Radiator Thermal Test Bench Progress

[Martinm210]

Spent alot of time working on this little testing facility project.

Idea being:

CrystalFontz to control and log Dallas DS18B20 digital sensors, .0625C resolution, 32 channels

Air IN = 2 sensors per 120mm fan
Air OUT= 1 sensor per 120mm fan
Water IN = 1 sensor
Water OUT = 1 sensor

I got all but the water sensors done, here are a few pics. I'm thinking I'll mount some heavy guage wires for the air in sensors so I can adjust their locations just right for different thickness setups.

I figured with the sensors all permanently mounted it would both eliminate the hassel of mounting sensors every time and also provide better consistency between tests for the sensor locations are fixed.







I don't have my air flow meter yet, so for the time being I thought I'd just get the stand built and maybe start tinkering with a fan only type of test.

Any comments on the sensor placement, etc?

The only thing I was thinking is the air out sensors will also be measuring heat from the fans, but I figured that's ok since those are more informational than anything.

UPDATE 4-18-08
Ran a few preliminary tests today.

Here is my string of sensor ready for logging, 4 of them are in my computer that I'll simply disregard, but 14 of them are specifically for my radiator test bench:


My very first test with a target heat load of 100watts, 15watts from the pump, 2 watts lost in my variac and 88 watts from the 300 watt water heater turned down until my "Kill-a-watt" registerd 88.

Takes a while longer to stabilize than I thought, I probably need to run this one again, but it's giving me an indication that at a bare minimum 20minutes of warm up is needed, but 30minutes is even better.

Then I tried a 200 watt run and found my first little glitch. The thermostat on the water heater kicked on mid way through the test...whoops..


Working out the bugs, but the logging is working nicely. My C/W results will be much lower because of heat lost through the tubing and reservoir, but I figured that's ok since a regular system will also. You just won't be able to compare c/w except other tests on the same test bed.

The first keeper:

[nikhsub1]

The only thing I was thinking is the air out sensors will also be measuring heat from the fans, but I figured that's ok since those are more informational than anything.

Thanks!
Martin

Moving along nicely. Yes, you are correct but it won't matter so long as you use the same fans on each rad...

[Vapor]

In fact, using the same fans on each rad might be more helpful than using the same airflow.

End users can control which fan they use, but only maybe a handful know the kind of airflow they're moving.

Great looking testbed btw....the work and a tests you do are just awesome.

[disruptfam]

nice martin!

[Martinm210]

Thanks!

Yeah, I figured I'm going to stick more in line with what previous testing was done using specific fans and undervolt them, etc. At the same time when I get my anemometer, I'm going to see about building some sort of outlet shroud so I can also just record the actual airflow produced by those fans, then I would sort of have both.

Not sure what I'm going to do with the air out or water in, but it'll be information to look at and could be numbers to check some things.

[systemviper]

Hi Martin.
Thanks for all your effort, all this extra info helps us spend our money more efficiently, and that is Xtreme savings
from even more Xtreme info
coming from even more Xtreme test set-up's

You work has already helped me make some buying decisions .

So I want to thank you for all your time and effort!

If there ever was a way I could help, I would.

I think we need a Martin fund, to help the cause......

Cause you need more test equiptment!

[biftek.]

You've got to be the Sheldon Brown of water cooling.
Thanks for everything you do.

The test set up looks really nice.
Is the Neoprene along the edges of the wood? Looks pretty thick.

[skinnee]

This looks great!

Can't wait for the testing to begin!!!

[DavidNJ]

You are one very industrious dude. Fortunately, my wife isn't expecting me to make cabinets! She just doesn't want me to spend money on manometers, temperature probes, rotational speed gauges, etc.

The testing setup could be better with a shroud; that would test the whole radiator and not just the space under the fan blades.. And the ability to vary up to a static load of .4-.6" with 40-50cfm/fan space flow to test the most restrictive radiators. A two-stage or some push-pull setups could get there with aggressive fans. The most aggressive here is rated at 51dba, in a two stage it would pull .7" with over 40cfm. With a shroud and some sound deadening would be in a range Ira would use.

I have an uninstall ed GTX480 here, and can easily imagine it improving right through .6". While I haven't tested it, my lowly MCR220 with single stage shrouded Panaflo 120x38 Ms could easily use more.

Some testing is needed, however I imagine the fans work best on the high flow side of knee in their curve. Then adding stages to get the pressure drop across the radiator to get there. However, without the shroud, a significant portion of the radiator surface may not be fully used.

Sidewinder has the Delta, and I'm sure he would make you a deal.

[Martinm210]

You are one very industrious dude. Fortunately, my wife isn't expecting me to make cabinets! She just doesn't want me to spend money on manometers, temperature probes, rotational speed gauges, etc.

The testing setup could be better with a shroud; that would test the whole radiator and not just the space under the fan blades.. And the ability to vary up to a static load of .4-.6" with 40-50cfm/fan space flow to test the most restrictive radiators. A two-stage or some push-pull setups could get there with aggressive fans. The most aggressive here is rated at 51dba, in a two stage it would pull .7" with over 40cfm. With a shroud and some sound deadening would be in a range Ira would use.

I have an uninstall ed GTX480 here, and can easily imagine it improving right through .6". While I haven't tested it, my lowly MCR220 with single stage shrouded Panaflo 120x38 Ms could easily use more.

Some testing is needed, however I imagine the fans work best on the high flow side of knee in their curve. Then adding stages to get the pressure drop across the radiator to get there. However, without the shroud, a significant portion of the radiator surface may not be fully used.

Sidewinder has the Delta, and I'm sure he would make you a deal.

I'll see what I can capture with this first. I figure a vast majority of users are using radiators without a shroud, probably 90% I would guess. In the end I want to capture performance that is closest to the conditions most people use them. The only thing artificial will be my heat load, everything else should be normal radiator operations and conditions. The fan hub definately affects performance, but if that's the way most people run them, then I would like to capture it like that.

Also with the open top, I purposefully allowed extra room with my air out sensor lengths so I can experiement with the effects of a shroud. It's pretty flexible like this, and I can try alot of different things, the only thing absolutely fixed is my water and air inlet sensors.

I also want to be able to display the results in a way that more people understand it. If I plotted CFM vs performance, I bet most folks would think that just means how many fans x their rated CFM which is not correct. But if I post a curve with a specific fan and fan voltage, that something people can relate to pretty well.

I will build a shroud I can slip over the fans and try to measure spot CFM when I get my anemometer. With a certain fan, I should be able to slip this shroud on and measure the actual CFM. If I do this with each type of fan, I should have captured enough to also do a CFM Vs Heat dissipated type of look. It would also indicate how restrictive the fins are (Not quite pressure drop, but an order of restriction). I might also try to measure pressure drop of the radiator fins in time, but that's going to be a bit tricky considering every manufacturer is a bit different and trying to get a one size fits all perfectly sealed shroud is going to be a challenge.

Just getting started, I'm sure I'll be tweaking something before I'm set in how I'm going to do the testing, and that will probably change over time as I learn more about it.

[plato333]

looks really cool man i was thinking about doing something similar.

[SiGfever]

Martin,

You do some fantastic work and we all appreciate your time and expenditures for these tests.

I noticed that you have the tubing tie wrapped to your Dwyer, that tubing is thick and tie wrapping was a good idea for a complete seal. I recently purchased a used Panduit tie wrap tool (GS2B) and it sure does a great job.

[DavidNJ]

I'll see what I can capture with this first. I figure a vast majority of users are using radiators without a shroud, probably 90% I would guess. In the end I want to capture performance that is closest to the conditions most people use them. The only thing artificial will be my heat load, everything else should be normal radiator operations and conditions. The fan hub definitely affects performance, but if that's the way most people run them, then I would like to capture it like that.

Also with the open top, I purposefully allowed extra room with my air out sensor lengths so I can experiment with the effects of a shroud. It's pretty flexible like this, and I can try a lot of different things, the only thing absolutely fixed is my water and air inlet sensors.

I also want to be able to display the results in a way that more people understand it. If I plotted CFM vs performance, I bet most folks would think that just means how many fans x their rated CFM which is not correct. But if I post a curve with a specific fan and fan voltage, that something people can relate to pretty well.

I will build a shroud I can slip over the fans and try to measure spot CFM when I get my anemometer. With a certain fan, I should be able to slip this shroud on and measure the actual CFM. If I do this with each type of fan, I should have captured enough to also do a CFM Vs Heat dissipated type of look. It would also indicate how restrictive the fins are (Not quite pressure drop, but an order of restriction). I might also try to measure pressure drop of the radiator fins in time, but that's going to be a bit tricky considering every manufacturer is a bit different and trying to get a one size fits all perfectly sealed shroud is going to be a challenge.

Just getting started, I'm sure I'll be tweaking something before I'm set in how I'm going to do the testing, and that will probably change over time as I learn more about it.

Yes, most don't use shrouds. And it seems most have their radiators in push, which if anything is worse than not having a shroud. Especially if it is push without a shroud! However, designing to those standards reminds me of a story I tell why NYC subway seats or so narrow: because NYC has the only trains designed to crash into each other (true story). Codifying a ridiculous design standard. My guess is your tests would show that someone running 25mm fans in push on a GTX would get better performance with 38mm fans with a shroud in pull on a BIX.

However, I was hoping you would develop PQ curves for radiators and fans, and make a spread sheet for that. Add in your thermal testing, and you would have a complete analytical picture. Plug in a heat load, and the PQ curve would determine your temps. Of course, your spreadsheet may have to change to using a macro call to goal seek or solver.

P.S.
It looks like your frame is blocking 5 sq in of the radiator. Are the cross braces necessary? Additionally, it may be too close to the surface, blocking flow in stronger setups or less restrictive radiators. No by much, however, why not vertical?

[twwen2]

This is gonna be some of the most comprehensive and complete testing we've seen in a while. Reminds me of Cathar and Vapor's fan testing, all excellent stuff. Man i miss Cathar...

Looking forward to the results Martin

[Yeknom]

Thank you so much for putting this together; it really helps everyone on XS.

Looking forward to the results!

[Martinm210]

Thanks guys,
I'm still going to try and see if I can also develop P/Q curves for fans and the radiators, but the fan spec format will get me started. I'm still waiting for an anemometer I ordered, that I'll try to use just for that.

Anyhow, I got the water sensors made up on the lathe, hook it all up and none of my sensors came on line , so I had to do a little troubleshooting and after cutting my string of sensors 3 times I finally found the little sucker. I wired one of the sensors wrong, now I get to do a whole bunch of splicing back together again... A little panic set in though, at about $5 each, loosing a whole string of 14 from a mistake can be a little scary...all is well though.

If all goes well and I'm not stuck out of town all week on business, I should get a chance to run a few preliminary tests by next weekend. First up is the PA120.3 to do some check ins and see how well I can or can't calculate c/w curves from this..

[Digz]

You guys are to complex all we need to know is temps at 12v , 7v and 5v

[DavidNJ]

You guys are to complex all we need to know is temps at 12v , 7v and 5v

With the fans correctly mounted or incorrectly mounted. In this test by Ira-k the difference between unshrouded and push and shroud pull was 3.25C in CPU temps and cooled Water to ambient Air temps went from 3.3C to 4.25C, an increase of 28%.. From measured input air went from 8C to 5C, 60% higher!

Comparisons......

Push-Pull with shroud average below ambient.....23.375C...3.625C cooler
Push-Pull with-out shroud average below ambient........19.75C
--------------------------------------------------------------------------------------------------------------

Pull only with shroud average below ambient.........21.125C......3C cooler
Pull only with-out shroud average below ambient..........18.125C
---------------------------------------------------------------------------------------------------------------

Push only with shroud average below ambient......20.25C.....2.375C cooler
Push only with-out shroud average below ambient..........17.875C
----------------------------------------------------------------------------------------------------------------

Water temp drop across rad with push-pull and shrouds.........1.025C
Water temp drop across rad with push-pull and no shrouds.....0.9C
----------------------------------------------------------------------------------------------------------------

Water temp drop across rad with pull and shroud..............1.275C
Water temp drop across rad with pull and no shrouds........0.95C
----------------------------------------------------------------------------------------------------------------

Water temp drop across rad with push and shroud...........0.975C
Water temp drop across rad with push and no shroud......0.875C
-----------------------------------------------------------------------------------------------------------------

Air temp drop across rad with push-pull and shrouds.........4.5C
Air temp drop across rad with push-pull and no shrouds....2.875C
-------------------------------------------------------------------------------------------------------------------

Air temp drop across rad with pull and shroud...............5.5C
Air temp drop across rad with pull and no shroud ........5.25C
-------------------------------------------------------------------------------------------------------------------

Air temp drop across rad with push and shroud..........6C
Air temp drop across rad with push and no shroud.....7.5C
------------------------------------------------------------------------------------------------------------------.

[voigts]

How you find the time to do all this is beyond me. Your work really is a great asset to the watercooling community as a whole. Just your flow estimator alone is so terribly helpful.

[septim]

another nice good long read from MartinM when this is over...

[Martinm210]

Yeah Ira has done some great work with the shroud effects. I'm thinking I might gut some old 120mm fans and run an experiement or two with shrouds as well. That's something anyone can make easy enough as a shround, take some old fans you don't use anymore and snip off the motor/blade, you've got a shroud..

[Xilikon]

That's a nice test bench As for the idea of holding the temp sensors wires in place, just use some steel wire

[DavidNJ]

Yeah Ira has done some great work with the shroud effects. I'm thinking I might gut some old 120mm fans and run an experiement or two with shrouds as well. That's something anyone can make easy enough as a shround, take some old fans you don't use anymore and snip off the motor/blade, you've got a shroud..

Just get some plastic spacers, or cut some wood or aluminum tubing...even pvc tubing and slip it over the screws between the rad and the fan. Then wrap it with duct tape.

The fan shell as shroud uncovers the hub but not the frame. Over 20% of the area lost is shrouding from the frame.

[gojirasan]

Just want to add a +1 to appreciation for your testing. I am really looking forward to this radiator test and want to thank you for the time, effort, and money you are putting into this.

The imminent release of the Cryo-Z (along with its noise/weight/wattage and CPU-only limitations) only demonstrates further to me that this "hobby" will not be dying out any time soon and your testing will continue to further our knowledge.

@DavidNJ: This shrouding thing seems interesting. The premade ones are expensive and hard to find. Seems tempting for a nice DIY project. Although I might wait for the results of Martin's tests first. Do you have any pics of a homemade shroud you could post to give a better idea of what it should look like?

[XS_RoB]

Too funny - Everything I have purchased for WaterCooling - after my live and learn EXOS system, has been upon Martin's Test Results or Reviews of the actual products!
If a company was smart they would hire him / you Exclusively for this type of thing!

@Martin - you should link your site in your sig, if allowed by staff. Also throw a PayPal (Donate button on your site.) I know I can't afford too much right now (Mrs. Laid Off last week) But I can squeeze in a 10 or 20 here and there for your efforts.

I actually feel bad for using so much of your info... teasing.

Have a great one and thanks yet AGAIN - for all you do and have in process!