Topic: keep a small mining farm cool with only air conditioners. - page 2. (Read 588 times)

an 11 mega watt data center is quite different to a 175kwatt sealed room setup.


At Mikeywith how did this room end up doing for you.

My 150kwatt under vented partially ac'd room has been holding up for  the summer. We have had to power off some gear (20kwatts) from 1pm to 8pm but we are doing pretty good for the last 6 weeks.

Maybe 90% of top hashrate. I am looking forward to Sept and Oct we will be able to boost the hashrate on the gear to around 105%

Completely sealed is close minded.

My datacenter (not  mining) consumed about 11Mw give or take 24/7/365.

Developed an outside air system that blended cooler outside air into the filtered intakes of the AC units and opened dampers for escape. If it was a bit humid outside the AC would take care of it. Considerable savings especially in the winter months.

Side note: People mentioning mixing cold air into the hotside before the AC is just plain dumb, don't do that.

It depends on how big the room is and some solution works better base on location, I think working air cooling fan into the farm is better in some.cases, I am using my own farm to analyst this question though, I don't want to run a air conditioner unless there are now newest air conditioner that takes less power consumption, the best I can find here are 1.5HP Air Conditioners and man that's a lot for me.

You said your electricity Bill is very cheap? Then you can run anything without worries of high bills on electricity then, AC draws a lot of power and that makes me want to forever stay away from them.

@mikey I know why its hot 🥵 environment.

I have shifted units it is due to two really  stubborn people that don’t want to vent the area just a bit more.
and downclock just a bit more gear.

I am still running 15 L3s that I don’t want to run. burning 🥵 12kwatts to make about 15 usd a day.

I would have sold them a long time ago. But I am outvoted so they will run to the LTC ½ ing.

Couldn't find a similar manual on the AC, the distributor of said brand guaranteed that the BTUs labeled on the AC will be achieved as long as the outside temp is below 52c.

Anyway, looking at the specs you posted, you can clearly see that the AC  has the highest TC when the room is hot and the outside temp is cold, so the hotter the room the more the cooling capacity, and, the greater the difference between in and out temp also the greater the cooling is, which makes sense, and that's what I picture the farm to look like, always hot inside - warm to cool outside.


Thanks for your input Powell, do you recall the total power consumption of your farm vs BTUs?

For the humidity part, the place is very dry, there should be no issues with humidity at all.

As for the noise coming from the compressor /outside unit, it should be manageable, I checked a unit running and it was at 65 decibels at pretty much close to distance, noise levels will increase by 3 decibels every time the noise source is doubled, so 10 of them will output 75 decibels, that's a lot but still a lot less noise than a single miner doing that fan test, I doubt we will face issues with the noise coming from the ACs, I am more concerned about those Whatminers, since a single unit does 84 db when fans are at 100%, 50 of them will do close to 101 dB, I have exactly no way of knowing how much the insulation is going to reduce, but we kind of need the noise to be below 75 dB, could get away with a bit higher, but we will see.

@phill

There is a close to 10 degrees difference between the env temps of 192.168.1.232 and 192.168.1.233, there is something wrong there, can you try to swap them and see?

Years upon years ago when I had our farm (2014) and we were using about 140-150A @ 208v I had a calculation that took all of that formula and then even converted it to how many TONs of a/c I would need. I will say as a few others have posted outdoor units can/will be loud.

Fast forward to today at my personal home.
I have a ~50ft x 60ft x 20ft (roughly 3000 sq ft) shop/garage that was built around 4 years ago. It has vapor barriers under with the concrete, every bit of insulation that can be done (minus bay doors, which I may do soon but they are automatic rollups so always been hesitant), 2x 5 TON A/C units that are mounted from the ceiling to cool it down. I live southeast of Houston so I am closer to the Gulf of Mexico which means humidity is something I always have to fight. One thing as a user or two posted is depending on time of day where the sun is hitting the building there will be hot spots in different places and that can take a wicked hit to things.

Another thing though is humidity, and this is where I've had friends that own HVAC companies say can be a large issue, and this did come up with my mothers companies small data center (we are a reseller for IBM/DELL/Pure Storage/etc. etc. so we have a large amount of equipment to demo) that you still have to battle humidity. Last summer I did not take that into account in my personal shop, I was just using the AC's to help pull humidity out. I was mining Etherium in Minerdude/Octominer chassis with 3090s and I started to notice the heatsinks/fans/etc showing signs of dew on them and oxidizing things. I was in no way overpowering my AC's considering the heat produced from that was no issue for the amount of BTU's available from the AC. After Eth mining was done I was getting annoyed because leaving cardboard, etc became a problem. I ended up recently adding 20,000 CFM in fans (just 2x wall mounted 10,000 CFM fans to cycle the air) and it has helped a lot when the AC is running where as before even with everything sealed humidity was still not manageable. Though in the evening when things cool down and the AC isn't taking as much load. I am having to add a large de-humidifier (shows up Thursday) to hopefully be the final peace of the puzzle.

Maybe someone else can chime in on there being a problem with humidity because lets say you in theory could keep close to ambient, there is still large risk of failure to equipment at that point from humid air taking its tole on equipment fast.

Well the what's miners can down clock a lot.

with freq set to -10% and power set to 3000-3050

I went from 3350 watts on most units down to 2536-2910

So say 2700 on average meaning a savings of 650 x 6  = 3900 watts

With 50 units that is 32500 watts saved. That's 110500 btu.

With my 6 pieces we did

552 th vs 652 th a drop of 15.3% hash

16200 watts vs 20100 watts a 19.4% power drop

So if you play with lower freq you can easy peasy save 100k BTU with 50 units.

Going back to doing 10 ac it should cool at best 600k BTU drop that to 540k BTU

But the down clock drops you from 597K BTU to 497K BTU

So a cooling power of 540k and a heating power of 497K which is a 10% safety factor.
After playing with my small hot room since 2018 I know that 10% safety factor may be good most days.

Also you can simply shut mining units off.

As you see below in the screen shot  you would turn 192.168.1.232 off as it pulls the most power and runs the hottest

No, the efficiency actually changes:



TC is Capacity PI is power consumption.
It's a pain in the ass-protected pdf file, but I'm pretty sure even your model has the same kind of manual.
Again, look at the pipe length, this rating above is for 5m linear, and once you count elevation it's a mess.


It will bring the room temperature slowly up till it reaches the exhaust temperature at which point they will probably shut down themselves.

Let's look at it from the thermodynamics point of view as heat is just energy:

At one point you have one extra unit of produced heat in a unit of time, if this process goes continuously in a closed environment, after 1000 units of time it's 1000 extra units of heat. In a million units of time one million units of heat!
This will not stop at any point if we don't assume the equipment will melt itself because you're still feeding more heat in that room every second than you extract, 10C, 40C, 100C, 300C it's like blowing into a balloon, the heat has nowhere to go.

Of course, this is in a perfectly sealed environment, so there is heat escaping the room through the floor and the walls, but if we talk about 30KW extra there is no way you will reach an equilibrium before you melt everything!
Especially since you also want to soundproof this room which will add to insulation and make less heat able to escape through the walls.

Based on your story, the math calculation you made is correct. And in my opinion, there should be enough cooling capacity to maintain the mining farm in terms of temperature. Perhaps all that is needed is to adjust the ambient temperature or maybe the settings on the AC unit, which of course depends on the weather conditions.

I down clocked all my whatsminers.

I used -10%
I used 3050 watts

Its 93f today and the room is toasty

Whatsminers have environment/room temp sensor, located far from the hash board, on the upper part of the control board, and gives pretty accurate readings, those temps could be easily viewed with an API request, and then a command to reduce the power limit for the miner can be sent, shouldn't take much to have something like in place, I think AwesomeMiner already has a function to check the environment temp.

So it's either going to be an hour to two of coding my own script or reaching out to Patrick/AwesomeMiner to see if they have that in place, they usually implement most of the suggestions I give them (given that they make sense). so ya, long story short, that shouldn't be an issue.


The efficiency of an AC shouldn't change based on outside temps, if does 1k BTU, it does 1K BTU regardless, now let's forget for a moment about mining, and let's just picture an empty room with little BTUs.

Now let's recall how an AC actually function.?  the inside unit will suck room air in and passes it to the evaporator coil of the internal unit, so that it would come out colder, and that same "room air" finds its way to the evaporator coil (outside unit) where the compressor, refrigerant, and pressure do their magic to cool that same air.

The whole process can only do so much, most places I read say 10-12c below ambient air temp (remember the outside unit that does all that sits in ambient temp), so for the same room we are talking about, if the outside temp is 50c, and the goal is to keep room at 20c while feeding the ac 50c room temps is not going to happen, so this is where the BTU calcs come into play.

To bring  a 4m*4m*4m room temp down to 20c where the ambient temp is 50c you are going to need a larger AC than to cool the same room to 20c where ambient temp is 30c, you will need the AC to do more BTUs per hour, this also explains why cooling isn't done instantly, as it's a gradual process, for the same example, when the AC first starts with room temp is 50c, the AC will suck in 50c air, bring it down to 40c, when the whole room is 40c, it starts sucking 40c air and it comes out 30c, all of that needs to be done fast enough before the room gains more outside heat.

So, BTUs are not related to ambient temps, but the overall cooling is.

So now, we can simply conclude that if the outside temp is 20c, and you want your room to be 20c, there is exactly zero BTUs that need to be removed, now what happens when you start producing heat inside the room?

Instead of using a miner as an example, let's use another AC turned on heating mode, so you have two ACs of the same size, one is hot to cold another is cold to hot, what would be the room temp when ambient temp  20c? since both do the same BTUs, they should cancel one another the room temp will still be at ambient temp, no?

If that's true (which I believe it is), what happens when you bring in another AC of the same size that is set on heating mode, so now you have 2 hot vs 1 cold? you end up with 1 hot AC since the cold ac will cancel one hot ac, correct?

How hot do you think that one lonely hot ac will bring the room temperature to? 10c above ambient temp? the room now is 30c, 20c? the room now is 40c.

Now replace that AC with a miner that does the same BTUs, which brings us back to my initial statement, if the ambient temp is 20c and you are okay with temps going to as high as 40c inside, you probably don't have to match the exact BTUs of the miners.

I could be wrong, but would like to know, how?

Hmm, I'm a bit curious about this one since checking the manual on our farm (not mining, true farm oink oink) HVAC the rating in BTU stands on the amount of heat it can move from the inside to the outside.

So a perfect 1 000 BTU unit will be able to move out 1 000 BTU at 10C or 40C, but in your case if you produce 10,236 units of energy those have to be removed be it 10C or 40C outside, you need the exact same amount of heat to be taken out, what will change if the outside is 10C instead of 30C is the efficiency and consumption of the unit, again, this is if we talk about a sealed room that won't lose that much heat through the walls.

I might be mistaken on this but using only half of it will end up with the room temperature going up and up till it reaches the miner's exhaust levels since you have more energy being produced inside the room than you have taken out of it!


14k BTU in 48mc2 versus 600 in 180mc2 the ratio is all over the place.
And the most important thing is that if the outside is colder even by a few degrees the room will lose heat, so if this guy had a wall in the shade with 5 degrees below and you're exposed on all sides it will be even worse.

My take would be to start with half of it and see how it works out, you wouldn't be wasting money on equipment you won't be able to sue such as the miners or you won't overspend on air units and installments you won't be needed.

Oh, and reading about the sound, just went outside, 32C right now, our office units are Fujitsu whatsoever, and my phone screams 69DB next to one of the outside units, (we have them in the parking space, cause...well, management!) so you might want to check one of those live before buying it if the sound is a concern.

Was thinking about it, and I don't know what the cost would be, but I wonder if you could get hire a programmer to work with the whatsminer API and the temperature monitors you have in the room.

As the temp goes up it throttles down the miners, as the temp drops it throttles them back up.

Would probably require a lot of trial and error and obviously a PC or 2 in the room but it might actually generate more BTC. If it's a cooler day or as the ambient temperature drops at night the miners clock up a bit. But, during the heat of the day they slow down to keep the temperature manageable.

Just a thought.

https://www.whatsminer.com/file/WhatsminerAPI%20V2.0.3.pdf

-Dave

Exactly what I expect/worry about, the relationship between room temp and hardware consumption isn't going to be linear, this is also true for air cooling, i.e I know when I underclock M30s from 3400 down to 3200, they get a huge drop in temps, going from 3200 to 3000 is good but not as effective, so without air flow, this should be even more noticeable, hot spots will be there, a single miner going online/offline could have a large impact on the whole room, this will require a lot of trial and error until we understand  "the place's behavior under different conditions" just like how you understand yours now.


Ya I have got one, I get instant notifications for temps and humidity levels that I set, it's very helpful when you are not watching the farm, I think it's a must in every mining farm.

What we have found in the small dense under ventilated room is there are knees or cliffs of rocket 🚀 to the move temps.

Ie 95f outside temp all good inside the room hotspot 99f

but 99f outside temp runaway thermals room hotspot 117f

or 150kwatts 90f outside temp 94f in room
but add 6kwatts to 156kwatts and same room will shoot to 117f

you are going to find out your pivot points by under clocking say 2000 watts a unit.

good.

but 2200 watts everything will over heat like mad.

get a temp app for the phone set it to warn you then under clock ⏰.

I believe this has to do with the quality of the AC and its climate rating, the ones I am looking to get are T3 rated, which means they should be able to keep their rated cooling BTU capacity at temps up to 52c.



Please refer to my above explanation of how I 'think' outdoor heat will affect the room.


Yes, this is one thing I really like about Whatsminer, after all, we could just start with 5-6 AC units, and underclock all gears to 2,000w and see how things go from there, the ideal way of doing this would be to run all gears at full speed during the average weather, and run them underclocked during the 1-2 months of heat, instead of adding way too much cooling just to run cool for 1-2 months.

whatminers m30 can clock down to 3050 watts vs 3400. That saves 17500watts or 59500 BTU's in heat.

I wonder how much outdoor heat will affect the room.

If you down clock to 3050 watts you may be good.
If you do 10 ac on the cold and 1 piped to the hot.

you have 660,000 btu

and miners are dropped to 538,000 btu

660000x80% =528,000 btu.

So you have a 20% safety factor by adding 1 ac unit and clocking lower.

Flat out you need more cooling. Keep in mind the air conditioners are 60k BTU in a perfect world, the will likely be a little lower then that. AND keep in mind you will need some other networking equipment in the room that will generate a bit of heat. AND slip air conditioners also put out a little heat. (blower fan, electronics and so on 1 is not a big deal 10 will be putting out a couple of hundred watts) once again not much in the normal world but you are hitting up against the maximum cooling they can do as it is.

Either add 2 AC units or take out a few miners. OR be even safer and do both, a little less profit is better then: https://youtu.be/fxGgx3YCCAA?t=8

-Dave

So far all gear is good I showed you the whatsminers they are within spec.

My setup is close to what you have but not the same.

I can get some air in and some air out not enough but some.
And we do 36k+36k BTU of ac.

We are at 165kwatts and the room is smaller.

The small mixing action is okay so far.

You are going you be like this.

The larger room size will help you.

The dependence on all ac will mean you need 24/7/365 temp monitor.

I have these going to 4 phones and an ipad

https://www.amazon.com/gp/product/B01N17RWWV/ref=ppx_yo_dt_b_search_asin_title?


https://www.amazon.com/gp/product/B08PKWPKM2/ref=ppx_yo_dt_b_search_asin_title?

They can't be piped by default, but with some ducting it could we could easily direct one or more ACs to blow air to the hot side of the room, sould not be too difficult to do.

Here is how thet look like https://www.daikinindia.com/products-services/floor-standing

They blow air from the bottom and blow at the top.

How did that affect the gear temps? It's hard to know if gear would prefer 80f intake and 105f out, vs 85f in and 95f out.

@stopmix, whatsminers would tune lower when temps go up, not much work needed to underclock them or shut them down when needed, but the cost of the setup will be close to 20k, slightly above, would rather size everything correctly since this will be one huge risk to test.

My plan is not to go full blast at first, so maybe just 1-2 ACs and the right number of miners accordingly، that should give us a good overview of how things will be on a larger scale.

The next issue we would face is noise, we need to soundproof the room as much as possible, also not sure how noisy a dozen ACs outdoor units will be.

This is going to be a very complicated project to say the least, which is why I am trying my best to be prepared for all scnerio, have to study everything, consulted a few HVAC folks and none of them had a clue of an operation of such type, they all know the math as we do, but none seemed to fully guaranteed it would work.