Flow Rate Estimator Spreadsheet                       

This page is dedicated to providing updates and development of a flow rate estimator spreadsheet.  This spreadsheet was created to help other water coolers with estimating their flow rate.  I'll be providing updates to the estimator here.

What is it?  How does it work?                    

It is an educational excel file I wanted to share with you to lean how different water cooling components affect system flow rate. It's important to keep track of all the different parts in a water cooling system and make sure you have enough flow rate.  Many components including water blocks and radiators have thermal efficiency curve where they cool better as flow rates increase.  This is generally because the water within them is more turbulent so more mixing of water occurs.  If water moves very slowly, there is less contact with the surrounding metal to transfer heat.  These days, the pumps we have available to use make flow rate less of an issue, but I still think it is very interesting and educational to understand.  I have some general rules of thumb for flow rate to help guide you.  While it's pretty difficult to get a system below 1 gallon per minute with a Laing D5 or DDC pump, it is possible if you put too much restriction into the loop.

All this spreadsheet does is calculates a pumping curve based on curves from products I have tested, and it adds up the system pressure drop curves.  A system flow rate is determined by the intersecting point of the pump and system pressure drop curves, that's what this spreadsheet does.  It calculates both curves, finds the intersecting point, and returns a flow rate.

Disclaimer

This is for educational purposes only!  If there is any particular curve you think is out and you have some better or more current information, please let me know and I'll update this tool. I've seen results off as far as 15-20%, so it's just an estimate.  There are other errors like viscosity added by coolant dyes, voltage differences in power supplys, etc, that will also have some impact.

Updates

  • Version 2.8 is out!  Added several XSPC components, retested a bunch of tops, and did some cleanup of old tests left from other sources, check out the latest listing below:

Contribute Product Samples For Testing

If you would like to have your product tested for pressure drop and included in this estimator, I would be happy to do so in exchange for the sample. Please email me if you would like to submit some products for testing.

Download:

By clicking the link below you understand:
  • Educational spreadsheet for educational purposes only
  • Pressure drop curve database was developed from internet sources and may be in error.
  • Estimator has been shown to be in error by as much as 20%
  • Author is not responsible for accuracy or error.
  • Use this information at your own risk!
MartinsWaterCoolingFlowRateEstimatorv2_8web.zip
Excel 97-2000 spreadsheet zipped

SUPPORT FURTHER DEVELOPMENT! or say THANKS!
If you would like to contribute to this effort you can do so by paypal donation.  I will use these funds for shipping loaner samples.  I hope you understand I have spent hundreds of hours developing this spreadsheet for my fellow watercooling community, I hope it's been helpful and I really appreaciate any support you can provide.  Or if you were just looking for a way to give back and say thanks, here is an option for you.  Just click the link below to send me any amount through paypal.  Thanks!!!  Martin

How much flow rate is enough?

I have alot of people ask me..."how much is enough?".  I've had a rule of thumb in the estimator for a while now, but I'm not entirely happy with that knowing that "enough" means something different to everyone.  In general the effect of flow rate is fairly small in comparison to the gain you might get from increasing your radiator size, but it's something you have decent control over, so it's always talked about.  To help clarify the effects of flow rate, I decided to use some c/w curves and put together a chart for a 200 watt load and 110 watt load to try to capture a feel for this and allow you to make that determination yourself.  Keep in mind there is no standard for c/w curves on waterblocks, so don't pay attention to the actual value as much as the difference between different flow rates.

This doesn't take heat dump into account from the pump, but that is also a very important consideration.  Every now and then I'll see someone post a large irrigation pump on the forums asking if it will work.  When only 40 watts of added heat can be responsible for .8C on a triple radiator, 1.9C on a double, or 2.8C on a single radiator...it quickly becomes clear that pump heat dump is extremely important when compared to the gain in flow rate.  That's why I would recommend that you match your pump to the components.  You want the least amount of pump heat dump to provide you adequate flow rates, it's a careful balance.  I generally try to shoot for 1.5GPM just so you have some reserve capacity to add more blocks in later, but it's not a real magical number.

Here is that comparison:

Components Version 2.8

Blue indicates new or updated curves

CPU Blocks:
Aqua Computers Double Impact
Danger Den MC-TDX
Danger Den TDX, Nozzle #1
Danger Den TDX, Nozzle #2
Danger Den TDX, Nozzle #3
Danger Den TDX, Nozzle #4
Danger Den TDX, Nozzle #5
D-tek Fuzion - 3.6mm Nozzle + Washer
D-tek Fuzion - 4.4mm Nozzle + Washer
D-tek Fuzion - 5.5mm Nozzle + Washer
D-tek Fuzion - 6.3mm Nozzle + Washer
D-tek Fuzion - Quad Nozzle + Washer
D-tek Fuzion - Stock + Washer
D-tek Fuzion - Stock
EK Supreme
Stinger V8
Thermalright XWB-01
XSPC X2O Delta CPU V2
GPU Blocks:
Danger Den IONE 8800GT/GTS G92
Danger Den 8800GTX
Danger Den Maze 5
EK FC-3850/3870
EK FC-88 (G92) (8800GT)
XSPC Razor 3870
Chipsets:
Danger Den MPC-680i
Danger Den MPC-Universal
EK NB-S-Max
Swiftech MCW-30
XSPC X20 Delta Chipset
Mosfets:
EK Mosfet Asus 3a
Fittings & Tubing:
Elbow 1/2" Nylon
Elbow DD Derlin 90
Elbow DD Acrylic 90
Elbows Copper 1/2"-5/8" Barb
Reservoir (1/2" Barb)
T  (1/2" Nylon Fitting)
T (5/8" Nylon Fitting)
DD Delrin Tee
DD Acrylic Tee
Tee Copper 1/2" 5/8" Barb
Tubing 10' 3/8" ID Tubing Tested
Tubing 10.16' 7/16" Tubing Tested
Tubing 10.58' 1/2" Tubing Tested
Radiators:
Heatercore '77 Bonnie
Swiftech MCR-320
Thermochill PA 120.3
XSPC RS120
XSPC RS240
XSPC RS360
Misc:
DigiFlow 8000T Flow Rate Meter
Swiss Flow SF800
Pumps:
Alphacool AP1510, 24V
Alphacool AP1510, 21V
Alphacool AP1510, 18V
Alphacool AP1510, 15V
Alphacool AP1510, 12V
Iwaki RD-30, 24V
Iwaki RD-30, 21V
Iwaki RD30, 18V
Iwaki RD30, 15V
Iwaki RD30, 12V
Laing D5 Vario, Setting 1, 12V, MCP655
Laing D5 Vario, Setting 2, 12V, MCP655
Laing D5 Vario, Setting 3, 12V, MCP655
Laing D5 Vario, Setting 4, 12V, MCP655-B
Laing D5 Vario, Setting 5, 12V, MCP655
Laing D5 Vario, Setting 5, 24V, MCP655
Laing DDC-3.2 (stock)
Laing DDC-3.2 (w/Alphacool Plexi Top) Top Inlet
Laing DDC-3.2 (w/Alphacool Reservoir Top)
Laing DDC-3.2 (w/Danger Den Top) Top Inlet
Laing DDC-3.2 (w/EK G1/4 X-Top)
Laing DDC-3.2 (w/EK G3/8 X-Top)
Laing DDC-3.2 (w/Koolance Top) Top Inlet
Laing DDC-3.2 (w/Petra DDCT-01s Top)
Laing DDC-3.2 (w/XSPC DDC Top)
Laing DDC-3.2 (w/XSPC Reservoir Top)
XSPC Dual Bay Reservoir Pump