S19 Fan Specifications and Alternatives

I looked everywhere online, and it's just a bunch of vendors hawking fans with claims of 5500 to 7500 rpm as exact matches... yeah, right. Does anyone know the real specs for the fans in the S19? Like, what's the RPM, CFM, and connector type? Also, has anybody switched to a quieter fan? I can’t imagine it’d be that much quieter, but a 5-10db drop would be nice if the airflow stays the same.

From my experience, the fans aren’t the loudest part. It’s really the heat sinks and other components in the miner that make the noise. Going with a 'quieter' fan isn’t likely to change much, since they all have to move a ton of air.

The fans spin at 6500 RPM, pushing out 250 CFM, and you've got a max air pressure rating of 29.0 mmH2O at no airflow. They use a 4-pin connector.

Wait, is that the total CFM for the whole machine or for each fan? I’m trying to figure out how many duct fans I need for each machine or if I can combine them.

That’s for each fan.

Thanks! So, if I have a 1300 CFM fan, I could split it between two ducts. I could lower it to 1200 CFM and run two machines, each getting about 600 CFM, right? Heard we need to keep the airflow equal on both sides too?

Two fans are for intake, and two are for exhaust. So, it’s better to aim for a system that moves 500 CFM per miner at 0 static pressure, and 0 CFM at 58 mmH2O. Or 500 CFM per miner at 28 mmH2O if you use two duct fans.

Gotta do more digging into this, I guess. I was thinking of adding a 1200 CFM duct fan for the intake of two machines and another one for exhaust. The ducts are 8 inches wide and about 8 feet long. I’ve got a filter box rated for 1300 CFM on the intake.

The specs I gave you apply if you're removing the stock fans. If they stay, you just need to deliver what the miner requires and manage the static pressure of your ducts and filters.

That 10" fan from AC Infinity has a static pressure spec of 1059 Pa, or 108 mmH2O. Sounds like it should work fine unless your ducts are super long.

By the way, that fan lets you control the speed, so you could reduce it if needed. Just know that reducing duct size means less airflow, so you might end up running it full speed.

Is there a way to calculate static pressure, so I know the max duct length I can use? I’m planning: Intake: AC Infinity filter > ~2 ft insulated 10" duct > Inline fan > reducer to 8" > Y-split to 2 ducts > ~8 ft insulated 8" duct to miner.

Just did some searching on flexible duct specs. For a straight run of 10" duct at 1000 CFM, it’s about 1" H2O per 100 feet. If you have bends, it’ll drop more, so safety factor is key. You might want to double that.

Thanks for the info! I can definitely shorten that exhaust duct. I’ve got a big 2500 CFM exhaust fan on the roof, might even add another for extra ventilation. Not worried about negative pressure.

All just theory until someone tests it... make sure to update us once you get your setup working!

I will, just ordered the fans today.

Wanted to share my experience with the duct fans. I’ve got a few Avalons 1246 all on the same rack. They’re in my attic in Texas, so today was a warm day to test things out. I connected an AC Infinity 10" duct fan and filter on intake, and just the duct fan on exhaust.

Side by side comparison shows the non-ducted machine fans running at about 70% (5200 RPM), whereas the ducted fan is at 48% (3775 RPM). Huge difference in sound!