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Although initially only the fan grates seem to rust, eventually the controller board rusts dead as well. What are some effective ways to slow or stop the S9 from rusting?

https://i.stack.imgur.com/Rrzge.jpg

You have too much moisture in your environment..

Put a dehumidifier in the environment - keep the humidity down.

I think there might be too much airflow to use traditional dehumidifiers. Even a large-scale dehumidifer like the dd1200 processes less than 1000 CFM. Compare that to a single antminer s9, which moves at least 100 CFM.

Would a ratio of, say, 1000 CFM dehumidified air + 9000 CFM ambient air be enough to have a noticeable difference on 100 miners? Or is there some easy solution to this problem that I am missing?

I don't know what your set up is. If you feel a dehumidifier can't keep up have you thought about placing a dessicant inline with your air intake?

I've never had to set anything up like this myself but it's what is used in boilers to prevent moisture.

What ever it is that you use if you have a hot side to your setup you can use the exhaust air to regenerate your dessicant.

http://www.canadiantire.ca/en/pdp/concrobium-moisture-grabbers-3-pk-1530256p.1530256.html?gclid=Cj0KCQjw4_zVBRDVARIsAFNI9eBrPqWHmt4BOKFkai-Gmu5aAeBCSBvS7bndYsS-GzkufMygIgKW9uIaAujhEALw_wcB&gclsrc=aw.ds&dclid=COuO8rKUmNoCFcVGXgod3T4EHw#store=286 (http://www.canadiantire.ca/en/pdp/concrobium-moisture-grabbers-3-pk-1530256p.1530256.html?gclid=Cj0KCQjw4_zVBRDVARIsAFNI9eBrPqWHmt4BOKFkai-Gmu5aAeBCSBvS7bndYsS-GzkufMygIgKW9uIaAujhEALw_wcB&gclsrc=aw.ds&dclid=COuO8rKUmNoCFcVGXgod3T4EHw#store=286)

I really appreciate this suggestion, but I don't understand where exactly you're thinking the dessicant would be within the intake process? The cooling process is passive, with ambient air entering a colder side, where it is run through the miners and exhausted again. The airflow is much too great to not have the dessicant inline somewhere, but it doesn't seem practical to have it right in front of the miners' intake fans. Perhaps lining the walls with dessicant breathers/filters is the best solution.

Well, it's hard to give a solid answer without much info. What are the details of your setup?

Yeah, you definitely don't want them near the intake for the miner itself.

What I'm suggesting is where the intake air for your mining room is should have the desiccant located there. This way as the air enters the room the moisture is removed. You could have a wire rack at the air intake with these packets hanging off it. Again I don't know what you have for a set up but this would cut down on the moisture in your air enough that it should no longer be a problem for your miners.

good luck

Thanks for the suggestions so far, I should have clarified a bit more at the beginning. Local ambient air enters through approx area 300 m^2 and is exhausted at a rate of ~1k m^3/s.

Probably the easiest solution, how often to change the desiccant though?

It's hard to gauge how often you will need to change it out. It might be worth having a dehumidifier, or at least a sensor monitoring the humidity in the room to give you an indication of when the desiccant has stopped doing it's job.

It will also help with the moisture that isn't being absorbed. Then like I said you should be able to place the desiccant on the hot side in the path of the airflow and the warm air should remove the moisture and exhaust with the hot air. This is the process of regenerating your desiccant. You would pretty much just repeat this process as often as is required.

Like I said I've never personally set this up but I think it would benefit you and your machines, hopefully it works out well for you.


If you don't mind me asking are you near the coast in BC is that where the problem is coming from ?

Now I understand what you mean about regenerating the desiccant. Together with a humidity sensor, hopefully the rust problem can be addressed. Thanks!

And yes, these machines are only 5-10 km from shore.

Saltwater has a strong effect in corroding metals.

Unfortunately so. At this rate, it is just a matter of time before more controller boards rust dead. Do you think bitmain would still cover repairs under warranty if there are obvious signs of rusting?

I think they might noticy if those signs are obvious.

You really need to try to fix that environment or move your miners to another location.  :-\

I'm gonna say they'll take a hard pass. The likely response would be something along the lines of moisture/environment as opposed to their hardware.

There are places that I think do out of warranty repair but it's at your own expense.

https://shop.bitmain.com/workOrderGuide.htm

#4 on the list is the out of warranty repair in the US. I've never used them so I can't speak to the service.

For out of warranty repair Bitmainwarranty is going to be your best bet, they're reputable and I've ordered parts and currently have an S7 hosted with them that has been up continually for about 5 months with no issues. Their new MyRig.com site isn't the greatest and they've stated that they are migrating from Bitmainwarranty.com for months now, but things are still broken there. Besides that, they're a good choice for repair.

Lightfoot (a user on this forum) was doing repairs for multiple miners including the S9 a short time ago. I've been off on break recently so I don't know if he's still doing board repairs for the S9, but there's a good chance he still does.

How long before the controller board rusts dead? It happened to u before?
Dehumidifier does not make sense when airflow is so strong. I think just have to change the fans. The hashboard does not rust right?
Those deciccents are far weaker than dehumidifiers and u have to get rid of the moisture they absorb by heating them later on. The moisture is released in the air when u heat them.

The rust is mostly noticeable on the fan grates, but yes, the miner in the picture has a controller board that seems to have failed from rust. And you brought up a good point. It seems that silica gel already starts releasing moisture below 20C. If the ambient air is already above that temp, it might be useless to try using it as a desiccant.

You need to put some dehumidification in your intake airstream - for reference, a standard "mechanical" air conditioner is ALSO a dehumidifier, and many if not most current "window" units have "dehumidify" specific settings as part of their controls.

You do NOT have to run your entire inlet airstream THROUGH a dehumidifier for it to be effective - just have it AT the intake area to soak up enough of the humidity to reduce it enough to keep stuff from rusting.

Yes they are not as effective as a dehumidifier, but OP did not feel a dehumidifier was the best for their setup.

The idea of the moisture being released into the air is the point I brough tup about "regenerating" the desiccant. When it becomes saturated you would move it to the "hot" side of the farm. Using the discharge air to remove moisture along with the heat. So the practicwe would be to have 2 or 3 sets of desiccant that can be swapped out as needed. This provides for a continuous cycle with no extra power consumption.

It's just an idea, I haven't needed it because I do not deal with that level of humidity.


This is an excellent point.

If I recall right, desicants are incredibly weak compared to a dehumidifier. U need a hell lot of space and alot of them before it even has any effect on this kinda airflow. Dehumidifier will heat up the air. Air con that dehumidifies is best but is costly and only gives so much airflow as well. U gotta also watch out for condensation risks.

Unfortunately there's no one intake area / airstream. Air just floats in passively through sheets of fine mesh (>500 m^2).

It's just too expensive. Even industrial dehumidifiers can't process 1 m^3/s, there would need to be dozens of them just to reduce humidity by 1-2%!

Desiccants are only viable in small ENCLOSED spaces, they do not soak much moisture from the air at all per unit of weight/volume.
Dehumidifiers do NOT heat up the air, every "mechanical" dehumidifier setup I've EVER seen was a specialized air conditioner and the air they put out of the "dehumidified" side was COOL to COLD.
There is NO condensation risk on the air out of the dehumidifier, there's pretty close to no moisture in there that CAN condense.

It won't take "dozens" of them to reduce humidity 1-2%, unless you are running MILLIONS of CFM airflow (hundreds of thousands of M^3/minute) and have 80%+ humidity air input - though it would get complicated a bit by the fact they would reduce your intake air temp some, they'd still be pulling SOME of the water out of the air so even if the RH didn't drop a lot the moisture content of the air WOULD which should reduce the rust issue.

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Moderator's note: This post was edited by frodocooper to remove multiple nested quotes.

Airflow is in the millions CFM. I was using m^3/s not m^3/min. Also, the humidity is often above 80%. I get that dehumidifiers would still have an effect even with these conditions but I don't think that effect is worth the expensive price tag.

I saw the comment about 1 m^3/sec but thought it was a typo as it's not a normal specification - airflows are normally specified in m^3/min or CFM depending on if you're in a metric area or not.

How bloody big of a farm are you running to need airflow in the millions of CFM?

I'm also curious about where, as I don't know of any area that is close enough to an ocean or a large salt lake to have significant salt water in the air that also has access to low cost electric.

Yep, desiccants are too weak.

Dehumidifiers do heat up the air. Do google it. It heats up the air to remove moisture. Hotter air cannot hold as much moisture as colder air. Thus, moisture is removed when air is heated.

Airflow is usually in the few hundreds per cfm. I think a typhoon is millions of cfm :)
A strong dehumidifier can do a few hundreds per cfm at most though. A smaller fan would remove air faster.

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Moderator's note: This post was edited by frodocooper to remove multiple nested quotes.

You are mistaken on how dehumidification works.

Hot warm air holds more moisture. As the air cools down moisture is released.

If you have been googling dehumidifer for industrial purposes. They pump hot air into a space and then exhaust it to take the moisture out of the plant. I work in a food processing plant and this is done at cleanup so the floor is dry and ready for production in the morning.

All this being said refrigeration or air conditioning dehumidify a space as well. Again by lowering the temperatures. That's why most portable home AC units have a drain on them.

@tim
I've been looking through different options for you because your setup does sound quite large. I don't know what your budget is or anything but I'll pass along ideas I think could work.

Are you opposed to running a cold water line "coil" in some ducting? If you do this at an airflow change in direction with a drain at the base it might knock enough moisture out of the air for you. This is really only a good option if your site has a certain level of water consumption already. Or you are willing to invest in pumps compressors and fans, this is then a refrigeration/ac system

Edited: sorry was on my phone forgot the blue bit

Oh yep, u are right. Hot air holds more moisture, not the other way around. It cools the air first to drain the moisture, and then it reheats the air.

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Moderator's note: This post was edited by frodocooper to trim the quote from Steamtyme.

Or perhaps a geothermal loop to cool the water before it goes into that "coil".

That's a great idea you could then get away with using a water reservoir and a small circulating pump.

Let us know what you come up with Tim. Good luck with the farm

These miners are in the west, in the Americas. The airflow is higher than it typically might be because fans are either running full pwm or have upgraded / additional fans in the stream to provide even more airflow (because of the heat).

It would be great to be able to pump water like you suggested in order to address both the heat and the humidity at the same time. Hopefully things will work out before everything gets hot again.

 *I* am "in the west, in the Americas" but there's no salt water within 100 miles of me and no issue with salt in the air anywhere in the area of very low cost electric I'm in.