Project measuring fan static pressure

[Martinm210]

I'm not sure where I'm going to go with this if anything, but I wanted to see if I could do it.

Most people refer to a fan's performance based on CFM, yet that's really no different than comparing pumps based on maximum flow rate only . As you know pressure is equally as important for the net result and a fan produces a curve very similar to a pump.

Vapor and Cathar already covered the based on actual air flow on a PA120.1, but I'm curious how that changes if at all when you have more dense finned radiators.

Anyhow, this is just more of a quick test to see if I could do it and compare my results to a manufacturers results.

So with that I acquired a more sensetive manometer -20 to 20 inches of water at a .01" resolution to add to my manometer collection:D

Then I built as small little box to seal a fan on, cut and tapped a 1/4" barb in the side and painted the interior with a coating of silicone for a good seal.

And here it is...
My test setup:
http://img214.imageshack.us/img214/8424/fanpressuretest1dd8.jpg

and a little interior shot of the rough box. I wasn't sure it was even going to work so I didn't spend too much time on it.

http://img214.imageshack.us/img214/6239/fanpressuretest2ti8.jpg

My results:

Fan: Panaflo FBA12G12M
Static Pressure: .18-.20" H2O (Specs .18" H2O)
Power consumption: 12.03V x .28V = 3.37 watts (Specs 3.36 watts)

Panaflos fan specification brochure:
http://www.panasonic.com/industrial/appliance/pdf/fans/i/fba12g.pdf

That's pretty darn close!:up:

When I get my anemometer I might add a hole to the back to create a port tube to measure and adjust air flow rate and see if I can plot a full fan curve.

Any wagers what a yate loon's D12SL12 or D12SM12's static pressure is?:D

Update 4-13-08:
These are the fans I had lying around, no suprise as the 38mm fan even though it's lower speed than the SilverStone, dominates in static pressure. I'll do one more fan that should be coming my way in a few days. Not many fans here, but as has been talked about 38mm fans really help with pressure, this probably makes the most difference on dense finned radiators.

Update 4-23-08

Ran a few more tests along with staking two medium speed yates. Putting two together does almost double static pressure, and it's really pretty quiet considering the noise other fans produced that were similar in pressure.

I'm thinking two fans on top of each other in pull may be the strongest radiator setup. Experimenting with my anemometer shows that even with a foot long duct, that air flow wasn't even in push, but very even in pull. This is probably why pull works better, it produces more even air flow over the whole radiator.
http://img166.imageshack.us/img166/4200/fanstaticpressure2hy6.png

[iandh]

Wow, nice!


We should see quite a few good numbers out of your little ghetto-rig. :)


e: Hey, that isn't part of your wife's cabinets is it?

[Martinm210]

Wow, nice!


We should see quite a few good numbers out of your little ghetto-rig. :)


e: Hey, that isn't part of your wife's cabinets is it?


Sort of... they are scraps, I have lots of scraps. I wasn't sure if it would even work right, so it was a quicky.

I had her fooled into thinking I was working on stage 2 cabinets until she saw the size of the box and a fan in my other hand..:eek:

:D

[Big_Daddy]

Wow, with that rig, couldn't you also test the fans out on an actual 120.1 rad? see which works best, push/pull, etc? Actually compare the fans ON actual radiators. Like this one works well with the pa series, but does horrible on the bix, etc.

[Vapor]

I love NMB-MAT ratings :D

(btw Martin, you misspelled "Vapor" ;))

[smee]

w00t for black beach towel!!!!!!

This is a very good idea Martin, I may have to send you one o' my fav fans to test, Tt 130mm Silent Wheel (http://www.newegg.com/Product/Product.aspx?Item=N82E16811999144&Tpk=thermaltake%2b130mm)...

You should make this the main thread where you post results on different fans or something. :up:

This is going to be very interesting!! :D

I had her fooled into thinking I was working on stage 2 cabinets until she saw the size of the box and a fan in my other hand..:eek:

:D

Ahaha! lol. :rofl:

[Martinm210]

Arghh.

Looks like my manometer reads fine above .10", but it doesn't seem to be registering anything lower...:(

I tride one of my old Thermaltake Thunderblade 77 CFM and registerd .11", but my medium speed yate won't even register.:shrug:

Looks like I need a more sensetive manometer for any of the low speed stuff..

I can put several fans together in series and get a reading.

The TT thunderblade was getting .11 by itself and in tandem with a medium speed yate loon it gets .17, so the yate medium speed must only produce about .06". Pretty small pressures.

[cegras]

Would there be any difference if you changed the outlet to being at the bottom of the box and made it so that the box width is 120mm x 120mm, to fit the fan?

[ArtosDracon]

Nice!

[smee]

Looks like I need a more sensetive manometer for any of the low speed stuff..

What if you made the tubing from the box to the meter like 1in. long? That'll probably help? :shrug:

[Martinm210]

Ahh, I figured a workaround.

I just have to zero out at something other than 0...:shrug:

If I zero out with the TT thunderblade at .11 in reverse then I get a .11 reading without anything. Then if I run the medium speed yate loon I get a .18, so the true pressure added is the difference (.18 - .11) or .07"

Just have to do a little math I guess, not sure why the manometer is so attracted to 0, but it doesn't like reading in the -.1 to +.1 pressure range.

These are still pretty small pressures to measure, You really need something down to .001" resolution to do it right.

The Dwyer 477-000 or 00 would be perfect for it.
http://www.dwyer-inst.com/htdocs/pdffiles/cat/pressure/477_cat.pdf

The barb position was purposefully on the side, it shouldn't matter with static pressure as pressure should be equal in all directions, but I'm not sure how it would react when under flow, probably some error no matter where you put it from the drag on the hole.

[Martinm210]

I love NMB-MAT ratings :D

(btw Martin, you misspelled "Vapor" ;))

Sorry, you can call me Martian if you'd like..:D

Fixed!

[iandh]

Sorry, you can call me Martian if you'd like..:D

Fixed!

Hey, can I call you martian too?

:shrug:

[Martinm210]

Hey, can I call you martian too?

:shrug:

Only if I can return the favor somehow...hmmm I guess I'm not very creative:rofl:

[iandh]

Only if I can return the favor somehow...hmmm I guess I'm not very creative:rofl:

My forum name already sounds pretty goofy, I'm not sure you could really change it for the worse... :p:

[DavidNJ]

What manometer do you recommend?

[KaptCrunch]

Ahh, I figured a workaround.

I just have to zero out at something other than 0...:shrug:

If I zero out with the TT thunderblade at .11 in reverse then I get a .11 reading without anything. Then if I run the medium speed yate loon I get a .18, so the true pressure added is the difference (.18 - .11) or .07"

Just have to do a little math I guess, not sure why the manometer is so attracted to 0, but it doesn't like reading in the -.1 to +.1 pressure range.

These are still pretty small pressures to measure, You really need something down to .001" resolution to do it right.

The Dwyer 477-000 or 00 would be perfect for it.
http://www.dwyer-inst.com/htdocs/pdffiles/cat/pressure/477_cat.pdf

The barb position was purposefully on the side, it shouldn't matter with static pressure as pressure should be equal in all directions, but I'm not sure how it would react when under flow, probably some error no matter where you put it from the drag on the hole.

martin you can make a Venturi to build up pressure so your meter can read smaller flow/pressures. the mill/lathe comes mitey handy or sheet plastic cut and solvented together.
for the math (http://en.wikipedia.org/wiki/Orifice_plate) use the gases equation

[ZoLKoRn]

Good ideal of way for measure it :up:

but.... i need to know if area of chamber bigged than it, How pressure on measure it same or different ? and one thing i think some pressure will have leaked back between gap of fan-blade and fan-housing because the box is close chamber, it don't same of fan free flow :)

however this to see all from you it very good ideal and easy making for measure way :up:

btw. Are you have ideal for measure flow rate of fan ?

BR.
ZoL

[DavidNJ]

That is simply an orifice between two block...you don't really need a venturi. You just use a larger orifice.

You would need different orifice sizes to populate different spaces on the the PQ curve.

[ArtosDracon]

My forum name already sounds pretty goofy, I'm not sure you could really change it for the worse... :p:

diane? couldn't help myself, I'm dislexic and I read dian about half the time I see your name anyways.

[Boogerlad]

just what i've been waiting for....

[iandh]

diane? couldn't help myself, I'm dislexic and I read dian about half the time I see your name anyways.

handi? I am a pretty handi guy. :shakes:


Martian's fan static pressure thread now = XS name scramble game

/derail

[Martinm210]

Alright back on topic Diane...:)

I don't have too many fans, I've been sort of a happy with yate loons and sticking with them guy..

I think radiator fins have a lower pressure drop, so max (open air) CFM may be more important than pressure for open finned rads, but the more dense types would probably benefit alot by sticking to 38mm fans with higher pressure. This is all I had lying around the house and in the attic:

Pretty hard to measure though, a more sensetive manometer or guage is definately in order for any of the low speed fans.
http://img119.imageshack.us/img119/8592/fanstaticpressureme2.png

Also if the Noctua specs are correct for their new high pressure fan (http://www.ncix.com/products/index.php?sku=27129&vpn=NF%2DP12%2D1300&manufacture=Noctua#Specifications) 1.68mm H20 is .062 inches of water, so it would have pressure that's almost as good as the medium speed yate and quite a bit better than the low speed yate.

[Eddie3dfx]

Damn, I thought my silverstones did better than that ;(

Darn, I have the yate loon 88cfm and silverstones on my radiator.. I have done everything wrong lol

Anyway you can test the ultra kazes

[Martinm210]

Damn, I thought my silverstones did better than that ;(

This is just static pressure, so on an open finned radiator, it probably doesn't matter as much as their max air flow.

If you had the whole curve and the radiator pressure drop curve overlaid, then you could see which fan would actually push more air through the radiator.

This is just one spot on the fan curve, more important for dense radiators than open types.

[Martinm210]

This fan is one I'm interested in, probably does really well in the pressure department.

Ultra Kaze 38mm 1000RPM 44cfm
http://img.ncix.com/images/26742_l.jpg
http://www.ncix.com/products/index.php?sku=26742&vpn=DFS123812L%2D1000&manufacture=Scythe

Linus is hooking me up with some of the high speed types, but I'll see if I can undervolt it to 1000RPM and test the rads with it

[Eddie3dfx]

See if you can get the 87cfm kaze as well, for those of us that don't mind a little buzzing noise :)

[Martinm210]

See if you can get the 87cfm kaze as well, for those of us that don't mind a little buzzing noise :)

I'm getting the 136cfm types, so I should be able to undervolt them to match the speced RPM of those as well.:up:

[DavidNJ]

All of the radiators are moderately restrictive. Yes...we need your testing to determine the curves for radiators and fans.

So far, I believe, you testing makes the strong case for 38mm fans.

[Martinm210]

FYI
I just bought one of these which is perfect for fan testing. I couldn't bare the pain of another manometer, but is a gauge with increments down to .005".

http://www.ssb5.net/users/75441/331_037.jpg

Magnehelic® Differential Pressure Gages
Model 2000-00
Differential pressure gage, range 0-0.25" w.c., minor divisions .005

http://www.dwyer-inst.com/htdocs/PDFFILES/cat/pressure/2000_cat.pdf

I'm hoping this has the accuracy and sensetivity I need for decent fan testing.. I bought one on ebay for $45 so I'm happy..:D

The Scythe Ultra Kaze seem to have a pressure around .22", so this should cover most fans pretty well, and the specified error is 2% of .25" which is .005", so that's good.
More toys!

[Cptn Vortex]

I'm running 4 of the ultra Kaze's at 1500RPM, and I must say they are more silent than my 1200RPM Yates, while pushing a LOT more air. I have them set up as Push/Pull on a PA120.2 and I am very impressed. You will LOVE these fans Marinm210, trust me!

[Martinm210]

I'm running 4 of the ultra Kaze's at 1500RPM, and I must say they are more silent than my 1200RPM Yates, while pushing a LOT more air. I have them set up as Push/Pull on a PA120.2 and I am very impressed. You will LOVE these fans Marinm210, trust me!

That's great!

That's also why I want to be able to plot the full fan curve, it should give me some ability to predict just that.

I like the fans and would have tested at 1000 RPM if they still registerd RPM, but you start looking the sensor when they are undervolted too much. I might have to pick up some of the slow speed Kazes though, I think with a shroud 38mm fans are the way to go, not sure about unshrouded though because they do have a much larger fan hub.

[Petra]

Most people refer to a fan's performance based on CFM, yet that's really no different than comparing pumps based on maximum flow rate only . As you know pressure is equally as important for the net result and a fan produces a curve very similar to a pump.

This is something that I touched upon in my recent heatsink mini-roundup... I'm somewhat surprised by how few people realize this (then again, I'm not... :rolleyes: ). My beef with the Ultra Kaze fans is their decision to use a sleeve bearing (they may be quiet, but they don't usually last long). Anyway, I'm looking at getting ahold of the 120x38mm Sanyo Denki 109R1212H1011 fans again as well as possibly snagging one of their 120x25mm fans (rated for 70CFM, 0.146mm H2O static pressure, 35dBA, same style as the aforementioned 120x38mm). The bad news is that the lead time is about 13 weeks.... :(

Martin, if you need/would like one of the 109R1212H1011 fans, then let me know (I still have one unused one here).

[Martinm210]

This is something that I touched upon in my recent heatsink mini-roundup... I'm somewhat surprised by how few people realize this (then again, I'm not... :rolleyes: ). My beef with the Ultra Kaze fans is their decision to use a sleeve bearing (they may be quiet, but they don't usually last long). Anyway, I'm looking at getting ahold of the 120x38mm Sanyo Denki 109R1212H1011 fans again as well as possibly snagging one of their 120x25mm fans (rated for 70CFM, 0.146mm H2O static pressure, 35dBA, same style as the aforementioned 120x38mm). The bad news is that the lead time is about 13 weeks.... :(

Martin, if you need/would like one of the 109R1212H1011 fans, then let me know (I still have one unused one here).

Yeah, that would be great! I'm hoping after I get this new guage I can start running some full fan curves to compare them, for now and the lack of accuracy with my manomometer, I'm just running static pressure. I still have your Koolance pump top too, I just need to finish up that DDC 3.1 testing and send it back. Hopefully this weekend I'll get that done:up:

I just wanted to get some sort of high speed fan on the radiator tests, I have no idea how long the Ultra Kazes will last though.

Anyhow, even while I wait for my new guage to get here, I decided to go ahead and retest the fans I had, and run one experiment where I stacked two of the medium speed yate loons together.

As expected series does almost double the pressure. What's suprising is how quiet it produces that pressure compared to the other fans that produce that pressure in single form.

I'm thinking there is some real merit to PULL/PULL
I was also tinkering with my anemometer trying to figure out the best way to measure CFM. I found even with a long duct I built, there is still very disturbed and uneven air flow on the outlet side of the fan, but the inlet side is very uniform. This is probably why pull works better, uniform air.

Anyhow, here is that update. The series test in red. I'd say it's only accurate within .02" or so..

http://img166.imageshack.us/img166/4200/fanstaticpressure2hy6.png

[SoulsCollective]

Could you perhaps try a Noctua NF-P12 (http://www.noctua.at/main.php?show=productview&products_id=12&lng=en)? From my own testing, the higher static pressure of the P model compared to the S produces a large drop in temperatures on a restrictive radiator.

[Martinm210]

Could you perhaps try a Noctua NF-P12 (http://www.noctua.at/main.php?show=productview&products_id=12&lng=en)? From my own testing, the higher static pressure of the P model compared to the S produces a large drop in temperatures on a restrictive radiator.

Their specs say 1.68mm which is .066" H20, that would put it somewhere between the low speed yate loon (Straight Blade) and medium speed yate loon (curved blade).

I might round one up sooner or later..:up:

[DavidNJ]

What may be interesting is two stacked Panaflo Ms or Noctua 12Ps. That should double the max pressure (no increase in flow), making the PQ curve more like those for a restrictive system. They would be quieter than fans producting the same pressure in a single unit. The second unit may also produce some sound reduction for the first fan.

[Martinm210]

What may be interesting is two stacked Panaflo Ms or Noctua 12Ps. That should double the max pressure (no increase in flow), making the PQ curve more like those for a restrictive system. They would be quieter than fans producting the same pressure in a single unit. The second unit may also produce some sound reduction for the first fan.

Yeah, I'll have to wait until I get may more accurate guage though, my repeatability on this manometer isn't very good.

I was just trying to see what happens with 3 or 4 stacked on top of each other and there appears to be a diminishing gain, so it's not quite double the pressure and as you add a 3rd and 4th fan the addition makes even less of a gain.

But yeah, that's exactly what I'm thinking too. If pressure is really important, then it you might get better cooling on some radiators by stacking a few lower speed/quiet fans over one higher RPM variety..:shrug:

[gojirasan]

This is very exciting. I know I am really addicted to this hobby because I check this forum every day to see if you have done some new testing. Maybe fan stacking will become the next big trend in water cooling. I'm sold on the idea now. Although I'm looking forward to your push-pull and shroud testing as well. Are those Yate Loons from Alex or somewhere else like jab-tech? I would like to see two of the Ultra Kazes at 2000 rpm stacked up. And it would be great to see results for the elusive San Ace as well. There are some very mixed reviews about the Noctua. In a lot of cases the Scythe S-Flex SFF21F seems to beat it. And so I suspect the Zalman would too.

[Eddie3dfx]

Is petra the only place that sells curved yate loons?
I am looking at my yate loons that I picked up at jab-tech I believe, and they seemed curved, but I'm not sure what the difference is.
Can someone post pics of a normal yate loon compared to a curved one.

I am also shocked the silverstones don't have better static pressure than the yate loons, because if you hold the silverstone up and the yate loon 88cfm up, the silverstone pushes a massive amount of air in comparison to the yate loon.
very interesting to say the least.
Thank you for posting this martin

[nikhsub1]

Very good stuff Martin. You were very wise to use Panaflo as a base off of their specs, they are just about the only fan mfgr. that actually uses the true specs. Most fan mfgrs. are slum lords when it comes to specs it is a joke, I can't wait to see them all with their asses handed to them :D . although, perhaps not as they usually lie in the dba department :(

[septim]

more info overload from martinm...

some sanyo denkis and s flex should round up your test nicely...

[Martinm210]

Is petra the only place that sells curved yate loons?
I am looking at my yate loons that I picked up at jab-tech I believe, and they seemed curved, but I'm not sure what the difference is.
Can someone post pics of a normal yate loon compared to a curved one.

I am also shocked the silverstones don't have better static pressure than the yate loons, because if you hold the silverstone up and the yate loon 88cfm up, the silverstone pushes a massive amount of air in comparison to the yate loon.
very interesting to say the least.
Thank you for posting this martin

My curve yates, I bought from Petra's. I completely missed the curved vs. straight thing myself, but Vapor and Cathar both were already on top of it.

Here is a side by side comparison, the obvious difference is the trailing edge of the blade. The straight version is fiarly straight where the curved has a much more pronounced curve to it.

SM is curved on the left, SL is straight on the right.

http://img135.imageshack.us/img135/7711/yatelooncomparisonqv0.jpg

[Vapor]

Very good stuff Martin. You were very wise to use Panaflo as a base off of their specs, they are just about the only fan mfgr. that actually uses the true specs. Most fan mfgrs. are slum lords when it comes to specs it is a joke, I can't wait to see them all with their asses handed to them :D . although, perhaps not as they usually lie in the dba department :(:up::up:

All NMB-MAT fans I've tested are spot-on with my CFM tester (I get within ~1% of rating). I definitely trust their ratings above others. (Panaflos and Scythe Minebea series are their fans I've tested, for the record)

Delta's a very close 2nd though.

From there it's all downhill :(

Martin....as for straight vs. curved and Petras vs. non-Petras....

...I think they're two separate arguments ;)

I have straight blade Yates from Petras that perform ever-so-slightly better than the curved blade ones, on a radiator as well (well, in my testing on an MCR at least). BUT, non-Petras Yates are noticeably worse regardless of blade design so far. Though my numbers are not in terms of CFM vs. RPM, they're CFM vs. dBA. Cathar also confirmed higher CFM per RPM on the curved design.

It's all so confusing :(

[Martinm210]

:up::up:

All NMB-MAT fans I've tested are spot-on with my CFM tester (I get within ~1% of rating). I definitely trust their ratings above others. (Panaflos and Scythe Minebea series are their fans I've tested, for the record)

Delta's a very close 2nd though.

From there it's all downhill :(

Martin....as for straight vs. curved and Petras vs. non-Petras....

...I think they're two separate arguments ;)

I have straight blade Yates from Petras that perform ever-so-slightly better than the curved blade ones, on a radiator as well (well, in my testing on an MCR at least). BUT, non-Petras Yates are noticeably worse regardless of blade design so far. Though my numbers are not in terms of CFM vs. RPM, they're CFM vs. dBA. Cathar also confirmed higher CFM per RPM on the curved design.

It's all so confusing :(


That's the next thing I'm after is figuring out the best way to use my anemometer. As you mentioned the inlet side has more laminar flow, but I'm thinking I might build an inlet tube to my fan box that's just big enough for my anemometer which is about 2.8" with a 3" valve. So I'm thinking like a 3" piece of PVC out of the box to a 3" valve, then another 3" piece to the anemometer on the inlet. Then I could always adjust my area to calibrate the anemometer to match the panaflo and leave it set like that for all the fans.:shrug:

[AllAgainstPaul]

I would like to see the Delta TFB1212GHE (http://www.sidewindercomputers.com/de12tfexhisp.html) test results, but I don't really think it's worth the cost. Getting a fan that costs > $15 USD for just one test is impractical. On the other hand it the site states that the air pressure is > 15 as well. As this is most likely the most powerful 120mm fan on the market, (let me know if there is one more powerful) it would be nice to see the upwards limit that fans have.

[NaeKuh]

bwahahaha... see martin i told you... scythe ultra kaze = good!

[Martinm210]

They are good. They do only have sleeve bearings though. I think this helps with the lower sound level, but probably wears out faster than something like the panaflos or other higher end types with better bearings.

136cfm/.32inH20 is no slouch though..:up:

[bigslappy]

anybody think about putting a squirrel gage fan on that tester ?? them things move awhole lotta air

[spotswood]

Slightly OT....Can somebody please post an equation for the area of the intake/"grill area" required for a given CFM. :shrug: In other words, I'd like to know how much of an area I need to cut out for the intake/grill area in a configuration where the air travels like so: case wall->shroud->internal PA 120.3->fans (pull).

[DavidNJ]

That would be an exhaust, since your fans should be in pull!

I don't have an equation, and it would be dependent on the velocity of the flow which would be dependent on the PQ curves of the fan and the radiator (which Martin has been resisting).

I've been told that 1 foot is a good rule of thumb for fans in our range.

What happens when there is insufficient distance between the fan exhaust (in pull) and an obstruction? In increases the pressure on the exhaust side of the fan, causing the pressure on the inlet side to be higher at a given differential, reducing the pressure differential and flow across the radiator, which is after all, what we are interested in.

[spotswood]

That would be an exhaust, since your fans should be in pull!


No, the rad is internal (with the fans in pull), so the area I'm interested in is the intake.


I don't have an equation, and it would be dependent on the velocity of the flow which would be dependent on the PQ curves of the fan and the radiator (which Martin has been resisting).

I've been told that 1 foot is a good rule of thumb for fans in our range.

What happens when there is insufficient distance between the fan exhaust (in pull) and an obstruction? In increases the pressure on the exhaust side of the fan, causing the pressure on the inlet side to be higher at a given differential, reducing the pressure differential and flow across the radiator, which is after all, what we are interested in.

Do you mean one square foot of grill/intake area?

[Martinm210]

Well I tried to make a means to measure flow and include a valve with my box, here is what I ended up with. I even went to the effort of machining the fittings to match my anemometer vane probe.

http://www.martinsliquidlab.com/img/FanTesting.jpg

Unfortunately it's far too restrictive. I need to probably find a way to make a louvered type valve and a nice large duct to do this.

I'm a bit suprised a 2" ID pipe would be that restrictive, I even used a ball valve which is really as good as it gets for a valve. If a 2" opening is restrictive enough to cut an 86cfm fan down to 50%, that's also support that pressure is pretty important, perhaps more than open air CFM ratings on a radiator.

Oh well..I'll have to figure something else out. I don't have my guage yet anyhow...

[F1ZZY]

Wow, that is interesting. I love all your bench kit esp the ghetto parts that provide all the functionality to the measuring tools.

Maybe the extension might actually be representative of what we get on rads. As long as it is less/same restriction as a thermochill (the least restrictive to air) it should be ok. Can you test and compare.

It's seems pointless to go to lengths to make a more free flowing version (apart from plotting graphs) where some will be out of practical range.

Fans in free air readings are as useless as max flow rate for pumps. (for w/c use)

Also maybe a lower cfm fan might loose less than 50%

[Vapor]

50% reduction on a Panaflo? Wow...that's more restrictive than the Big Typhoon's radiator!

[Martinm210]

50% reduction on a Panaflo? Wow...that's more restrictive than the Big Typhoon's radiator!

I'm not sure I trust the air flow measurement, but it's definately lower.

Are you using an anemometer for your air flow measurements? Are you just putting it in the corner of a duct of known dimensions and calculating air flow that way.

My anemometer has an "Area" function where I can enter in the duct size down to .001 Square Feet and it'll read CFM direct, or I can just read velocity, but it's a bit tricky. it seems like you can get slightly different readings at different corners, etc..:shrug:

[Vapor]

I've ducted straight between the entrance of the fan and the 'exit' of the anemometer. ~3" of distance between the two.

I just use raw airspeed and convert in a spreadsheet. My anemometer does the area thing too, but it rounds/bins a lot when you do that for some reason :(

[WhiteFireDragon]

No, the rad is internal (with the fans in pull), so the area I'm interested in is the intake.


so you're going to have warm air coming into the comp? wouldn't this raise the ambient temp of inside the case, therefore slightly raising the water temp also? or would the difference of air temp inside and outside of the case be so small it wont matter?

[Martinm210]

I've ducted straight between the entrance of the fan and the 'exit' of the anemometer. ~3" of distance between the two.

I just use raw airspeed and convert in a spreadsheet. My anemometer does the area thing too, but it rounds/bins a lot when you do that for some reason :(

Thanks for mentioning that, I hadn't checked mine against air velocity.

I think for my radiator testing, I'm just going to build several shrouds maybe 6" or a foot long that I can seal up against the inlet side of the radiator and measure CFM.

[spotswood]

Has anyone had any experience with these 200/220mm fans?

Antec Big Boy 200 (http://www.antec.com/Detail.bok?no=490)
* Dimensions: 200x30mm
* ???

Koolance Fan 220x30mm (http://www.koolance.com/water-cooling/product_info.php?products_id=689)
* Dimensions: 220x220x30mm
* Type: Dual Ball-Bearing
* Connector: 3-pin (3-wire with tachometer)
* Rated Voltage: 12VDC
* Current: 0.34A
* Speed: 800RPM (max)
* Static Pressure: 0.86mm-H2O
* Airflow: 40.5CFM (max)
* Noise: 34.7dBA (max)

I'm wondering how two of these fans on one (or two :shocked: ) 120.3 rad(s) (w a shroud, in "pull" mode) would perform. :shrug:

[Anemone]

I was just playing with the Minnebea vs S Flex last night and noticed the higher pitch noise of the NMB's... which I didn't appreciate.

Going to have to watch how this develops. I very definitely prefer longer lasting bearings of which many these days are not all that durable.

[eXa]

Huh... i thought 2 25mm fans would produce more pressure than 1 38mm fan. Guess not

This fan is one I'm interested in, probably does really well in the pressure department.

Ultra Kaze 38mm 1000RPM 44cfm
http://img.ncix.com/images/26742_l.jpg
http://www.ncix.com/products/index.php?sku=26742&vpn=DFS123812L%2D1000&manufacture=Scythe

Linus is hooking me up with some of the high speed types, but I'll see if I can undervolt it to 1000RPM and test the rads with it

I look forward to when u get them. A freind of mine is using the 2000 version but even undervolted they have abit too much engine noise than i like. Can u run the ones u already have @ 1000rpm and see if there is any difference in engine noise (3k rpm @ 1k vs 1k)?