Topic: Ducting (Read 1246 times)

You'll have problems, each miner is generating ~ 225CFM. So 5 of those are 1125 CFM plus you'll want some extra. If you merge all that airflow you'll need way bigger ducting than 8", and on top of that you're running it 30'.

Don't do it. These things need to be able to breathe and any kind of resitriction is to be avoided whenever possible even when using booster fans. Also beware of using any kind of flexible duct tubing - they have horrible resistance to air flow. Standard rule-of-thumb is that 1ft of flex tube has the same flow resistance as 10ft of solid ducting. Be sure to account for that.

Dear smart people, I'm reworking my rig with a series of ducting, fans, etc. I'm amazed by the differences that subtle changes can make.

I have 5 asic miners in an insulated plywood box about 44" x 44". I'm thinking of running 6" ducts from each of these to lead outside of the box and combining a few of them (all of them?) into an 8" duct with an inline vortex fan. The fan can displace over 750 cfm. I'll then lead the one 8" duct about 30ft out a window or basement wall (will need to drill a hole or modify window...nbd either way). Also, can i step down the 8" to a 6" duct further down the line...maybe 10 feet down the line from the inline fan?

One a side note, I plan on reversing the flow of air from out to in during the winter months and pipe the hot exhaust directly into my hvac ducting to warm my house. I'm already siphoning some of the cold ac air from a nearby duct directly into the asic units...works like a champ!

Any thoughts on these ideas? I know that the math doesn't quite work out, but I can make some quick mods and exhaust 1-3 of the miners directly into my unfinished basement area without much of an issue. As most of you already know, I, fortunately, learned the hard way that offsetting the exhaust by 1 or 2 units eases the load on the others...less hot exhaust to displace=cooler air=cooler boards=less work for fans=less noise=less energy used=saved $.

Sadly, I've almost forgotten about making $, because I'm fascinated by the science of making the system more efficient! Such a fun project.

Thank you for your honest feedback!

 

It looks great. Cant wait to get them. 9 hours is a long time to print. I can see where high volume would be hard to do.

He's using ABS now, here's a few pics of the new material. I had also asked him to reduce the OD slightly to make it easier to fit ducting over it, previously it was a little too tight. He said he thinks your's should go out this weekend. He is a stickler on quality so they take like 9 hours to print! High volume is not his goal

Ok great thanks.

I texted him to make sure they are ABS

Ok I ordered 4.

Yes sir he is, although I have asked him to start using ABS as my M3s deformed the other material. If you do order let me know and I'll double check he uses ABS.

Link https://www.thegeekpub.com/product-category/mining-hardware/antminer-accessories/

Raymond: Is your buddy still printing those 6” shrouds? I could use a couple.

Please refer to the Dew Point description here.
https://en.wikipedia.org/wiki/Dew_point

If your intake air is 100% relative humidity, you only need to raise the air supply temperature about 5C to eliminate condensation formation. If you have the intake and exhaust of all your miners fully isolated, you can add a small fan to return a little of the exhaust air back into the intake plenum to provide the needed intake temperature rise. Really, you should heat the intake air whenever the humidity reaches 90% or whenever the Dew Point / Temperature spread is <5 degrees.

Filters are good. They must either be relatively huge or fan powered. I prefer to use a heavy metal grid to keep bad people and animals out, then a smaller gauge metal grid to stop the big stuff then finally the filter.

I live in one of the most humid northern places, i've never had a problem. I think the humidity can be a risk if the miner is hot and the air is under 0C. I believe condensation can occur because the miner is hot and then water pellets freeze there. So when you turn it back on, it may cause a short circuit.

I by no mean am an expert on this particular subject, but i can say with assurance the big miners do not filter their intake either, it takes too much intake surface area out. And i'm not actually sure removing the humidity is feasible at all in the first place, because all proper setups will vent the heat out. So as you try to remove it, an infinite intake of it will keep getting in.

Extracting heat from air in a closed environment to be able to remove all humidity sound like incredibly expensive hardware and upkeep costs.

Here's the link to the Marketplace thread https://bitcointalksearch.org/topic/antminer-6-to-120mm-duct-adapter-2853173

Link?  I am interested in the 6"

Alright, my friend decided he wanted to sell the shrouds rather than put the file up on Thingverse. For those waiting for the file, sorry I have to respect my friend's wishes

I will post a for sale link in the marketplace

It uses the 4 screws that hold the fan to the body.

Looks like a very good design. I was planning to switch from 4" to 5" but after seeing this will go with 6". How is shroud attached to the fan?

Quick update, went back outside and measured the noise. It's as I thought, no difference between inside and outside DB levels.

To be clear though, the ASICs are only 2.5' or so from the wall so the ducting is very short. Also these are venting in to a 3 sided carport, which turns out to be good as that insulates most of the sound unless you are in direct line of sight of the duct outlet.

So, outside measurements are:

20'  65DB
10' 70DB
1' 79DB

Roughly 40' at my fence-line looking directly at the exhaust outlet 55DB. Going the opposite way, with carport door closed and on the other side in my backyard 20' 45DB. For my location and township I am well within code and no issues with neighbors

I just hit him up, he's going to try to get it uploaded tonight. Sorry for the delay, but he'll do it, eventually

Thank you!!

@caxibrema I will ping him right now.

Any updates on the 3d model on thingsverse?

8" insulated ducting is about a foot in dia once you add the insulation. Im guessing it would take 15' or so to make a nice loop exiting in the same direction as the entry to keep air flowing. It comes in 25' lengths so I'll see what happens. I'll need to get a DB meter to measure the actual noise reduction. I don't have one. Its gonna take up some space for sure.

Nice, someone doing it the right way. Just Kudos. I was just trying to explain this to someone else earlier today, it's like trying to reason with an hysterical kangaroo. Let me try this new merit thing on you. Edit: Seem like i can't send much but i did. Anyways, Good Job.

An interesting test would be to do a straight run and then one with a loop to see if that could cut down on noise, but not affect cooling.

Thanks for the update. I bought some 8” insulated ducting at Home Depot last night. I’m going to do some longer runs. 8 foot or so to get the heat out of the room I have them in. I’m hoping the 8” size will allow enough flow at the longer length to keep everything cool.

Forgot to update, I went back in and performed sound measurements. No change on the interior noise, outside at the duct exits is another story. Heat's not the only thing making it out! Now granted my run from the miner exhaust to the duct panel is very short less than 3ft. but the sound outside is approximately the same as inside. I never measure before, but I know it was not anywhere near as loud.

Interior measurements:

20' Interior Garage door closed ~ 45DB
20' @ interior door threshold ~ 65DB
10' ~70
At the miner 78-79DB

Outside at the exhaust exit ~75DB, I need to verify this again. Last night seemed to be a cacophony of airplanes, Harleys, and dogs barking

Foam board, or any foam for that matter does not "deaden" sound. It only controls echos of higher frequency sounds
(like drum cymbals or above the 12th guitar solos). Materials like mass loaded vinyl or Rock wool based insulation
"deaden" sounds. A much cheaper option is double layered drywall/rockwall. Or venting out into a box that has
a "maze" inside it. The box needs to be big enough to allow a good flow through it ofcourse.

Ok you may have just saved me a bunch of work for nothing lol. I thought I read something on here where they took an 8’ long piece of ducting. Looped it so it exited in the same direction the miner was pointing to help knock down the sound.

I'll break out the decibel meter tonight, but I am pretty sure it had no impact.

Ok I was thinking the 6” ducting would knock down the sound some. Maybe insulating the room would be a better idea.

I have not tried to quiet mine down. I would think if you have the space just build a small room and compartmentalize the hot and cold side within that. Then just work out the appropriate intake and exhaust ducting.

I might have to look into getting a few of those.

Do you know of a good sound absorbing insulation board? My miners are on a 3' x 72" tall shelving unit that you can get a Menards.  What I am thinking about using is 1-1/2" foam board. I would put a piece on each side and one on the front of the shelf. The front piece would have a hole in front of each miner that the ducting can come through. Now the back is close to the concrete wall in my basement. I thought if I space the shelve about 6" from the wall and put a piece of that same foam board on the concrete behind it that I would still get some good intake air flow and the board would help knock down the sound. This is all in a room in my basement. I wanted to leave the back open also for ease of access.

I also dump heat - (even in the winter in Wisconsin). If you only try to only provide cool air to the miner from outside  -  the room heat will eventually overwhelm the miners.  filters are a bad idea imo they get clogged and you have a problem - you're better off having a air compressor and (carefully) blowing out the dust once a week.   It's also a good idea to put some leaf/rodent proofing on the intakes - one errant leaf and mess up miner by blocking the intake - Also a 1" gap at the inlet side of the miner - instead of a direct connection allows for blockage inspection and adequate intake temp/cfm.  In the case of a rainy humid day the gap helps to equalize humidity and reduce condensation - a hash board killer.

My friend will be adding the duct adapter to Thingverse, so just search for Antminer. It should be there soon.

Looking forward for the 3d file if you can get with your friend.

Thanks!

I am not using any filters, this is all set up in my garage so the air intake is simply inside and fairly clean. From there it is blowing in to a 3-sided carport. Long term I plan on converting a small 20' X 4' (skinny rectangle) storage room for the miners I keep at home. The thin long room looks to be a perfect setup, it's at the back of my lot well away from neighbors so I can run some large CFM exhaust fans to draw airflow over the miners. In that setup I will definitely run filters built in to the wall opposite the exhaust fans.

Very nice! I too am using the 6 inchers, on both sides though. I'm in the middle of building a Small room in my basement,
where I will draw in cool air from outside, and vent the heat into my HVAC system. In the warmer months, I will draw in the
cool basement air, and vent the HOT air out a window. On a 90 degree F day, the basement is about 65 degrees F.

Have you ,or do you, use any type of dust filter?

Me? I am just getting rid of waste heat.

Can you give a more general idea of what you're doing with this? Is it just for sound or are you drawing outside air?

I have 25 miners running in my house - I found on the outlet side a 6" flex duct goes nicely over the end of the miner with no reducer.  The duct can be up to 8' w/o causing back pressure.  On the inlet side I use 4" flex and leave a 1" gap away from the miners - to mix in room temp air.  The differential between inlet & outlet temps can form condensation on the hash boards.

No problem, let me ask my friend.

Hey would you mind sharing 3D model of 6" one... I got 3D model of 4", and my temperatures are pretty high at the moment around 85ish more-less. I forget how to work in Solidworks. In last few years i worked in Tekla Structures, but that program cant export STL

I see lots of folks here asking about adding ducting to their miners. And while you should really house your miners in a dedicated space with adequate airflow, sometimes we have to make do. So I thought I'd pass on a few things I learned.

1st be careful of the 3-D printed stuff on eBay, some are OK, but others are overpriced and not very well thought out. Not to mention printed out at very coarse resolutions.

Personally I feel that to provide the least amount of restriction you should use a 6" adapter and 6" ducting. I tried a 4" eBay duct adapter on my S9 and the temps skyrocketed *without* any ducting. Then I tried a 5" and it was better, but I could tell temps were still a few degrees better. Finally I had a buddy make a nice 6" adapter, this had no effect on the miner's temps.

Here's a view of 3 miners with the 3 different sizes in ascending order from left to right.



Here's a couple of closer pics of the 6" adapter my friend made and what I plan to use on all my miners.



Here's a mock up of the 6" ducting (I need to clean everything up ), the other one in the background is 5" ducting. I wanted to make sure the 6" worked out before my friend made one for each miner. Also the two blank holes are for my 2 M3s that'll be here mid-late Feb.



Here's a couple of pics of the backing board with the 6" starter ring holes, it is going in a hole cut for an old window A/C unit. I cut this out on a CNC router.



EDIT:

My friend will be adding the duct adapter to Thingverse, so just search for Antminer. It should be there soon.

Here's my parts list:

6" semi-rigid duct http://amzn.to/2DyBDW5 semi-rigid is kind of a PITA to work with, but I feel it has a smoother tract with less airflow interference.
6" Starter ring https://www.homedepot.com/p/6-in-Starting-Collar-Take-Off-Snap-Together-SCF6/100396966
Duct sealant, used this to seal the starter rings to the plywood http://amzn.to/2DyvbhT