L3+ heat question

Discuss issues with mining rigs and connectivity issues with experienced Prohashing miners.
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CSZiggy
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Re: L3+ heat question

Post by CSZiggy » Fri May 11, 2018 6:15 pm

No I said exactly what I meant.

"Even when the chip or board temps are above 90F?" and "Im not seeing how 90'F air can be pulled across 170'F chips and make them go under 90'F".

The warning temp is 80'C for the cutoffs on the bitmains which is what I thought we were talking about, sorry if I misunderstood.
80'C is 176'F, so if the ambient is 90'F I'm not seeing how any amount of air no matter how fast its pulled is going to cool 170'F chips down UNDER 90'F.

How I am reading that is somehow the movement of the air is effecting the temperature of the air being moved over the components.
I agree you can remove the hot air with cooler air than is in place currently, I disagree no matter how fast it moves it can cool it down under the temp of the air you are starting with. You would need to precool or air condition the air to cool it, a fan does not change the temperature it just moves air.

If you have a fan running in a room that is set to blow on you and you leave, the fan serves no purpose, it doesn't cool the room, only you and only when you are there to get the breeze. So if you are starting with 90'F ambient air, I dont see how you can cool the miner rig down under that 90'F minimum.
GregoryGHarding
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Re: L3+ heat question

Post by GregoryGHarding » Fri May 11, 2018 8:34 pm

CSZiggy wrote:No I said exactly what I meant.

"Even when the chip or board temps are above 90F?" and "Im not seeing how 90'F air can be pulled across 170'F chips and make them go under 90'F".

The warning temp is 80'C for the cutoffs on the bitmains which is what I thought we were talking about, sorry if I misunderstood.
80'C is 176'F, so if the ambient is 90'F I'm not seeing how any amount of air no matter how fast its pulled is going to cool 170'F chips down UNDER 90'F.

How I am reading that is somehow the movement of the air is effecting the temperature of the air being moved over the components.
I agree you can remove the hot air with cooler air than is in place currently, I disagree no matter how fast it moves it can cool it down under the temp of the air you are starting with. You would need to precool or air condition the air to cool it, a fan does not change the temperature it just moves air.

If you have a fan running in a room that is set to blow on you and you leave, the fan serves no purpose, it doesn't cool the room, only you and only when you are there to get the breeze. So if you are starting with 90'F ambient air, I dont see how you can cool the miner rig down under that 90'F minimum.
youre opening a physics can of worms, if youre not verse in thremodynamics i can see why youd disagree

theoretically, if the room temp is 90F, and the miner is 90F, due to convection, the moving air has the ability to cool the miner BELOW 90F because of the fuild surface area is increased with air movment thus causing heat transfer from high temp to Low temp of the cooling effect of the moving air. the stagnant air around the heatsinks actually increase the temp

edit
i guess i should also mention the heatsinks, they are designed to pull heat away from an item, if the temp of the headsink is 90F the item its connected to will be colder due to the transfer of heat energy, and subsiquent disapation of that heat energy with 90F airflow

excuse the spelling, new keyboard

this is going way off the OP topic
Darzl
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Joined: Fri Mar 02, 2018 1:22 am

Re: L3+ heat question

Post by Darzl » Sat May 12, 2018 4:36 am

I was messing about testing and oil cooled system and when I put my l3+ back together I put the fans blowing the wrong way and the temps were nearly 20°c lower so I have switched my other L3+ and they had the same effect. Nearly 3 weeks and no issues.
Foxx
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Re: L3+ heat question

Post by Foxx » Sat May 12, 2018 8:09 am

CSZiggy wrote:No I said exactly what I meant.

"Even when the chip or board temps are above 90F?" and "Im not seeing how 90'F air can be pulled across 170'F chips and make them go under 90'F".

The warning temp is 80'C for the cutoffs on the bitmains which is what I thought we were talking about, sorry if I misunderstood.
80'C is 176'F, so if the ambient is 90'F I'm not seeing how any amount of air no matter how fast its pulled is going to cool 170'F chips down UNDER 90'F.

How I am reading that is somehow the movement of the air is effecting the temperature of the air being moved over the components.
I agree you can remove the hot air with cooler air than is in place currently, I disagree no matter how fast it moves it can cool it down under the temp of the air you are starting with. You would need to precool or air condition the air to cool it, a fan does not change the temperature it just moves air.

If you have a fan running in a room that is set to blow on you and you leave, the fan serves no purpose, it doesn't cool the room, only you and only when you are there to get the breeze. So if you are starting with 90'F ambient air, I dont see how you can cool the miner rig down under that 90'F minimum.
okay. well, i guess i don't understand your thought process then if you meant what you said.

"Even when the chip or board temps are above 90F?" your board and chip temps are always above 90F even when they are running cool.

"Im not seeing how 90'F air can be pulled across 170'F chips and make them go under 90'F". ummm... i don't think even if you pulled 0F air over 170F chips that you could get them under 90F.

the warning cutoffs are different for type of ASICs . the first S9s came with an option to shut them down when the chip temp reached 80 degrees Celsius. that is no longer the case with the S9's you can comfortably run them into the 90 degree Celsius area with no problems, though i would not want them to run there for long. L3s... you can comfortably run them into the 70 degree range much huger than that and i would become concerned. the D3s are junk so.... don't really know about their other machines.

ask yourself why then when the fans on the machiunes ramp up to a greater rpm, why do the machines cool down with the same ambient temp.
GregoryGHarding
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Re: L3+ heat question

Post by GregoryGHarding » Sat May 12, 2018 10:26 am

Foxx wrote:
CSZiggy wrote:No I said exactly what I meant.

"Even when the chip or board temps are above 90F?" and "Im not seeing how 90'F air can be pulled across 170'F chips and make them go under 90'F".

The warning temp is 80'C for the cutoffs on the bitmains which is what I thought we were talking about, sorry if I misunderstood.
80'C is 176'F, so if the ambient is 90'F I'm not seeing how any amount of air no matter how fast its pulled is going to cool 170'F chips down UNDER 90'F.

How I am reading that is somehow the movement of the air is effecting the temperature of the air being moved over the components.
I agree you can remove the hot air with cooler air than is in place currently, I disagree no matter how fast it moves it can cool it down under the temp of the air you are starting with. You would need to precool or air condition the air to cool it, a fan does not change the temperature it just moves air.

If you have a fan running in a room that is set to blow on you and you leave, the fan serves no purpose, it doesn't cool the room, only you and only when you are there to get the breeze. So if you are starting with 90'F ambient air, I dont see how you can cool the miner rig down under that 90'F minimum.
okay. well, i guess i don't understand your thought process then if you meant what you said.

"Even when the chip or board temps are above 90F?" your board and chip temps are always above 90F even when they are running cool.

"Im not seeing how 90'F air can be pulled across 170'F chips and make them go under 90'F". ummm... i don't think even if you pulled 0F air over 170F chips that you could get them under 90F.

the warning cutoffs are different for type of ASICs . the first S9s came with an option to shut them down when the chip temp reached 80 degrees Celsius. that is no longer the case with the S9's you can comfortably run them into the 90 degree Celsius area with no problems, though i would not want them to run there for long. L3s... you can comfortably run them into the 70 degree range much huger than that and i would become concerned. the D3s are junk so.... don't really know about their other machines.

ask yourself why then when the fans on the machiunes ramp up to a greater rpm, why do the machines cool down with the same ambient temp.
the numbers were arbitarary, but to prove a point, use more realistic cnumber and it will make sense
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CSZiggy
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Re: L3+ heat question

Post by CSZiggy » Sat May 12, 2018 12:01 pm

OK Ill use more real numbers.
My L3+ is running 55'C. That's 131'F.

Greg stated I could pull 90'F air over the 131'F chips and cool them under 90'F
I have an issue with that statement. That is all.

I do not think you can pull 90'F air over 131'F chips and EVER get them to go UNDER the starting 90'F ambient air you stated with.
Somehow, its being said, that when the 90'F air takes on some of the heat of the 131'F chips, that either the chips or the air somehow cools itself UNDER 90'F.

I'm not seeing it, when two temperatures equalize in the middle, how does either of them become colder then when they started.
Is air exothermic? Does it give off heat as it cools or something I'm missing? There are no pressure valves, so this isn't a pressurized vessel where changing the pressure would change the temp, so again....
GregoryGHarding wrote:even 90dF air moving over the chips will cool below 90F

Fluid and thermo Dynamics

And as FOXX said..... ummm... i don't think even if you pulled 0F air over 170F chips that you could get them under 90F.
And I agree, but according to Greg, 90'F air being pulled will lower it under 90'F.
egik
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Joined: Mon Jan 29, 2018 7:04 pm

Re: L3+ heat question

Post by egik » Sun May 13, 2018 2:28 pm

According to Bitmain operating temperature of L3+ anminer is from 0C- 40C. That's from 32F-104F. That's the temperature next to the miner in the room.
I think it's for all Bitmain Antminers.
ryguy
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Joined: Sun Apr 01, 2018 10:20 am

Re: L3+ heat question

Post by ryguy » Mon May 14, 2018 12:03 am

CSZiggy wrote:
Greg stated I could pull 90'F air over the 131'F chips and cool them under 90'F
I have an issue with that statement. That is all.
You should have an issue with that statement. It would imply that blowing air that is the same temperature as a surface over that surface would produce a heat engine.
alim
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Joined: Fri Apr 06, 2018 3:08 pm

Re: L3+ heat question

Post by alim » Mon May 14, 2018 10:05 am

If you tick the box to turn the miner off if the temperature hits 80C, you will never have to worry about this..
cc4506
Posts: 43
Joined: Wed Mar 28, 2018 10:07 am

Re: L3+ heat question

Post by cc4506 » Mon May 14, 2018 10:55 am

Yes I have all my miners set to shut off if they get to hot but I prefer not to push them that far. Maybe it doesn't hurt them but I just have to much invested in them since I bought them way before they came down to 700.00 each...
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