Question for experienced "semi-large" scale bitcoin miners

[VentMine]

 You are still sucking that 12000 CFM of air in from the outside from SOMEWHERE, or you get no airflow.

 Setting it up as INTAKE ventilation lets you have more control over what the input air is doing, and where it comes in at, and allows for the possibility of filtering it.

 I've never understood the preference for "exhaust" fans over "intake" fans except in certain very narrow circumstances which don't generally apply to mining.

Hey QuintLeo, the advantage of an exhaust fan is you can build your filtered intake wall / area a variety of ways. If you use a supply fan you have no choice but to pick one, like a blower style, with the filter drum attached. Or, make a more complicated build where the supply fan is pulling from a filtered wall (in which case you might as well go with exhaust fans). If filtering is not a concern then my point is moot.

Negative pressure is a downside for exhaust fans for sure, but probably not a big deal in many cases.

[jpass022]

Negative pressure decreases cooling efficiency...

[QuintLeo]

 You are still sucking that 12000 CFM of air in from the outside from SOMEWHERE, or you get no airflow.

 Setting it up as INTAKE ventilation lets you have more control over what the input air is doing, and where it comes in at, and allows for the possibility of filtering it.

 I've never understood the preference for "exhaust" fans over "intake" fans except in certain very narrow circumstances which don't generally apply to mining.

Hey QuintLeo, the advantage of an exhaust fan is you can build your filtered intake wall / area a variety of ways. If you use a supply fan you have no choice but to pick one, like a blower style, with the filter drum attached. Or, make a more complicated build where the supply fan is pulling from a filtered wall (in which case you might as well go with exhaust fans). If filtering is not a concern then my point is moot.

Negative pressure is a downside for exhaust fans for sure, but probably not a big deal in many cases.

 You have plenty of options for filtered air as well, especially if you build a "plenum" type setup - I commonly use standard Lasko room fans on my intake setup and ordinary 20x20 furnace-type filters.

 I dunno why you think you need to use anything special like you're talking about.

 Also, you get unfiltered air entering your mining area from any LEAK in the entire room, if you use exhaust fans. If you don't care about filtering, this generally isn't an issue though.



 The difference in cooling efficiency for negative (exahust fan setup) vs positive (intake fan setup) pressure isn't enough to be noticeable unless you have a HUGE backpressure issue.
 You MIGHT see a 1 degree difference at times.


 To GMPoison - to exhaust air out of the room you have to have intake SOMEHOW from outside the room, so it doesn't matter if you use intake fans or exhaust fans, you WILL be sucking "hot outside Florida air" into the room one way or another.

[GMPoison]

To GMPoison - to exhaust air out of the room you have to have intake SOMEHOW from outside the room, so it doesn't matter if you use intake fans or exhaust fans, you WILL be sucking "hot outside Florida air" into the room one way or another.

Makes sense, thanks.

I've been thinking more and more of just going with Baikal miners though. I would consider it a more risky investment as they can't mine bitcoin but a variety of other algorithms and altcoins such as Dash. However, the potential profits make them very attractive being much more efficient and 50% more profitable. They're so much more efficient that renting a warehouse/garage wouldn't be necessary, and their would be no need for an elaborate cooling/exhaust solution. They sell out very quickly when they release a new batch, and go for over twice as much on ebay, which is making me consider just going with these to see a very very fast ROI.

http://www.baikalminer.com/product05.php

[VentMine]

Hey Quint since we're on the topic of supply vs exhaust fans, can you point me to a quality high volume supply fan? I'm trying to source a fan to do maybe 6000 - 7000 cfm for exhaust purposes, although I expect many supply / exhaust fans are interchangeable (?).

Also what kind of pressure drop do you typically see across a standard furnace filter?

[QuintLeo]

I don't bother with "high quality" fans - I just use cheap Lasko stuff with a custom-built plenum setup (2 or 3 cheap doors and a piece of plywood or particleboard or even fiberboard for the top works real nicely and is low cost), then when the fan dies in 3-6 years (sometimes a little longer) I can just swap out a spare I bought from Walmart or such.

I don't have a pressure meter or anything fancy, I just have to estimate that I lose 30-40% ballpark (depends on the filter, the cheap fiberglass stuff is more like 10% but don't filter squat, the high-level "filters out pollen" stuff drops quite a bit more) based on the air pressure I feel a few feet from the fans.


 I've been looking at the Baikal off and on for a while - I suspect it will stay profitable for a long time since they're THE most efficient miner available for any of the algos they support, but their process to order one is a nightmare and availability the last couple months when I've HAD the spare $$$ for one has been very very spotty as they seem to keep selling them out faster than they can make them.

[GMPoison]

I don't bother with "high quality" fans - I just use cheap Lasko stuff with a custom-built plenum setup (2 or 3 cheap doors and a piece of plywood or particleboard or even fiberboard for the top works real nicely and is low cost), then when the fan dies in 3-6 years (sometimes a little longer) I can just swap out a spare I bought from Walmart or such.

I don't have a pressure meter or anything fancy, I just have to estimate that I lose 30-40% ballpark (depends on the filter, the cheap fiberglass stuff is more like 10% but don't filter squat, the high-level "filters out pollen" stuff drops quite a bit more) based on the air pressure I feel a few feet from the fans.


 I've been looking at the Baikal off and on for a while - I suspect it will stay profitable for a long time since they're THE most efficient miner available for any of the algos they support, but their process to order one is a nightmare and availability the last couple months when I've HAD the spare $$$ for one has been very very spotty as they seem to keep selling them out faster than they can make them.

From what I've heard, they have the worst customer support out of any company they've ever dealt with, but people are still buying them until they go out of stock within the first week that they release a new batch. People don't care because they're so profitable that they're willing to put up with it. I check their page like 5 times a day to make sure they haven't released a new batch.

[arielbit]

i got the humidity numbers...my sump pump and humidity/temp meters arrived...

humidity in 1st floor is 60-65

humidity in 2nd floor (in my mining room) ranges from 30 to 50 depends on the weather...but i noticed that when it is cooler humidity is higher....so if during the day when it is hottest i can run an evaporative cooler setup because during the hottest periods humidity is between 30-40 (more like nearer to 30's like 30-35)..

my 24 hr room temp today is 99f lowest and 116f highest

i don't know if being on a higher ground reduces humidity etc...the air conditioned room beside my mining room is currently 30 humidity and my mining room is 39 maybe because my mining room is sucking more air than my air conditioned room therefore sucking more humid air.

so for my mining room setup I can implement an evaporative cooling without worrying about humidity....good humidity is between 30-50..climate here is getting cooler, summer here is ending so i'm not in a hurry anymore for setting up my evaporative cooling..next summer it will be running for sure  

[Unacceptable]

i got the humidity numbers...my sump pump and humidity/temp meters arrived...

humidity in 1st floor is 60-65

humidity in 2nd floor (in my mining room) ranges from 30 to 50 depends on the weather...but i noticed that when it is cooler humidity is higher....so if during the day when it is hottest i can run an evaporative cooler setup because during the hottest periods humidity is between 30-40 (more like nearer to 30's like 30-35)..

my 24 hr room temp today is 99f lowest and 116f highest

i don't know if being on a higher ground reduces humidity etc...the air conditioned room beside my mining room is currently 30 humidity and my mining room is 39 maybe because my mining room is sucking more air than my air conditioned room therefore sucking more humid air.

so for my mining room setup I can implement an evaporative cooling without worrying about humidity....good humidity is between 30-50..climate here is getting cooler, summer here is ending so i'm not in a hurry anymore for setting up my evaporative cooling..next summer it will be running for sure  

A/C units are dehumidifiers,so to speak.You notice the condensate line outside?? A 3 ton A/C system can make up to 15 gallons of water per day 

[WarrEagle]

Well, hello there neighbor! I live across the bay in St. Pete. I'm not at that scale nor would I ever consider placing that much gear in a 'room' like that. I doubt you'll be able to get 100 amp service let alone 200. I did not see a panel in the room or on the outside of the unit. Did you confirm power?

I ran 5 ETH rigs pushing 600 MH/s out of my garage last summer. 6 KW constant draw. I did not give a crap about filtering air. I left my garage door open 4 inches, and placed a screen over my garages side exit door. I also built a canopy over the door out of PVC and vinyl tarp. The fans I used were the 30 inch versions of those max airs, stacked on top of each other on a wire shelf. They pulled air across the rigs, and temps were acceptable even through August. The issues I had were surface corrosion from the humidity on the heatsinks and lots of dust. The issue you'll face is you can pull the air out, but fresh air has to come in from somewhere. Is there roof vents to draw air in?

[arielbit]

i got the humidity numbers...my sump pump and humidity/temp meters arrived...

humidity in 1st floor is 60-65

humidity in 2nd floor (in my mining room) ranges from 30 to 50 depends on the weather...but i noticed that when it is cooler humidity is higher....so if during the day when it is hottest i can run an evaporative cooler setup because during the hottest periods humidity is between 30-40 (more like nearer to 30's like 30-35)..

my 24 hr room temp today is 99f lowest and 116f highest

i don't know if being on a higher ground reduces humidity etc...the air conditioned room beside my mining room is currently 30 humidity and my mining room is 39 maybe because my mining room is sucking more air than my air conditioned room therefore sucking more humid air.

so for my mining room setup I can implement an evaporative cooling without worrying about humidity....good humidity is between 30-50..climate here is getting cooler, summer here is ending so i'm not in a hurry anymore for setting up my evaporative cooling..next summer it will be running for sure  

A/C units are dehumidifiers,so to speak.You notice the condensate line outside?? A 3 ton A/C system can make up to 15 gallons of water per day 

thanks..I once looked at how dehumidifiers work, it was like an A/C system..missed and forgot that one...the secret is condensing air to water.

[GMPoison]

Well, hello there neighbor! I live across the bay in St. Pete. I'm not at that scale nor would I ever consider placing that much gear in a 'room' like that. I doubt you'll be able to get 100 amp service let alone 200. I did not see a panel in the room or on the outside of the unit. Did you confirm power?

I ran 5 ETH rigs pushing 600 MH/s out of my garage last summer. 6 KW constant draw. I did not give a crap about filtering air. I left my garage door open 4 inches, and placed a screen over my garages side exit door. I also built a canopy over the door out of PVC and vinyl tarp. The fans I used were the 30 inch versions of those max airs, stacked on top of each other on a wire shelf. They pulled air across the rigs, and temps were acceptable even through August. The issues I had were surface corrosion from the humidity on the heatsinks and lots of dust. The issue you'll face is you can pull the air out, but fresh air has to come in from somewhere. Is there roof vents to draw air in?

Awesome haha! Maybe one day we'll end up collaborating. Although the owner said there should be no problems having additional power ran to my unit, I never confirmed it with an electrician or anything like that. I'm still a month or two from knowing if I will even pull the trigger on this so I haven't talked to electricians or the power company.

Like you said though temps were acceptable for you with proper intake/exhaust, it's just humidity that's the issue. Have you ever placed a humidity thermometer in the room? I'd love to know what numbers it reads for the humidity level around this time of year when it's really bad. You wouldn't think humidity would be too big of an issue if you've got all those miners pumping out hot air. I suppose because you only have 5 ETH rigs rather than something like 30 Antminers the heat they produce isn't able to combat the humidity? I talked about the idea of an industrial dehumidifier (http://www.homedepot.com/p/XPOWER-125-Pint-Commercial-Dehumidifier-with-Automatic-Purge-Pump-and-Drainage-Hose-XD-125/300863366) previously in this thread but most people said it would either produce too much heat, draw too much power, or not do an effective job, although theoretically it seems like it should work for this type of situation. Either way, when the time comes for this project I'll probably end up going with a slightly larger unit capable of facilitating the power and proper intake/exhaust.

[WarrEagle]

Well, hello there neighbor! I live across the bay in St. Pete. I'm not at that scale nor would I ever consider placing that much gear in a 'room' like that. I doubt you'll be able to get 100 amp service let alone 200. I did not see a panel in the room or on the outside of the unit. Did you confirm power?

I ran 5 ETH rigs pushing 600 MH/s out of my garage last summer. 6 KW constant draw. I did not give a crap about filtering air. I left my garage door open 4 inches, and placed a screen over my garages side exit door. I also built a canopy over the door out of PVC and vinyl tarp. The fans I used were the 30 inch versions of those max airs, stacked on top of each other on a wire shelf. They pulled air across the rigs, and temps were acceptable even through August. The issues I had were surface corrosion from the humidity on the heatsinks and lots of dust. The issue you'll face is you can pull the air out, but fresh air has to come in from somewhere. Is there roof vents to draw air in?

Awesome haha! Although the owner said there should be no problems having additional power ran to my unit, I never confirmed it with an electrician or anything like that. I'm still a month or two from knowing if I will even pull the trigger on this so I haven't talked to electricians or the power company.

Like you said though temps were acceptable for you with proper intake/exhaust, it's just humidity that's the issue. Have you ever placed a humidity thermometer in the room? I'd love to know what numbers it reads for the humidity level around this time of year when it's really bad. You wouldn't think humidity would be too big of an issue if you've got all those miners pumping out hot air. I suppose because you only have 5 ETH rigs rather than something like 30 Antminers the heat they produce isn't able to combat the humidity? I talked about the idea of an industrial dehumidifier (http://www.homedepot.com/p/XPOWER-125-Pint-Commercial-Dehumidifier-with-Automatic-Purge-Pump-and-Drainage-Hose-XD-125/300863366) previously in this thread but most people said it would either produce too much heat, draw too much power, or not do an effective job, although theoretically it seems like it should work for this type of situation. Either way, when the time comes for this project I'll probably end up going with a slightly larger unit capable of facilitating the power and proper intake/exhaust.

I never considered humidity as a problem. The air being drawn across the heatsinks never condensated because they were so warm. Outside airflow even at 105 degrees is still cooler than the temps my cards ran at. On average the cards ran around 75 degrees Celsius. That's over 160 degrees Fahrenheit. Nothing will condense at those temps. IMO it's waste of electricity and unnecessary expense. Just stick to intake + exhaust, maybe a filter to keep the lizards and moths from falling victim to the fan blades.

[QuintLeo]

A/C units are dehumidifiers,so to speak.You notice the condensate line outside?? A 3 ton A/C system can make up to 15 gallons of water per day 

thanks..I once looked at how dehumidifiers work, it was like an A/C system..missed and forgot that one...the secret is condensing air to water.

 No "so to speak", A/C units ARE dehumidifiers and vice versa - if you look at almost any recent window A/C unit it will have specific "dehumidity" settings on it.

 That is the reason A/C coils will literally ICE UP sometimes if you don't allow enough airflow to the condenser coils.


 Higher ground will *sometimes* have lower humidity - depends on the details for your specific area - but it's usually not by a lot even when it is the case.


 Humidity IN your mining room will be lower because of all the heat generation raising the temperature - which lowers relative humidity because the capacity of the air to hold moisture increases as the temp rises.

[arielbit]

i got the humidity numbers...my sump pump and humidity/temp meters arrived...

humidity in 1st floor is 60-65

humidity in 2nd floor (in my mining room) ranges from 30 to 50 depends on the weather...but i noticed that when it is cooler humidity is higher....so if during the day when it is hottest i can run an evaporative cooler setup because during the hottest periods humidity is between 30-40 (more like nearer to 30's like 30-35)..

my 24 hr room temp today is 99f lowest and 116f highest

i don't know if being on a higher ground reduces humidity etc...the air conditioned room beside my mining room is currently 30 humidity and my mining room is 39 maybe because my mining room is sucking more air than my air conditioned room therefore sucking more humid air.

so for my mining room setup I can implement an evaporative cooling without worrying about humidity....good humidity is between 30-50..climate here is getting cooler, summer here is ending so i'm not in a hurry anymore for setting up my evaporative cooling..next summer it will be running for sure  

A/C units are dehumidifiers,so to speak.You notice the condensate line outside?? A 3 ton A/C system can make up to 15 gallons of water per day 

thanks..I once looked at how dehumidifiers work, it was like an A/C system..missed and forgot that one...the secret is condensing air to water.

funny my mining room humidity at present is 32 and the air conditioned room beside is 37 .....the A/C system's dehumidifying effect isn't that great hmmm..

last night humidity in mining room is higher...at  day time mining room humidity is lower but temps is now 114f

[QuintLeo]

And what TEMP is the room with the A/C at?

 The curve of how much water a cubic meter of air can hold at a given temperature is NOT linear vs temp - it is a curve that goes up quite a bit faster as the temperature increases, with a MAJOR spike upwards at boiling, and a major drop at freezing.


 If your A/C room was at the same temp without the A/C dehumidifying the air, it would be probably in the 80-100% RH range.

[Unacceptable]

And what TEMP is the room with the A/C at?

 The curve of how much water a cubic meter of air can hold at a given temperature is NOT linear vs temp - it is a curve that goes up quite a bit faster as the temperature increases, with a MAJOR spike upwards at boiling, and a major drop at freezing.


 If your A/C room was at the same temp without the A/C dehumidifying the air, it would be probably in the 80-100% RH range.

Correct,and if its not running enough it will not pull the humidity out........

Check your A/C filter (& check evap coils) for build up on the suction (return) side of the evap,most folks forget that it gets VERY dirty quickly  

[813bits]

I too have been trying to find an ideal location in Tampa to scale an operation, but I found a few better options.   Sago Networks in South Tampa is a miner friendly data center that will charge you electric as a pass through, so your only additional cost is the racks.  Considering it is a conditioned data center, that would solve a lot of your problems.  I was close to parking 50 miners at Sago until I stumbled on Toomim as a host, and I just had 25 come online there where I am paying 6.5 cents p/watt, which is much cheaper than 11 cents at Sago and 13 cents with TECO.  If I had 30k to invest in another 20 miners, Toomim would be my first inquiry.

[QuintLeo]

I keep forgetting Toomim are around here - somewhere - more or less close.

 (I know where they are at, and might even "drop in" on them next time I'm in their area, if it's during "business" hours, just to say "hi" and ask if I can get a tour).

[secup]

dont bother calculating, GET as much air to come IN as possible. if u wanna go technical , get twice as much CFM coming in than out.