my diy 133 cfm inline fan

So I made this ghetto 4 inch inline fan for about 15 bucks. I used a 120mm 133cfm Ultra Kaze computer fan, which also has decent static pressure… for a computer fan. On the intake side I used a dryer blocker, I took out the blocker and hacked one of the sides off. On the out-take side I used a 5" to 4" reducer, (5 inches is just a little bigger than 120mm). I foil taped the reducer from the inside to a 6" drain frame after drilling some holes in. It's not a perfect fit… but it works pretty well. The reason one side is tapered and the other is not is because I noticed most inline fans don't taper on the intake side because no drag is created by NOT having a taper… which of course isnt the case for the exhaust.





You could probably do something nicer with a piece of masonite and 5" hole saw. After that I just put some 120mm gaskets on the fan, and screwed everything together with some 2" screws.



I've attached this about 5 inches away from my bake-around with a 400w hps, just to test it out, sat it on the stove and ran it for about 30 min. Got pretty damn hot around the light, but the ends of the cooltube kept cool to the touch. However there was no ducting attached to the end of the fan or the other end of the cool tube, so some more static pressure will be added to the load when I really put it to use. I just hope the thing doesnt melt… I want to run the fan right next to the light to keep the air moving fastest next to the bulb, I read that somewhere. I think it will stay cool enough to be pretty safe. If it doesnt work, I'll use the fan for something else and cough up the money for a real duct fan.

I like this.

Does it work better than if it were just left normally?

fucking great idea
mind if i borrow it
and how well did it run over a long period of time

Arrid said:

I like this.

Does it work better than if it were just left normally?

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Thanks.

By normally, do you mean non-air cooled? I imagine so… I'll update the post when I put it to use

Scalded Dog said:

fucking great idea
mind if i borrow it
and how well did it run over a long period of time

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go for it. let me know how it goes if you put it to effect before me. I gotta wait on my mom to bush out a lil more. It ran fine for the 30 min i tested it out. I'll post up the final analysis after I install it into a cab.

i meant does the pc fan work better like this, or is it the same as it was when it didn't have the bits added to it.

Arrid said:

i meant does the pc fan work better like this, or is it the same as it was when it didn't have the bits added to it.

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Oooh, right. I'm sure it would be better off without the add-ons, it would be perfect for bolting onto the side of a veg box. The bits just add drag.

This fan is going to be put on the same timer with the light, and have its own ducting independent of the rest of the cab. I wouldnt put a filter on it, or add to many bends in the duct work.

pdillo said:

Oooh, right. I'm sure it would be better off without the add-ons, it would be perfect for bolting onto the side of a veg box. The bits just add drag.

This fan is going to be put on the same timer with the light, and have its own ducting independent of the rest of the cab. I wouldnt put a filter on it, or add to many bends in the duct work.

Click to expand...

Yeah i thought so.
I'm used to using pc fans for venting etc.

Just wondered if this offered any advantages

only advantage is price vs. a true inline fan