Topic: 30kW mining farm - need ventilation advice [Reward] - page 2. (Read 1129 times)

They might be responsible if the bill is in their name.  I imagine it will be in yours.    I was pretty surprised to find out all of the rules of my power company!  Mining is not an activity that the power grid was designed for.  The power company did not size their distribution network to give everyone 200A who has "200A" service...

Also, I was thinking about it and it would probably cost less to AC the room than dehumidify.  Maybe it would only be close, but AC gives you control.  Depending on the warehouse it might make sense to insulate the walls a little more too.

@SGMPhil: I considered data centers, but what I could find nearby was only for rack mounted servers, and probably not a machine using 1500 watts. Haven't asked though, but I suspect it would be more expensive than renting a warehouse... thanks for the idea though.

@eissug: Sure, I think whoever rents out the warehouse is in charge of that, if you ask them what power you need, but good point, don't wanna break anything..

Make sure you call the power company and tell them what you are doing.  Give them the steady state load and total demand.  The transformer might be undersized for what you want.  They will probably replace it for free if it isn't, but if you burn it up they will probably want you to pay for it.  It might take them 2-3 replacements before both parties figure out what happened.  I was lucky and got a call before things scaled up.  

You are somewhat lucky with that humidity.    Miners have dried me out.  I'm at 8% RH with the things going.  Dumping 72 gallons of water per day into the air gets me to about 30%.  

I'm not sure about the HVAC numbers.  You should need around 9 tons and that should only consume around 1.2kw per ton.  It sounds like they were listing the heat capacity of the AC unit in KW rather than the power consumption.

I would probably size the AC system for an ambient temperature of 75-80 in the room.  You could probably get by with fewer tons.  You'll want it to run non-stop I think???

Disclaimer:  AC for me was an intellectual exercise.  Never had the pleasure of needing it and none of my vehicles have it.  

Just a thought, but have you considered just leasing some space in a data center? They handle all of the power and environmental issues for you and would keep you from having to worry about any of this

I did, both with an HVAC firm, and a Ventilation (?) firm, but none seem to have experience with getting rid of 30kW of heat from a rather small room.

The ventilation guy told me to contact the HVAC which then recommended to put 2 x 14kW AC units, to keep the room at 16C which is probably to cold, and insane power cost. I believe the extra unit is for backup, in case the first fails, but even 14kW sounds too much.

Then I got back to the ventilation guy, and proposed to have a solution with 2 x 500mm fans, and he was unsure if it was going to work at all, but they can build it for me. So I ended up here to get some more feedback...

The relative humidity here is 60-80 around the year, and I'd be happy to get insights into how that should be handled. Should the air on the intake ge dehumidified? I don't see anything like that on the big farms which have something like 1200 mm intake fans, but maybe they are located in dryer climate?

Thank you in advance!

If you are going to invest into 20 miners why not hire a professional to calculate this out? Humidity can cost you a lot more...

Hi, I'm helping someone build a smaller mining farm and the capacity for the electricity will be 30kW.

According to this video by Block Operations https://www.youtube.com/watch?v=D7e-bKDFidk for each miner we need 200 cfm of airflow, which is equal to 340 m3/h and a total of 4000 cfm. To start with, does that make sense if a rig produces around 1500w? For this we would have 20 rigs.

Here's an drawing of what it will look like:
https://imgur.com/qMnrqS8.png

Here's the plan:
- 4-6 shelves (The pink boxes in the image).
- 3-4 rigs on each shelf
- Air intake on the floor, which basically is a raised floor, with a 20x50 cm (8x20") hole that blows air from an intake. Each vent will be 0.1m2.
- Each rig will be 8xGPU, about 80cm wide, with 7 Delta fans (0.8A, 113 CFM) on each, blowing a total of 791 CFM air per rig into the middle of the room.
- Intake fan is 500mm (20"), pushing 5800 cfm at max, taking air from outside with a dust filter
- Exhaust fan is 500mm (20"), pushing 5800 cfm at max
- The fans can be regulated according to the outside temperature

So the flow is cool air from outside, to each rig, out into the room, and out of the room.

At the end of the room (top in the drawing) will be an exhaust fan, moving the air out of the room, and to the outside, through the roof or front of the building.

So the questions are:
1) Will the air from the floor vents be equally distributed so all rigs get cool air? Or is there any better option? Would a continuous vent along wall like 300x20cm (120x8") be better?

2) What's the best location for the exhaust fan, to make sure all rigs are cooled equally. Now that I think of it, centered in the room might be better. Or would two fans be better?

3) Would it be better to just have an intake fan in the bottom of the room (where it says 3.4) and make a wind tunnel through the room? Where would the rig fans get their air from in that case? Some kind of turbulence?

4) With 500mm (20") vents connected to the fans, the area of the vent is 0.2m2, so I'm considering if this should be equal to the floor vents, but I'm not sure.

5) Is 200 cfm per rig adequate and would each fan need to move 2000 cfm each? Which means I basically can triple the power consumption and still move the hot air out if the fans are on max?

6) Does the size of the room matter? Would it be better to have it less wide?

I'm looking forward to hear your thoughts on this. If you have a lot of experience in building farms with direct air cooling, and can consult me on this by email, PM me and we can discuss a reward.

Thanks!