Can someone recommend a more quiet 92mm fan for my AVP 625 in my G20 Upright?

[dcpmark]

I'm trying to make it as quiet as possible. Home environment, nothing on either side, never gets played for more than an hour at a time, has SSD already, and with both the middle and upper cabinet fans disconnected, it never gets higher than 98 degrees. I'd like to change out the external BB fan for a lower CFM 92mm x 92mm x32mm fan, if possible.

Thanks in advance for any help!

[Stayouttadabunker]

My OCD is wondering what the temperature is inside the cabinet, WITH those two fans plugged in and running normally, as they are designed to do?

[dcpmark]

My OCD is wondering what the temperature is inside the cabinet, WITH those two fans plugged in and running normally, as they are designed to do?

Ha! I can plug them both back in and let you know. But seems like the design was for when there are CRTs in both the middle and the top instead of LCDs as the interior of the cabinet is completely cool even with both fans off. Even the temperature of the output of the BB fan is not warm at all.

[Stayouttadabunker]

We both know that these machines were designed to be as LOUD as possible, and with the biggest, brightest lights too.
That's the casino environment.
I imagine you could do a world-wide search for something that runs on 12 volts, but a little slower.
Whether or not it will push out the same CFM - remains to be seen.
Sounds like you some R&D on your hands...lol Good Luck!
Let us know what you find.   

[sccarlso]

The key isn't always just CFMs.  Good airflow through the cabinet has a few variables. 

On many old machines the intake / exhaust vent grills get gummed up with dust as casinos never clean them and then they block almost all airflow.

If all the vents are clean and the fan on the brainbox itself is good.  You just want it to pull in air at the bottom of the machine, and exhaust it out the top.  Cool air in, heat rises, exhausts it out the top.  Pretty sure there are several vents behind the top screen, but they don't have fans, but usually have screw holes so a quiet fan "could" be installed there to increase exhaust airflow.  They just need to be clean as well to let hot air out the top.

Just check the voltages.  Pretty certain the brainbox fan is 12v but the cabinet fans are 24v.  And verify the cabinet fans are DC fans.  I could swear I replaced a cabinet fan in a machine where it was 24v AC...   But it was awhile ago.  lol   Just ensure it's right voltage and that it's DC and not AC.  If it is AC, just as easy to find fans as well. 

Then just go here:  https://www.digikey.com/en/products/filter/fans/dc-brushless-fans-bldc/217

It's a table of fans with every filter you can think of.  Select say 24v, and the rectangular size of Square - 92L x 92H (don't select the width).  Click the "in-stock" button and apply.  Now it's filtered down to only about 270 fans.
 
It seems like a lot, but each fan is a line item that lists every spec.  And you can sort the list by noise level, CFM's, etc.  Shouldn't be hard to find one that has the most CFM's and the least noise level.  Ones with lower noise and higher CFMs are likely thicker than the stock fans but slower RPM's.  But thicker fans should work fine, you can measure to ensure the thicker fans fit.  You'll just need to get longer screws from the local hardware store to secure the fan.

The brainbox fan should be 12v and the stock fan is pretty loud if I recall.  But you can do the same.  The location of the brainbox fan allows for a thicker fan to be installed as well.  So just need longer mounting screws if a fan is thicker than the original fan.  And plug connectors really don't matter as long as it has the same number of wires.  Just use the connector from the orig fan and solder its wires to the new fan leads, or use small wire nuts to reuse the original connector with the new fans.

[dcpmark]

Thanks, all! This is what I was able to find out about the stock BB fan:

The Delta EFB0912HHF is a high-performance 92x92x32mm axial DC cooling fan, operating at 12V DC with a 0.44A rating. It typically features a 3-pin connector (likely with tachometer/speed sensor output), 3200-4000 RPM range, and is designed for heavy-duty industrial or server cooling, often characterized by a 32mm depth rather than the standard 25mm.

I was thinking of trying this one, which is thinner at 25 mm, but only spins at 1900 RPM. But I’m gonna go to the.Digikey site as well to see what I can find.

https://www.amazon.com/dp/B09VGWCH8K?ref=ppx_yo2ov_dt_b_fed_asin_title

[dcpmark]

Ok, thanks to the DigiKey tip, I found and ordered this one….. spins at 1700 RPM, and is only 17.7db! I’ll post if there’s any temperature issues after installing it. Does anyone know what temperature reading a G20 Upright should stay under?

https://www.digikey.com/en/products/detail/same-sky-formerly-cui-devices/CFM-9225V-117-177-20/7605694?

[Chris-socal]

LCD monitors do generate heat, not as much as a CRT but a smaller CRT only draws 65-70 watts once started. Look at the wattage rating on an LCD, it isn’t tremendously lower. Airflow is very important, especially for the power supplies.
If those fans run on DC you can get a small inline PWM speed control on Amazon and reduce the RPM about 25% which will reduce the noise level quite a bit.
https://a.co/d/0auii1BN

Unfortunately some machines use AC powered fans so there aren’t many options other than put a higher voltage rated fan in….if you can find one.

Chris

[dcpmark]

LCD monitors do generate heat, not as much as a CRT but a smaller CRT only draws 65-70 watts once started. Look at the wattage rating on an LCD, it isn’t tremendously lower. Airflow is very important, especially for the power supplies.
If those fans run on DC you can get a small inline PWM speed control on Amazon and reduce the RPM about 25% which will reduce the noise level quite a bit.
https://a.co/d/0auii1BN

Unfortunately some machines use AC powered fans so there aren’t many options other than put a higher voltage rated fan in….if you can find one.

Chris

Wow, thanks!!! Yes, all DC fans, but I’ll need a 4-wire replacement fan to make this work, correct? The BB fan is 3-wire, and the mid and upper cabinet fans are both 2-wire. It would be awesome to convert all three to have speed control for each one.

[Chris-socal]

No, PWM controls the speed on a 2-wire dc motor. I use them on 2-wire windshield wiper motors all the time. You only need 3 wires if you want to read the actual rpm, which you don’t need to in this case, you just want to be able to turn it down a bit.

[dcpmark]

No, PWM controls the speed on a 2-wire dc motor. I use them on 2-wire windshield wiper motors all the time. You only need 3 wires if you want to read the actual rpm, which you don’t need to in this case, you just want to be able to turn it down a bit.

Perfect, thanks again!! I saw the 4 inputs on the speed controller so I assumed all 4 were needed.

[dcpmark]

My OCD is wondering what the temperature is inside the cabinet, WITH those two fans plugged in and running normally, as they are designed to do?

Testing complete....it's about 10 degrees cooler with all 3 fans running, 83 average without playing a game (it's a Game King video poker). With just the BB fan on, it's a 93 average. Now, that measurement is from wherever the G20 is outputting the machine temp. I also put another temp sensor inside the bottom cabinet near the BB fan output, and it was 80 with all 3 fans vs 90 with only the BB fan on. Actually playing the machine for an extended period of time only raised temps by a few degrees in either scenario.

[Stayouttadabunker]

Here's a known fact...>>> Heat kills electronics.
Here's another fact...>>> You're messing around with slot machine designer specifications for fans inside your cabinet.
You want to place a bet on who's going to win this one?

Think about it, any resistance placed online to slow down a motorized fan has to be released as_____...you guessed it...heat!
Put it on a scale...your expensive AVP G23 video monitor/ brainbox burning out versus a slightly noisy fan?

I'd just get new fans with the same specs. 
New fans will have smoother motor bearings...which WILL be quieter than 20 year old ones. 
You might get away with the cabinet being 10 degrees warmer.
However, it makes you wonder how much hotter the brainbox's CPU and video cards are running?

[dcpmark]

Here's a known fact...>>> Heat kills electronics.
Here's another fact...>>> You're messing around with slot machine designer specifications for fans inside your cabinet.
You want to place a bet on who's going to win this one?

Think about it, any resistance placed online to slow down a motorized fan has to be released as_____...you guessed it...heat!
Put it on a scale...your expensive AVP G23 video monitor/ brainbox burning out versus a slightly noisy fan?

I'd just get new fans with the same specs. 
New fans will have smoother motor bearings...which WILL be quieter than 20 year old ones. 

All good points….. I’ll loop in my service tech to this little project to get his input about the best ways to quiet it down while still in spec. Thanks!

[Stayouttadabunker]

I added some more text after you copied & pasted...sorry...I'm always updating my posts. 

You have a personal "service tech"...wow! lol

[dcpmark]

I added some more text after you copied & pasted...sorry...I'm always updating my posts. 

You have a personal "service tech"...wow! lol

Ha! Well, I love to tinker, but I’m a noob as far as these machines go, so I have to pay SOMEONE to fix them if they go bad. He’s actually my pinball tech who happens to also do video games (and video slots, apparently).

I wish I knew where the machine temp measurement is coming from, but I’m guessing it’s gotta be near the CPU/GPU. Obviously these things are nothing but computers, so I’m guessing they have to be cooled the same way as regular computers.

[Stayouttadabunker]

Exactly!
You really want to keep the video chips cooled.
The newest video graphic cards actually have large heatsinks & copper pipes running on them, showing you how important the designers want to keep them cooled!

[Chris-socal]

Three things.
Slowing a motor with a pwm does it digitally, no heat like the old school method with a big resistor.
The reason for 4 pins is +/- in, +/- out. Simple.
I greatly respect the cooling engineering but these were designed to be left on 24/7 in a casino whete no one cares about accumulative sound. We are neither. And lets face it, they can be so loud you my not be able to use them in your house if you don’t do something.

Just be sure to keep the air flowing, pull air out the top. As mentioned, heat kills electronics.

[dcpmark]

Three things.
Slowing a motor with a pwm does it digitally, no heat like the old school method with a big resistor.
The reason for 4 pins is +/- in, +/- out. Simple.
I greatly respect the cooling engineering but these were designed to be left on 24/7 in a casino whete no one cares about accumulative sound. We are neither. And lets face it, they can be so loud you my not be able to use them in your house if you don’t do something.

Just be sure to keep the air flowing, pull air out the top. As mentioned, heat kills electronics.

Yep, I should’ve looked at the diagram in one of the photos of the PWM at the link you provided to show what the four inputs are for. This is gonna be a fun little project for me, finding a way to keep all three fans spinning while severely reducing the fan noise.

[Stayouttadabunker]

I just ordered one of those PWM's...I wanna try it too!