New build - airflow advice

[danieleither]

I am in the process of setting up a small farm in the basement of my business premises. I am proposing a split-room setup with around 25-30 units, most likely S17 73 TH/s.

The ‘hot’ room will be approx 6.5 cubic metres and sealed against a brick wall, miners exhausting into it obviously, and with 2 x 450mm commercial extraction fan mounted in the wall, venting Directly to the outside (with louvres). The fans extract a total volume of 9600 cubic meters per hour, or 2.6 cubic meters per second. This means the volume of air in the ‘hot’ room will be entirely replaced once every 2.5s, in theory at least.

Initially I thought this should be fine however I’m wondering now is it too much? For example could it cause a vacuum type effect and over-speed the miner fans? I tried to find some stats on miner cooling airflow but couldn’t find anything. The airflow of the mines will of course counter-act the vacuum of the extractors to a degree.

I could install a filtered vent into one of the side walls or roof of the ‘hot’ room if this would be better than having it ‘sealed’, or alternatively fitting a speed controller to the extraction fans is also an option.

Can anyone offer some advice on this please?


Giving some further thought, is the simple answer to ensure 2 of the same size and rating fans are fitted to the ‘cold’ room side, and therefore equalising the air pressure. This should give a balance + very healthy airflow.

Is it possible you can have too much airflow and the miners will run too cold?

[nc50lc]

Is it possible you can have too much airflow and the miners will run too cold?

Silly question.
Even if you put it in a fridge (theoretically) it won't run cold since the chips themselves will produce more than enough heat to fight the external cold temp.

Too much airflow won't cool-down a room that much anyways.
You can copy mikeywith's mining farm set-up: My "mini" mining farms , set up + wiring

[danieleither]

‘Running cold’ is a term for something running below optimum temperature...

[mikeywith]

Just a reminder, my set-up is far from perfect, however, after all these years I have come to realize that heat isn't really the main reason these gears get toasted or become useless, they either become obsolete due to profitability or fail due to bad "luck" or quality if I may call it. if you look at my topic which nc50lc quoted, I have two farms (currently building a new one), one had a very poor airflow, miners did run pretty hot almost all summer long, but the effect of that on the lifespan of those miners was almost NOTHING.

Add to that stories I have heard from various miners, some people who had a mediocre cooling reported less failure rate compared to those running their miners in high-quality data centers, I know many people who "go by the book" will criticize me for saying this, and they have the upper hand because their point is "scientific-based", I am telling you this because I believe you shouldn't go to the extreme about airflow.

Now the numbers:

Phill thinks that S17 move about 500cfm of air, assuming you have 5 of them, you will need to bring in 2500cfm and exhaust a little more than that, later on, if you think the airflow is not sufficient, you can add more fans.

[danieleither]

Thank you for this. It's actually 25 units in total, however I opted for Whatsminer M31S+ in the end instead Antminer S17+.

I've ordered 2 x fan controllers so I will be able to control the intake and exhaust fans (on the rooms) independently to get a good balance. In hindsight perhaps it was overkill!

[philipma1957]

yeah a pair of these. will cool 5 s17pros set to high

https://www.homedepot.com/p/Master-Flow-1600-CFM-Power-Gable-Mount-Attic-Fan-EGV6/205924917

Master FlowModel # EGV64.3917(120)
1600 CFM Power Gable Mount Attic Fan

you can. do 2 simple  intake vents with these filters

https://www.amazon.com/Trophy-Air-Electrostatic-Replacement-Environment/dp/B0741YSTM2

they are washable  that saves big money.

two out put fans

two intake vents

you can do 5 s17 pros maybe six.

edit I just read your post

as long as you filter the intake you should be good.

those machines will do about 300cfm x 25 = 7500 cfm.  can you link the fans. as your method of cubic meters an hour is not as common as cfm.

2.6 cubic meters a second is 2.6 x 3.1 x 3.1 x 3.1 x 60 = 4650 cfm.

so. you said you have 2 fans correct?

IS it 1 fan in 1 fan out. or 2 fans out. with passive vents and filters.

if you are 1 fan input to 1 fan output. you are no go.

Let me check math again

correction

2.6 x 3.3 x 3.3 x 3.3 x 60 =. 5600 cfm. still short of 7500 cfm if you are push pull

input[5600]  >>>>> gear >>>>>  output [5600cfm].  is not good enough

passsive vents with washable filters.  >>>>>>>> gear >>>>>> output{ 2x5600 cfm}.  should work.

[danieleither]

Unfortunately I have ordered the fans already, however I have 4 in total. Here is the link to the fans:

https://www.ebay.co.uk/itm/Industrial-Extractor-Fan-8-10-12-14-16-18-And-20-Ventilation-New/162575872687 (18" / 450cm version)

The fans are rated at 4800 Cubic meter per hour = 2825 CFM each.

The plan was to have x2 fans input and x2 fans output to give the following:

input[5600]  >>>>> gear >>>>>  output [5600cfm] (as per your diagram).

I do have the option to use all 4 fans on the output / exhaust as follows:

input[passive vents with filters] >>>>>>>>>>>>>>> gear >>>>>> output [4x2825] which will give 11,300 cfm extraction.

[robione]

I am in the process of setting up a small farm in the basement of my business premises. ...

Initially I thought this should be fine however I’m wondering now is it too much? For example could it cause a vacuum type effect and over-speed the miner fans?  ....

Is it possible you can have too much airflow and the miners will run too cold?

Too cold? No. Best time of year here in North Dakota is winter. I leave the window open in my garage for that nice -10°F air.

"Vacuum-type effect": I'm not an HVAC expert however contrasted to my setup yours is superior. I would think if this is a factor that is produced (although if I read correctly you have fans on both sides now) I'm unsure if it would have a significant impact on the miners. However I believe your thoughts are not correct regarding the consequences. The fans on the machines have an easier time to spin. This means less work for the same desired effect per machine the control boards are seeking... in other words, at the miner level less electricity. The speed of the fans is a function of the temps. So if you're getting good flow from the room fans you'll probably see the miner fan RPM decrease.