good pal Rig did suggest - how about adding the D5 into the mix.
.................obviously i told him due to size, noise, expense and versatility due to the G1/4 thread it was straight out the reckoning ;)
Hmmm, interesting, I never realized that the DDC had so much heat dump. Currently I only use D5's so what would I know. Now I know not to buy a 18 watt DDC.
if you lower d5's speed to say 2 heat dump almost dissapears... imho...
seems to me a test should be done of just the heat dump of all the pumps
IE; closed loop = pump > Xlarge resevior > temp probe > back to pump
start the loop at the same water temp each time for each pump let run a set amount of time then measure the heat gain .. you could even do 2 tests of each pump = one with a large fan blowing on it & then a 2nd test with no fan ...
I'd do it but all I got are Iwaki RD-30's :woot:
but I do also have one DDC/petra top that's on the test bed .....
as i have done a test with the Iwaki RD-30 in closed loop...... pump>GTX480 rad (no fans) > EK400 RES > pump > ....
and after 4 hours of run time at 18volts the loop tubing/rad top was warm to the touch ..I'm guessing here on temp !
about as warm as a toddlers forehead with the Flu
water temp at the start was 65F air temp was about the same the water in the loop was sitting in my garage & the setup was runnig also in the same gargage(NO WIND factor) as it was a cool NorthBay day
didn't do this test for temps just was checking for leaks , flow , vortexing & bleedout times of all the air bubbles of the setup
if I had all the pumps I'd do the testing .. SOO send pumps ! :rofl:
but then agin Been eyein' another 4870X2 :ROTF:
if this has been done already then my life is Really tough & I'm stupid as hell !
bigslappy,
Wow.. you have really horrible pumps! The worst kind imaginable.
Hmm I would still get the DDC3.2 if its more powerful with a modded top...so which is more powerful the DDC3.2 with mod top or DD CPX-Pro?
A DDC3.2 with top is quite a bit stronger than a CPX-pro.
In the end of all this, it probably depends on the waterblock/rad setup. Naeku said he saw good gains with the RD-30 at around 21V.
A DDC3.2 with XSPC res top is pretty close in performance to an RD-30 at 15V, where dual DDC 3.2s with XSPC tops is closer to an RD-30 at 21V.
From the little bit of discussion I have heard on the RD-30, 24V is almost always worse, and back in the day most people were running them around 18V. Somewhere in the 25-21V range is probably optimal.
Think of it like an air/fuel mixture ratio on your motorcyle, too much air and you can lean out your motor and fry a piston, too much and you'll foul plugs....neither of which produces the best horsepower
That's similar here, there is not any bad pump or perfect pump, it's all about tuning....the only way to know whats perfect is to test and tune your own specific setup....there may not be any sort of rule of thumb to follow..
All we know at this point is:
-There are thermal gains to flow rate, more is always better but that gain is quickly flattening beyond the 1-1.5 GPM range
-Pump heat dump plays a significant role and will quickly cross the lines of the thermal gain at some point
-Open channel blocks from several years ago had nearly 4X the thermal gains from flow rate in the 1-2GPM range than some of todays blocks
-Pumps of today such as the D5, DDC, CPX-Pro, etc...have significantly higher pressure capabilities that pond style pumps from several years ago.
The best pump and setting for your system will be one that gives you the most delta between flow rate thermal gain and heat pump heat dump loss. It's likely not going to be any set number and will heavily depend on the radiator fan combination, the waterblock used, and the amount of heat generated by the pump.
I never said an RD-30 was a bad pump, all I'm saying is heat is important and you need to spend the time to balance flow rate gains from pump heat dump losses if you truely want the "perfect" setup. We can't generalize like that, we need the patience and will to test our own setups if you really want the best possible performance possible. An RD-30 at 24V is likely well over optimal for any system, but it is an awesome pump and can run clear down to 12V if needed, so it's tunable and an excellent pump. If we don't want to bother with the work, we need to accept it's probably not perfect. For most people that don't care about a degree, which may mean the larger audience, I wouldn't worry about it...pick something and go with it.
thank you martin for your excellent info and advice!
Just a quick thought based on the first post, and I may be way off base here...
but if the DDC is an 18w pump and its consuming 21 watts while running, doesnt that mean that ~18 watts of those 21 watts are going into spinning the impeller and ~3 watts of it is going into sound and heat??... just thinking about it from a conservation of energy perspective :confused:
Different pumps for different.....umm...strokes, I guess. If you're in the market for a new pump, gotta use Martin's calculator for best results. :)Quote:
Originally Posted by Martinm210
Good question...Quote:
Originally Posted by SNiiPE_DoGG
This is good to know. My pump is the loudest component in my pc when my pc is at idle.Quote:
Originally Posted by coolmiester
Quote:
Originally Posted by SNiiPE_DoGG
The energy of the pump consumption leaves in three forms.
- The biggest is motor heat energy lost into the water, which is generally somewhere between 80-90%, small pumping motors are just very inefficient.
- The second is in the form of water horspower, you can covert the energy of water flow rate and pressure into wattage. This energy leaves the pump and is then lost in the restriction of the system. Most people don't think about this, but you do actually gain heat by the restrictions. Pressure drop in a waterblock for example is energy lost. That lost energy is transmitted into heat energy, most of which is absorbed by the water in the loop.
- The third is motor heat lost in the air from the pump motor casing. If you've felt the bottom of a DDC pump, you know what that is. Some pumps loose more heat in the air than others and it depends on the pump motor design and how the motor does or doesn't transfer heat into the fluids. It likely also depends on how much air movement occurs around the pump.
But yes, all that energy goes somewhere, unfortunately most of it ends up getting watercooled...:D
Another set of calc's for the log book...ty! :up:Quote:
Originally Posted by Martinm210