Yet another Bluefront case filter.

Bluefront · Post by **Bluefront** » Sun Jul 23, 2006 9:10 am

I'm trying out another type of filter material....cut from a furnace filter called electrostatic. Apparently airflow over the plastic-like filter screen, creates a static effect which traps/holds dust and dirt. I tried a piece of this stuff in a window AC unit....works pretty good, and traps dust well. It seems to be of very low restriction.

I'm using this on a rear case fan (blowing in). The housing is cut out of a plastic jar. One jar can make two filter housings. I used the top, cutting off the center, but the bottom would also work. This jar is slightly wider than the 120mm fan. I cut four holes in the plastic, and then held it to the fan with four std fan screws with washers.

The filter material rests against a foam edge, and is held tight using small strips of cloth duct tape. This is a cheap, easy build.....anybody could do it.

InMused · Post by **InMused** » Sun Jul 23, 2006 10:36 pm

Looks like a bought one. Nice job.

Is the filter wasable? or do you just repace when it gets restricted?

Bluefront · Post by **Bluefront** » Mon Jul 24, 2006 2:01 am

It's washable since it's made from plastic. My window AC unit with the same filter material has been washed four times so far. Since this is easily accessable I'll just clean it off with a cannister vac.

theyangster · Post by **theyangster** » Fri Jul 28, 2006 8:34 pm

so it is very durable yes?

the fact that it low restrictive makes it excellent

Bluefront · Post by **Bluefront** » Sat Jul 29, 2006 3:15 am

The only problem I can see with this filter is the initial cutting procedure. The edges have a tendency to fray. As soon as you cut the filter piece, take some small strips of duct tape, and tape the entire edge of the filter. This makes the thing stable with no tendency to come apart. You could also run a small strip of glue around the edge.

When finished with this procedure the filter is reasonably stiff, much stiffer than a piece of foam filter. It doesn't require any extra stiffeners to hold it over an opening.

How restrictive? I ran a globe fan at 1850rpms (12V).....then temporarily set this filter assy over the fan. The fan speed dropped to 1815. This is pretty good compared to most pleated paper filters I have used. Some filters will drop 100 or more rpm. How well this particular filter will perform at eliminating dust.....don't know yet. Check back in 4-6 months.

As you can see this filter is much bigger than a 120mm fan opening.....plus there is a 2" air space between the fan blades and the filter. Cut down on those dimentions and the filter assy would not work as well. IMHO

InMused · Post by **InMused** » Sat Jul 29, 2006 4:14 am

Bluefront wrote:The only problem I can see with this filter is the initial cutting procedure. The edges have a tendency to fray. As soon as you cut the filter piece, take some small strips of duct tape, and tape the entire edge of the filter. This makes the thing stable with no tendency to come apart. You could also run a small strip of glue around the edge.
...

An old trick for stopping ribon bookmarks in prayer books was passed to me by an old sage. It may work for this situaltion too (though you already have a solution). Use clear nail poilish. It's an epoxy resin and works wonders for preventing fraying and is durable too.