Topic: keep a small mining farm cool with only air conditioners. (Read 501 times)

yeah a round tube over the vent would direct the sound up.


https://www.menards.com/main/plumbing/pipe-fittings/culvert-pipe-accessories/corrugated-solid-culvert-drain-pipe/48gf20np-wt-m294/p-14462876080127497-c-9567.htm


this could do 4 vents.  cut it to 5 feet long

it would direct the sound up.

 I own 3 of the vents and they are good but if you stand on the flat roof they are noisy.


this would make the noise go up not out.

also both the vent and this would last a long time.


this is 60 inch by 20 feet

https://www.menards.com/main/plumbing/pipe-fittings/culvert-pipe-accessories/corrugated-solid-culvert-drain-pipe/60gf20np-wt-m294/p-14462876080127404-c-9567.htm

the first was 48 inch  by  20 feet.

BTW if these work these would lower your ac use a bit.

4 vents and 1 pipe would be around 3500 usd here in the states.

Still not enough air out the room with them but you could move 8000 - 10000 cfm with 4 of them.

here is one of ours not yet installed.

In that case: I guess an underground man cave isn't an option?

It's the same principle they use then building sound barriers (between roads and houses).

The above conversion of mine was correct, the mistake I made was not specifying that the numbers are per day which of course made everything seems 24 times larger than what they are, but then using the correct time unit makes your source and mine identical, thanks for the correction.


Thanks for the source, I will be looking into it, it seems interesting.


could you explain this further? how would noise escape up and not to the sides?

You're confused with the units (and imperial units don't help). I already gave you the number: 1362 W/m² (high in the atmosphere). When calculating in watt, there's no reason to use BTU (or even joule). You took a unit of energy per day, and incorrectly converted that into a unit of power.
To start: 1 BTU/h is 0.293W. When you forget the "per hour", you'll end up with a 24 times larger number per day. So it would be 33.291kWh/m²/day, or much simpler: 1362 W/m².

Let's call it 0.25MW.

Aren't those exhausts usually at the roof of large buildings?

Correct. And you're blowing all this heat out.

So my concern is unnecessary. I haven't been in mining farms, I've been in (very big) power plants though, but they used water cooling or cooling towers.

Have you considered acoustic wall insulation (see Dutch webshop)?

one last item but only with a flat roof

https://roofvents.com/gravity-ventilators-aura-ventilator/av-30-c8-aura-vent-30-inch-diameter-8-inch-collar/


this vent on a flat roof on the hot isle side would allow hot air to leave the building.

I have three of them in my easier to cool room.

Noise would escape it with the heat.
                                                                     
                                                                     noise
                                                                     hot air
                                                                  << ^ >>
                                                                   !    ^  !
 roof.  >>     __________________________! vent  !____________


So it likely would not be good.



other than you had some way to direct the noise up rather than out the vent's sides.

much more of an afterthought last thing on the list idea.

built a lot of speaker cases and sound proofed a few recording studios.

If you can do mdf inside make a sandwich.

mdf/pond fabric/mdf/pond fabric/mdf

you can use 1/2 inch mdf sheets . the wall would be about  2 inches thick and stop a lot of the noise as most of the noise is higher than 400hz

https://www.youtube.com/watch?v=rXu61z8yiMc

stopping that is easier that stopping this 40 hz

https://www.youtube.com/watch?v=rXu61z8yiMc

note they (sonic electronix ) have a lot of frequency you can test.


yeah I found the paper on mdf/rubber/mdf/rubber


http://www.woodresearch.sk/wr/201904/16.pdf


notice the improvement they got with multi layer

mdf/rubber and glue

I did 5 layers

3 of 12.5mm mdf
2 of pond fabric
 I glued, clamped and screwed them together.

I was hoping to find the paper.

I was building enclosures 1994-2004  these guys expanded and tested a lot of the work I did with a few others in the Brooklyn navy yard with our speaker building group.


 this paper clearly shows that the sandwich method of

mdf-glue-Rubber-glue-mdf  works really well


'CONCLUSIONS
By using rubber-based composite materials, it is possible to create a sandwich structure with superior acoustic performance while retaining the same thickness of the single-layer density fibreboard for sound insulation performance. Using MDF face sheets with a rubber core increases the sound insulation at the resonant frequency and causes the coincidence frequency to move to higher frequencies, effectively inhibiting the anastomosis effect and making the coincidence valley shallower. Moreover, core materials with high damping performance corresponded to multi-layered composites with improved acoustic performance. As the thickness of the rubber layer increased, so too did the loss modulus of the composite. The weighted sound insulation of single-layer MDF was 28.0 dB, which increased to 37.4 dB for the wood damping composite material, increased by 25.1%. As the thickness of the rubber increased, the storage modulus and loss factor of the composite both increased accordingly. The greater the damping loss factor, the greater the energy loss, making the composite material more resistant to sound waves caused by stronger vibrations. Compared to the rubber samples, the multi-layered composites showed higher storage modulus and loss modulus values. Since the loss modulus is a measure of the energy dissipation, a higher loss modulus of the multi-layered composite denotes that more acoustic energy would be dissipated during sound wave propagation in the material. Therefore, the sound insulation ability of the composites can be enhanced by controlling the rubber thickness, keeping in mind that a good balance between the sound insulation ability and the mechanical properties is required. The density of rubber is not significant for the sound insulation performance of composite materials.'

source is above

We could use MDF inside, we have to build a second wall, it doesn't mean it needs to be outside the current wall, although technically, it would be easier to build outside.

Those pond fabrics seem like good sound insulators, they are high-density which is the most important element in soundproofing, will check to see if I can find them around, hopefully the price is reasonable.




source: https://www.extension.purdue.edu/extmedia/ae/ae-99.html#:~:text=Everyday%2C%20the%20sun%20beams%20to,available%20at%20the%20earth's%20surface.

1 BTU = 0.293 watts
so 10,560 BTU = 3,094 W per square foot
1 square meter = 10.76 squer foot
3,094 * 10.76 = 33,291w
1kw = 1000w
33,291w = 33.291kw per square meter.

ya, a lot of that is lost along the way, but really, 0.25mw is not a lot as far as ambient is concerned, have you ever walked next to a hotel or a large building and felt that it was "strangely warm" in the street? ya standing on the exhaust side of the HVAC or near the external ACs units will be too hot, but just by walking around, it would be hard to tell if the building is consuming 1mw or none just by the "feel of it".

0.25mw is a lot of "heat" in a closed place if the size is not too large, but as far as the outside it's too tiny to be noticeable.



what happens when you put 20 patio heaters inside the house and walk outside, are you still going to feel the heat? probably nothing much unless there is enough airflow forcing that heat to your direction, I have personal experience walking in and out of mining farms as large as 2MW, it's only warm at the exhaust side because heat is being pushed outside into that direction, walking around the other 3 walls you feel nothing.
 


I wouldn't be even attempting that in a crowded city, the nearest building is roughly 100m away.



We don't have the ACs in place yet, the noise is coming out the wall and more so from under the door, but sound travels in all directions so it goes through everything at different levels, there is at least a 20db drop between door open and close, but generally, it's not close to as quiet as we need it to be.

heat might not be as bad if you keep them in an open area, instead of in a tight closed space.

That's incorrect:
On the surface of the earth, it's less. Depending on your location and time of day, most of the time it will be much less. So 235 kW is really a lot.

Compare the 20 patio heaters

That solves all worries I was thinking of a small building in a crowded city.

That's hearing damage level.

Does the noise come through the walls of the building, or does it reach the outside through the airco system? Or both?

Soundproofing is hard as you are in a wet humid climate.

you can't use mdf it is not water resistant.

can you get sheets of pond fabric?


https://www.amazon.com/gp/product/B0964RTYPT/ref=ox_sc_act_title_1?

it is pretty good at stopping sound.



__________________
!___!____!___!__!___


layer of rubber
ribs of 1 inch pvc
layer of rubber

or

layer of rubber
2 by 4 pressure treated wood
Layer of rubber

that 3 part wall will stop a lot of sound

I am not sure if you get pvc pipe

or if rot resistant wood is easy.

these strips would work
https://www.lowes.com/pd/PVC-EMB-1X2-1-1-2-8/5013353085

use these screws
https://www.lowes.com/pd/Tuftex-10-x-1-in-Tan-Galvanized-Self-Drilling-Roofing-Screws-100-Count/3018299


attach top sheet  and bottom sheet  to same pvc strip in the middle

it is water proof and very sound resistant.

On average there is 30kw worth of heat reaching from the sun for every 1 square meter on earth, the effect of that 235kw on the outside tempters is so negligible unless someone stands right in front of the external AC unit, they won't even notice that there is much heat being generated from the building.

Even with the normal setup of using only airflow, you would need to stand right in front of the exhaust fans to feel the heat, standing near the other sides or even leaning against the wall won't be enough to notice the heat, probably a little warmer to set next right next to the building during winter, but nothing much.

Furthermore, the building is isolated, the only problem is the noise, miners can be very noisy, I took a measurement of my farm running 200 S9s + 100 of a mixture between M30 and M20s, when the miners boot at start up the overall noise on the exhaust fan of the building reaches up to 110 db, that's as loud as a subway train, I went to the farm once in the winter around 11 pm it was very quiet in the area, I was able to hear the fans of a distance over 1000m (I made sure it the noise was coming from the farm).

Honestly, I am now more concerned about the noise than the cooling for this project, cooling will be solved by just adding more ACs, if 10 of them don't cut it, just power off or underclock some miners till we can add more ACs, the noise part is not something you can predict, it has to be a trial and error process until we reach desired noise levels.



No windows, just a door that isn't perfectly sealed, your point is valid, we want to seal the cold side as much as possible while trying to get away with not so much sealing on the hot side to allow air to escape, doesn't matter summer or winter the exhaust side of the room will always be hotter than the outside temp so we could use every little crack or just bad insulation, but then again, every little crack will allow the noise to escape, it is extremely difficult to balance the two aspects here, you want

1- low noise.
2- less ACs.
3- less spending.

if option B mentioned above works, the noise level could be low enough that might even allow us to make a few holes at the exhaust side so that more heat can dissipate, but then having to buy an inline fan for every miner, printing the shrouds, buying different expensive shelves that are big enough for the miner + fan could be way too expensive, it might be better to build a second wall, make things worse as far as heat is concerned, and then just add more ACs than initially planned.

It's like trying to win in competitive eating without having to eat too much  , not an easy task, I knew it wasn't going to be easy, I just didn't think it would be this difficult, so ya, going to take a lot of time and money for this to happen.

Thanks for your kind and quick reply. Sounds nice, congrats man and keep up the good profits

If it is sealed then are we forgetting about the input and output math about the energy here?
If it is sealed and the heat output that is getting released into the divided environment is more than the Air Conditioners capacity, then obviously it is going to be a big issue. For one reference purpose, it is evident that there will be war between the miners and AC units in either heating up or down the room environment.

However, I am also adding one more point about "how sealed the room is?" Is it a perfectly sealed room or it does have few cracks due to door hinges, windows etc? In a small room the pressure wont be much thus outer air can easily parse through these crack openings.

If so then it changes everything about that room. In summer hot air can easily take away the coldness with it. In cold it might have some positive effects. I am sure these details will help a lot when it comes to mining operation that will be run for virtually permeant.

my current farm earns 9-10k a month

my share is 20%

last month I cleared 1800 usd.

If noise is a problem for the outside, how about heat? You'll be emitting 175 + 60 = 235 kW. That's the equivalent of 20 of those things on full power:
Anyone walking by may be in for a surprise.

That would mean the other half of the heat has to flow through the walls. I'm not used to using BTUs, so I'd just keep everything in W. You produce 175kW, and have to remove 175kW. The efficiency (COP) of the airco will go up if the outside temperature is lower. Usually the COP is around 3-4, so when it's not too hot outside, you'll need 175/4kW for your airco. If it's hot outside, you'll need 175/3kW. That keeps the math much easier than bringing in BTUs.

Note that I have no practical experience whatsoever with running miners.

out of curiosity: how many people are you in the team and what was your invest for that farm? sounds nice, but also big and expensive :p

Also he has a lot of whatsminers.

their software can allow for shutdown or underclock really fast.

So I do have an interest in what he is going to do.

Off topic I found a new spot for mining.

I will be checking it out this week.

we may get 1200 amps at 240 watts.

Talking about two orders of magnitude, the difference between firing a pellet gun and 155mm gun in a room or nearly the sam thing as saying that my computer with its GPU it's having no problem running in a room without AC and I'm not bothered by it.

175kw is much by some standards but at the same time is outside the rounding error for others.

Back on topic, I too wonder how Mikey is doing with the room!
Might be difficult but as some say, If it can be done someone will be doing it sooner or later.


A tiny advantage Mikey has, since it's a closed room it means it can set a standard temperature and stop everything at the moment of a single fluctuation, he knows that if one fails there is no way the setup will keep working as intended so the moment one goes down he can shut down  the same amount of consumption. Far easier to implement and less of an issue compared to a server farm for which a 20% cut can be as bad as an 80% in some cases. The local logistic hub of my company doesn't even have that luxury, it's either black or white, and everything works or everything goes down till is repaired, we stop and go all offline data entries that need to be checked before being added when everything is up again.

Yep the more gear in a space the more likely something breaks.

Our setup is 2x 3 ton ac's lots of fans in and 2 fans out.

Side note, since Phil bumped this the other day one of the DCs we have server equipment / routers in sent out an email overnight that they have lost backup cooling in one of the suites.
They have n+2 cooling, so sometime in the last few hours they lost 2 units. Not sure what happened, the last email was they have repair coming but no ETA.

It was more of an advisory since as of now there is no effect on us. This has happened once before in a different location. But the point remains the same. As you get more and more units, the odds go up that sooner or later one of them will have an issue. Every once in a great while, 2 will have issues. So if you really have no wiggle room be prepared for this.

This is a multi story DC built with all kinds of other backup plans it's not a big deal, and because suite we are in is about 20% empty it means even less, but if it was at 100% packed to the walls it would be different.

-Dave