Bitcoin Forum

Bitcoin => Hardware => Topic started by: Adrianrff on August 23, 2017, 06:38:26 PM



Title: Avalon 741 fan max CFM's info and advice on how to properly ventilate a rig.
Post by: Adrianrff on August 23, 2017, 06:38:26 PM
Hi, folks.

My brother asked me to help him set up a room for his mining rig. He has several Avalon 741 miners and I want to compute out how much fresh air I need to inject to the room. It's a small, enclosed room.

What I'm planning to do is use the maximum air flow that the fan of a single machine can handle and the number of machines to select an appropriate fan and size the ducts. I know my way around ventilation, but I have zero experience on setting up mining rigs, so aside from getting the air flow specs of this particular machine (which I can't find online and I don't have access to the miners at the moment), I could use some advice in this regard. Am I going about doing this the right way? Is there something else to consider?

This is more or less what I'm planning to do:

https://s4.postimg.org/e0mc4rgyl/Captura.png
https://s4.postimg.org/sxut5ru71/Planta.png

Any advice/input will be much appreciated.

EDIT: My brother also has a couple of 18.000 BTU/h HVAC (we live in a tropical country, and temperatures range from 27 to 30ºC) but I think that the heat load of the rig is much, much larger than the HVAC units capacity, so I'm not really sure how much of a difference it would make.



Title: Re: Avalon 741 fan max CFM's info and advice on how to properly ventilate a rig.
Post by: philipma1957 on August 23, 2017, 07:23:39 PM
Hi, folks.

My brother asked me to help him set up a room for his mining rig. He has several Avalon 741 miners and I want to compute out how much fresh air I need to inject to the room. It's a small, enclosed room.

What I'm planning to do is use the maximum air flow that the fan of a single machine can handle and the number of machines to select an appropriate fan and size the ducts. I know my way around ventilation, but I have zero experience on setting up mining rigs, so aside from getting the air flow specs of this particular machine (which I can't find online and I don't have access to the miners at the moment), I could use some advice in this regard. Am I going about doing this the right way? Is there something else to consider?

This is more or less what I'm planning to do:

https://s4.postimg.org/e0mc4rgyl/Captura.png
https://s4.postimg.org/sxut5ru71/Planta.png

Any advice/input will be much appreciated.

EDIT: My brother also has a couple of 18.000 BTU/h HVAC (we live in a tropical country, and temperatures range from 27 to 30ºC) but I think that the heat load of the rig is much, much larger than the HVAC units capacity, so I'm not really sure how much of a difference it would make.



exhaust is the key.

1 machine = 1x  200cfm fan  and about 1200 watts which is about 4100 btu

6 machine = 1200 cfm and about 7200 watts which is about 25000 btu.

if you feed in 2000 cfm of air  but only some from the ac unit  and suck out 2400 cfm

with  only some ac in you will be fine.

I would blend in some a/c enough to drop the intake air  to 28c  at a 2000 cfm  rate  with exhaust at 2400 cfm



Title: Re: Avalon 741 fan max CFM's info and advice on how to properly ventilate a rig.
Post by: Adrianrff on August 23, 2017, 08:09:01 PM
Thank you, @philipma1957.

My brother tells me to plan for a maximum of 50 machines. So that'd be at least 50*200 = 10,000 CFM of air to inject, correct?

I'm concerned about the required size of the ducts and the available space. If I follow industrial recommendations of air velocity in ducts, I'd have to select a duct with around 40 inch diameter (a little over 1 meter) to keep the air velocity below 1500 ft./m at 10,000 CFM. The corridor is 1.10m wide and the ceiling is a little over 2 meters. So it seems impossible to place such a large duct. The space is just not enough.

Also, the enclosed space for exhaust is also very small (racks are ~1 meter apart). I'd have to use fan to force extraction.

This doesn't seem viable at all.


Title: Re: Avalon 741 fan max CFM's info and advice on how to properly ventilate a rig.
Post by: NotFuzzyWarm on August 24, 2017, 12:56:53 AM
Some juicy pics of what the GreatNorthData mine has setup... BuildingCanada's largest bitmine (https://bitcointalk.org/index.php?topic=1512967.msg16936801#msg16936801)