Air Filter Questions

[Pete Staehling]

I have been tweaking all aspects of my my dust collection system and am now to the point where I think an air filter might be the next logical step. I have not ruled out a "store bought" filter like the Jet, but am considering cobbling something together. It seems like something could be done without much expense.

Does the Jet, Rikon, Wen, or similar actually do much more good than a box fan with a high end filter designed to be used with central air?

I am thinking of a 20"x20" box fan with a 20"x20"x4" electrostatic pleated air filter. My initial thought is to hang it from the ceiling flat wise and blow the air up. Does that sound like a reasonable plan?

[John K Jordan]

I have been tweaking all aspects of my my dust collection system and am now to the point where I think an air filter might be the next logical step. I have not ruled out a "store bought" filter like the Jet, but am considering cobbling something together. It seems like something could be done without much expense.

Does the Jet, Rikon, Wen, or similar actually do much more good than a box fan with a high end filter designed to be used with central air?

I am thinking of a 20"x20" box fan with a 20"x20"x4" electrostatic pleated air filter. My initial thought is to hang it from the ceiling flat wise and blow the air up. Does that sound like a reasonable plan?

I think what the commercial filter offers is a nice package with remote controls, timer, and a handy mount for the filter. I've read of lots of people who built one from a squirrel cage or other fan. As long as the filter is good and the air movement is sufficient it should work as well as any, if not better.

About the placement, from what I understand the air circulation is key. The Jet manual recommends mounting part way along one wall so the air can make a big circle. A lot depends on the shop configuration, dead air spaces, where the primary activity is, etc.

If aimed straight up, the air would blow outwards in all directions. Without monitoring the flow my concern would be that the air would move in tight loops near the fan and not draw in dust from further away in the shop. You could position it temporarily and use streamers and perhaps smoke wands to watch the flow and see how far it goes.

If possible, consider acquiring or borrowing an air quality monitor. Without a way monitor you can only guess and hope. I have the Dylos (DC100 Pro) which uses a laser to count both the larger particles and the very small invisible particles which have been found to cause significant lung problems. With this you can watch the numbers shoot up as you work and see how long it takes for them to drop at various points in the shop, with and without the filter/fan running. It would be a shame to spend a lot of effort on installing something just to find it wasn't too effective. You might read Bill Pentz for his educated opinion on the subject.

I haven't moved my Jet into my new shop yet but I plan to support it high on a panel jack and do some tests before I mount it permanently. Even with a good cyclone DC it is amazing how much fine dust is in the air after even minor wood tasks and how long it lingers. I've started wearing my respirators more.

JKJ

[glenn bradley]

I built one out of a gable fan and 'off the shelf' filters. Judging by the filters it does a very good job. Dad bought the JDS 750 (has a new model number now) as at the time it consistently won the bake-offs. His is quieter, has a remote with various timer selections, better filters and can run much longer between filter changes. There are many things I will build myself because I can save money or get just what I want. In the area of ambient cleaners I think you can do a decent job but, for size versus performance the commercial units will win.

This is one place that I found price or paint do not make the machine. Do your research and pick a winner. One Fine Woodworking review used data from Rowan University on five brands and although they all cleared the air about the same after 20 minutes, some were faster, noisier, had better remotes, etc. The Jet AF-1000B won that one due to being second quietest, having a decent remote and easy filter changes. Remember that if your unit is doing its jib, filter changes are a regular activity so ease of maintenance is more important than one thinks while setting at the computer reading stuff ;-)

[Ole Anderson]

A box fan is designed to move a lot of air at basically zero restriction. As soon as you introduce any restriction, like a filter, even new, performance drops drastically. Just not enough horsepower. Double up the filters, particularly one that has a high MERV rating, and flow drops to almost zero. Been there. Find squirrel cage furnace fan and you now have a good starting point for a home built ambient filter box.

[Jim Becker]

The blowers in the commercial offers are setup differently than a typical box fan and Ole is correct about performance. Cleaning the filters on these units is sometimes a pain, but they do a nice job with getting a bunch of the ambient fines out of the air if you place them properly so air circulation in the space is optimal for collection. You don't want to put them "just anywhere"... ;)

[Ken Fitzgerald]

I bought two of the Jet filters. I mounted them in my shop in manner such that they each blow the air in different directions and thus try to move the air in the same direction. The air in my shop moves in CCW direction when they are on. No particular reason for moving in that direction. I hung the first one from the ceiling, then purposely hung the 2nd one to aid air movement in the same direction.

[bill kaminski]

I made mine..furnace blower..it was free..only negative, a little noisy..but, it works

[Jim Huelskoetter]

I used the air handler from a 4 ton ac with two cheap filters, then a good furnace filter, then a Spaceguard filter. The cheap filters caught more than I expected, but I was still glad that I had the spaceguard. In total, it moved plenty of air for my small space and was very effective.

[Jim Finn]

I have a ceiling mounted air cleaner that has a squirrel cage fan and bag filters. It filters my entire shop air in six minutes. Less than $200. Space guard, as mentioned, will also work well.