Hardware Labs Black Ice 480GTX Radiator Pressure Drop Flow Testing

Introduction                   

Welcome to my pressure drop testing of the HWlabs Black Ice GTX 480.  That's right it's a 480 (4each X 120mm fans), and this is the only radiator on the market to hold not three but four full 120mm fans. I would like to give special thanks to Jeremy from Danger Den for sending me this radiator sample for testing.  These 480GTX radiators have been very popular amongst the extreme forum members and it was nice to get my hands on two of these beautys to step up another notch in my own system.

With this review I will initially focus on pressure drop testing and as I complete building my radiator testing rig, I will expand this review to capture thermal performance as well.  First off, let's take a look at the size comparison of the 480GTX next to the PA 120.3.  They are both extremely thick radiaors, and the 480GTX is simply one more fan long.  I'm a strong believer in recommending as much radiator as you can possibly fit.  When it comes to water cooling, the biggest advantage comes with the ability to dissipate heat over a much larger surface area than you can with convential tower air cooler, so you might as well go BIG and the 480GTX does just that!...It's HUGE!!

Radiator Characteristics

• Dual Row Tubes, Dual pass flow
• Top Chamber splits flow to front and rear of radiator instead of the typical side to side configuration.
• Brass 19.0 x 1.2mm Ultra Thin Tubes for Increase Heat Transfer
• Copper Non-Louvered Fins arranged with a splitter fin (two rows between tubes)
• Brass Water Chambers
• G1/4" Threads
•  517mm x 133mm x 54mm
  (L x W x H)
• I measure approximately 20 folds per inch, see fin detail photos below.
• Electrostatic polyurethane painting finish for uniform coating with high temperature curing for increased finish durability.

Ultra Thin 19.0mm x 1.2mm Tubes

 

Front to Rear Two Pass Flow

Compact Core High Density Fin Structure

HWlabs also has a higher desity fin stucture optimized for medium to high speed fans (although you'll see "Slow Speed" fans do well also).  It has a couple of unique features.  Fist the "Folds Per Inch" is on the order of 20 folds as opposed to the 11 of the PA120.3 and Fesser fin densities.  Also it has a compact core in which is uses another layer of copper sheet between the folds to allow double rows of fin folds in between each set of tubes.  In addition the GTX fins themselves are not louvered, instead it is relying on the density of the structure for turbulence and heat transfer (Less dust getting traped in louvers).  All of this is purposely part of the design to maximize the total surface area and the contact area between the tubes and fin structure.  This added heat transfer area means it should be able to exchange more heat with less air.  Below is a fin comparison of pictures at the same scale for the 480GTX, PA120.3, and a prototype of the new Fesser X-Changer.

Hydraulics and Pressure Drop Testing

The most scientific way to determine a blocks hydraulic resistance is to test pressure drop. Pressure drop is a measurement of pressure loss across a radiator that varies with flow rate.  This is basically a measurement of energy loss, and directly influences how much flow rate you will have.

Equipment:

• Dwyer Digital Manometer 477 Mark V - Accuracy .5% of Full Scale.  Range 0-20.00 PSI range, Resolution .01 PSI
• King Instruments 7520 Series 0-5GPM, 250mm scale - Accuracy 2% of Full Scale.  Range 0-5GPM, Resolution .1 GPM (can be interpolated to .02GPM)
• Water Source - Household water pressure - 50PSI at >5GPM - Because flow rate readings are instantaneous, household tap water and water pressure are a good and powerful source for pressure drop testing.   
  

It was in interesting test, and one that I completed three times just to make sure over two radiators and different directions.  Comparing to other radiators it would fit into the "High Restriction" category, but in comparison to your average CPU block, I wouldn't consider this a huge issue.  At 2 gallons per minute it compares reasonably similar to a D-Tek Fuzion with washer and no nozzle which isn't considered a highly restrictive CPU block setup.  I would just recommend using a stronger pump like the Laing DDC or D5 pumps and esure you maintain at least 1 GPM.  The "interesting" part about it besides being more restrictive is how linear the results are, most pressure drop curves have a much more pronounced "curve" to it.  My theory is the flat and thin tubes inside the radiator are expanding a very small amount as pressure climbs which lowers the restriction.  More pressure, more tube expansion, less restriction creating a relativley flat curve.  So as expected it's a bit on the restrictive side, now we just need to see if this tradeoff was worth it for better thermal efficiency.

Thermal Testing Links (Temporary Until Thermal Testing Complete)

Price Considerations

Where to buy