Ventilation Help?....

[FizZle]

just gonna set up ventilation in my new studio...as of recent i have had a fan out the window...just moved to a new spot setting up some hoods...just wondering if anyone uses flexible duct...or if i should get aluminum duct...was looking at this flex duct on home depot website...
http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&langId=-1&catalogId=10053&productId=100396925

any advice would be appreciated....

[nafglass]

Use the search function. There are lots of threads on this that will go way more in depth. Short answer: Don't use flexible ducting. It causes turbulence.

[J Howard]

it's all about the cfms.... how fast can you clear your room, and how small is your "room" (i.e. shoot your torch into a ventilated structure... block off the sides, creating a box around your bench). 100feet x length and width (square footage) of the structure's opening is a standard OSHA regulation for toxic spray booths (and a good place to start) = cfm of the fans needed to properly vent a toxic spray booth.


example: you box off your bench (5' long x 4' high = 20 sq ft opening x 100ft/min ventilation = 2000 cfm = 2 attic fans from lowes @ 1600cfm each mounted in the window = lots of ventilation and fresh air, above OSHA standards. in the winter, you can use riostats to slow the flow so you don't freeze. this is my set up and i swear by it. your fresh air should come from behind you for optimal circulation

hope that made sense.

thx to brett odie for the OSHA calculations, posted YEARS ago!

[boxfan willy]

http://www.theflowmagazine.com/pdf/Ventilation.pdf

An article with some good facts. Also some pics of my studio. We later found that the openings were to small and created back pressure on the fan. We tripled the area and improved flow without trashing velocity.

Hope it helps...

boxfan
www.theflowmagazine.com

[Emmett's Glass]

Here's another good vetilation link.
http://www.lni.wa.gov/Safety/Topics/AtoZ/Ventilation/default.asp
E

[FizZle]

Thanks everyone for your replies...the flow magazine article helped alot...i remember reading it a few months ago and couldnt find it again...thanks for the link...soooo now i understand what i need...just bout 1500 cfm fan...with 8 inch circular duct...now it is just a matter of getting the right fan...and figuring out a way to route the duct work to the window with the least amount of turns/angles so i dont have alot of turbulence...the space im workin with is very minimal...its gonna be tricky...

[HOSS]

If you can go with a duct bigger than 8", then do... I think mine's 14".

[J Howard]

If you can go with a duct bigger than 8", then do... I think mine's 14".

absolutely!!!!!


the fan itself is close to 14" across.... you don't want a bottle neck effect