Check it out, I found these ultra low db fans, 8.7db! Not bad.

Oh here's a couple more as well.

SilverStone FM121 120mm 17-39db (adjustable)

COOLER MASTER SAF-S84-E1 13db

Evercool SFF-8 80mm 20db

Thermaltake Silent Wheel 16db

VANTEC SF6025L 60mm (my personal choice, it's really small, 20db, 2600rpms, and only $7 )

Hey Blake,I have 4 of those 8.7 db fans in ver2!
Not sure about the 33 cfm,but they are pretty much silent!!
I am loving them!
Cheers P

You think the actual cfm is higher or lower?

I have the 120mm fan from the LL store mounted in the inside of my box and i can't even tell when its on!

my computer fan is louder and its on the other side of the room! I just crank the 1000w surround sound system and then i don't hear that one either

12cfm is like someone breathing on you when they are sleeping

All I know is that my 2 x pcac's whine.
The scythe fans may make some noise,but they do not whine!
I could have 3,647 of these in my pj,and they would still not whine!
Apparently the bearings are made by sony,and are in liquid.They do not emmit the same audible frequencies that regular fans do.
I have had all 4 going at once,and held my ear to them and all I can hear is the air buffeting my ear!
They definateley don't push as much air as the pcac's,but I could not really make a valid guess at what they do push,sorry.
Cheers P

PS: They also have a lifespan of 15 years running constantly!!!

yea but if you have 3,547 in your projector then your room would be pretty bright

Maybe an elephant.

Another thought, since everybody seems to be buying a lumen meter, will the next big thing be a Db meter?

I think i've seen this asked, but has anyone used the 120mm 120v fans. I see them at this computer store I go to, but never purchased one yet. Just curious it they last, if they are loud, and what they push for air flow.

Loud...

I had an arctic 120vAC fan in my first projector. It was the sleeve bearing version, which is actually supposed to be quieter than ball bearing. It pushed plenty of air, but when I turned the projector on it sounded like a jet engine revving up for takeoff, except not quite as cool.

Not to say that all 120vAC fans are loud, but the one I bought sure was.

Nick

Ok, thanks. No need to waiste my money then.

I have 2 of the Radio Shack 120mm 120v fans in my projector. They don't seem that loud to me. My 60" Sony Lcd has a fan that's just about as loud.

And on the plus side they cool WONDERFULLY. I don't even need a Lexan heat shield and the LCD still stays below 85degrees.

Pun15er,

Are your 2 winy PCAC fans made by Evercool? How long did it take before they started to wine? In an earlier post (different thread) the following link was given for the PCAC/CB model, which appears to have some promising ratings.

For the PCAC/CB the air flow is rated up to 100 CFM, with a rating of 23db, I was planning on picking up a couple of these, for my PJ. They are priced at $10/each + shipping.

Fulcrum

For those interested

Below is a quick chart of common dB(A) levels which can be found at "Howstuffworks".

Near total silence - 0 dB
A whisper - 15 dB
Normal conversation - 60 dB
A lawnmower - 90 dB
A car horn - 110 dB
A rock concert or a jet engine - 120 dB
A gunshot or firecracker - 140 dB

On another note... Concerning air flow rates in cubic feet per min (CFM), most cars have an air flow rating between 200 cfm and 300 cfm.

Very interesting, thanks for the post.

The problem most people have with the PCAC fans is that it operates on a frequency that most find annoying. Another problem is that once under a load (by pulling air through an opening that is not quite large enough) the dB level and frequencies both increase. The 120mm fans run at lower frequencies, so people prefer them to the PCAC's... one of the reasons Brain no longer carries them in the LL store...

cheers,
gs

edit: I should note that i've changed my cooling from one PCAC fan to 2x the Scythe S-Flex SFF21D's (8.7dB fans as listed above).... these things are completely silent, but they also don't move as much air as the PCAC. I've only used two (33.5 CFM /each) so I guess I need a third like Pun is using to get my temps down where they were with the one PCAC... Also; a quick thanks Pun15her for finding these fans... VERY quite.

GadgetSmith,

Excellent Point!
I definitely don't want myself or any of my family members to be annoyed by an irritating frequency.

Also by using 3 of the S-Flex SFF21D fans (rated at 8.7 db each) to achieve the same air flow as one PCAC fan (approx: 100 cfm), the total dB output for the 3 fans would be 12.2 dB (rounded), which is much lower than the 23 dB rating for one PCAC fan.

My BOM for my PJ has now been updated to reflect these fans.

Cheers,

Fulcrum

I also bought 2 of the PCAC barrel fans from the store for my Haas design...

They were annoying, so what I did was take the speed control part out of the two fans and built a little panel to house them (and my switches and fuse holder).

Now I have two 120mm fans that I can adjust the speed on... they are a little loud at full speed, but they are moving about 260cfm ! .... I run them about half speed and the box stays very cool.... probably moving 130-150 cfm.

Chris

My pcacs were bought over a year ago,I cant remember where from!
With the pj running,The pcacs are facing me at floor level,and they bug me!
My wife sits maybe 2 feet away from me on the same sofa,but further along from the pjand she reckons she can't hear anything! If I had positioned them facing the front,I don't think it it would have been a problem.

I have 4x scythe 8.7db fans installed in Ver2 now.3 pulling air out at the back,and 1 blowing air over the lamp.With everything going at full speed,and tinkering around with the box,maybe 12" away,the only noise I can hear is a feint buzzing noise,which I have never noticed before.It turns out it is coming from the e-ballast!
Cheers P

SPL (Sound Pressure Level) is logarithmic. An increase of 10dB seems to your ear that the noise has doubled in volume. Good post Fulcrum.