Pump Noise Testing Round 1

Welcome to my very first standardized round of pump noise tests in my continued pursuit of silence (The primary reason I water-cool).  This round will be much more controlled with an emphasis on consistency between pump tests.  Anything with the pump noise Round 1 will have the same test conditions.  Pump noise is normally not a concern for folks with higher speed fans or for installs where the pump is allowed to float freely avoiding vibration transfer.  However,  solid mounts and/or when users begin dipping below the 1000 RPM level are conditions where pump noise can become the primary noise annoyance.  This testing effort is looking at a variety of DDC/D5 series pumps in various flavors and tops measure dbA relatively to flow rate on a low restriction loop.

I want to give a huge thanks to my many sponsors.  Tim at Koolance.com, Gabe at swiftech.com, bmaverick, and XSPC.biz have all sponsored in some way.  Without their generosity this test would not have been possible.   Tim from Koolance.com sponsored most of the items in this test including the pump controllers used on voltage regulated pumps.  Thanks!!!

Test Conditions

Test Setup, sorry for the poor phone picture, camera in use.:)

This round will use a low restriction CPU block only type loop that includes the Danger Den MC-TDX, XSPC RS120 radiator, King Instruments Flow meter, 1/2″ tubing, and a custom 3″ ABS reservoir with 5/8″ fittings.  The loop also contains some very low restriction brass globe valves for easier swapping between pumps.  I chose a low restriction loop for this round so I could get a greater number of data points. I may later attempt the same for a more restrictive loop although you could cross correlate with RPM values to PQ pump curves if desired as well.  Some noise is actually generated at the restriction points (blocks) as well, but this will be a good relative test between pumps.

I am also testing in two decoupling scenarios.  The first is a near ideal soft foam free floating type test, the second is direct metal contact.  This gives you sort of a worst/best range of noise.  In my earlier testing I found that thinner foam neoprene would fall somewhere in the middle.  Other options such as rubber washers/grommets would also fall in between and likely a bit more toward the worst case condition.  This best/worst case should give you a sense of possible noise range which is fairly dramatic in most instances.  This will also likely emphasize the importance behind decoupling pumps.

For relative scale, I’m including approximate noise level tests from my Gentle Typhoon fan on the left from my fan/radiator round 6 based testing here.  It was tested at roughly the same distance so I thought it would give some sense of scale to the charts.

Laing DDC-1 + XSPC top

This is the old model DDC-1 pump rated at 10 w and manufactured in 2003.

I think noise level is subjectively higher than average due to a buzz type noise present, but the pump is fairly consistent with very little issue with harmonic spikes even without decoupling.  Fully decoupled at 12V it measures roughly the same noise level as a GT-15 at around 1400RPM.  Noise scales well with voltage and at lower volts is approaching the 940RPM fan mark.  A good performer for it’s age, but not quite as silent as the newer models.

Koolance PMP-400 (DDC3.25) + Koolance COV-RP400 Top

This is the latest PMP-400 pump (18 watt) flavor with a nice thick/heavy acetal constructed top from Koolance.  Being acetal and extra thick, this top will likely provide some improvement to the thin and hard factory top material.

The pump/top combo does very well when completely decoupled.  Even at the extremely strong 12+V mark it’s just a hair more noise than a GT15 at around 1,000 RPM, that’s excellent!  You should however noticed there are two harmonic bumps that may or may not be associated with the simulated test rig.  The metal contact test however was all over the place with harmonics causing increased noise over the decoupled test from 3 dbA to  15 dbA.  This pump & top combo really likes to be decoupled completely if possible, the trick is likely some sort of lift or UN bracket system that will allow cooling and vibration decoupling.

Swiftech MCP-35X

This is the new PWM “Smart Pump” by Swiftech.  One obvious difference is the much larger operating range over voltage control of similar non PWM pumps.

Results are also similarly good when fully decoupled as the Koolance PMP-400 with some slightly higher numbers in some areas by 1-2 dbA.  It does have an extended range and the PWM feature could potentially be scaled dynamically, so those are all details to consider as well.  Overall a good showing that also like to be decoupled for best noise results.  Solid mounting can result in anywhere from 1 to 10 dbA more noise than a really well decoupled installation.  Of course being a DDC series high performance pump, you also may want to consider lifting the pump off the base to provide cooling and decoupling

Koolance PMP-450 (D5 Vario) + COV-RP450 Top

Well how does our larger vario pump model with factory speed controller work, these have generally been popular by the noiseless priority folks as they are factory built with a manual speed controller.  This first test is with the Koolance COV-RP450 top which is somewhat unique in that it includes an aluminum casing for the pump motor.  This serves to mount the pumps, but also to clean up the visual.  In addition, I suspect this help mask motor noises as well…  Let’s take a look:

Decoupled the Koolance PMP-450 with Koolance COV-RP450 top is the top performer, only hitting around 33 dbA at full speed, very good! However, similar to the other pumps when not decoupled, the noise levels climb significantly as RPMs increase creating up to 13dbA more noise than the fully decoupled test.

Koolance PMP-450 (D5 Vario) Sample #2 Stock Top

This is a second sample pump I had hand and initially decided to test it simply because I still had the factory top on it.  My intent was to compare stock top vs aftermarket top, but it turns out I also found some significant sample variance over the first sample.  This pumps had some rather pronounced spikes in noise level in a few places.

Overall this pump sample did good at middle speeds, but had higher than average noise levels at slow and high which I suspect is an impeller that’s slightly out of balance.  Sample variance is obviously a big factor in results so far and is going to make solid conclusions difficult with the low sample quantity being tested.

Koolance PMP-450S (D5 Strong)

The new king of power on the test bench…running with the factory top which it seems to like the best.

The Koolance PMP-450S strong did well, particularly under 14 V with the exception of a blip at 3800 RPM. Very good pump for noise and power.

Laing DDC 3.2

I’ve had this pump for a while, these are the last generation Laing DDC 3.2 series which is being replaced by the DDC 3.25 model.  This one also has the base “Feet” and a solid blue impeller.

This pump did very well and similar to the Koolance DDC 3.25 and only measuring about 1 dbA (less than perceivable noise difference) at full speed.  The thicker Koolance acetal top again seems to help reduce noise levels of the DDC series pumps.  It keeps noise at similar levels to an extremely silent GT fan at 1000RPM which is very good when decoupled.  Loosing the foam decoupler however reveals a similar erratic and harmonic variable results up to 9 dbA higher than the decoupled test.   I’m starting to sound like a broken record here, but decoupling is everything when it comes to pump noise reduction.

Summary Comparison Charts

Noise vs. Low Restriction Loop Flow Rate

First, lets look at the “Best Case” scenario where the pump is completely floating freely on a thick piece of foam.  Note, DDC series pumps should have a stand to allow base heat dissipation.

At the 2.3 GPM mark there are many pumps within about a 2dbA (not perceptible) grouping.  The Koolance PMP-450 with COV-RP450 top having a very slight (and perhaps testing error) edge in the charts.  The Koolance PMP-400 + COV-RP400, Swiftech MCP-35X, and Koolance PMP-450S are all similarly good here as well.  The PMP-450 sample 2 for some reason (suspect sample variance/impeller balance), was slightly higher.  The DDC-1 was also a bit more noisy.

All of the pumps were of good noise level though, and generally when decoupled were producing under the GT-15 noise level at around 1500 RPM.  If you had 10 each 40 dbA fans running in the background that total is 50 dbA, so it doesn’t take a whole bunch of fan noise to quickly mask pump noise “WHEN” the pump is properly decoupled.

So…what happens when you have a worst case mount, direct metal to pump contact….

All bets are off….There is really no consistency other than the general lack of consistency and general rise in noise level.  There are some things to learn here though, the bumps and dips are scattered throughout which means the vibration frequency and speed can be potentially “Tuned” to hit a low point.  If you have a solid mounted or less than desirable pump mount that is causing noise problems, you should seriously consider turning it down/up to see if you can find a low point in the noise curve.  Each case and each installation will likely have a unique harmonic noise/rpm profile/pattern, you just need to find the right pump speed to fall on the dips or low points.

CONCLUSIONS

• Pump decoupling has HUGE benefits, up to 15 dbA lower noise levels than pumps without decoupling.
• Pumps without decoupling are erratic in noise with massive peaks and valleys in noise level throughout the RPM range.
• Thick Acetal pump tops may provide some benefit to reduction in noise levels over thin factory pump tops.
• Pump sample variance does also affect noise levels, this may be due to how balanced the impeller is. Luck of the draw.
• PWM pumps such as the Swiftech MCP-35X provide much more control and RPM range than voltage control.  They also provide the ability to dynamically increase decrease pump speed on thermal needs.
• In general, all of these pumps are extremely silent pumps when decoupled.  Most general users with fans over 1000 RPM would typically have a hard time hearing these pumps at all in a normal fan noise masking environment.  Critical noise folks using ultra slow speed fans should put extra emphasis into pump decoupling methods and undervolting or reducing pump speeds.

Bottom line, if you want an extremely quiet pump, work on completely decoupling it from your case and consider tuning speed to seek the low points along the noise profile.  I would also highly recommend using pumps with PWM or fan controllers with thermal throttling capabilities to dial these pumps up and down with load.  Dynamic pump speed reduction setups allow for both ultra silence AND peak power when needed.

Cheers!

Martin

Laing DDC-1 & DDC-1T

Yes that’s right, we’re taking a step back in history due to finding a source for new old stock DDC-1 pumps manufactured in 2003. bmaverick from overclock.net and xtremesystems has boxes full of these. Perhaps I’ve been in the water-cooling hobby too long, but I was pretty excited to get my hands on these guys especially since they were in new condition.   bmaverick explained to me that he and his father acquired a whole lot of these (a few hundred) prior to their heading for the scrappers.  What a save!

He went into more details about the history behind the various companies that were involved with the development of these pumps that now shape a big part of what water cooling is today.  That includes Delphi Electronics Cooling, Laing and ITT.  I don’t quite understand all the various historical details, but I do know this DDC-1 pump was one of the first in the extremely popular DDC series we use today in various flavors.

bmaverick was interested in verifying the PQ performance curve and I was happy to do so.  I also figured I will include this for some additional pump noise work later.

OVERVIEW

DDC-1s ready for action!

The black impeller with the larger inlet is the key identifying feature

DDC-1 PCB

DDC-1T

My sample plug pinout

These pumps were destined for OEM use, so you will need to solder/crimp on your own molex connections.    The DDC-1 only has a power/ground,  but the DDC-1T includes four wires.  As the photo shows above, #1 was power, #2 was RPM sensor, and #3 was ground.  I found the RPM reading was high using my crystalfontz by what I believe may be a factor of 6.  RPM would read around 22,000RPM, but when divided by 6, it gives more reasonable 3600-3800 RPM.  This pump also does not have any voltage protection to prevent over volting.  You probably could experiment with 14V or more which would get closer to DDC2 performance levels, but I’m not sure what that would do to life span.  These are a piece of watercooling history for me that I wanted to keep in perfect condition, so I didn’t want to push overclocking the pumps for testing purposes.

TESTING

First I tested both pump models with the factory top and they both performed the same. The two wire model (DDC-1) was easiest to wire as it was fairly intuitive that red = +, black = ground. I just recycled an old fan molex adapter and made a molex out of it. The DDC-1T took a bit more work figuring out the wiring, although the above pictures should make that pretty easy now. Here is how the pumps tested with the factory top:Even in stock top form, the pump is very powerful. An average restriction system will still see just over 1 GPM, and a low restriction system will see around 1.4 GPM. In addition the pump is extremely efficient in power consumption and heat dump. About 9 watts is all it consumes which leave the pump base feeling cooler than the higher speed models.To add to the testing, I ran a quick test on the XSPC top. Here is how it looks with that top installed:XSPC top, DD fatboy barbs, and soldered molex

With the XSPC top, it does have a fair performance boost along with some additional power consumption/heat at higher flows.   With the top in place the pump will have enough power to maintain 1GPM for medium/high restriction loops to low restriction loops.  A low restriction loop could see around 1.75GPM.

The following is a compilation of the above two tests along with my previous DDC3.1 testing.

In stock top trim, the DDC-1 is actually a touch more powerful than the DDC3.1, particularly for higher restrictions. When the XSPC top is installed the tables turn slightly as the DDC3.1 has a slight advatage at lower restriction conditions.   The top is just slightly more tuned for the newer pump model and the smaller impeller it seems.  Both pumps perform very similarly well and most people would not tell a difference thermally.

HEAT

After testing, I did notice some warmth to the base of the pump, but nothing as extreme as the current 18watt models.  The base was warm to the touch, but much cooler than the current DDC3.25 or MCP-35X pump models drawing 18+ watts.  The pump typically draws around 9-10 watts, so it has about half as much heat to dissipate and does a good job at that without any extra cooling.  As always, it never hurts to have some airflow over the base, but these are not nearly as warm as the higher watt DDC2, DDC3.2, DDC3.25, DDC35X pumps.

NOISE

I will be doing more on this later, but I think these are a touch noisier than your current generation DDC3 series but still good for most water-coolers which likely have multiple case fans driving radiators.

OVERALL

The price is amazing for purchasing a piece of history like this and these little pumps are plenty of reliable power for most users.  For those looking to put away some history or for those that simply want a very reliable and strong pump at an amazing price, look no further.

WHERE TO BUY NEW OLD STOCK

Head over to bmaverick’s for sale thread.  He is selling these privately at OCN here for an amazing price…get them while they last!

Or you can contact him via email here:

bmaverick@juno.com

Or one of his sites here:

http://bmaverick.jufreeservers.com/index.html

http://bmaverickddcpumps.wordpress.com/buy-ddc-pumps-here/

http://bmaverick.jufreeservers.com/BUY_PUMPS.html

Prices may change, so check with him prior, but his latest for sale thread had them for $35 shipped to the USA.  That’s about half price of the new generation pumps, so that’s a heck of a deal!

Koolance PMP-450S (D5 STRONG) Pump

We have a new “King of Pumping Power” quiet pump, the PMP-450S.  While the PMP-400 pumps are more electrically efficient (Less Heat Dump), they are no longer also king of power with a top.  The Koolance PMP-450S pumps when run at higher than average voltage 16-24V is simply turning at a much higher RPM and producing more pumping power.  This review will explore this pump in more detail and consider the various differences and requirements of the Koolance PMP-450S “STRONG!”.

I would like to give special thanks to Tim from Koolance for sponsoring this powerful pump:

 

Overview

The pump comes in a factory box as a “Bare Pump” type product.  So while you’re not paying for accessories you may or may not use, you are very much getting a bare pump…nothing more.  It does come wired with a four pin molex to feed the pump and a blue RPM sensing wire, but nothing more.  Don’t expect a manual or base decoupler or clamps or any screws…it’s a bare pump.  This is good for keeping costs down, but you’ll need to plan out purchase of any accessories separately. Fortunately the pump does come with 1/2″ barbs, so there is no need to change out the top to use larger diameter tubing.

 

No Speed Dial (Voltage Control Only)

Notice the lack of any speed controller, the only control of speed is via voltage regulation which I’ll get into more of below.

Easy to take apart with the factory decoupling ring gives full access in just a minute

There are a couple of important features to point out here on the internals.  The metal cup stainless housing is an improvement over the PMP-400 series pumps for a couple of reasons.  The metal material is better at transferring heat to keep the pump motor (water-cooled).  This could be looked at negatively from a loop heat standpoint, however this is also a positive for keeping the motor cool.  No need to worry about the pump overheating with this metal cup design, it’s essentially acting as a water block of sorts keeping that motor nice and cool.   In addition the metal cup design is superior to the PMP-400 series pumps in regard to PCB leak protection.  In the event of a leak on this pump, water will run down the metal cup and retention ring, and drip to the metal base essentially protecting the valuable PCB and electronics inside.   These are fairly important features that protect this pump from water and heat related damage and probably why you rarely see any incidents of failures.

The other improvement over the PMP-400 series pump is the easy and quick pump coupler.  No need to find just the right torx head or screwdriver…there are no tools necessary to take these pumps apart and they are also extremely easy to put back together.

Downward Spiral Volute with elbow at the exit

The volute design is actually very good.  While there is an “elbow” at the outlet, the outlet is much less critical than the inlet since it doesn’t impact how the impeller is loaded. Generally the factory top is very good and you will see very little if any gains from after market tops.  These pumps also feature a downward spiral volute instead of your typical perimeter spiral.  This seems to be effective just the same, as long as you’re providing additional volume throughout the circumference, the pump is efficient.

Cermaic Ball Bearing

As with all of the PMP-400, 450, 450s pumps, this one too has the highly desirable ceramic ball bearing construction.  I have yet to see one wear out when properly used.  This little ceramic ball bearing is the only wearing part on the entire pump and works exceptionally well in proper wet conditions.  I’ve personally run the similar PMP-450 pumps for many years in plain distilled water without any sort of lubricating additive and have never had an issue, they are by far what comes to mind when I think “Pump Reliability”.  Just be careful not to run the pump dry and it will serve you for a very very long time.

Size PMP-450S vs PMP-400 Modified

Another consideration and often a reason some prefer the PMP-400 series pumps is size.  The PMP-450 and PMP-450S pumps are bigger in stock trim than the PMP-400.  However, I have found that many times once you have modified a PMP-400 series pump to provide additional cooling and the added extra thick top, that it too increases in size.  The PMP-450S is approximately 4-1/4″ tall by about 3-1/2″ wide/long, so it’s not a tiny pump by any means and does take up some real estate in stock trim.  Fortunately we also have bay reservoir options such as the Koolance RP-452×2 or 402×2 which can hold one or two of any of these pumps in a double bay.  Regardless here is a quick comparison of the PMP-450S in stock form compared to a lifted and modified top PMP-400.  The PMP-400 is slightly smaller, but not significantly so.

 

PMP-450S (Stock Top) vs PMP-400 (Lifted + Performance Top)

Performance Testing

Onto the lab bench for full pressure vs. flow rate testing to take a complete look at performance in all possible conditions.  I’ll be doing my normal pump PQ testing which includes measurement of pressure differential across the pump from shut off flow rates to the maxium of my test rig.

• Flow Rate – King Instruments 7520 with valve.
• Pressure Differential – Dwyer 477-5 and custom 1/2″ ID T fittings to ensure flow is not disturbed entering or leaving the pumps.
• Reservoir –  3″ ABS custom built with 5/8″ fittings for minimal restriction and nearly instant bleeding of air.
• Power Supply and Current (Amps)  – Mastech HY3005D variable power supply
• RPM –  Mastech MS8209 to read frequency in Hz.  Occasionally I have also used my Crystalfontz CFA-633, but find the Mastech is much more precise.  Most fan controllers only provide approximate RPM.
• Warm Up/Bleeding – The pumps are typically allowed to warm up at least 15 minutes and all air is bled out of the loop prior to commencing.

Testing in progress

 

Voltage Requirements for “STRONG” performance

While 24V seems to do very little for the PMP-450 or vario pumps, having the ability to control voltage above 12V is critical on this pump to get full performance.  While 12V still provides a very good amount of power, it’s not enough to get full potential out of this pump.  I would simply suggest trying the pump at 12V and if you want the extra performance, then consider a means to feed the pump 24V.  The Koolance CTR-SPD24 is a great solution to converting the typical PC 12V to controllable 24V.

I’ll be showing you the relative performance differences at various voltage levels, starting at 12V.  You should also be aware that these pumps do not “Undervolt” very much.  11V is about the minimum voltage where the pump is willing to start, so those that are extremely particular with noise level or having the ability to turn the pump down will be better served by the PMP-450 or variable speed model.

 

Voltage Controller Connection

Test Results Detail

The pump scales with voltage very well.  12V would be plenty of power to exceed 1 GPM for average to low restriction systems and consumes a nice low 13 watts.  While 24V is sufficient to nearly get 1 GPM on the most restrictive 5 block+ type system, but it does consume a more hungry 30 to 36 watts.

 

12V

16V

20V

24V

WOW…over 8PSI at Shutoff, very impressing pumping power!   This is more than the PMP-400 series even after modifying with an aftermarket top.

 

RPM scaling of the PMP-450S and PMP-450

Comparison to the PMP-400 plus COV-RP400 top

 

Comparison to the PMP-450

AFTER-MARKET TOPS

While I haven’t tried the many flavors out there, I wouldn’t recommend them for this pump at high speeds. The higher speeds of this pump makes it susceptible to vibrations at very high speeds.  Stick with the factory top for anything over 12V.

NOISE

I’ll be including this pump in my future noise comparisons, but subjectively I have a difficult time perceiving a difference between the PMP-450S running at 24V vs 12V or the PMP-450 at setting 5.  I am sure there is some sort of measurable difference (It is turning 1000 RPM faster), but it’s extremely small when the pump is decoupled properly and not likely to be noticed in your typical fan speed system.

When I stop and think about some of the other high-powered pumps I have tested in the past, such as the Iwaki RD-30 or Alphacool AP-15, this pump is subjectively superior.

Noise testing will be coming soon…My only suggestion is consider your own tolerance level with the PMP-450 vario pump.  If you’re happy with that pump at setting 5, you’ll likely be happy here as well.  However if you find setting 5 is too much and resort to setting 3, then you probably should stick with the variable PMP-450 model.   In other terms I would estimate the following:

• PMP-450 = Setting 1,2,3,4,5
• PMP-450S without controller = Setting 4.5
• PMP-450S with voltage control = Setting 4,5,6,7,8

CONCLUSION

The PMP-450S is an excellent pump, and it does take the crown for most power between the PMP-400, PMP-450, and PMP-450S.  The trick is the requirement for a voltage controller feeding it more than the standard 12V.  Fortunately, Koolance has developed a controller to do just that if needed.  The pump in stock trim is compatible with 1/2″ tubing, so the pump has a very upgrade friendly path.  Here are some pros/cons:

PROS

• King of Pump Power performance for under $100
• Cool motor operation (metal pump housing keep motor running cool)
• Factory 1/2″ Tubing compatibility
• Factory stand allows pump decoupling without creating heat trap problems
• Factory RPM wire
• Metal housing minimizes PCB flooding risk if o-ring is improperly sealed

CONS

• Factory top is larger in size than PMP-400
• Not electrically or heat dump efficient as PMP-400 (A bit more heat added to the loop)
• Requires a voltage controller and 24V to get full power performance
• Higher speeds are more sensitive to the top used, suggest sticking with the factory top for high speeds.

So there we have it.  The PMP-400 (DDC series) are no longer king of power.  The Koolance PMP-450S with factory stock top when operated at 24V will produce more pumping power.  At 1.5 GPM this pump will produce around 6.7PSI, the PMP-450 @1.5GPM produces about 4.4PSI.  That translates to about a 50% increase in pressure over your typical PMP-450 at setting 5.  That’s about equal to running 1.5 PMP-450s in series.  That should translate to about a 25% improvement in flow rate for your average system vs. running a PMP-450 at setting 5.

For a more detailed flow rate estimation, you can try this pump in the latest pump/rad estimator here.

I’m personally a big fan of this along with the PMP-450 and PMP-400 pumps.  They all have their own pros/cons.  The PMP-450S is focused on raw 24V power.  At 24 volts it’s basically 1.5X as strong as a PMP-450 in the same package, it has the more desirable metal pump casing which keeps the pump running cool, and it’s less likely to have PCB water damage.  It may not be as efficient as the PMP-400 series pumps, but that’s generally of less concern once you get to triple rad sizes or more.

I could see people buying this pump to start out their system and simply running it at 12V until some time down the road when they expanded to a more restrictive system.  Then they could simply upgrade the pumping power by adding the 24V controller. At 24V, this pump is going to be more than enough power for even the most restrictive of setups such as full motherboard blocks etc.  You won’t need that for your typical CPU/GPU loop, but it’s nice knowing the power is ready to be tapped with a simple voltage boost.

Where to buy

There are only two places where I shop that carry the pump and controller, and I’ve included links to both below:

Direct from Koolance – PMP-450S CTR-SPD24

Sidewinder – PMP-450S CTR-SPD24

Cheers!
Martin

PMP-400 or MCP-35X (DDC Series) Cooling Lift

If you’ve had any of the DDC series pumps, you’ll know that they tend to run hot to the touch.  Unfortunately, efforts to decouple the pump from the case usually involve some sort of foam pad or other vibration absorbing material at the worst place for heat.  The base of the DDC series pumps is their hottest place, so many users have gone to extra efforts to cool these areas.

One option is to suspend the pump via tubing, but that too may not completely decouple the pump.

Another option is to lift the pump, and I’ve worked up a quick potential option to do that.  I basically just cut out a square of acrylic the same size as the pump base, tapped the pump mounting holes to M4 threading, and used some 1″ nylon spacers to create a lifting base.  This base is rigidly mounted to the pump, but it allows enough space for air to flow and/or adding of heat sinks to the base while allowing the pump to sit on a foam decoupler.

 

Cutting out the square on the mini band saw

A little belt sander work

Tapping the pump mounting holes with an M4 tap, no drilling necessary.

We have lift!

Fairly simple and easy, and this allows a variety of heat sink cooling options.

Plenty of space for heat sinks if desired

 

 

But that’s just one of many alternatives.  You could probably do something similar with some aluminum c-channel, or aluminum or steel spacers, or just about any sort of sheet/tube material.  The pump base includes two untapped mounting holes in most DDC series pumps, and an M4 tap is a perfect fit without the need to drill.  I removed the pump cover to ensure no plastic bits get inside and simply tapped the holes and cut some M4 bolts to length.  Now the pump is lifted to all air to pass over the base and you can also add some ram-sinks or other heat sink to the base as well if you wanted to.

Cheers!
Martin

 

Special thanks to my pump sponsor:

Pump Decoupling Comparison – Metal vs. Neoprene vs. Eggcrate

Welcome to a pump decoupling noise comparison test.  This test will focus on consistency using just one pump, the Swiftech MCP-35X and compare a direct metal contact (no decoupling), the factory neoprene pad, and a chunk of egg-crate.  I was also experimenting with microphone and sound level meter setup because I wasn’t very happy with my previous video results.  It seems having the microphone on the test bench was artificially introducing some vibration type noise into the audio recording and possibly into the sound level meter as well.  This time around I docked my Zoom H1 on top of my Canon T2i which is sitting on a tripod a couple of feet away.  I also place the sound level meter on some cushion to also decouple the sound meter from vibration.  I’m starting to notice that while fans generally have very little vibration, pumps obviously do to the point where the instruments can be affected by those vibrations if instrumental decoupling isn’t done as well.

Also doing a little work in YMEC software to take a more detailed look at frequency response.  Here are the three scenarios with the egg-crate decoupler as the baseline in the middle overlayed each of the other two so you can see the frequency spike differences.  While the neoprene pad helps, it’s not nearly as good as the thicker softer egg-crate foam.  The downside is that any sort of foam like this will trap heat, but this is just comparing some decoupling scenarios.  Decoupling AND cooling the pump base at the same time is a challenge.  I have heard of some people suspending pumps by tubing alone.

Here is that frequency response comparison at 100% PWM.  Zoom H1 microphone is approximately 2′ away mounted to camera on separate tripod.  This does seem to avoid any vibration induced noise on the microphone itself.  Of coarse this is tested in extreme silence to try and sort out any fine details.  Even with the microphone place a couple feet away, using software A-weighting I’m seeing upwards of 6dbA improvement using the neoprene pad over direct metal contact, and around a 12dbA improvement using the egg-crate as a decoupler.  This is fairly substantial and easily perceived difference in this silent testing environment.  No doubt that decoupling makes a noteworthy improvement to pump noise in silent environments.

A quick A-weighted frequency response comparison/overlay

And the video recording, zoom to the very end for just the 100% PWM sound clip comparison.

The pump used in this experiment was sponsored by Gabe from Swiftech.com, thanks!

 

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