Thanks for the info, that does make sense!  That's where I was headed just hoping for confirmation.

Hello,

I know in general we want to control the humidity levels for ASICS to a reasonable level, but I was curious what your experience has been if you're working with miners in un-airconditioned spaces.

In the climate I'm in (U.S. Desert Southwest), I can control the temperature pretty well with evaporative cooling because the weather is so dry.  In the early summer, the humidity might only be 15% outside, so cooling with evap will lower temps by 20 degrees or so, and will raise humidity up to about 40-50% which should actually be healthier for the miners.   In the late summer this gets worse, with a chance for humidity to reach 60 - 70% if I cool the miners down to a level that is suitable for running.

If there is no condensation risk due to the heat, and the humidity is still below the mfg's specs (90% for S9), do you see any risk in this or am I tempting fate?

The other option is powering down for the worst days of the year and accepting a $0.00 profit those days (Actually negative because of rent / depretiation etc.).  That still seems cheaper than buying enough A/C to cover any sizable install of S9's.

Is anyone using AC to cool ambient from maybe 110 down to 85 or so and then exhausting the airflow outside?  When I look at CFMs needed from the AC to keep each miner exhausting ~200cfm, the AC winds up having about 2x's the tonnage than would be expected based on the heat load of the actual miners.

thanks for any insights

Circuits are rated for a given amperage (20A for example) but are not intended to run at that amperage continuously.

When you are sizing circuits for server rooms for example, there is an expected overhead of 20% for each circuit if you will be running the loads 24x7 (like a miner).  This is to help compensate for the heat buildup that would occur in the wire if it was used at full capacity for an extended period.

As was stated above, you should assume a max sustained load of 16A if your usable ceiling.

A managed PDU (fancy power strip) can have temperature and humidity sensors as well as providing access to switching off individual plugs to cycle the miner.

You can write a small script to read these values out of SNMP and take the appropriate action if you choose, or you may find the software that the PDU comes with has a similar function.

If you have 3 rows of rack space, you could fit a ton of S9 style miners in there.   How many are you hoping to run? 

I'm going to guess you'll run out of power or HVAC way before you need that space unless you're in a larger industrial building.

You need to calc up the CFM needed for all of the miners you're planning to run, estimate the size of the exhaust and supply fans you'll need.   If Im on the right track, you might find it easier to concentrate the miners a bit more and have just one or two racks with the hot side facing your planned exhaust fan.  That will shorten your duct runs and straighten them out.  (All those kinks / turns in the duct put a strain on your fans / exhaust).

For an example only.   if you had 10 S9's @ ~200 CFM you would need 2000 CFM of supply and at least that much in exhaust in a perfect system with no loss to air leaks or bad bends in your duct work.    That same setup will need 60 - 70 Amps of 220v service minimum.

Hey,

I put this simple powershell script together to aid in checking on the status of miners.   Its nothing fancy, but I wanted to play with PS and JSON a bit and this gave me an excuse to do it.    Feel free to use / change it to your hearts desire.   

I understand a lot of guys on this board can make this on their own very easily (and probably better!). For those of you that can't, here's a head-start you can use to build a monitoring script of your own.

Copy the text below into a text file with a 'ps1' file extension.    You may have to either digitally sign the script or disable signature checking to run it.
 Disabling Signing - https://technet.microsoft.com/en-us/library/ee176961.aspx
 Self-signing (Optional) - https://community.spiceworks.com/how_to/122368-signing-a-powershell-script-with-a-self-signed-certificate

Launch from the command prompt    ./[scriptname].ps1  BTCAddress
i.e.
'./CheckNiceHash.ps1 1JZRzjuf1rw9g3i9pFhLZKrMdQ7CzbBjLZ'


Theres obviously nothing malicious in the code - feel free to read through it - its too simple to be dangerous! 


#Leverages NiceHash API to display the current mining stats for a given BTC address.  Only shows active Algos or pending balance.
#
#This was written as a simple test to learn a bit about leveraging JSON, and learning a tiny bit of PowerShell.   
#Most of this code is rough and can be cleaned up quite a bit, but it is functional and can be used to build some
#simple monitoring scripts for your own purposes.
#
#Provided for public use, no charge or credit needed.
#BTC Donations: 1JZRzjuf1rw9g3i9pFhLZKrMdQ7CzbBjLZ


function CheckMiner ([string]$addr)

{
    $Request = "https://www.nicehash.com/api?method=stats.provider&addr=" + $addr
    $Result = Invoke-RestMethod -Uri $Request -Method Get
    $Rig = $Result.result.stats
    return $Rig
}
   
function PadTotal ([string]$Total)
{

    [int]$TotalLen = $Total.Length
    [int]$MissingChar = 12 - $TotalLen
   if ($MissingChar -eq 11){
        $Total = "0.00000000"
        $MissingChar = 0
    }

    Do {
        #Write-host "made it!"
        $Total = $Total +  "0"
        $MissingChar = $MissingChar-1
        } While ($MissingChar -gt 0 )
return $Total

}

#build an array with all of the descriptive names of the Algos that NH will report back with
$Algos = "Scrypt     ","SHA256     ","ScryptNf   ","X11        ","X13        ","Keccak     ","X15        ","Nist5      ","NeoScrtpt  ","Lyra2RE    ","Whirlpoolx ","Qubit      ","Quark      ","Axiom      ","Lyra2REv2  ","ScryptJaneNf16","Blake256r8","Blake256r14","Blake256r8vnl","Hodl       ","DaggerHash ","Decred     "
#pass the BTC address at the command line
$BTCAddress = $args

#get the stats from the API
$minerStats = CheckMiner ($BTCAddress)

[float]$TotalHash = 0
[float]$TotalRej = 0
[float]$TotalBal = 0

cls
$Now = Get-Date
Write-host $Now "Stats for " $BTCAddress

write-host "Algo             Speed (GH/S)    Rejected (GH/S)    Balance     "
write-host  "--------------------------------------------------------------"
ForEach ($Algo in $minerStats) {
    $AlgoSpeed = $Algo.accepted_speed
    $AlgoBal = $Algo.balance
    $AlgoRej = $Algo.rejected_speed

    if($AlgoBal -ne "0.00000000")
        {
        $TotalHash = $TotalHash + $AlgoSpeed
        $TotalRej = $TotalRej + $AlgoRej
        $TotalBal = $TotalBal + $AlgoBal
        $AlgoName = $Algos[$Algo.algo]
   
        write-host  $AlgoName "    " $AlgoSpeed "      " $AlgoRej "         " $AlgoBal
        }
       
}

#add white space to the vars so they print to the screen a little better (Im sure there is a better way to do this!)
$TotalHash2 = PadTotal($TotalHash)
$TotalRej2 = PadTotal($TotalRej)
$TotalBal2 = PadTotal($TotalBal)

write-host "Total Speed:    " $TotalHash2 "    " $TotalRej2 "       " $TotalBal2