Power/airflow for a dedicated rig room

[miner417]

I have some questions about airflow and power for a dedicated rig room.

I have a small room, about 3.5x5x8 Ft that I'm converting into a dedicated mining room. It has 2 windows for intake/exhaust, and I can run power however I need to.

From testing my rigs, each rig pulls about 8 amps, so for safety sake, say 10 Amps per rig. I was wondering why people use 220volt lines for their rigs, how it helps.

Currently I only have 20 or 30 amp breakers on a 120volt line, I can do whatever is needed to run it most efficiently, I just don't know what is the best to do.

As for air, just having 1 window be an intake with a fan, and 1 window with an exhaust fan. With only having 5 rigs, will that be sufficient?

[Samos95]

Two reasons for 220v:

1. Efficiency. Most PSUs operate around 2% more efficient when on 220v vs 110v.

2. If your rig draws 8 amps, its drawing that at 110v. Volts * Amps = Watts, so at 220v it will only draw 4 amps. Power cost is the same, but you can run more rigs per circuit this way, as the amps drawn is lower.

For airflow, one in and one out is the best way to exhaust heat, but how much air you're actually moving and intake temperatures matter as well. Unless you just have a single desk fan and are pulling in air from the surface of the sun, you're probably ok, though.

[felixbrucker]

Unless you just have a single desk fan and are pulling in air from the surface of the sun, you're probably ok, though.

welcome to my life

i use 220V as i live in europe and in a single small room (about 15m^2) with only one window i can operate multiple rigs for a total power draw of about 3.4kW while having just the window open about 50-60cm (its dimensions are rather large: 130cm x 130cm).
Of course this doesn't work in the summer, but with outside temps below 22°C it works fairly good.

I tested with a regular fan installed in the open window (no insulation or other stuff) and it didnt help that much, but a properly installed intake and outtake fan with insulation and pipes and stuff should help quite a bit.

[alucard20724]

It has 2 windows for intake/exhaust, and

exhaust during summer time, and intake during winter time... but to work that method most efficiently, you need direct airflow to/from window.  

I normally buy the reference cards so i can direct the airflow. it's worked pretty well for the last few years.  Everyone hates on the reference blowers, but they work perfectly for me.

[miner417]

Two reasons for 220v:

1. Efficiency. Most PSUs operate around 2% more efficient when on 220v vs 110v.

2. If your rig draws 8 amps, its drawing that at 110v. Volts * Amps = Watts, so at 220v it will only draw 4 amps. Power cost is the same, but you can run more rigs per circuit this way, as the amps drawn is lower.

For airflow, one in and one out is the best way to exhaust heat, but how much air you're actually moving and intake temperatures matter as well. Unless you just have a single desk fan and are pulling in air from the surface of the sun, you're probably ok, though.

So 220v is probably the better way to go. Aren't the receptacle outlets different for 220v though? Do I need anything else special? I have an electrician friend who can do the actual wiring, but everything I need for the rigs to run is on me.

For airflow, it's going to be rough since we're going into the summer months here. Both windows are rather large, I don't have the exact measurements, but I can definitely fit more than 1 fan in each if needed. In the summer months should I pretty much just do all exhaust?

[Samos95]

Two reasons for 220v:

1. Efficiency. Most PSUs operate around 2% more efficient when on 220v vs 110v.

2. If your rig draws 8 amps, its drawing that at 110v. Volts * Amps = Watts, so at 220v it will only draw 4 amps. Power cost is the same, but you can run more rigs per circuit this way, as the amps drawn is lower.

For airflow, one in and one out is the best way to exhaust heat, but how much air you're actually moving and intake temperatures matter as well. Unless you just have a single desk fan and are pulling in air from the surface of the sun, you're probably ok, though.

So 220v is probably the better way to go. Aren't the receptacle outlets different for 220v though? Do I need anything else special? I have an electrician friend who can do the actual wiring, but everything I need for the rigs to run is on me.

For airflow, it's going to be rough since we're going into the summer months here. Both windows are rather large, I don't have the exact measurements, but I can definitely fit more than 1 fan in each if needed. In the summer months should I pretty much just do all exhaust?

Typically anything on 220v will also be high-amp, which requires a special outlet. I use L6-30P receptacles paired with a metered PDU with the same plug (the model number escapes me). That outlet is used with 30A, which at 220v gives you ~5.2kW to safely use (80% capacity). There isn't really any one-size fits all electrical setup when it comes to mining. Most cheap PDUs I've found use L6-30P though, so that's what I would stick with.

Airflow is airflow, the more the better. Summer/winter won't change the airflow, only the intake temperature. The only reason to only exhaust in the summer is if it gives you better airflow/temperatures, but that's something that you will really just have to experiment with.

[hinvestmentgroup]

To piggy back on the 220v questions. 

I had a new outlet installed when I purchased by L3+/APW3+ and figured out it wouldn't run on a standard 110v outlet.  The electrician said it was a 240v outlet, though I always hear 110v or 220v, so not sure where the discrepancy comes in?  I'm sure it's just a gap in my understanding.  In any case, the new outlet is on a pair of 20 amp breakers in the panel.

My real question though is if I can run another miner off this circuit?  Above it was described that the posters miners are likely running 4 amps on a 220 line, not sure how that fits in with "that outlet is used with 30A"?  If I could run more miners on this circuit, what would I need to do?

Sorry to piggy back on the discussion, but seemed like it may be interesting info for the original poster as well.

[philipma1957]

To piggy back on the 220v questions.  

I had a new outlet installed when I purchased by L3+/APW3+ and figured out it wouldn't run on a standard 110v outlet.  The electrician said it was a 240v outlet, though I always hear 110v or 220v, so not sure where the discrepancy comes in?  I'm sure it's just a gap in my understanding.  In any case, the new outlet is on a pair of 20 amp breakers in the panel.

My real question though is if I can run another miner off this circuit?  Above it was described that the posters miners are likely running 4 amps on a 220 line, not sure how that fits in with "that outlet is used with 30A"?  If I could run more miners on this circuit, what would I need to do?

Sorry to piggy back on the discussion, but seemed like it may be interesting info for the original poster as well.

220 = 240  no worries


a 30 amp 240 volt outlet  can do 20-24 amps   safely

http://www.ebay.com/itm/122648-001-Compaq-220-240V-Power-Distribution-Unit-High-Voltage-PDU-NA-only/272357256873?


this  would allow you  to run multiple machines

and power cables 14 gauge

http://www.ebay.com/itm/Lot5x-pcs-6ft-Male-Female-PDU-Power-Extension-Cord-Cable-IEC-C13-C14-14awg-15A-/292113962521?hash=item4403595619

[gwestcot]

As far as cooling you can do it with ambient temperature and fans but I have elected to get a portable air conditioner to help cool the room. The model below is the one that I decided to go with when I only had 20 gpus running in 3 rigs. Just an FYI 3517 BTU's is needed to cool 1000 kwh so it doesn't really keep up with my 32 card setup anymore but it could easily do 24-26 GPU's or so. I pay an additional 80 dollars a month in electricity but even with my cards being overclocked like crazy they don't run any hotter than may 62 degrees Celsius or so with the air temperature being anywhere from 81-87 F depending on the weather and the time of day.

https://www.amazon.com/gp/product/B003PCSR82/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

[spiz0r]

As far as cooling you can do it with ambient temperature and fans but I have elected to get a portable air conditioner to help cool the room. The model below is the one that I decided to go with when I only had 20 gpus running in 3 rigs. Just an FYI 3517 BTU's is needed to cool 1000 kwh so it doesn't really keep up with my 32 card setup anymore but it could easily do 24-26 GPU's or so. I pay an additional 80 dollars a month in electricity but even with my cards being overclocked like crazy they don't run any hotter than may 62 degrees Celsius or so with the air temperature being anywhere from 81-87 F depending on the weather and the time of day.

https://www.amazon.com/gp/product/B003PCSR82/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

Thanks for the info, it is really useful. I think you had a typo, it's 1 kWh not 1000 kWh, right?
I also plan to get some air conditioning for the summer, so I can calculate the exact BTU.

[gwestcot]

ya its 1 kwh... I was quick with writing the post. 

[miner417]

So I the room I have is roughly 4x5x8, so 160 Cubic feet. What sort of fans should I look for for air flow? Right now I have 2 rigs in it, the entire room is pulling about 2KW after the switch/current fans are taken into account as well. I have a huge intake right now, but no fan on it, and I know thats an issue. I have a couple small furnace exhaust fans that I had leftover from another project that are exhausting the air.

The intake hole is on the bottom right of the 4 ft wall, and 2 exhausts are on the opposite 4 ft up near the ceiling, and 1 exhaust on the wall with the intake, above it.

So

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The vertical walls are the 4 Ft, the horizontal the 5. I have 2 exhausts on the left 4 foot near the top, the intake on the right 4 foot on the bottom, with an exhaust near the ceiling.

I plan on expanding this room to 2 more rigs soon, so probably something just under 4KW after I do that.

Ambient temps will probably get to be 90's during the summer, hottest time around 4-5 PM when the sun is hitting this room directly.