Question for experienced "semi-large" scale bitcoin miners - page 3.

QuintLeo

legendary

Activity: 1498

Merit: 1030

Quote from: VentMine on May 09, 2017, 07:26:16 PM

Quote from: QuintLeo on May 09, 2017, 03:07:39 PM

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.

jpass022

member

Activity: 65

Merit: 10

Negative pressure decreases cooling efficiency...

VentMine

full member

Activity: 236

Merit: 105

Quote from: QuintLeo on May 09, 2017, 03:07:39 PM

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.

GMPoison

sr. member

Activity: 434

Merit: 250

Quote from: QuintLeo on May 09, 2017, 03:07:39 PM

Quote from: GMPoison on May 06, 2017, 11:03:09 AM

That's what I'm curious about because really the cost of a good cooler isn't too expensive when you're talking about spending tens of thousands on mining gear. I just think sucking in hot air from outside would be a bad idea, even if the air inside is warmer than the warm air outside. Makes more sense to me in my 650 sq ft warehouse scenario to use the fans at the garage door for exhaust and generate some sort of "intake" via a cooler in the back of the room with fans right in front of it pushing "cooler" air, creating what would be like a wind tunnel, then sucking the warmer air out of the front. I would rather have three of those fans up front exhausting 12,000 CFM of hot air rather than sucking 12,000 CFM of warm air inside. 12,000 CFM is around 500 square feet/minute, nearly the entire size of the entire 625 sq foot unit, every minute.... Hot air wouldn't have time to stick around for long if you had those fans exhausting that much air per minute, no?

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.

I suspect the air exhaust out of your miners, even if the intake air was at 80% RH, would be well under 40% and likely so low you can't measure it with a "common" humidity meter.

I can't remember the last electronic device I've seen that wasn't specified to work at 80% RH - many go to 90%, and while they do tend to specify "non-condensing" that's NOT an issue with a miner that's inside a building.

Thanks. It just made more sense to me for the fans to be exhaust rather than intake. I would understand the logic if I lived anywhere except Florida, but the last thing you would think that you'd want is to be sucking in hot and humid air from outside, but rather exhausting the hot air from inside that the miners are generating. Especially with an evaporative cooler or two, you wouldn't think that with that you would want to be pushing hot air back inside of the unit when you could just be exhausting it all.

QuintLeo

legendary

Activity: 1498

Merit: 1030

Quote from: GMPoison on May 06, 2017, 11:03:09 AM

That's what I'm curious about because really the cost of a good cooler isn't too expensive when you're talking about spending tens of thousands on mining gear. I just think sucking in hot air from outside would be a bad idea, even if the air inside is warmer than the warm air outside. Makes more sense to me in my 650 sq ft warehouse scenario to use the fans at the garage door for exhaust and generate some sort of "intake" via a cooler in the back of the room with fans right in front of it pushing "cooler" air, creating what would be like a wind tunnel, then sucking the warmer air out of the front. I would rather have three of those fans up front exhausting 12,000 CFM of hot air rather than sucking 12,000 CFM of warm air inside. 12,000 CFM is around 500 square feet/minute, nearly the entire size of the entire 625 sq foot unit, every minute.... Hot air wouldn't have time to stick around for long if you had those fans exhausting that much air per minute, no?

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.

I suspect the air exhaust out of your miners, even if the intake air was at 80% RH, would be well under 40% and likely so low you can't measure it with a "common" humidity meter.

I can't remember the last electronic device I've seen that wasn't specified to work at 80% RH - many go to 90%, and while they do tend to specify "non-condensing" that's NOT an issue with a miner that's inside a building.

GMPoison

sr. member

Activity: 434

Merit: 250

Quote from: QuintLeo on May 08, 2017, 09:52:36 PM

Quote from: GMPoison on May 06, 2017, 04:30:31 PM

Quote from: QuintLeo on May 06, 2017, 04:29:32 PM

Which reminds me - a portable-type evap MIGHT work even in Tampa humidity, taking hot air from the output of the miners (which will be fairly low humidity) and sending it back into the input at 20-30 degrees cooler than the output - but you will STILL need quite a bit of ventilation to keep the humidity from building up, optimally more total vent CFM than the evap unit pushes.

That's the idea, a portable type evap. It just makes sense in my head. Dehumidifier to keep humidity under control (or not since I suppose if I have enough exhaust, it would "suck" the humidity out?), evap cooler to keep temps under control, which would be able to operate efficiently because of the dehumidifier

Dehumidifier = mechanical A/C = LOTS of power consumption, and NOT NEEDED if you take the air comming out of the miners (which will ALREADY be pretty low humidity) and evap cool that then send it back to their intake.
As long as you have more airflow THROUGH the area than you have going through your evap setup humidity buildup should not be an issue.

Yeah, I didn't think about how the air being pushed out of the miners wouldn't be very humid since it will be so hot. I can measure it but if that's true, I can just sit the evap cooler right near their exhaust and route it back to their intake.

QuintLeo

legendary

Activity: 1498

Merit: 1030

Quote from: GMPoison on May 06, 2017, 04:30:31 PM

Quote from: QuintLeo on May 06, 2017, 04:29:32 PM

Which reminds me - a portable-type evap MIGHT work even in Tampa humidity, taking hot air from the output of the miners (which will be fairly low humidity) and sending it back into the input at 20-30 degrees cooler than the output - but you will STILL need quite a bit of ventilation to keep the humidity from building up, optimally more total vent CFM than the evap unit pushes.

That's the idea, a portable type evap. It just makes sense in my head. Dehumidifier to keep humidity under control (or not since I suppose if I have enough exhaust, it would "suck" the humidity out?), evap cooler to keep temps under control, which would be able to operate efficiently because of the dehumidifier

Dehumidifier = mechanical A/C = LOTS of power consumption, and NOT NEEDED if you take the air comming out of the miners (which will ALREADY be pretty low humidity) and evap cool that then send it back to their intake.
As long as you have more airflow THROUGH the area than you have going through your evap setup humidity buildup should not be an issue.

QuintLeo

legendary

Activity: 1498

Merit: 1030

Quote from: arielbit on May 06, 2017, 07:05:31 PM

this is the setup I have in mind for my evap cooling.

if it is really hot and when the water in the tank gets warm you can leave the faucet on and by pass the floater so cool water will always come to the tank and let the overflow/drain handle the excess water

The temperature of the water being evaporated is an INSIGNIFICANT factor in the cooling - the amount of heat to evaporate one gram of water is appx. 22 TIMES the amount of heat needed to raise that gram of water from freezing to boiling.

QuintLeo

legendary

Activity: 1498

Merit: 1030

Quote from: Unacceptable on May 07, 2017, 05:22:47 AM

Ok,I live in Florida,how much is the electric?? 10 cents....still not a big enough margin...ROI in MAYBE 2 years...IF Bitcoin hits say $2500 Cheesy

Oh and IF the difficulty doesn't go up Cheesy

Mine is 13 cents per kwh,Bitcoin mining WILL not make anything at my rate..

Now in Washington state at 2 cents it can allow for a profit...or Iceland at 1 cent or china at 1 cent..... Roll Eyes

Best rate in Washington state on an "all up" basis is closer to 3 cents than 2 - though it IS under 3.

I suspect the only areas that see a LOT less in China are way out-of-the-way near an underutilised hydro dam complex - but getting net into those areas likely isn't all that hard, given a significant probability of existing mining farms already in those areas.

I don't think Iceland gets that low - but they DO have a very low cost of cooling given their climate.

To GMPoison - don't sweat humidity, the miners don't really care about it as long as water isn't condensing on them.
Since they generate a LOT of heat, the air comming out of them is going to be pretty dry.
Think of them as a low-density hair drier.
Volume of airflow should be plenty, but keep in mind derating for temperature on your electric wiring and breakers when you plan THAT part out.

GMPoison

sr. member

Activity: 434

Merit: 250

Quote from: VentMine on May 08, 2017, 06:48:50 PM

Hey GM sorry if I missed it, just scanned the thread, but can you not just use standard ventilation and forget the evap cooling / dehumidification? Just curious why the standard set up won't work for ya?

It may, I'm just assuming it will get too hot and humid in the unit if I only do exhaust and don't implement some sort of intake/cooling/dehumidification system. Three of those industrial fans I linked earlier can exhaust 12,000 CFM which is far more than the miners put out. That much CFM is close to exhausting the volume of air in the entire unit every minute. It's a crazy amount of exhaust, I just never assumed it would be enough to combat the extreme Florida heat and humidity.

VentMine

full member

Activity: 236

Merit: 105

Hey GM sorry if I missed it, just scanned the thread, but can you not just use standard ventilation and forget the evap cooling / dehumidification? Just curious why the standard set up won't work for ya?

GMPoison

sr. member

Activity: 434

Merit: 250

Quote from: Unacceptable on May 08, 2017, 06:43:25 AM

Let's see.......

1 S9=$1269+shipping ??

S9 per Month @ 521974519554 diff 0.20527922 BTC $333.32 (exchange rate $1623.76)

10 cent per KWH per S9=1400 watts (rounded off) @ 744hrs per 31 days=1041kwh=$104.16

So say $200 profit per S9.Now deduct shop rent,wages,other utilities (cooling solution cost per month) & maybe insurance??

What ya got left over?? Guessing about $85-125?? Maybe if you don't charge for your time $150 profit per S9?? Oh then you split the profits with the investors.............

Don't forget diff climbing about 3% per month or more......

I really don't see ya lasting very long...sorry Wink

Why assume I would rent a shop and setup the HVAC solution if I were mining with a single S9? I've ran the numbers and I will turn a big profit, I don't care to take the time and break it all down for you here, but I can see why you would think mining wouldn't profitable if that's how you actually just tried to figure it out, lol. Stick to the thread topic of HVAC, I've got the rest figured out guy Wink

Unacceptable

legendary

Activity: 2212

Merit: 1001

Let's see.......

1 S9=$1269+shipping ??

S9 per Month @ 521974519554 diff 0.20527922 BTC $333.32 (exchange rate $1623.76)

10 cent per KWH per S9=1400 watts (rounded off) @ 744hrs per 31 days=1041kwh=$104.16

So say $200 profit per S9.Now deduct shop rent,wages,other utilities (cooling solution cost per month) & maybe insurance??

What ya got left over?? Guessing about $85-125?? Maybe if you don't charge for your time $150 profit per S9?? Oh then you split the profits with the investors.............

Don't forget diff climbing about 3% per month or more......

I really don't see ya lasting very long...sorry Wink

GMPoison

sr. member

Activity: 434

Merit: 250

Quote from: Unacceptable on May 07, 2017, 05:22:47 AM

Ok,I live in Florida,how much is the electric?? 10 cents....still not a big enough margin...ROI in MAYBE 2 years...IF Bitcoin hits say $2500 Cheesy

Oh and IF the difficulty doesn't go up Cheesy

Mine is 13 cents per kwh,Bitcoin mining WILL not make anything at my rate..

Now in Washington state at 2 cents it can allow for a profit...or Iceland at 1 cent or china at 1 cent..... Roll Eyes

I've ran the numbers, at $0.10 kWh you're looking at a ~240 day ROI. That doesn't include all of the money I will get back from selling the miners. Selling off the miners to upgrade to newer ones down the line (or not) and you're looking at cutting that ROI number in half. No other investment will ever make you that kind of ROI except for gambling/day trading. Even after electricity and rent for the warehouse you're looking at $4000+ per month. That's insane. Sure other forms of investment will be less risky as bitcoin technically could go to $0 overnight, but I don't plan on doing this forever. As far as difficulty going up, I expect the difficulty to go up. I also expect the price to go up. They always follow each other, so I'm not concerned about difficult.

Like I said, I've already ran the numbers, I know what it's going to cost and what I'm going to make. Lets keep the conversation focused on my HVAC questions and not on the money. All I'm concerned with now is efficient cooling/ventilation. Don't think just because you live in Florida you can't mine! I'm determined to make it viable, even if it means a lot of work and a lot of planning to get it to work with our heat/humidity. Cheesy

Unacceptable

legendary

Activity: 2212

Merit: 1001

Ok,I live in Florida,how much is the electric?? 10 cents....still not a big enough margin...ROI in MAYBE 2 years...IF Bitcoin hits say $2500 Cheesy

Oh and IF the difficulty doesn't go up Cheesy

Mine is 13 cents per kwh,Bitcoin mining WILL not make anything at my rate..

Now in Washington state at 2 cents it can allow for a profit...or Iceland at 1 cent or china at 1 cent..... Roll Eyes

GMPoison

sr. member

Activity: 434

Merit: 250

Quote from: gbBit on May 06, 2017, 08:29:16 PM

Quote from: GMPoison on May 06, 2017, 04:27:34 PM

Quote from: gbBit on May 06, 2017, 04:13:17 PM

I've really enjoyed reading your thread and I would recommend that you take another look at the hosting option. See this thread as it can get lost at times. https://bitcointalksearch.org/topic/hw-hosting-directory-reputation-622998 I've also looked into doing something similar as you and I think until you're ready to grow larger hosting is the way to go. You can find a hosting company for around $55 kWh/month or $.07 KWh which can do the same as you much more efficiently. The biggest drawback of using a hosting company is that your machines are away from you therefore you're somewhat out of control. As long as you can handle this then it's not such a big deal. The other big lost is that most hosting companies want payment upfront for usually 3~6 months which will cut into your initial investment into miners where the power company will want post payment.

They way I looked at it was to decided But in any case even if you have power at $.06 kWhr you're looking at saving about $16/miner doing it yourself versus hosting. So if you're looking at getting 30 miners that's a saving of about $500/month.

How can they afford to do that? A hosting company only charging a rate of $0.06 kWh would save me $1000 in power costs (nearly half of my $0.10 kWh rate). They don't charge any other fees for providing the free cooling, maintenance of the machines, the space? Sure it's ~$1000 saved in electricity, but that doesn't even account what they would charge for using their space, that's only for the electricity bill!

If you decide to go with a hosting company you need check all their fees. Some do charge setup fee and maintenance fees, but most will only charge a hosting fee and provide free setup and basic services like hard restarts for free in case you can't reset via vpn . But as I mention the biggest drawback will be the miners are away from you so if there's a major issue then you'll have to rely on someone else to do your troubleshooting who will either charge you a lot or not be too interested in looking too deep since they're not being paid to do so.

Yeah, if I can help it I want to do it all myself. Even if it means some lost profits, I want this to be more than just an investment but a hobby as bitcoin always has been for me. Plus like you said if something goes wrong with the miners, or I want to sell them, or anything like that. It started to sound like QuintLeo was expressing the plausibility of my evap cooler/dehumidifier/exhaust combination, so hopefully that looks like it could possibly work.

gbBit

member

Activity: 84

Merit: 10

Quote from: GMPoison on May 06, 2017, 04:27:34 PM

Quote from: gbBit on May 06, 2017, 04:13:17 PM

I've really enjoyed reading your thread and I would recommend that you take another look at the hosting option. See this thread as it can get lost at times. https://bitcointalksearch.org/topic/hw-hosting-directory-reputation-622998 I've also looked into doing something similar as you and I think until you're ready to grow larger hosting is the way to go. You can find a hosting company for around $55 kWh/month or $.07 KWh which can do the same as you much more efficiently. The biggest drawback of using a hosting company is that your machines are away from you therefore you're somewhat out of control. As long as you can handle this then it's not such a big deal. The other big lost is that most hosting companies want payment upfront for usually 3~6 months which will cut into your initial investment into miners where the power company will want post payment.

They way I looked at it was to decided But in any case even if you have power at $.06 kWhr you're looking at saving about $16/miner doing it yourself versus hosting. So if you're looking at getting 30 miners that's a saving of about $500/month.

How can they afford to do that? A hosting company only charging a rate of $0.06 kWh would save me $1000 in power costs (nearly half of my $0.10 kWh rate). They don't charge any other fees for providing the free cooling, maintenance of the machines, the space? Sure it's ~$1000 saved in electricity, but that doesn't even account what they would charge for using their space, that's only for the electricity bill!

If you decide to go with a hosting company you need check all their fees. Some do charge setup fee and maintenance fees, but most will only charge a hosting fee and provide free setup and basic services like hard restarts for free in case you can't reset via vpn . But as I mention the biggest drawback will be the miners are away from you so if there's a major issue then you'll have to rely on someone else to do your troubleshooting who will either charge you a lot or not be too interested in looking too deep since they're not being paid to do so.

arielbit

legendary

Activity: 3416

Merit: 1059

this is the setup I have in mind for my evap cooling.

if it is really hot and when the water in the tank gets warm you can leave the faucet on and by pass the floater so cool water will always come to the tank and let the overflow/drain handle the excess water

arielbit

legendary

Activity: 3416

Merit: 1059

Quote from: OgNasty on May 06, 2017, 10:35:43 AM

Quote from: arielbit on May 05, 2017, 08:50:27 PM

I'm no HVAC expert, been mining for some time now so if I'm at your shoes this is what comes to my mind as a solution...lets get creative Wink

i think assembling your own evap cooler is cheaper, good for customization (special case to case basis), parts are bought separately (you can go high quality per parts), you can go bigger...just look at this pump https://www.amazon.com/Zoeller-Mighty-mate-Submersible-Sump-Pump/dp/B000H5PYR2/ref=sr_1_1?s=hi&ie=UTF8&qid=1494031508&sr=1-1&keywords=zoeller+sump+pump , this is the one i bought..

i haven't assembled my evap cooling so my creative setup isn't finished and i can't show a running setup and pitfalls in making one...I'm also in the process of acquiring a filter roll...

I've been very curious about HVAC cooling use with mining for a while. Have you implemented this yet? I didn't see anything in your pictures. I'd love to hear/see more about this. I think it would be an ideal situation for those living in warmer climates looking for a cheap method of introducing cool fresh air as opposed to sucking in hot air from outside.

not yet. my mining room can still manage the heat by just venting air, and i think I'm getting close to the max safe limits of my Electrical supply so maybe I can max out my electrical supply without needing to use evap cooling, but there are times when the days are hot like in summer so I will still implement evap cooling, but it is only going to run during hot days..besides I haven't completed the parts that I needed yet.

my mining room is in second floor with the door open, so the mining room is sucking air in from the ground floor and in the ground floor the windows are sucking more air(more dust), so i figured out using filter rolls to filter dust..

the attic manhole that I opened is also an outlet where cool air can get in from outside, specially at night when the roof is cold and the air is cold, it is like a huge blower of cool air in my mining room.

sucking air from the outside is still the norm, evap cooling can make that air more cooler.

GMPoison

sr. member

Activity: 434

Merit: 250

Quote from: QuintLeo on May 06, 2017, 04:29:32 PM

Quote from: GMPoison on May 06, 2017, 12:16:32 AM

How does hot gear solve humidity issues? Heat + humidity = death lol

amount of water in the air is constant, but air gets hotter = lower humidity level.

Even WITH my evap running, I rarely see 40% humidity anywhere INSIDE my place, even when it's raining outside.

Without the evap, commonly somewhere under 20% (can't tell HOW far under sometimes as my meter won't read anything under 16%).

Which reminds me - a portable-type evap MIGHT work even in Tampa humidity, taking hot air from the output of the miners (which will be fairly low humidity) and sending it back into the input at 20-30 degrees cooler than the output - but you will STILL need quite a bit of ventilation to keep the humidity from building up, optimally more total vent CFM than the evap unit pushes.

That's the idea, a portable type evap. It just makes sense in my head. Dehumidifier to keep humidity under control (or not since I suppose if I have enough exhaust, it would "suck" the humidity out?), evap cooler to keep temps under control, which would be able to operate efficiently because of the dehumidifier, then a few big industrial fans to exhaust it all. It just seems perfect in my head. What exactly is a 2-stage evap cooler though? The one I linked above that I was looking at is here: http://www.homedepot.com/p/PORTACOOL-16-in-Vertical-Tank-3900-CFM-3-Speed-Portable-Evaporative-Cooler-for-900-sq-ft-PAC163SV1A1/206757987. And here are the fans which would be able to exhaust far more than the miners and evap cooler would be able to put out at 4,000 CFM per fan: http://www.homedepot.com/p/MaxxAir-Pro-24-in-Industrial-Heavy-Duty-2-Speed-Multi-Purpose-PRO-Tilt-Drum-Fan-BF24TFORGPRO/204631701. Let me know what you think. Where are you based out of curiosity? Sounds like somewhere that gets humid as well.

Topic: Question for experienced "semi-large" scale bitcoin miners - page 3. (Read 10290 times)