I’ve been searching around and all I find are tons of sellers offering fans with speeds from 5500 to 7500 rpm, all saying they're perfect replacements... but that's clearly not true.
Does anyone actually know the specific details of the fans in the S19? Like RPM, CFM, and connector type?
Also, has anyone tried swapping in a better fan that’s supposed to be quieter? I doubt it’ll be a huge difference, but even a drop of 5-10db would be awesome if it still keeps up the same airflow.
The fans usually don't make most of the noise, it's the heat sinks and other paths through the miner.
You'll probably make no difference with a supposedly 'quieter' fan due to how much air they need to move.
Hi, is that the total cfm per machine (s19 / Avalon 1246) or for each fan. Trying to calculate how many duct fans I need per machine or can combine across per machine
Thank you.
Thank you. So, I could technically split the a 1300 cfm fan across 2 ducts, i could reduce it to 1200 cfm and split it between 2 machines, giving each machine ~ 600cfm?
Same route for the exhaust side - read somewhere on this forum, I got to keep the cfm the same on each side?
2 fans are intake, 2 are output, so it would be more accurate to find a setup that moves 500cfm per miner with 0 static pressure, and 0cfm at 58 mmH2O. Or 500cfm per miner and 28 mmh20 if you are doing two duct fans, on one the intake, one on the output.
Also, you'll need an even higher static pressure spec depending on how long your ducts are.
Need to research this more I guess. I was going to add 1x1200 cfm duct fan and split it to 2 machines on the intake side, and another 1200 cfm duct fan on the exhaust side for every 2 machines. ducts were 8" and about 8ft long. Input side was going to have a filter box capable of 1300 cfm
Duct fans were the AC Infinity 10" duct fans with a reducer to 8" ducts
The specs I suggested would be if you are removing the original fans and replacing them with ducts and duct fan(s). If you are not removing the fans on the miner, then the specs are a lot lower since all you need to do is deliver the max airflow the miner will require and only overcome the static pressure of your ducts and filter.
The 10" AC infinity fan lists a static pressure spec of 1059 Pa, which is 108 mmH2O, so I'd guess it has a good chance of working if your ducts aren't too long.
as an aside that fan has a speed control which will allow you to reduce speed if needed.
Duct size reduction = less air flow so maybe you can just run the fan at full speed.
if the ducts are 20 feet long you may need a booster fan near the exit at the window.
Is there a calculation to see the static pressure, to see the max duct I can have.
The plan is:
Intake Inside: AC Ininity 10" Air filter box --> ~ 2 ft Insulated 10" duct --> AC Infinity 10" Inline duct fan --> Reducer to 8" --> "Y" Split to 2 ducts( far each machine) --> ~ 8 ft Insulated 8" duct to the machine to attached 8" shroud
Exhaust side": ~2 ft Insulated 8" duct from machine --> Combine ducts with Y from another machine; will look preferably for 8" to 10 " --> ~ 2 ft 1nsulated 10" duct -->AC Infinity 10" Inline duct fan --> ~8 ft Insulated 10" duct possibly pointed upwards towards 2500CFM exhaust fan
Should I expand the duct from 10" to 12 " On the exhaust side, afte the duct fan, to minimize any resistance
Do you forsee any static pressure issues / what is the longest duct you think I could use?
Planning to use this duct - https://www.homedepot.com/p/Master-Flow-8-in-x-25-ft-Insulated-Flexible-Duct-R6-Silver-Jacket-F6IFD8X300/100396936
Thank you. Yeah, I may just run the fans at max. I wish I knew how to calculate the max duct run I could use before needing another fan at the end
Just did a search for flexible duct specs and this was what came up (from Thermaflex), you may be able to find similar specs for the exact duct you're looking at with enough internet searching...
For a straight run of 10" duct at 1000cfm (which includes safety factor since the fans on the miner max out at 500cfm each at 0 static pressure), it looks like about 1"H2O per 100'. I assume you'll have some bends in there, so the drop would be higher. Maybe just give yourself a factor of 2 more safety factor. Or click on the image below to open the pdf where they go into depth about how to calculate equivalent lengths with bends.
This is awesome info - thank you.. For the bend, I can shorten that exhaust duct, just needed it pointed upwards towards the exhaust fan. I have a ~2500 cfm exhaust on the roof, may add another, enough ventilation, so not worried about the negative pressure.
Just wanted to report back on the duct fans.
I have few Avalons 1246's all on the same rack. These machines are in the attic, in Texas, and today is a warm day, which I was waiting for to report back
On 1 machine I hooked up AC infinity's 10" Duct Fan and Filter box on the intake side and just the duct fan on the exhaust side. Both fans at about 600 cfm (50% of their 1200CFM capability)
Comparing the identical machines side by side - the non ducted machines fans are running at about 70% (5200 RPM) , the ducted machine fan is running at 48%(3775 RPM).
Also the high pitch of the machine was silenced to low rumble. With this POC done, will hook up 2 machines per duct fan and hopeful quieten my house more, while I plan to plan to sound proof the area more.