What is the CFM of the Front fan and the rear fan of the Ant miner S9?

[BitcoinIntern]

Can somebody help me with the CFM of the Front fan and the rear fan of the Ant miner S9 please? Thanks. 

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[VRobb]

Didn't notice all the data regarding this already in the S9 thread?

[BitcoinIntern]

Very new here so do not know exactly where I can find things. I will go and find it now. Thank you Vrobb!!

[VRobb]

S9 thread is here: https://bitcointalk.org/index.php?topic=1493601.0
Do a search for CFM in there and I'm sure you'll get more than you wanted!

[BitcoinIntern]

Thank you very much Vrobb!!

[alh]

Very new here so do not know exactly where I can find things. I will go and find it now. Thank you Vrobb!!

If you are thinking of replacing an Antminer S9 (or S7) fan, there is more to it than just CFM. These miners are pretty "dense" in terms of their heat-sinks inside, and require a fair amount of "pressure" by the fan in order to actually push the air through the miner to the other end. Virtually all fan CFM ratings are in "free air" meaning that they don't encounter obstructions to impede the flow of air. It's easy to find a high CFM fan that fairly quiet, but when paired up to an S9 won't actually push through enough air.

The "static pressure" rating of the S9 fans are pretty high, and that's a significant part of their noise.

[Philopolymath]

Indeed..that's why I use and highly recommend one of these....They are a little loud mind you..
General Electric GE90

[QuintLeo]

And as a result you need to stick with the various Delta "Focused Flow" fan series (FFB or derivatives) or the VERY FEW similar fans from other companies.

 Even though they have comparable CFM ratings, I would NOT put a Delta AFB series fan on any Antminer past the S5.


 Exhaust of the GE90 is a bit hot for miner usage.
 Perhaps a CFM56?

 8-P

[BitcoinIntern]

Very new here so do not know exactly where I can find things. I will go and find it now. Thank you Vrobb!!

If you are thinking of replacing an Antminer S9 (or S7) fan, there is more to it than just CFM. These miners are pretty "dense" in terms of their heat-sinks inside, and require a fair amount of "pressure" by the fan in order to actually push the air through the miner to the other end. Virtually all fan CFM ratings are in "free air" meaning that they don't encounter obstructions to impede the flow of air. It's easy to find a high CFM fan that fairly quiet, but when paired up to an S9 won't actually push through enough air.

The "static pressure" rating of the S9 fans are pretty high, and that's a significant part of their noise.

Thank you for mentioning this...I had little clue about it. But to tell you more about it...I am not planning on changing the fans to reduce the noise. I was originally planning below:

1) Install 32 antminers on a 8Ft X 2FT X 6 FT rack and
2) Put the racks back to back to create a hot tunnel. Leave 30 inch of distance between the two racks for the hot tunnel.
3) Put drywall on the back of the rack (Question for the experts: Is Drywall a good idea?) so only the hot air will go through the fans in the hot tunnel and hopefully there won't be any hot air leaks
4) Put fans on the top of the hot tunnel to suck out the hot air.
CHALLENGE: Now the issue or more so confusion is how much CFM exhaust should I put for the exhaust? I will have total of 2 racks on one side and 2  racks on the other so total of 4 racks and 128 miners on them in total. So that is the reason why I was asking about the CFM rating so I can figure out the exhaust...Am I even thinking right? I thought that if each exhaust is 250CFM then 250*128= 32000 so I need atleast 35000 CFM. Is there anything like more exhaust then needed? And for the intake I was planning on keeping 30000 to maintain a negative static pressure in the suction i.e. on the exhaust side

Does this design have any teeth to it? Am I even thinking in the right direction? Should I be careful about anything?

P.S. Thanks to everyone who has contributed to the post so far....

[Philopolymath]

[/quote]
1) Install 32 antminers
[/quote]


Ok..yeah thats not going to happen
That's when I knew you are way out of your league with more money than brains and just pipe dreaming

[NotFuzzyWarm]

<snip>

Thank you for mentioning this...I had little clue about it. But to tell you more about it...I am not planning on changing the fans to reduce the noise. I was originally planning below:

1) Install 32 antminers on a 8Ft X 2FT X 6 FT rack and
2) Put the racks back to back to create a hot tunnel. Leave 30 inch of distance between the two racks for the hot tunnel.
3) Put drywall on the back of the rack (Question for the experts: Is Drywall a good idea?) so only the hot air will go through the fans in the hot tunnel and hopefully there won't be any hot air leaks
4) Put fans on the top of the hot tunnel to suck out the hot air.
CHALLENGE: Now the issue or more so confusion is how much CFM exhaust should I put for the exhaust? I will have total of 2 racks on one side and 2  racks on the other so total of 4 racks and 128 miners on them in total. So that is the reason why I was asking about the CFM rating so I can figure out the exhaust...Am I even thinking right? I thought that if each exhaust is 250CFM then 250*128= 32000 so I need atleast 35000 CFM. Is there anything like more exhaust then needed? And for the intake I was planning on keeping 30000 to maintain a negative static pressure in the suction i.e. on the exhaust side

Does this design have any teeth to it? Am I even thinking in the right direction? Should I be careful about anything?
P.S. Thanks to everyone who has contributed to the post so far....

Very good! Yes you are thinking right. What you are setting up is called 'hot-aisle/cold-aisle' and is the most common way of controlling and routing airflow in data centers. Ja figuring 250CFM per miner is a good ballpark to base total airflow needed in worst-case incoming air temps. Use multiple fans preferably with speed controls to throttle them as the conditions dictate.

As long as the incoming air temp is around 95F or less they can tolerate very high exhaust side temps of around 120F so as long as enough air is moved to get that heat out you are good.

Hardest part of you plans will be getting the miners themselves as supply is very tight from both Bitmain and Canaan (Avalons).

Mine on Dude!

When doing temp rise calcs keep in mind that every kw of miner power = 3,412.14 BTU of heat.

[BitcoinIntern]

<snip>

Thank you for mentioning this...I had little clue about it. But to tell you more about it...I am not planning on changing the fans to reduce the noise. I was originally planning below:

1) Install 32 antminers on a 8Ft X 2FT X 6 FT rack and
2) Put the racks back to back to create a hot tunnel. Leave 30 inch of distance between the two racks for the hot tunnel.
3) Put drywall on the back of the rack (Question for the experts: Is Drywall a good idea?) so only the hot air will go through the fans in the hot tunnel and hopefully there won't be any hot air leaks
4) Put fans on the top of the hot tunnel to suck out the hot air.
CHALLENGE: Now the issue or more so confusion is how much CFM exhaust should I put for the exhaust? I will have total of 2 racks on one side and 2  racks on the other so total of 4 racks and 128 miners on them in total. So that is the reason why I was asking about the CFM rating so I can figure out the exhaust...Am I even thinking right? I thought that if each exhaust is 250CFM then 250*128= 32000 so I need atleast 35000 CFM. Is there anything like more exhaust then needed? And for the intake I was planning on keeping 30000 to maintain a negative static pressure in the suction i.e. on the exhaust side

Does this design have any teeth to it? Am I even thinking in the right direction? Should I be careful about anything?
P.S. Thanks to everyone who has contributed to the post so far....

Very good! Yes you are thinking right. What you are setting up is called 'hot-aisle/cold-aisle' and is the most common way of controlling and routing airflow in data centers. Ja figuring 250CFM per miner is a good ballpark to base total airflow needed in worst-case incoming air temps. Use multiple fans preferably with speed controls to throttle them as the conditions dictate.

As long as the incoming air temp is around 95F or less they can tolerate very high exhaust side temps of around 120F so as long as enough air is moved to get that heat out you are good.

Hardest part of you plans will be getting the miners themselves as supply is very tight from both Bitmain and Canaan (Avalons).

Mine on Dude!

When doing temp rise calcs keep in mine that every kw of miner power = 3,412.14 BTU of heat.

Thank you very much NotFuzzyWarm...

What about humidity? What aspects of low or high humidity should I be concerned about? I read that ESD i.e. Electro Static Discharge is generated when the humidity is too low. And I am thinking that the humidity will be way too low during the winter if I am sucking out the outside air. Let me know your thoughts everyone.


Thanks to everyone...

[GMPoison]

<snip>

Thank you for mentioning this...I had little clue about it. But to tell you more about it...I am not planning on changing the fans to reduce the noise. I was originally planning below:

1) Install 32 antminers on a 8Ft X 2FT X 6 FT rack and
2) Put the racks back to back to create a hot tunnel. Leave 30 inch of distance between the two racks for the hot tunnel.
3) Put drywall on the back of the rack (Question for the experts: Is Drywall a good idea?) so only the hot air will go through the fans in the hot tunnel and hopefully there won't be any hot air leaks
4) Put fans on the top of the hot tunnel to suck out the hot air.
CHALLENGE: Now the issue or more so confusion is how much CFM exhaust should I put for the exhaust? I will have total of 2 racks on one side and 2  racks on the other so total of 4 racks and 128 miners on them in total. So that is the reason why I was asking about the CFM rating so I can figure out the exhaust...Am I even thinking right? I thought that if each exhaust is 250CFM then 250*128= 32000 so I need atleast 35000 CFM. Is there anything like more exhaust then needed? And for the intake I was planning on keeping 30000 to maintain a negative static pressure in the suction i.e. on the exhaust side

Does this design have any teeth to it? Am I even thinking in the right direction? Should I be careful about anything?
P.S. Thanks to everyone who has contributed to the post so far....

Very good! Yes you are thinking right. What you are setting up is called 'hot-aisle/cold-aisle' and is the most common way of controlling and routing airflow in data centers. Ja figuring 250CFM per miner is a good ballpark to base total airflow needed in worst-case incoming air temps. Use multiple fans preferably with speed controls to throttle them as the conditions dictate.

As long as the incoming air temp is around 95F or less they can tolerate very high exhaust side temps of around 120F so as long as enough air is moved to get that heat out you are good.

Hardest part of you plans will be getting the miners themselves as supply is very tight from both Bitmain and Canaan (Avalons).

Mine on Dude!

When doing temp rise calcs keep in mine that every kw of miner power = 3,412.14 BTU of heat.

This isn't necessarily what the thread is about, but I've got an idea about heating/ventilation that I may be implementing when I start mining in October.

I plan to use two racks side by side (not back to back) to put the miners on. I'll put an insulated tarp on the back of the two racks and cut holes in it for the exhaust fans of the miners (should work better than drywall as BitcoinIntern suggested). From there I'll put two "poles" up vertical to each end of the rack, creating the frame for a small square "room". Then I'll fasten more of the insulated tarps from the pole to one end of the rack on each side, and then a tarp over the top. This should effectively create a small insulated room which you could then place an industrial portable AC in front of which would shoot cold air into the room for the miners to suck up.

It's difficult to picture but imagine a small room with a bunch of holes cut out of the back, and one hole cut out of the front to stick the AC output into. The exhaust of all of the miners can be ventilated out of the room without ever recirculating back into the miners intake, or heating the air up that the miners will be sucking in. I'm thinking that even if the room the miners were in is 100 degrees, with the insulated tarps and an industrial portable AC creating positive air pressure in the makeshift room, the miners should run as if it were only 70 degrees out, which would be extremely cost efficient. Another note, I wouldn't consider the AC and would simply use outside air as intake to the small room, but I live in Florida, so sucking in 90 degree air would be a bad idea. Let me know what you guys think.

[BitcoinIntern]

This isn't necessarily what the thread is about, but I've got an idea about heating/ventilation that I may be implementing when I start mining in October.

I plan to use two racks side by side (not back to back) to put the miners on. I'll put an insulated tarp on the back of the two racks and cut holes in it for the exhaust fans of the miners (should work better than drywall as BitcoinIntern suggested). From there I'll put two "poles" up vertical to each end of the rack, creating the frame for a small square "room". Then I'll fasten more of the insulated tarps from the pole to one end of the rack on each side, and then a tarp over the top. This should effectively create a small insulated room which you could then place an industrial portable AC in front of which would shoot cold air into the room for the miners to suck up.

It's difficult to picture but imagine a small room with a bunch of holes cut out of the back, and one hole cut out of the front to stick the AC output into. The exhaust of all of the miners can be ventilated out of the room without ever recirculating back into the miners intake, or heating the air up that the miners will be sucking in. I'm thinking that even if the room the miners were in is 100 degrees, with the insulated tarps and an industrial portable AC creating positive air pressure in the makeshift room, the miners should run as if it were only 70 degrees out, which would be extremely cost efficient. Another note, I wouldn't consider the AC and would simply use outside air as intake to the small room, but I live in Florida, so sucking in 90 degree air would be a bad idea. Let me know what you guys think.

Tarps will surely be very easy to work with. But what if the Tarps catch fire due to excessive heat?

[GMPoison]

This isn't necessarily what the thread is about, but I've got an idea about heating/ventilation that I may be implementing when I start mining in October.

I plan to use two racks side by side (not back to back) to put the miners on. I'll put an insulated tarp on the back of the two racks and cut holes in it for the exhaust fans of the miners (should work better than drywall as BitcoinIntern suggested). From there I'll put two "poles" up vertical to each end of the rack, creating the frame for a small square "room". Then I'll fasten more of the insulated tarps from the pole to one end of the rack on each side, and then a tarp over the top. This should effectively create a small insulated room which you could then place an industrial portable AC in front of which would shoot cold air into the room for the miners to suck up.

It's difficult to picture but imagine a small room with a bunch of holes cut out of the back, and one hole cut out of the front to stick the AC output into. The exhaust of all of the miners can be ventilated out of the room without ever recirculating back into the miners intake, or heating the air up that the miners will be sucking in. I'm thinking that even if the room the miners were in is 100 degrees, with the insulated tarps and an industrial portable AC creating positive air pressure in the makeshift room, the miners should run as if it were only 70 degrees out, which would be extremely cost efficient. Another note, I wouldn't consider the AC and would simply use outside air as intake to the small room, but I live in Florida, so sucking in 90 degree air would be a bad idea. Let me know what you guys think.

Tarps will surely be very easy to work with. But what if the Tarps catch fire due to excessive heat?

You can buy fire retardant insulated tarps but they are very costly. Assuming you never have any part of the miners touching the tarp directly which shouldn't be difficult to do, the tarps shouldn't spontaneously catch fire. Especially if you're going to use the A/C which would keep the inside of the tarps cool. The holes that you cut for the miners exhaust may get hot, but the holes can be wrapped with fire retardant duct tape so the inside layers of the tarp are never exposed to any hot metal.

[fanatic26]

Dont use tarps. Use foam board insulation to build your hot isle. Tarps have no structural rigidity and will just make a mess of things.

[BitcoinIntern]

You can buy fire retardant insulated tarps but they are very costly. Assuming you never have any part of the miners touching the tarp directly which shouldn't be difficult to do, the tarps shouldn't spontaneously catch fire. Especially if you're going to use the A/C which would keep the inside of the tarps cool. The holes that you cut for the miners exhaust may get hot, but the holes can be wrapped with fire retardant duct tape so the inside layers of the tarp are never exposed to any hot metal.

Have you done this as a proof on concept in the past? Creating a hot tunnel has been a proven method. I am not sure if this would really work. You will need a lot of AC's to actually get this going. Just my thought here....I could be wrong...Would want to see what other pro miners think. Thanks.

[BitcoinIntern]

Dont use tarps. Use foam board insulation to build your hot isle. Tarps have no structural rigidity and will just make a mess of things.

How about Drywall? Thanks.

[GMPoison]

Dont use tarps. Use foam board insulation to build your hot isle. Tarps have no structural rigidity and will just make a mess of things.

Those insulated foam boards are really cheap too, not a bad idea. Instead of using two poles to attach the tarps to, I could just use two more racks on either side. Use the back of them facing the inside to put the foam boards on, use the other side on the outside for storage. I wonder if they would do as good of a job though. I'd also probably still need a tarp for the roof of the structure, I don't think they make foam boards long enough.

[GMPoison]

You can buy fire retardant insulated tarps but they are very costly. Assuming you never have any part of the miners touching the tarp directly which shouldn't be difficult to do, the tarps shouldn't spontaneously catch fire. Especially if you're going to use the A/C which would keep the inside of the tarps cool. The holes that you cut for the miners exhaust may get hot, but the holes can be wrapped with fire retardant duct tape so the inside layers of the tarp are never exposed to any hot metal.

Have you done this as a proof on concept in the past? Creating a hot tunnel has been a proven method. I am not sure if this would really work. You will need a lot of AC's to actually get this going. Just my thought here....I could be wrong...Would want to see what other pro miners think. Thanks.

I haven't. I would go with your idea because doing a hot/cold isle like you described with exhaust out of the top is really smart, I just don't think it would work nearly as well as my idea with an AC.

It would be far more cheap as I wouldn't have to purchase the AC, but I live in Florida, so I think if I don't make some sort of smaller insulated room within the warehouse (which will probably turn into an oven), no amount of airflow or hot/cool isle is going to keep them cool enough.