help; air ducting mounting

[Nagstaku]

So It all started with my new 27$ aluminum case i was going to build up for watercooling. So I decided to put a 120mm front intake fan/blowhole that would go direct to the radiator.

Well, now ive kinda gone a tad bit overboard (crazy.). I was gonna use some air ducting and have a 120mm intake fan, (front), the radiator with its 120mm, and then a kinda 90' elbow exhaust duct with a 120mm pushing air out the bottom of the case. (meaning no putting the case on carpet and i have to use feet). Im coming to the point now where i question if the front 120mm will actually be neccesary, since theres one just after it for the radiator.

So here I've drawn up a basic schematic for how i wanted to do the intake/exhaust systems:

Basic schematic for intake/exhaust:

Done with breifing, now for problems.

First, i found it impossible to find 5" or 120mm flexible ducting at any hardware store here in Portland. The sizes went 2", 3", 4", 6", and 7". damn i wish i we used metric. But anyways, i finally got down to measuring the actual diameter of the fanblade on a 120mm, and it was only 4.2". I figure, meh, ill have to go with 4" tubing since its easy to find, and its close to the actual fan blade size.

4" Flexible Mylar Ducting:
(special thanks to, uh... modthebox.com?)

So for the next adventure, I'll need to figure out how to mount all this ducting to the case. With or without the front 120mm intake fan, I was thinking i would try to get a piece of sheetmetal cut to 120mm^2 and have the 4" duct mount to that (i bought some foil ducting tape ). So i made another sketch here, and all the 'fins' with red dots on them, those would be cut and the bent in the direction of the ducting so i could easily tape it to the sheet metal. i hope you understand...

Basic Schematic for 120mm-->4" shroud:
(red dots would be bent)

However, I would prefer if i could find some prettier and less time consuming premade ones like:
Premade shrouds, Sunbeam kit:

So before i go hacking and cutting away at stuff and spilling blood, I'd like a tad bit of feedback, ideas, constructive criticism, anything. Is this whole intake/exhaust system useless? Is there a better way to make the shrouds? Can my dremel cut sheet metal to make those shrouds? Am i really a loser for spending like 40 min making this post? Any interaction with this thread will be greatly appreciated,

thanks.

 

[hignaki]

Ditch one of the 120's....unless you have something of VERY high airflow resistance (you don't), the 2nd one isn't needed, unless you want it.

 

[Decker87]

The front intake fan wouldn't be needed. Three fans in series would be an overkill. I would take off the first intake, rather than the second fan.

I like working with wood myself...what tools do you have? It would not be too difficult to make a shroud out of a soft wood (do not use oak or any other hardwoods, or ply or pressed wood).

Even more practical, try making something out of cardboard. Due to ebay, I have shiploads of cardboard laying around. It's easy to get and free. Find a nice solid piece and cut it into a 5" square. Then open up some program (MSword) where you can draw a circle 4" in diameter. Print and use as a stencil on the cardboard, cutting the hole with a razor. Cut the fins like you wanted to, then bring them through to the other side of the cardboard, and glue down. That way, you can cut an identical cardboard piece and glue that overtop of the fins, for a clean look. You could also try duct taping over the edges of the cardboard and painting it beforehand. It will come out not looking like cardboard, and you could easily make nice holes for screws to fit through.

EDIT: If you mean shroud to include the fan, cut edges to 120mm, not 5". I had the idea in midn you would be attaching the shroud directly to the case.

 

[Nagstaku]

yea, im pretty sure im gonna scratch that first intake fan. I'll need to make mounts on the case there though because i got a 120mm dust filter for the spot that ill have to mount.

and as for using cardboard or wood, ive thought about it. wood not as much just because i have little experience. cardboard i liked, because i have it, its easy to work with, afaik it would work, and i have some shiny foil style duct tape i could use to completely cover the peice of cardboard. the only downside to cardboard so far is if i disassemble/reassemble it often enough or have tension they might fall apart.


more feeeedbackk...............

 

[Decker87]

This might sound a bit too in-depth for a cardboard discussion, bu there is some very strong stuff out there...If you work at a store (or even if you don't), ask if you can go get some cardboard outta the stockroom...stuff that they use to package cleaning stuff like bleach, detergents, dish soap, etc is very very strong. I have an empty box from some cascade, and I can easily stand on top of it.

 

[Nagstaku]

hmmmmmmmmmmm

 

[KoZLop]

Leave the fan on the bottom of the case and mount the radiator on top of that then run tucting to the intake.. It would look more cleaner (I would think..)

 

[Nagstaku]

well its not drawn out, but theres very limited space height wise. im afraid if i mounted it on the fan, the duct would have to come from above it and make a big, camel hump, persay of the duct sticking up.