Bitcoin Forum

I have a sizable amount of money that I'm considering investing in bitcoin mining ($40k-60k). I've mined bitcoin in the past, I've been in the community a long time, and I've run all of the numbers to know it will be profitable, so I know for the most part what I'm getting myself into, and I finally have the money to invest in something I whole wholeheartedly believe in. I just have an HVAC question for those of you who have done it before or are currently doing it and know anything about heating/cooling.

1) For a mining operation this size a small ~1000 sq ft warehouse would need to be rented out, how have you dealt with temperatures and heat? A small warehouse like this (https://tampa.craigslist.org/hil/off/6072781671.html) in Florida would absolutely cook my miners, especially in the summer. I've seen Youtube videos of guys in similar situations do different things, but it seems like industrial fans lined up with the door rolled down on top of them pulling air out of the room would be best. Some sort of solution like this (http://images.wisegeek.com/garage-exhaust-fans.jpg) seems extremely ideal where you can just exhaust all of that hot air out of the door. As far as humidity which we get a lot of in Florida, I'm thinking something like dehumidifier and an evaporative cooler combination would work well (http://www.homedepot.com/p/MaxxAir-145-Pint-Bucketless-Portable-Dehumidifier-DH-075-ORG/207155737) and (http://www.homedepot.com/p/PORTACOOL-16-in-Vertical-Tank-3900-CFM-3-Speed-Portable-Evaporative-Cooler-for-900-sq-ft-PAC163SV1A1/206757987). The dehumidifier would keep the humidity somewhat stable and low enough for the evap cooler to be effective, which would then cool the air in the back of the room down so I could then blow that air over the miners, creating a sort of wind tunnel, finally with the fans at the front exhausting the warm air that was passed over the miners. I really like the idea of it and how effective this combination could be, but I have NO IDEA how I would run the numbers without dropping all the money on them and the miners. Theoretically, would something like this work? I know without the dehumidifier it would be too humid for the evap cooler to run, and with the evap cooler it would probably be too hot in there.


update: Dehumidifier/Evap cooler likely won't be optimal, I will most likely go with a warehouse that has two large roll up doors means for trucks. One door will be intake, the other will be exhaust, and the miners will sit in the middle for optimal airflow.

I know you want experienced semi-large miners to reply, and I am not one of them, but here's my 2 satoshis anyway.

Regarding heat ventilation: Exhaust fans are the only way to go. A/C is not an option anywhere really, primarily due to the extra power consumption resulting in a higher operating cost which will likely yield your operation unprofitable in the long run. Short run, with BTC on the up and up, maybe economic... but as you say you know the economics so you know you need $0.03-$0.07 / kw-h to have a chance long term. So while I don't know the full layout of that warehouse, you are going to need to size your exhaust fans properly. I would size them to be able to handle the max CFM / miner. You are in Tampa with a hot climate, you will definitely want to make sure your exchange CFM exceeds your total miner CFM. Location of fans play a role as well but I can't comment without more info.

In regards to power, that picture you posted doesn't have near enough room for 10 megawatt... But anyway, first you need to choose a proper location (low cost power is primary consideration, leasing agreement secondary) then find out the maximum service you can install (considering capital and labor costs), then spec out the total # of miners you can run, then spec out the fans / ventilation system.

Edit - I remembered you said you only have $10-30k, that could only get you about 20-25 Antminers without any electrical costs etc. Realistically, with such a low amount of money you are better off buying the Antminer / Avalon miners and sending them to a reputable hosting facility. You don't have enough money to justify leasing a commercial or industrial lot.

Thanks for your input! Regarding heat ventilation I agree that A/C is out of the question for something like this, exhausting heat is the only way to go. I can turn a very nice profit with up to $0.10 kWh but if I go with a warehouse I'll get commercial rates which will likely be cheaper, thus allowing for even more profits.

Is there any reason to believe power for ~20 Antminers would be impossible to have installed in a space like that? Do you believe the building wouldn't be capable of handling it? Remember it's not just that small warehouse/garage, it's a larger building with many more attached. As far as how much that would cost if it were even possible, I've never gotten any quotes but I'm under the impression that sending them to a hosting facility would be much more costly, in multiple ways (rent, if a machine broke down, etc.).

Including renting the warehouse but not including power installation (would probably eat the first few weeks of profit at most), I would stand to make somewhere around ~$2200 per month after plugging the numbers into a mining calculator. That's a good amount of money to me that would be made on the side compared to something like buying a rental property which would make 1/4 that much money per month. I'm just searching for something to invest in, and I love bitcoin and believe in it, so I figured mining would be the best thing for me to invest in right now, not even including how much more money you can make doing this than anything else I've researched. $2200 a month in real estate or the stock market with only $10k-$30k would take years and years to achieve.

Make sure you can vent a LOT of air through the space.
The recommendation of "more CFM than the total of your miners flow" is a good one - but IMO it's better to use filtered positive-pressure INTAKE fans over exhaust fans and ghods only know what kind of dust pollen and whatnot come into your space from wherever.

Tampa is to damp for evaporative cooling to work, unfortunately.

20 Antminers should be handled comfortably by 200 amp (220) service, which is pretty commonly available but NOT universal anywhere I've ever been on spaces in the 1000-2000 square foot range.
 That's only 26 KW or so, well within the 43KW+ rating of a 200 amp service (even with derating for continuous draw service you should have over 33 KW available COMFORTABLY).

 Be sure to CHECK the space for service availability and venting capability before you actually lease it though.

 I dunno where the MEGAWATTS figure came from.


 In theory, it should be able to keep the garage-type door open 3-4 inches without being a security issue, if you can figure out how to lock the door at that point without having to make modifications the landlord would find unacceptable. Perhaps reuse an existing bolt in the side of the door and a bracket that bolts to the door "rails", so you can remove it and put it back how it was when the time comes to move out.

20 T9s is only 32kva. Any commercial building can handle that no problem. The biggest problem you will face is actually making a profit. 10 cent power is pushing the limits of viability.

You will also have to purchase a small amount of electrical infrastructure, network gear, power supplies, and find a way to cool it all. You also need to find a warehouse that is not a concrete bunker as it will just absorb the heat and make it even harder to cool. Also most commercial establishments are not going to enjoy the sound of a small airplane buzzing around their property 24/7/365 either so you will have to factor noise into the location you pick.

Making $2200/month means it will take close to a year to recoup the initial investment. In another year the difficulty and network hashrate will be so much higher the chances are you wont be making close to $2200/month at the end of the first 12 month period it will be more like $1500. Im not saying you wont eventually make a small profit but dont expect to make a bunch of money on this investment. To make real money mining bitcoin you have to go large in a dedicated facility with ridiculously cheap power. At that point you are looking at millions of dollars to make it through year 1.


P.S. You will be using like 35-40kilowatts, not even scratching the surface of the megawatts. 1 megawatt of power is like 650+ T9s on its own.

This kind of cooling is cost prohibitive and unnecessary for what you are doing. If it is a dusty environment just blow them out with a compressor every couple months or so. You wont find a profitable large scale mine out there that gives two shits about dust and spends a ton of money on air filtration. At best they use swamp pads and consider those their filtration system.

Thanks for your reply. I got 10-20 megawatts from the following calculation: 20 antminers x 1130W = ~22600W or 22.6 kWh. 22.6 kWh is 16272 kW/month or 16.2MW per month. I may be doing the calculations wrong but that's how I got 10-20 megawatts per month. A 220 amp 220v service is 44000 watts which is twice as much as I would need, so that would be plenty, even if I wanted to purchase more miners one day. Any rough estimate that you could give me on how much something like that *might* cost? I know I'll have to get quotes for actual numbers.

Thank you too for your suggestion about exhausting the heat. I'm sure I could come up with something like that, somehow securing the door and the fans to the ground. I was thinking more along the lines of 3-4 feet though not just 3-4 inches, so I could put a couple industrial high cfm fans like this one next to each other for really good airflow: goo.gl/dRQJ8E I could see something like that working where I would just close the door to the top of the fans, and secure the door to the chain of fans with some heavy duty metal chains so there would be no way to get in or out without completely busting the fans as they would all be linked together to the door and to the ground. Even then there would be security tapes and whatnot.

Thanks, but I just posted above how I got my megawatts calculation which was per month by the way not per hour or anything like that. 22.6 kWh is 16.2MW per month, at least as far as I understand.

As far as profits go, you have to believe that the price of bitcoin will rise as the difficulty rises. That's how it has pretty much always worked, and how I believe it will continue to work. I will probably hold onto the miners until Bitmain releases the next most efficient miner, who knows when that will be, but I don't believe that I will ever *not* make a profit by mining. If I do, I sell the miners off and make a lot of that money back.

So now what I'm trying to figure out is heating/cooling. Here in Florida it gets hot. Not only does it get hot but it gets humid too. I have exhaust worked out which would be three of these (http://www.homedepot.com/p/MaxxAir-Pro-24-in-Industrial-Heavy-Duty-2-Speed-Multi-Purpose-PRO-Tilt-Drum-Fan-BF24TFORGPRO/204631701) lined up like this (http://images.wisegeek.com/garage-exhaust-fans.jpg), so now I'm figuring out how to deal with humidity and temperatures, because I don't think those exhaust fans will be enough. (650 sq foot warehouse/garage btw)

I'm considering some sort of dehumidifier or portable a/c. I know it's very bad practice to try and cool miners with an a/c rather than spend the money on venting the hot air out, but this is a very small and confined space, so I think some sort of combination between a dehumidifier and an evaporative cooler could work. Dehumidifier to deal with the humidity, and the cooler to deal with the temperatures.

A combination of something like this (http://www.homedepot.com/p/PORTACOOL-16-in-Vertical-Tank-3900-CFM-3-Speed-Portable-Evaporative-Cooler-for-900-sq-ft-PAC163SV1A1/206757987) and this (http://www.homedepot.com/p/MaxxAir-145-Pint-Bucketless-Portable-Dehumidifier-DH-075-ORG/207155737) I'm thinking could work. I don't know if there is any way to test that however before dropping a bunch of money. There are so many variables involved that I don't see how anyone could tell me if something like this could work or not unless they've actually done it before, but it seems like theoretically it would work well enough to keep the temps down and humidity down so the miners would be comfortable, even in the summer heat. I'm going to find people that are pro's in hvac to speak to but I figured I would ask here. I have no clue if the dehumidifier would make the room dry enough for the evaporative cooler to work well enough, and I don't know if the evaporative cooler would work well enough to give me a 15-25 degree drop in temps that it claims it would. I don't care so much about how much those two things cost as long as they work, but if anyone has a more cost efficient way I'd love to hear it.

Any input from guys that know heating/cooling?  

edit: For that cooler specifically the manual says the following: "For optimum performance, the temperature should be 85˚ F or higher and the relative humidity should be below 75%. However,
Portacool evaporative coolers will reduce the temperature in almost any environment, making it more comfortable." That sounds like it would work nicely as I should be able to keep humidity below 75% with the dehumidifier, and the temps will definitely be at least 85 degrees. It also says that it consumes it's entire 42 gallon reservoir every 2 to 10 hours depending on humidity, so I have 0 clue about how I would regulate the flow of water so it would get enough and not too much every day since the humidity levels fluctuate outside... then again with the dehumidifier, I guess the goal is to get a somewhat stable environment humidity wise?

GMPoison - If you expect your power cost to be $0.10 / kW-h I recommend that if you want to pursue mining to use your money to buy just the Antminers and send them to a reputable hosting operation. Not only do you not have to pay any extra capital cost for power / ventilation / property renovations etc, but you also don't have the headache of running the operation. You also need to consider that renting a commercial property has it's own operating costs, which add to the overall $ / kW-h.

Or, you can also buy bitcoin with your money and earn with a price increase. This is often a better option than mining when your power costs are > $0.10 (picked that # arbitrarily).

Without getting into detail on your recent replies, your calculations are incorrect. There are plenty of resources online how to calculate current draw (Amps) based on rate of power consumption (Watts) and voltage. I like your optimism, but I recommend you spend a lot more time getting down the basics (spend time researching the forum and internet, there's plenty of details on building small bitcoin mines and what to consider). If you can't spend time on this now and learn what you need to, you will end up making a bad, rushed investment. Good luck

Thanks for the advice. I'm just not sure how it would be cheaper to rent space at a reputable hosting location than spend a few more cents on power. Even with rates as high as 10 cents per kWh, I will still make a very nice profit (for me at least), including costs such as rent for the warehouse, the heating/cooling equipment, installation of additional power, etc. I've ran the numbers, and those profits don't even include reselling the equipment at a later point in time to recoup some of the costs. Even if it was cheaper by a small margin to go that route, what fun would that be?

I'm also not sure how my power calculations are wrong, I've run through them so many times. 20 Antminers requires 23000 watts of power (20 miners x 1150w per), also known as 23 kWh. 24 hours a day makes 552 kW consumed per day, which makes 16560 kW consumed per month, or as I said, 16.5 MW, resulting in a very expensive power bill, yet still cheap enough so I can generate large profits. Having a 220 amp 220v line run to my unit would provide me with 44000 watts of power, plenty enough for my size operation. If that's not how you properly calculate power usage then I'm totally lost and I have my head on backwards. I've ran the numbers, it comes out to over $2000 a month in power costs, but even after paying that huge bill I'll still be pulling in even more than that in profits. Also I may throw in a few Baikal miners, they're much more profitable than Antminers as they consume far less power, but I'll only have a few of those for diversification. Like I said, I'm not too concerned with startup costs like the dehumidifier or swamp cooler (if those would even be viable) because I know how to resell them and recoup a lot of their costs, so don't factor those into the equation. I've done plenty of research on bitcoin mining over the years, and have mined multiple times in the past, just not on this scale. I'm fairly confident that I already know the basics :P

I just want to hear from some guys that know HVAC really well to see if the scenario I posted above is viable, or if the dehumidifier and evaporative cooler would end up working against each other and produce no results. Theoretically it seems like it should work to both reduce humidity and drop temperatures, and they should play off each other. Dehumidifier to keep the humidity stable and low enough for the evaporative cooler to work, which would then keep the temperature in check.

The wattage / antminer S9 varies per batch (total TH/s) and ranges from 1125 - 1325 Watts. Assuming 1225 Watt 20 x S9's will pull 24,500 watts. It's not that you're wrong I guess but you keep incorrectly labeling kw-h and kw.. I'll just run through it. So yes, at 24,500 watts the total energy usage in a day is 24,500 * 24 / 1000 = 588 kW-h consumed / day (note, not kW consumed / day as you said). A kW-h is a unit of energy (can be converted to Joules). A kW is a unit of power or rate of energy consumption. If you're running at 220 V then your expected current draw is 24,500 / 220 = 112 Amps. Plenty of room on 220 Amp service. You're on the right track, I have no doubt you can figure out how to set up a nice little mine, just confusing on your units.

Just keep this in mind - right now BTC price is awesome and economics look good for a mine at a wide range of power costs. However, time has proven that the network will self-regulate; difficulty will increase to match price increases so that only the low cost miners can mine more profitably than simply buying bitcoin. I personally would not build out a sizable mine unless my operating cost was $0.05 / kW-h or less. Hosting is a pretty cheap solution as the going hosting rate equates to running miners at a power cost of around $0.06-$0.09 depending where you host with, and you do NOT have to pay off the other capital costs as you would with your own mine.

PS - I've never even heard of Baikal miners... Right now it is widely accepted that Bitmain provides the most efficient / profitable miners. Be VERY careful about buying other brands, there are tons of scams on the go. Personally I only trust Bitmain and Avalon right now with my money, but other names will undoubtedly turn up soon with the price going crazy as it is.

Good luck brotha

Thanks! Yeah I do keep mixing up kW and kWh, my bad on that. Baikal miners have been around for a little while now, they make multi-algorithm ASIC miners, which are very profitable as of recently with the rise of a few altcoins. They used to sell out in the first day then be resold on ebay for twice as much because of how profitable they were, but for some reason they still have some in stock and it's been days. We'll see how bitcoin does in the coming months, right now I'm only considering doing this. If it continues to rise in price along with the difficulty as it's done for years now, I should be able to remain profitable (I was considering doing this months ago before the huge price increase, and even then with 10 cents kWh it was still very very profitable). Once a new miner comes out you sell your old equipment to recoup a lot of those costs, and upgrade. If the price of bitcoin tanks, so does the difficulty, thus allowing the "larger" miners to remain profitable. If it's ever not profitable for whatever reason, so long as I can run for a few months before whatever catastrophe would cause that, I sell everything off, eat the cost of the lease, and still make profit, just not as much. $0.05 / kW-h would net insane profits, I can't even imagine making that much money from mining. If I had $0.05/kWh there would be no hesitation to start mining lol. I really want to know though if that dehumidifier/cooler combo will work as well as I think it will, that's the only thing I'm unsure of at this point.

Depending on the batch they use more than that. I have some older S9s here running nearly 1500w at the wall socket.

Also there is no S9 that only pulls 1125....you are forgetting to add another 10% to those figures.

From bitmains site:

 Power Consumption 1127W (11.5TH/s batch), 1225W (12.5TH/s batch), 1274W (13TH/s batch), 1323W (13.5TH/s batch), 1372W (14TH/s batch) (at the wall, with Bitmain’s APW3 PSU,93% efficiency, 25°C ambient temp). Expected discrepancy of +10%

so thats a minimum of ~1239 for the slowest up to ~1509 for the fastest

I've done my calculations based upon 1250w for the 11.5TH/s batch, plus some head room for overclocking or if they happen to consume more for whatever reason, and it's still plenty profitable at $0.10/kWh, even before this spike in price (and difficulty). Like I said I'm not too concerned with that right now, but with heating/cooling. If I can't come up with a solution for that, there is no point in contemplating any further.

FYI if you buy any new S/T9s they are autotune. There is no overclocking.

There have to be some HVAC experts here that can give their input to my dehumidifier/evaporative cooler idea posted above!

Nobody does it so why do you want to? Ventilation is king

I don't know about 'nobody' but sure, it's definitely uncommon. I'm a special case though since I'm in Florida, no? I just feel like exhausting the heat out won't be enough.

looking at that warehouse reminds me of something....ahhhh a brick oven hahaha

btw OP i think you are underestimating the power of ventilation, the sheer amount/volume of air passing thru will make things good enough for miners just take a look at a typical cpu heatsink with fan, it simply relies on air going thru the heat sink fins.

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  ;)

https://s1.postimg.org/q938d7o4v/vent.jpg

an example of roof turbine..
http://www.batticdoor.com/images/roof-turbines.jpg

use this filters for air..they are cheap .... dust problem eliminated...there are different type of materials used and rating (there are different standards in filtration measurement like MERV rating)...typically filter rolls are in pre-filter category, but for dust they are very good specially the highest rating and thickest.

https://www.addfiltration.co.uk/image/cache/data/filter-media-roll-500x500.jpg

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   (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...

also buy some humidity measurement devices.

Thanks. I never bothered to ask the owner about installing some sort of roof ventilation, but I suppose if that would be possible it would be better to use the fans on the garage door for intake rather than exhaust to get fresh air in. I just never though of that because it would be sucking in hot Florida air, but with an evap cooler or two right in front with a dehumidifier the air wouldn't be as hot or humid as outdoors.

it is humid here in southeast asia...none of my 280x's since 2013 died because of humidity..all are still fine.

What are the humidity levels like there? I'm sure you're not running your miners out in the open without regulating humidity, but they're inside where the humidity is controlled to some degree like I want to do with a dehumidifier. 

haven't used a dehumidifier...like I said to you in PM, my pump and humidity measuring devices are still on ship from abroad so i can't give numbers yet, they will arrive this middle of May..excited to see those numbers myself. BTW i dry clothes better in my mining room compared to drying them in the open that's why i feel that humidity isn't a problem..

I'd love to see some pictures of your setup if you want to PM me :)

i already posted it here, twice in this forum here: https://bitcointalk.org/index.php?topic=1584973.msg17247745#msg17247745 (https://bitcointalk.org/index.php?topic=1584973.msg17247745#msg17247745)

it a bit outdated..i added a rack with 5 gpus already in there and 3x 1080 ti coming today.

Just for the record, if you'd bought 2 weeks ago with your money some bitcoins when price was below $1200 now you'd have earned $10,000 on your $40,000.
I know mining bitcoin will eventually lead to profit one way or another, but it's about the time which you could save if simply enter trading.
Does any of you know bitcoin mining needs at least $1M and adding more every day in order to compete?

i say do both, mine, trade and do altcoins too..it is a journey, learn and get better.

Yeah I know I could just trade, but that's much higher risk. If the price of bitcoin drops, so does the difficulty, keeping my miners profitable. If the price of bitcoin raises, so does the difficulty, keeping my miners profitable. It's easy to say I could have made $10,000 after the fact, I believe that's called the hindsight bias. Plus I can imagine trading would be more difficult to deal with taxes, where the point of mining is to keep all the profits clean and easily reportable.

read this from other thread..an old timer miner says..

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

humidity does it magic when gear is not running (metals are cold)...I remembered an old timer in cars here told me that it is better to run a car for a bit more far than using your car in short distance driving, because the cold air from evening and early morning makes the exhaust pipe wet/moist, running short distance does not eliminate all moisture/water therefore causing rust..longer distance usage eliminates all water/moist in the exhaust pipe.

another example:
some mildew grew in a picture frame in my house...brought that picture frame in the mining room = dead mildews

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.

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?

 A LOT of commmercial spaces, especially smaller warehouse or retail, have 100 amp OR LESS service available.

 The BUILDING may have more, but many commercial spaces are not the entire building.

 The ONLY additional cost is the air filters - common 20x20 furnace filters work fine for this application, and are NOT all that expensive.
 At the scale OP is positing, you're basically be replacing 1 or at most 2 filters a month.

 I do agree that it's redundant in cases where evaporative cooling is in use.

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://bitcointalk.org/index.php?topic=622998.0  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.

 Heating is NOT an issue.
 I have somewhat less total power consumption on my rigs than you are targeting, yet I've had to keep at least 2 windows open during the last 2 winters (one of those in IOWA, where it hits negative-F COLD pretty much every winter at least some of the winter, the other in central Washington were it never saw 0 this past winter but did see sub-freezing for a few months straight every night) to avoid OVERHEATING during the winter.

 Your only issue is cooling - and given Tampa humidity, massive airflow is your only viable affordable option.

Given the humidity levels you don't think a dehumidifier would do any good? Or an evaporative cooler to be able to be able to keep the temps down to a reasonable level? When you say "affordable" what do you mean? The dehumidifier and evap cooler I linked above are about $1k each. Does that not qualify as affordable to you?

 It's not that they are wrong, it's that nobody does the computations in power used per month when figuring how much power you need to be available.

 Evaps do NOT work well (except the EXPENSIVE 2-stage stuff) at the normal humidity levels in the Tampa area.
 One thing to keep in mind - a "dehumidifier" is nothing more than common mechanical air conditioning specifically used in a dehumidifier mode - most "common" window-type A/C units have a "dehumidity" option.
 ANY usage of mechanical A/C kicks your power costs up a TON - and it's rather redundant to use both an Evap unit and mechanical A/C.

 It's not so much that the units are expensive, but that dehumidifier is going to be expensive to RUN, while the Evap unit isn't going to work very efficiently.

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!

 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.

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.

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

https://s11.postimg.org/e3ksig38z/evap.jpg

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

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.

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  :D

Oh and IF the difficulty doesn't go up  :D

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..... ::)

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. :D

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  ;)

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 ;)

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.

 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.

 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.

 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.

 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.

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.

Negative pressure decreases cooling efficiency...

 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.

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

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?

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.

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  :D

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  ;)

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?

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.

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.

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.

 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.

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

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  ;)

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.

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).

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.

Gotta say, staying temporarily in central FL myself (Wildwood), I think a conditioned third party data center would probably be your best option for a larger set up.
Just running a couple of S7's at my brothers place last summer I had to come up with a Rube Goldberg setup -- took the doors off of an older mini fridge and put it in a well insulated closet with the miners, along with a butt load of fans and a small dehumidifier. Worked out pretty well, but at the time I was running at a calculated loss of about 15% due to power costs ($0.10 per kWh at the time).
I could only justify mining due to my unwavering faith that BTC would climb well above $400 at some not to distant future point. (And yep it suuure did, wish I had held on to more than I did).
When it gets to be 97 degrees and 75% humidity everyday cooling becomes a very expensive proposition for mining rigs.

I would only setup a mining operation in these conditions for the same reason you did, my unwavering faith in cryptocurrency and what it stands for.

It sucks that you ran at a loss, but those S7's suck up a lot of power! I'm fairly certain though that with Litecoin looking as good as it does, I'm going to be grabbing a bunch of the Antminer L3+ and not S9's. Even though they don't ship until August/September, if you run the numbers they're the most profitable miner on the market. They pay themselves off in less than 60 days which is ridiculous.

If I'll actually make the profits that the numbers say I should make off a $40k investment in those L3+ miners, I may rent out a warehouse somewhere more north where it's colder and electricity is cheaper and manage it from here, buying a plane ticket to the warehouse whenever I need to. I know difficulty will rise and price can change in the next two months before these things are released, but the potential profits that I'm seeing don't even seem real, and a plane ticket across the country a few times a month would be equivalent to buying a tank of gas. $40k spent on the L3+ miners nets you something like $30,000 per month which is ridiculous. Like I said I know things can change in a big way very quickly, but there's no way I'm not taking that risk. Those kinds of numbers are literally life changing. Even if the difficulty doubles and the price is cut in half (close to no chance of that happening) these things would still be profitable. I'm especially confident now that Charlie Lee has left Coinbase to work on Litecoin full time.

Yeah, I'm thinking a warehouse with two large garage doors rather than one so I can do something like intake for one door, have the miners lined up in the middle, exhaust for the other door and create a "U" if I were to visualize the airflow. Cold air in one side of the room on the intake side of the miners, hot air in the other side of the room on the exhaust side of the miners. It will be more expensive but if the numbers don't lie, upgrading to a larger warehouse won't be but an extra 1% of the profits per month with those new Antminer L3+ miners. It's also more likely that power won't be an issue with a larger place. Also like I said above, if I make even a fraction of what the numbers tell me I will with $40k in L3+ miners, I'm thinking it would be beneficial to rent a place up north where electricity is cheaper and it's colder all year and just buy a plane ticket whenever I need to visit it, which again would be pennies on the dollar for what the numbers say I "could" profit.

That´s a curious perspective that I haven´t measured. I am going all the way now for some 20 s9 after testing profitability for 3 months but I haven´t tried litecoin mining.

Yeah, just run the numbers on the Antminer L3+. Haven't done much research into LTC mining with GPUs and how profitable that would be, but even if you (and should) account for a huge bump in difficulty when those L3+ miners ship out August/September, the profits are mind blowing. Before doing some research on LTC a few weeks ago I was convinced that I'd be going with S9's but no way now, if anything I'll mix some in for diversification. I thought LTC was dead so I didn't even consider it, haha.

lol. just as I assumed :D Thanks for the tip.

On your project if I may give a different point of view, I am planning to open soon in Cadiz. Spain. Hot and rather humid too. My approach is not to avoid and get rid of the heat but to reuse it. I have contacted some research groups in the local university to explore the possiblibilty of using the heat to grow some useful algae, catalize some profitable organic reactions, produce some pressure batteries. I have to check too if this can be applied for some industrial process, in particular membrane water desalination.

I will be happy to share it here if I find something useful or the things I try that fail. by now is merely some exploratory approach.

 One space I was looking at to move my operation into was a smallish warehouse with a garage door on each end (part of a "warehouse/shop" building complex).

 The primary reason I decided against it was that there was no "man door" at all, and my knees don't handle stairs reliably any more - both garage doors were at "pickup/semi trailer" height.

 Airflow would have been trivial to set up though - louvered "inserts" under each door and straight-through airflow.

Ah. Yeah if I go with a warehouse it must have not only the large garage doors but a small standard sized one as well, because I'm trying to come up with a solution to stack fans on top of each other to maximize the space of the door and not just have one row of fans on the floor. I would find a way to chain them all together along with the door to the ground, so you wouldn't be able to get in or out of the large doors for better security. I'm sure there is some industrial fan out there that is meant to be stacked for what I'm looking to do. If anyone has heard of anything like that, post it here!

I'm considering an investment of about the same amount for 20 S9's, though I may also have to look into L3's after reading the last few posts. I'm not particularly experienced, but I've run preliminary numbers on the S9's and they seem like a solid investment as long as they last for longer than a year. Does anyone have any info on their longevity, or is it too early at this point? They've been released for near a year now, so if they're not sturdy enough to consistently hit the break-even point I'd think that should be starting to become clear by now.

I'm not sure about renting a warehouse, it'd be a bit expensive in my area and more of a hassle to operate. Just how hot and noisy are these miners? I'd like to put them in a building separate from the main house on my own property if possible, as that would also let me install solar panels and generate a portion of the electricity for the system as well as generating income from SRECs to offset the remaining electricity cost. I'm in the Northeast, so the climate should be a bit more friendly to this kind of thing, but might need to look into insulating a building for sound if they're extremely noisy. My electric costs are roughly $.09/kWh, but with solar panels I'll be able to yield an extra $200 in SRECs for every 1000 kWh generated that way. At that rate, having air conditioning might be feasible if necessary; noise would definitely still be a consideration though, and in fact even more so. It looks like the S9 runs at about 77 dBa, which would put 20 of them at about 92 dBa. That might not even be legal in a residential area without some serious noise reduction. https://www.youtube.com/watch?v=LvzP4g1bfh0 (https://www.youtube.com/watch?v=LvzP4g1bfh0) seems like it could be a solid strategy, though 20 in that kind of setup might not be possible without expanding the space I was thinking of using. Any thoughts on all this?

9 cents / kwh is going to be VERY marginal on if you will achieve ROI on the S9 - depends on how many of them Bitmain can pump out in the next year coupled with how many competing units the competition can manage to pump out.

 I've never owned a S9, but have been told they're somewhat louder than the S5's I HAVE operated.
 They're NOT quiet.
 With that said, it shouldn't take much baffling to keep the sound getting out enough to bother the neighbors - most of it is fairly high pitched, you're not dealing with a "boom car" deep bass type of sound that's HARD to block out.

 Heat generation is easy to figure - 1000 watts of power used 24/7 is appx 3400 BTU/hour.

 S9's use somewhat more than 1 kilowatt (depends on the specific batch how much more per miner) - 20 of them is going to add up to a LOT of heat.

The numbers I ran didn't account for how much power it would eat up to keep the space quiet and cooled, and I came up with an estimated $90 spent per month per S9 to generate .1 BTC... if I were actually paying for the electricity. Assuming I went fully with air conditioning rather than exhaust cooling, that'd cost another 1 kW/S9/hr and go up to $180 per month per S9 to generate .1 BTC. As you said, fairly marginal but still profitable, unless I'm missing something. The price on bitcoin would have to fall by another 33% for it to be unprofitable. Certainly possible, considering we just saw a 20% drop, but at a profit of only $70 per month per S9 that would still take under 2 years to fully pay for itself. I wouldn't be investing for a little while anyway, which would give me some time to see how the upcoming halving of the reward rate will affect the profitability.

The addition of solar into the equation does help either way, though. My state has net metering laws that restrict interconnection on solar projects exceeding the site's annual needs, which means that the bitcoin mining should enable me to install/interconnect more solar and profit on that as well. If bitcoin mining ends up so difficult that I'll be operating at a loss, I can disconnect the S9's and move to Ethereum or something else profitable, or just generate electricity and sell it back to the grid at wholesale price while earning an extra $200-225 per 1000 kWh on SREC's. Even that is a profitable, though long-term, investment - so the electricity coming at $.09/kWh is more of a worst case scenario. Ideally I'll end up able to pay all the electric costs for this with the solar panels; though 20 miners with air conditioning might be a bit of an overambitious initial investment on solar, I don't have $1.2 million lying around that I'm willing to spend on a 400 kW solar grid. If I go with 5 of the S9's and use cheaper cooling methods, I could bring that down to a 100 kW or lower ground-mounted system and expand it depending on how profitable it is. A 100 kW system would generate $20k a year or so just in SREC's as well as providing electricity for several miners, and should cost $2-3/watt installed worst-case - a 10-15 year ROI if you completely discount the tax credits and electricity generated. If it's unprofitable with Bitcoin, I still have a decent renewable energy setup to turn into some other sort of server farm to rent out for decentralized computing in a setting other than Bitcoin, perhaps another cryptocurrency if they continue to be popular for speculation. Anyway, assuming that the solar will pay for itself and then some over time, the bitcoin mining will then be happening at wholesale electric rates for the most part and only going to $.09/kWh for overages. It seems like that should be enough to turn a tidy profit on the whole operation, better than the stock market and less risky anyway.

This is very nicely described. Indeed the problems you described are very common and I think it is really not a good idea to put all the set up into residence or commercial building. There is safety concern in regard to our mining love as they get heated up quickly and many times fire hazards has been reported with them around the globe. Its better to build your own small shade away from city. This would be good for cooling as the global warming effect is lesser in the area away from city. You can let the noise disappear into empty space around. With open space and no tall buildings around you can set up three to four solar panels to harvest electricity from the solar energy. This will atlas cover the 30-40% of your energy cost. This will give you push factor to gain profits quicker. Nice concept and ideas have been implemented already and you can try searching over the internet for best cost effective project. If sat up properly it is really profitable thing.  :D

That would be really cool to build out a property for mining specifically with ventilation and power in mind, but that's way above and beyond what you would ever do for a $50k investment into mining, no? I also can't imagine they would be much of a fire hazard so long as the proper power supplies are used, proper cables are used, a proper electrician installs everything, and I get a very good system for airflow going. Also now looking at the L3+ rather than the S9 or T9, the profits off a $40k investment aren't looking like $2,200 per month but more like $22,000 per month, even at $0.10c/kWh.

If it sounds too good to be true, it probably is; if it isn't already, it probably will be soon. A 50% ROI per month, to me, certainly sounds too good to be true. Even that potential 5% ROI per month from S9's is exceptional, in terms of real money. Consider what that $22k/month is dependent upon and how much of a possibility there is for those factors to change quickly, because if they can they very likely will.

 Difficulty rise as more S9s (and other units) get sold is what you're missing.

 Most calculators don't even allow you to ESTIMATE that and factor it in - that's why I stick with BitCoinWisdom even though they haven't fully updated it for a while.

 The only serious limit to how fast the difficulty went up for most of the last year is how fast Bitmain could get the chips to make more miners with - but it looks like Bitfury is FINALLY getting into the game on the current node generation, and at least 2 other companies have publically entered the field with their own chip designs (and who knows how many miners BW.COM has been pumping out for their internal usage after they decided to NOT sell their current-node-gen miners to the public after all, along with at least one other large private farm I'm aware of that's working on their own chip for internal use, and what the heck is MegaBigPower AKA GigaWatt planning to fill THEIR new mining halls with?).

 The question isn't "is difficulty going to double", the question is "how long will it take for difficulty to double".


 While "many" and possibly even "most" commercial spaces have 200 amp 220V service in the US, I've been in quite a few that did NOT - retail shops and warehouses in particular are known for sliding by with lower power service since they're intended mostly for storing stuff.

Fair point, they might not even stay profitable for long with grid-provided electricity, depending on how long it takes the technology to become obsolete or commonplace. The price also might continue to rise as the difficulty goes up due to more money being invested in the infrastructure. Bitcoin might be made illegal in more countries as Ethereum continues to attract governments, which could cause a drop in prices due to the currency being less real-world-applicable. I'm not necessarily anticipating that things would stay the same in Bitcoinland for two years, though at this point there's no technology available to surpass the S9 that seems to be coming up on the horizon any time soon from what I've read so there should be some small degree of stability. It seems the price has consistently risen in the past based on difficulty increases, which is only logical; more people trying harder to generate the same limited resource. If the people trying to generate that resource (hypothetically) don't invest more in it, the difficulty shouldn't rise appreciably. Obviously it will continue to unless something happens to stop it, at this point, but the price should rise as well making the mining continue to be at least marginally profitable even with average electricity costs.

That being said, my plan is to install solar power and use renewable energy to power the miners for the vast majority of the time. If there are overages at the end of the annual "true-up" period it would cost $.09/kWh, if I've generated more than they use to run I'd be refunded somewhat less based on wholesale prices. I'll probably aim to have miners using slightly more energy than I generate for that reason, so that I wouldn't have to sell it back at wholesale, but would therefore end up paying $.09/kWh for some of the electric costs. As for the solar power, it'll probably take about 5 years to pay for itself from SREC's and then continue to generate more income on top of the electricity generated, so it's pretty much a no-brainer as long as I have enough investment capital. Clearly this isn't something that would happen with 20 miners for a $50k investment, as GMPoison was originally talking about, so I may be straying off-topic somewhat discussing my own plans; I wanted to discuss the possibilities of doing it entirely with grid-provided electricity as well though. It would be possible, in a state with good solar laws, to do the same on a smaller scale with a $50k initial investment so it's not entirely off-topic, just more limited in size. Either way, it should be able to continue to generate a profit as long as the S9's remain viable technology at all.

Hey, the concept of cryptocurrency to me is too good to be true, so I think anything is possible. When you hear people say that people are becoming millionaires overnight because of bitcoin and crypto, they're not making that stuff up, it's actually happening. In terms of real investments (stocks, real estate) 50% ROI per month obviously is absolutely nuts. Even 5% per month like you said is insane.

If you run the numbers, I figure the worst case scenario is that the difficulty of LTC quadruples when people start firing up their L3+ miners in September and the price remains where it is now without rising at all. Even in that very unlikely scenario a $40k investment into L3+ miners right now would net about $11,000 a month which is still nuts. Now cut that in half in case you think my worst case scenario wasn't worst case enough. Now you're looking at $5500 a month which is 13% ROI per month. Even if the worst of the worst happens (relatively speaking) you're left with 13% per month which is still considered unobtainable in the real world of investing.

Not a single time out of ten would I pass up an opportunity like that.

Maybe you're right and I'm just being overly cycnical. I'm planning to make this a long-term venture rather than just banking on being able to capitalize fully on having better technology for the first few months it's out, though. If the L3+ really perform even close to how you're saying, the pre-order list will probably be very long already and it won't be possible to get one at a good price for several more months, much less 20 to spend $40k on. Bitmain does mining itself as well as selling parts, after all; and even now, trying to order Antminer S9's from Bitmain itself would be a 2-month wait according to their store page. That's with the unit currently in production, having been out for over a year, and with competitors launching soon. If we're just considering the L3+ now, we're probably late to the party, and considering it'll take months to be able to order them anyway I think it's worth waiting to see what sort of results people actually get before putting down a large unrefundable deposit. Personally I'll be moving forward planning on 5-10 S9's and trying to figure out how to get the whole mess powered by solar, if I have enough room for that many panels. The initial investment cost will be higher but once the solar has paid for itself I'll be working with mostly free electricity, giving me a decent competitive advantage on efficiency compared to all except the largest mining firms or other renewable miners. If BTC somehow ends up not reliably returning a profit as time goes on, even as the 16nm barrier remains and S9's stay top-of-the-line, I can cut my losses and sell the miners while still keeping the solar as a framework for some other more-solid decentralized computing work. The solar itself is virtually guaranteed to hit the break-even point after 5 years or so, at least in my state, and after that will continue to generate income for another 10 years as well as free electricity for probably 20+ years more. Even if the S9's only end up producing $100 a month, reflecting the fact that running them at a cost of $90/month would be the new standard, that's still a 1-year ROI on the machines themselves and the rest would be at profit rates nearly as good as what I'm currently earning with my standard investments.

 The problem is that 9 cents / kwh is very iffy for making ROI on - and that solar power investment will probably take longer than you're thinking to recoup it's investment.
 Keep in mind that you are competing with HUGE farms with power costs of under 3 cents/kwh (one specific well-known example, MegaBigPower aka GigaWatt in East Wenatchee, WA) - they're going to be profitable with the S9 for quite a while after the "next gen semi tech" makes it into miners, while you'd be struggling to break even WITH the new tech.

 If you're serious about mining, you move into Cheap Hydropower areas - central Washington state, most or all of Quebec, part or all of Labrador being the "hot spots" in North America due to large hydropower projects that subsidise low local rates through selling off excess production to HIGH cost power areas - though there are a few other places you might get to 5c/kwh on "industrial" scale mining, usually ALSO close to large hydropower projects.

 Funny note - the Grand Coulee Dam output almost all gets shipped quite a long ways from the dam itself, as the "local" county PUDs own their own Columbia River power dams with lots of excess capacity and doesn't NEED power from the Grand Coulee.

 *IF* Bitcoin resumes a price climb, and that price climb stays ahead of or stays very close to network hashrate increases, then you should make good money even with your "high cost by mining standard" power.
 Keep in mind though that sometimes "IF" is the biggest word in the English language.

I'm not actually planning to operate at 9c/kWh personally; that is the price I'd be paying for electricity that *isn't* generated by solar, if extra is needed. I will be competing with huge farms with power costs of under 3 cents/kwh, of course; however, I'm already in a state that is dedicated to increasing the renewable energy share, and through the SREC program my state is basically forcing the utility companies to subsidize private installations of solar energy. I'm planning to take advantage of that to install solar energy at a cost that will be fully amortized over time, though it will require a fairly large initial investment of up to $200k or more. That being said, renewable energy will continue to have applications even if bitcoin mining proves unprofitable with my farm operating entirely self-sufficiently (aside from repair/replacement costs for the S9 units, which are not terribly reliable from what I've read) - decentralized computing isn't going away, I think, and even if there are no profits available in that I could retreat to the safety of running server farms for others. There are several people on here who seem to offer hosting for 3-6c/kWh, and I'm sure there are others out there as well. The internet's a big place.

When I say the solar power will pay for itself within 5 years that is perhaps a bit overly optimistic, you're right about that; I've done some calculations for 20% lower efficiency than rated rather than the 10-25% higher which is apparently the norm for a well-functioning system. Even if it's coming in at 20% under for 80000kWh/year, that's still enough to earn $12-18,000 a year selling SREC's - and that does not actually factor the cost of electricity in, only the credits I'll be able to sell to local utility companies. I do still need to do some research on pricing for ground-mounted systems, though; they might be priced higher than I was thinking, the average I've come up with from browsing NREL files is about $2.30/watt installed for commercial solar projects of 100-200kW with a premium of $.40-50/watt for ground-mounting. I still have yet to ask my solar contractors what their price point would be, since I'm finalizing another contract with them now for a roof-mounted system to provide power to my house. After comparison shopping with 8 other installers in the area, the one I'm going with did eventually come in with a bid using premium equipment at about $.20/watt cheaper than the national average for roof-mounted residential systems, so I may be able to get the ground system for a better price as well. If I pay the price that the NREL files estimate, I'd be paying $280k for a 100kW system and then receiving a federal tax credit of nearly $100k, so I could be almost presidential and dodge my taxes for the next 30 years - the remaining $190k or so would be amortized over 13-15 years at worst, based solely on selling energy credits and leaving me with 1,200,000 kWh produced over those 15 years. Even if I couldn't find anything to do with all that energy, I would be able to sell it back to the utility companies at wholesale rate due to my state's favorable net metering laws. If all these worst-case scenarios come to pass, I'll still end up with a large solar installation and about a $40k profit from selling energy at wholesale costs. That also assumes that bitcoin mining, other cryptocurrency mining, and all decentralized computing ends up being a total bust even at those wholesale electricity rates and that I'm therefore better selling the energy for wholesale rates rather than using it - which seems like worse than a worst-case scenario, really. In that case, I'll *still* make a profit, just at an opportunity cost of not being able to pursue other profits. Find me an investment that doesn't have potential opportunity costs, though. :P

*n.b. Most solar panels are actually warranted to produce at a minimum of 82% efficiency for 25 years, so the assumption that they'll operate at 80% efficiency is again worse than a worst-case scenario, unless we're getting truly fanciful and assuming that my contractors, the solar panel manufacturers, the inverter manufacturers, and the warranty insurers all go out of business at the same time my system fails and that I can't find anyone to repair them at semi-reasonable costs. If that's all the case, I think we should also assume that hydroelectric production will be interrupted because all the water has dried up due to global warming; and that world governments have descended into anarchy due to rising civil unrest, overpopulation, limited food and water supplies, and the disruption caused by the Martian war against the Illuminati, the Bilderbergers and the lizard people.

I am in a very similar boat here in Central Florida. I am no HVAC expert but was wording if the following would be possible……take a portion of my existing warehouse and build two small insulated rooms divided by Server Racks. Then use an evaporative cooler set up in a closed loop configuration, similar to the attached diagram. The humidity output by the miners should be low enough for the evaporative cooler to work properly. The server racks would pull cooler air from the room with the evaporative cooler and push the exhaust to the other room. There would then be a duct that connects the two rooms together to feed the evaporative cooler.

Am I totally crazy or would something like this actually work?

https://image.ibb.co/merfiG/diagram.png

I forgot about this thread haha, I just recently got my mining operation up and running and it's coming along well! I'll post a photo of my mining operation here for anyone else curious, but I'll link the main thread below where you'll find the rest of them. Funny that you're in central Florida, what is probably only a few hours from me. Message me if you have any questions or just want to chat!

https://bitcointalk.org/index.php?topic=2359425.0

https://i.imgur.com/y2i71XH.jpg

 The Evap(s) should be placed at the input of the "duct", but otherwise that's somewhat similar to my current setup where I am at now.
 I'm doubtful it would work AS WELL as where I'm at, as the air around here tends to be very dry - but it should help some.
 DEFINITELY invest in a humidity meter to keep an eye on the RH at the intake of your miners when you try it out - I rarely see anything over 40% RH (and it has to be actively RAINING outside to get close to 50) but the humidity in my area tends to be very low.

 I don't bother with the "duct" as such - I put my evaps in the "hot output air" area and the output of them pointing at my air intake area.

 I currently have 2 Brisa "window" type units (BW3004 units IIRC, both bought during "end of season" sales from the local Ace Hardware) stacked on top of each other with some boards for spacing, and enough space that I can add a 3'd one on top if I need it in the future.