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parsonic
Joined: 23 Feb 2008
Posts: 7
Location: Hannover Germany
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| Posted: Sun Dec 21, 2008 9:46 am Post subject: |
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I've used the Scythe fans to mod my barco 1200 some time ago, and I am quite happy with the result.
They are reasonable priced, quiet fans that deliver lots of air flow. 
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SisterOfMercy
Joined: 31 Oct 2007
Posts: 155
Location: Zwart Nazareth, The Netherlands
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| Posted: Sun Dec 21, 2008 10:40 pm Post subject: |
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| jkruger wrote: | | I'm thinking of swapping out the fans in my 1209s with some much quieter ones. |
Good luck at that. The stock NMB fans are very good. Fans from other manufacturers always make more noise at the same flow. Papst is coming close, as are other quality manufacturers.
But by all means, replace them with cheapskate rebranded low-quality fans that spin at lower speeds and generate less flow. 
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HighDefDude
Joined: 02 May 2008
Posts: 20
Location: Netherlands
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| Posted: Sun Jan 25, 2009 2:04 pm Post subject: |
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| Gary M. wrote: | thats great so now we can replace fans if needed and not have to worry about problems
I had to replace the fans on my 1209s, they were filled with mold, the originals were impossible to locate and I didn't want to buy used ones
I used Scythe KAZE-JYUNI SY1225SL12H which match the internal fans specs as close as possible, PJ is a pinch quieter afterwards
I wouldn't waste time trying to quieten the 1209s, it is barely audible thanks to the large 120mm fans, I replaced for other reasons
adding resistors and slowing fans is NEVER the answer, with newer fans you can increase CFM and lower noise albeit slightly
-Gary |
Sorry Gary, this doesn't mean you can swap fans without problems!!
A thermistor controlled environment doesn't mean temperature controlled!
There are two ways to control the temperature of a projector:
-The 'intelligent' way: Used in most laptops: The temperature of the device (CPU) is measured, and fans are started
when the temp exeeds a certain level, fans are stopped when the temp drops below certain level.
In that case, when you swap the fans by more quiet ones (with less flow!) they are kept operating longer, long enough to, if ever, reach the minimum fan-cutoff temperature.
-Then there is the thermistor controlled environment: More simple, but not measuring the actual temperature! It just sends a higher voltage to the fans when the thermistor 'feels' a higher temperature.
These systems are based on a certain type of fan with a minimal airflow at rated power! Swap fans of a system like that with silent ones with less flow, and the temperature will definitely rise until a stable situation is reached at a higher temperature!
I've done some tests on this with my Barco yesterday: First measured the temperature on one of the fan-exausts and on one of the heatsinks on the H-board. The temp in my room was (and always is..) 20,5 degrees Centigrade.
After 45 min, I measured 31 C at the fan and 38 at the heatsink.
The thermistor-system sent 7.4 volts to the fans.
Then I swapped the fans by superquiet ones, it was a delight to my ears! practically no sound at all!
But soon the voltage began to rise and stabilized at 11.8 volts, with a temp of 42 C at the fan-outlet and 48.5 C at the heatsink! This means a minimal 10 degrees rise of temperature!
Ok, that might not be entering the dangerzone, these projectors should be able to operate in much hotter environments, which also means higher internal temperatures.
But it always is better for electronics, especcially IC's, to operate at temps as low as possible (within limits ofcource..)
10 degrees temperature rise was too much for me, so I put the original fan's back in place.
But I'm not done: I know I can find a compromise between a tiny bit noisier than absolute quiet, and sufficient cooling!
I just need to find the right fans for that.
Also: As my room is airconditioned, temperature is kept stable at 20-21 degrees C, If you have a similar situation, a few degrees higher internal projector temperature will not damage things..
Hope this helps..
All the best,
HDD.
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HighDefDude
Joined: 02 May 2008
Posts: 20
Location: Netherlands
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| Posted: Fri Jan 30, 2009 10:57 am Post subject: |
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OK for those who are intereted: I did some more testing...
I obtained 4 Noctua NF-P12 fan's, they actually have sharkteeth! And are about as silent as sharks as well.
The most important problem I encountered during testing is that the internal heatproduction highly depends on the scanrate I was using!
I got a reasonable situation at 1080i/60 (2x30Hz) that works at 33kHz scanrate. At 56kHz (1600x900P/60Hz), the internal temperature (which already was some 6 degrees higher than with the original fan's!), already raised some 3 degrees C
After I switched to High scan (74kHz, 1600x1200p/60), I stopped testing after some 5 minutes, for that, the Noctua's absolutely didn't provide with enough airflow! (in my opinion that is...I always keep things on the safe side!)
Fact: The fan's that came with my pj have 65 CFM (140 kubic mtr/hr) airflow at rated power. The Noctua's have 43 CFM
(93 Cmtr/hr) airflow.
Fact: The PJ operated the 65 CFM fan's at 7.4 volts (at 56 kHz). The Noctua's were driven at 9.6 Volts after the internal temp stabilized.
In my case, if I want to use my PJ to the full, I need the 65 CFM airflow! Silent fan's always have lower airflow.
With the same airflow, noise can only be lowered by aerodynamicly formed blades and case, and low friction bearings.
I learned that only a few dB's can be won that way(when RPM is not altered). Ok, a few dB's already means almost half the noise.
Problem remains that the high-flow/low noise combo is hard to find, I never found a silent fan that operated at 2400 RPM,
and high RPM's is the first thing you need when you need decent airflow! At certain RPM, difference in shape of case or blades will not affect airflow with more than 10% tops!
So you simply cannot expect a 1600 RPM fan to have the same flow as a 2400 RPM fan !!!
So, when you want to install silent fan's, know what you are doing! Always check internal temperatures (heatsink's) first and compare them! (be ware that some heatsinks are connected to high voltage!)
Best regards,
HDD.
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Ile
Joined: 09 Mar 2006
Posts: 1491
Location: Jyväskylä, Finland
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| Posted: Fri Jan 30, 2009 1:49 pm Post subject: |
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HDD
What 65 CFM fans your Barco have?
Most Barcos have NMB 4710NL-04W-B30 120x25 fans. 2050 rpm, 79,5 CFM, 3,5 mmH2O and 35 db at 12V.
Without husbox I'd probably go with
Japan servo SCNDM12D4 120x38 fans. 1950 rpm, 78 CFM, 4,0 mmH2O and 30db at 12V.
http://www.japanservo.co.jp/digital/english/general/pdf/SCND.pdf
I think G90 have four of these without speed control.
I use two almost similar CNDC12D7 to feed my hushbox, those are good quality industrial fans. Not that pc crap they are selling and claiming 80 CFM airflow with 1200 rpm and 14 dbA.
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benareeno
Joined: 22 Mar 2006
Posts: 1614
Location: ottawa, canada
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| Posted: Fri Jan 30, 2009 5:40 pm Post subject: |
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Ile,
what do you mean when you say "feed your hushbox"? I don't understand that...
I would love to find a simple way to quiet my Barco a bit more...and I will probably run a pretty easy scanrate...I'm thinking 1280x545 at 47.952Hz (for 2.35:1 movies..so most movies)....that should be pretty easy for the projector to work with.
If I use such a res though...I'm thinking I won't have enough VSize range to shrink the picture appropriately. Is there a pot somewhere in the chassis that will shrink the Vsize adequately?
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Ile
Joined: 09 Mar 2006
Posts: 1491
Location: Jyväskylä, Finland
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| Posted: Fri Jan 30, 2009 8:14 pm Post subject: |
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| benareeno wrote: | Ile,
what do you mean when you say "feed your hushbox"? I don't understand that...
I would love to find a simple way to quiet my Barco a bit more...and I will probably run a pretty easy scanrate...I'm thinking 1280x545 at 47.952Hz (for 2.35:1 movies..so most movies)....that should be pretty easy for the projector to work with.
If I use such a res though...I'm thinking I won't have enough VSize range to shrink the picture appropriately. Is there a pot somewhere in the chassis that will shrink the Vsize adequately? |
I use those two fan to blow cool air from another room floor level to my hushbox between sheetrock wall. Projectors own fans blow hot air back to that room through hole in living room back wall.
http://www.curtpalme.com/forum/viewtopic.php?p=133857#133857
There is only pots for R/B Vsize in Vdeflection board to match sizes, but I think it's possible to add resistor/pot to make all rasters Vsize smaller.
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kal
Forum Administrator
Joined: 06 Mar 2006
Posts: 18114
Location: Ottawa, Canada
TV/Projector: JVC DLA-NZ7
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| Posted: Sun Feb 01, 2009 2:25 am Post subject: |
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| HighDefDude wrote: |
-Then there is the thermistor controlled environment: More simple, but not measuring the actual temperature! It just sends a higher voltage to the fans when the thermistor 'feels' a higher temperature.
These systems are based on a certain type of fan with a minimal airflow at rated power! Swap fans of a system like that with silent ones with less flow, and the temperature will definitely rise until a stable situation is reached at a higher temperature!
I've done some tests on this with my Barco yesterday: First measured the temperature on one of the fan-exausts and on one of the heatsinks on the H-board. The temp in my room was (and always is..) 20,5 degrees Centigrade.
After 45 min, I measured 31 C at the fan and 38 at the heatsink.
The thermistor-system sent 7.4 volts to the fans.
Then I swapped the fans by superquiet ones, it was a delight to my ears! practically no sound at all!
But soon the voltage began to rise and stabilized at 11.8 volts, with a temp of 42 C at the fan-outlet and 48.5 C at the heatsink! This means a minimal 10 degrees rise of temperature! |
I said it before and I'll say it again: Anyone swapping out Barco fans for "quieter" ones is frying their projector faster.
How can you determine that 10 degrees is minimal? How do you know what is ok and what isn't? Yes, your projector still seems to run fine, but it may run for only 1 year instead of 5.
Most of the noise comes from air turbulance, not the fan itself. Take that NMB brand fan used by Barco and run it outside the chassis and you'll see that it's very quiet. It's the air moving that makes that noise, not the fan. The air moving makes noise becase THE PROJECTOR NEEDS TO MOVE THAT MUCH AIR TO KEEP THE PROJECTOR COOL. Anything else is simply killing your projector faster.
I would never buy a Barco from anyone who does fan mods as the projector is closer to death.
Kal
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