my issue with the gravity intake is simple will you add duct work in the garage so the air goes really low to the ground? if you do that it will work well.
gravity intake with an attached duct to the floor >>>>> miners >>>>>>> roof fans
the above will pull air from roof down a flex duct past a filter at the miners up to the roof
so how big is the gravity intake ?
here is a 20 inch flex duct
http://www.homedepot.com/p/Master-Flow-20-in-x-25-ft-Insulated-Flexible-Duct-R8-Silver-Jacket-F8IFD20X300/302001685?
and a 16 inch flex duct
http://www.homedepot.com/p/Speedi-Products-16-in-x-12-ft-Insulated-Flexible-Duct-with-Metalized-Jacket-R8-FD-12R8-16/203393287?
attach the flex duct here
two intakes
The gravity intake I ordered is 19 inches ,vs the 26 inch one that is way to big for my roof. So i need a matching size flex duct I see.
I see that makes a ton of sense attaching the flexible ducts to bring the outside air close to the ground, on the placement of the gravity vents ? Why so close to the edge of the roof ? I was going to put then in line with the exhuast fans just along the same end of the roof
as your diagram
Thanks allot for the tips
btw we turned on just two of the fans today and I kid you not it was AMAZING , the temps on my GPUS went down from 90 degrees and 100% fan to as low as 68 degrees 45% fan for most cards !
some cards are at 74% still but fan speeds can now be set to auto instead of the fixed 80% fan i was using.
room tempreature is basically equal with outside now around 75degrees compared to low 100s
Another thing I notice is there is no more heat transfer to the metal racks, before i would nearly burn my hands on the racks sometimes they were so hot, not they are cool to touch.
My 4k PSUs also were very hot and needed powerful fans or they would shut down, now I can even turn off the fans and they are cool to the touch, I might try my hand at dual mining again when all the fans are running to see what temps look like.
All this is cooling around 100 GPUs with basically one 1500CFM exhaust fan , no gravity intake yet in a poorly insulated garage , these fans are amazing. I say one fan because the other one still has a tarp over it, we did not finishing replacing
the shingles on the other two before it started to rain and rain was getting in the garage so we tarped it up till tomorrow.
One finaly thing these Dayton fans are high quality, super quiet , you cant hear them, I actually wonder if they are running at all or at full speed , I guess I'll play with them more when we bring down the controls.
[/quote] answer to bold is the 20 inch flex duct was 25 feet long it was 185 usd so if you cut it to 12.5 feet for two intakes and the roof is tall it won't go that low
the 16 inch flex duct was 12 feet long and was 58 bucks.
it looks like you would need the 20 inch duct and ½ the length is 12.5 feet.
I would love for the 2 flex ducts to be 3 feet off the ground. wait for a photo
can you take the photos I ask for below.
