Topic: [Help]Small mining farm airflow problem (Read 116 times)

It's not that exhaust fans that are sucking air in, the air has to come in from somewhere when the pressure isn't balanced.



You still have to fix the air pressure regardless, this way you are hurting the miner's fans and the exhaust fans, it's a bit hard to follow your set-up without seeing an actual image or at least a sketch, but I gave it my best, can you reduce your intake to 6000 CFM without reducing the exhaust and do the "paper test" again?

This rate is for 6000RPM fans?
Because I have experienced a lot of orders from alibaba of fake Delta/Nidec fans which can't surpass 4200RPM.

I don't know does the room size matter? I'm thinking about the air volume.


The thing is I made a small piece of manhole that's being held by silicon adhesive. I opened it few days ago and tried doing a similar test like what you asked (sorry didn't see it ahead of time).

The test was, I was holding a small piece of paper and tried bringing it near to the suction fans. And they were sucking the air but the movement of the paper was being a bit strange when I bring it to the edges of the fan. It was like a mixed movement of suction and discharge. It's like the exhaust fans does need to take from an outside air a bit of air to compensate the air they need to suck (I'm not sure about it).

But I definitely notice when I opened the manhole and the hot air returned to the cold room, the miners' fans sound/noise changed. Since the fans now has enough suction.

I'm thinking now to add one more swamp cooler. But I'm afraid that it won't be enough. But based on the calculations, the 2 swamp coolers should have been enough.

One important piece of information which you need to consider would be the difference in pressure between the two rooms, the split room design is good but it's hard to work with when it comes to air pressure, I don't know the exact setup of your farm but if I understood you correctly I believe you might have to increase the exhaust and reduce the intake.

One way to confirm this would be making a small hole in the outside wall of the hot room, and then place a piece of paper on it (from the inside), if the hole sucks the paper then you are good, if the paper is pushed to the inside (which is what I believe to be the case) then you need to balance the pressure.

and there is heat sink resistance so they likely pull 220-230 cfm

The s9 fans are rated for 250CFM, not 200.

I thought about that too. That's why on my second farm I increased my intake air of the room. But I'm confused. The only thing about the computation that I'm not sure of, is the antminer s9 fan intake CFM. I based my calculations that an S9 14th/14.5th can intake 200CFM per unit ( I read that somewhere in the forum few months ago) but I think fans at 100% full speed draw a lot more than 200CFM.

Cuz in the second farm my intake air is around 12,000 CFM, and let's say 45pcs S9 intake at 200CFM each that's 45x200= 9000CFM there should be 3000CFM which won't be replaced in a minute (based on the equation).

If you have any idea about how much air does an S9 Fan at 100% full speed suck kindly guide me.

The miners are sucking out more air than you supply in ( for the cold side ), when that happens the cold room will need to replace that gap in "air supply", and thus it pulls air from the hot side of the room if you were to completely block the wholes in the MDF sheets the air will be forced through the miner's fans even if they were running at 100% speed, if it can't, the whole room will collapse.

You HAVE to add more air to the intake side, if you can't do that on the walls, simply use the roof, if you can't, then you have to reduce the number of miners, there is really no workaround to by-pass physics.

Hello dear community, I am new miner with 2 small farms now. First farm includes 45 antminer s9 (mixed) and 15 cheetah miner F1 20th.
This farm is divided into 2 parts (cool room and hot room).
Total room size is 7mx3m and a height of 2.5m. The cold and hot sides are separated by an mdf wood with the miners exhaust fan exiting to the hot side. The cool room side size is around 4x3m, has an evaporative cooler the one used in green houses with a size of 2m x 1m (this is my only suction of cool air).

This farm was my first ever built farm. With 30 Antminer s9 as starters everything was fine. When I added the rest, I faced a problem where the hot air exhausted to the hot area is going back to the cold area from the small holes where the miners exhaust fans are inserted.

I tried too many things, tried increasing my exhaust fans to a total of 13,000 cfm but no help. The other fans keeps slowing down their rpm. Tried putting the same fans to suck more air from the evaporative cooler but still some of the fans loose their speed because some of the suction is coming from the inside of the room. I somehow think that my suction opening is smaller than it should be. But I have no choice I can't increase the size of the suction wall (as of what I think).

The same thing happened to me with the second farm which has 45 antminer s9 in a total area of 5mx2.5mx2.4m height which this room was divided into 2 exact areas for the cold and hot room. With an inlet automatic coolers which can supply around 12,000 CFM of air with temperature between 28 to 35 degree Celsius With an exhaust fan of 8000 CFM and another 4200 CFM.

I really hope someone can guide me with what to do to improve these farms cuz a lot of the miners are being affected because of this returned hot air specially with the weather here reaching 45°C ambient temperature.
Or even how to calculate the correct room size /suction/exhaust/etc. For my other coming projects.

Thanks a lot.

I will include some pictures in the coming days to visualize more about the farm.