Woodworker's Journal 2008-32-2, страница 72

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tables and dust collectors), AFDs are still important tools for ridding the air of fine floating wood powder that's evaded collection. An AFD not only makes your shop air healthier to breathe, but also reduces the amount of fine dust that settles all over the shop and needs cleanup.

For air filtration to work effectively, an AFD must be installed and used properly. AFDs don't have much suction power to draw fine dust into their filters, so it's important to mount an AFD so that the clean air blown from its exhaust creates air circulation around the shop. The drawing below shows that the ideal place to hang an AFD is one third of the way along your shop's longest

wall, with its intake oriented to the closer short wall. Because fine wood powder can float around in the shop air for hours, you must run an AFD for at least a couple of hours after you're done making sawdust. If your AFD doesn't have a built-in timer, you can plug it into a electrical timer (available from hardware stores). Just make sure the timer you buy is rated to handle the amperage of your AFD's fan motor.

If a single AFD doesn't seem to be doing the trick (fine dust still settles all over everything), there are a couple of ways you can improve filtration performance. First, try mounting a box or circulation fan on the shop's opposite wall, oriented as shown in the drawing. When run on

low speed, this fan encourages the circular airflow that moves dusty air towards the AFD. Another way to get better results from a single AFD is to locate your power tool bench and/or sanding area close to the AFD's intake side, so that fine dust doesn't have to travel far before being drawn into the filters. Remember to clean and/or change your AFD's filter regularly.

If air filtration still isn't up to snuff — no pun intended — then the best solution (after doing all you can to improve your primary collection system) is to mount a second AFD on the wall opposite the first one, as shown in the drawing. The exhaust air from each AFD helps feed dust towards the other.

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Sanding area near your AFD

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April 2008 Woodworker's Journal