Quote from: philipma1957 on October 02, 2017, 09:56:06 PM

Quote from: Marvell2 on October 02, 2017, 07:53:26 PM

Quote from: philipma1957 on October 02, 2017, 11:11:15 AM

Quote from: Marvell2 on October 02, 2017, 06:41:04 AM

Quote from: Elder III on October 02, 2017, 03:40:03 AM

Quote from: Marvell2 on October 02, 2017, 01:10:43 AM

screws from the bottom seems a good idea but it will be hard to get up there because there are a ton of rafters up to criss crossed
I guess we could but why is it different from screws from the roof side ?

No - screws down through the flange into the plywood from above. That DAP roof sealant is good stuff, but it's meant to keep water out, not to really hold something in place. Depending on how wide the flange is you may end up putting some roofing nails through it anyways when you lay down the felt paper (ice paper) and shingles, but a few nails or flat head screws into it to hold it in place would be more then worth it.

Usually when someone says tar in reference to a roof it's what you would find as "roof cement" at your hardware store. It's good stuff and every house should have a bucket of it on hand for patching shingles, flashing, gutters, etc...

http://homeguides.sfgate.com/use-roof-cement-28831.html

I see thanks for the tips.

I though the same thing about the DAP stuff , no where on it does it say it is like a glue. SO i still need to find some caulk or glue to keep the ventilator in place, could I just use the roof tar to glue down the vent AND the shingles ? after I put them on top of the ice paper ?

Or do you recommend another glue or caulk to hold the vent down before nails then ice paper ?

thanks again

I have 1 vent like that I used 4 screws

I put down this under it

http://www.homedepot.com/p/Nashua-Tape-6-in-x-50-ft-Select-Window-and-Door-Flashing-Tape-1343003/206495170

then a thin layer of tar
then the vent with 4 screws
then the roll of flashing tape
then tar
then singles

it is more then 18 years old

3 hurricanes
winds gusted up to 95 in one of them

does not leak

I did have to replace the motor after 2 years the replacement moter is like 15-16 years old.

700 is a good price for his labor

do not worry about intake my guess is the garage is not air tight and enough air will get in.

you kind of want a low intake with a air filter on it

i will show an idea later

Thanks @philipma1957 I will grab the flashing paper and the tar and 24 screws later today , the installer gets off work at 4pm and will head here directly so I will be ready
I already ordered the low gravity intake , but I can return it if your Idea is better, I figured I could put a filter on the gravity intake after its installed

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 75degress 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.