Antminer S9 - Actual CFM at full fan RPM

[lrowland21093]

As a newbie to home mining I acknowledge I made a mistake in buying the S9.  I read over and over that is was loud and designed for data centers but I did not listen.
I decided after trying to quiet it down to sell it and fall back on three Avalon 741s with the voltage offset configured to -2.  These are still industrial miners but with that setting the fans are tolerable.  In addition the Canaan hardware seems to be much more reliable.  The Avalons have a better heatsink arrangement which definitely cools better than the Antminers.

Trying to change the fans on any of these miners is A BAD IDEA.  These high CFM and high static pressure fans are actually very high quality and specifically chosen for this cooling job.  They are loud because they are pushing a lot of air.  No PC style or quiet consumer fan is gong to work on these and keep things cool enough.

[m3hm3t]

As a newbie to home mining I acknowledge I made a mistake in buying the S9.  I read over and over that is was loud and designed for data centers but I did not listen.
I decided after trying to quiet it down to sell it and fall back on three Avalon 741s with the voltage offset configured to -2.  These are still industrial miners but with that setting the fans are tolerable.  In addition the Canaan hardware seems to be much more reliable.  The Avalons have a better heatsink arrangement which definitely cools better than the Antminers.

Trying to change the fans on any of these miners is A BAD IDEA.  These high CFM and high static pressure fans are actually very high quality and specifically chosen for this cooling job.  They are loud because they are pushing a lot of air.  No PC style or quiet consumer fan is gong to work on these and keep things cool enough.

so what about with this cooling warehouse system? (internal temperature is 0°C)

Evaporator Cooling Room

[lrowland21093]

so what about with this cooling warehouse system? (internal temperature is 0°C)
Evaporator Cooling Room

Interesting picture...  It looks like industrial style air handlers in a dedicated mining space.  That probably cost a lot of money to install and requires the dedicated space.  Most home miners are not going to have a room like that available (especially if it requires approval by the spouse). 

I guess it is really a case of accepting that these miners are industrial - trying to change them to fit the needs of a home miner is a mistake.  But if you have a room like that and the power to run to it, then go for it!  (Just my humble opinion!)

[BKMining]

so what about with this cooling warehouse system? (internal temperature is 0°C)

I realize this thread is a little old, but just wanted to make a point that making the air "cold" is not as important as creating enough air flow. The ideal setup for S9 is to have a negative pressure room for the exhaust and a positive pressure room for the intake, even in the dead heat of Florida in the summer, this concept works very well at room temperature believe it or not, as long as ambient is not too hot. Typically miners are happy at up to 80 degrees if there is sufficient air flow. Making a room cold doesn't do anything for you if you can't allow the machines to breath and isolate them from the hot exhaust air. How you achieve this is irrelevant, there are 100 ways to do it.

[artinian_aua]

...making the air "cold" is not as important as creating enough air flow. The ideal setup for S9 is to have a negative pressure room for the exhaust and a positive pressure room for the intake.. [] Typically miners are happy at up to 80 degrees if there is sufficient air flow. Making a room cold doesn't do anything for you if you can't allow the machines to breath and isolate them from the hot exhaust air.

This is a very good and important point. I was wondering about the 25-40˚C operating temperature specified in the S9 official manual. Saying 'Typically miners are happy at up to 80 degrees' do you mean they operate at the maximal hashrate and then over 80˚F the hashrate starts decreasing?

[artinian_aua]

Good idea, maybe I can finally contribute something useful to the community hehe. Will update with results

+VentMine Any progress on measuring the pressure drop/differential? 

[VentMine]

Good idea, maybe I can finally contribute something useful to the community hehe. Will update with results

+VentMine Any progress on measuring the pressure drop/differential? 

No I never bothered to do it lol. I found out the fan CFM was 220 / S9, made some assumptions and built my farm out on the assumptions :S

[ccgllc]

Fully agree with Fanatic26 - these units were never designed for home use.  That said, I had ( running in my basement heating my house for over a year.  If you have an understanding family, its not that bad.  I did use vent filters to quiet down the whinny ones.  Fortunately our TV room was on the 2nd floor.

Oh, regarding CFM through the unit, eg. actual airflow from front to back with the 2 fans combined, I had previously read on the forum that at top speed the fans move about 300 CFM total.

[bpg2001bpg]

I didn't do the research. I bought an industrial miner. It's too loud (I think the pitch of the fan is annoying) to run in my home. I still want to fix it and I'm hoping for some help. I found this forum looking for some data on static pressure.

My current plan is to use a grow tent blower to replace the fans. If the previous post of @VentMine is accurate, there is 18mm or 0.7 WG of static pressure. This amazon blower can move 190 CFM at 0.7 WG and operates at 33dB(A)

https://www.amazon.com/dp/B01M7PWPPA/ref=sspa_dk_detail_6?psc=1&pd_rd_i=B01M7PWPPA&pd_rd_wg=KSpw7&pd_rd_r=782MA6JN488PG4QG8NMB&pd_rd_w=wH5V2

My plan is to use a blower with a fan-b-gone:

https://www.ecwid.com/store/fan-b-gone/

I understand that if the blower goes out, the miner will burn up. At this point I am okay with that. Maybe in the future I can find a way to monitor the fan speed and shut down the miner if it goes out.

If this plan is even sound(criticism welcome), I have a few other blower options that are less expensive, smaller, quieter, or blowers that are even more powerful, but louder.

Thoughts?

[aspe01]

@bpg2001bpg Any update on your project ?

I've seen this product which is quite similar but was unable to get any feedback on it : https://www.silent-miner.eu/store/Silent-Miner-p103601773

[minefarmbuy]

I mine at home, tried all kinds of fans. It's really a waste of time, resources and downtime of your unit to install and test. The only thing close was the ultra kraze fan which still barely moved enough air for an s7.

Tried the Notcrula's or what ever their brand name is for these machines its junk, for your PC their awesome. If you can down clock your unit significantly you can use these fans but even at full speed they wont move much air through the heat sinks of an asic. Tenting is not a good idea with s9 but maybe for gpu farm.

I would down clock and drop fan speed to reduce db's. There should be write ups on how to do both for auto tune s9's. Good luck.

[ccgllc]

So guys, still didn't get an answer to the topic yet. I'm aware of the specs of the stock fans that come with the S9, but I am hoping to find out what is the pressure differential across the fan so I can calculate the actual CFM through the S9 considering pressure drop across heat sinks etc?

 

I calculated my air needs based on a combined total of 300 cfm/s9.  So far, so good (at least as far as air flow is concerned).  I'm running about 120 S9s using that calc.

It should be noted that 841s draw less air.

[ccgllc]

So if I wanted to put in 24 S9's, would I need a intake fan that can supply a total of 24 (S9's)*300 (CFM each) = 7200 CFM? Or should I go a little higher?

Would the out take fan in the hot room need to be at the same level of the intake fan?

Actually, I'd focus on the exhaust fan and perhaps oversize it a bit to handle hot days, but no need to be excessive about it.

Getting rid of the hot air is the primary goal.  Then all you need to do is supply sufficient reasonably filtered (say Mirv 3) intake air.  You can do that by providing approximately 1 square foot of intake per miner or by using fans.  Of course, you save power by just having intake space.  Given a sufficient intake opening, the fans on the miners will be happy to pump the air into your hot aisle.