Help me design a tall skinny flat window box fan

October 2, 2008 2:50 PM

Help me design a tall skinny flat window box fan!

I've got an idea for a box fan that consists of about a half dozen small PC-type fan enclosures mounted into a tall (3'-4' high), skinny (4" wide), flat (thickness of the fan enclosures) window box.

This insert would go into a side-sliding Milgard window, opened to the security stop (about 4" to the left). I'd like to put an in-line switch on the wire, and run it to a nearby outlet.

Here's where I need help: any suggestions for make and model of fan? And how can I wire these all together to run off of a standard 110v AC outlet? Thanks for your advice!

posted by Aquaman to Home & Garden (7 answers total)

120mm fans on a 5v or 12v dc line (depends on the fan spec's), that's all it takes, anything smaller than 120mm will likely be too loud.
posted by iamabot at 3:01 PM on October 2, 2008

For a start, go to mcmaster.com and search for "fan" (page 619 in their online catalog should give you a good start). You need to figure out if you want to use 115 AC straight up and wire them in parallel or if you want to use some hybrid parallel-series solution (or give up the high voltage and try something with an AC/DC adapter).

The fans you see there are probably more expensive than anything you would want to buy a lot of, but it is a good start to see what is out there. Mounting and wiring configurations are up to you.

PM me if you have additional questions problems or concerns.

Good luck!
posted by milqman at 3:02 PM on October 2, 2008

Best answer: I built the exact thing from case fans for my AV cabinet. I used 3x 120mm with this AC adapter to molex. It only does 5 fans max, which might be too few for you.

Fry's had a good deal on case fans, 120mm for $5 and 80mm for $3, you may want to check back when they have them on sale.

Construction is fairly simple since they are square. You will want to buy fan grills.
posted by wongcorgi at 3:04 PM on October 2, 2008

Response by poster: McMaster looks like the pro place, but ~$35 per fan is definitely a little more high end than my project goals. I'm guessing that's about it for AC cooling fans?

And the DC route involves finding a power supply and building that into the box (or leaving it separate on the outside), then wiring several case fans in series?

I'm planning on grilling the box enclosure on the inside with screen & wire throughout.

Thanks so far! The more details the better.
posted by Aquaman at 3:40 PM on October 2, 2008

Herbach & Rademan has plenty of cheaper fans, both AC and DC, and low-cost power supplies if you decide to go DC (which sounds safer to me!)
posted by moonmilk at 4:02 PM on October 2, 2008

Have you calculated how much air would flow through this thing compared to a regular fan? You would want to make sure the amount of air moved by your construction would be worth the electricity used and noise generated. Six PC fans = the hum of six PCs, right?

Also, have you thought about constructing a cowl that would focus the air of one large fan through the slot? A single large fan may be more efficient (cheaper, cooler, quieter) than several small fans, though I suppose building an attractive and efficient cowl might be a lot harder for a DIY project.
posted by pracowity at 3:05 AM on October 3, 2008

Best answer: You probably want to pick a fan size that is approximately the same size as the window gap (a little smaller), so you can have a single width stack (as opposed to like 2x4 or something). The AC vs DC discussion is something you have to figure out. With AC, you won't need an extra adapter (and the power restrictions that come along with it).

You probably also want to think about the idea of adding in a dimmer (just in case the the noise is a little over the top).

We can be much more specific unless you provide measurements and a budget :)

Again, good luck
posted by milqman at 2:06 PM on October 3, 2008