I believe you are right on about the smaller particles. Of course, there is some consideration with wood about sensitive people and some woods having irritating properties/chemicals that can cause damage to folks even with the larger particles.fixit wrote:...I have one mounted on a Delta collector and have been very pleased with it for over a year now. The bag that came with the collector put out dust (only caught stuff 3 micron size or larger if I remember correctly) but the smaller stuff - the stuff that causes lung damage - just went right through the bag...
When dealing with size, I think back to Missoula Montana where an inversion layer sets in every winter and is very stubborn and persisted for weeks. We were violating Federal and the more stringent State Air Quality Standards. During the 70s and 80s the major pollutants in the air (trapped below the inversion) were: 1) Wood smoke and 2) Dust from road sand (so folks could stop their cars at intersections. The smoke was mostly from stoves and fireplaces. We were told the smallest particles of the smoke were the most harmful as we couldn't cough them up. They got into our bloodstreams. It was also said by the health people we could cough up the larger smoke particles.
I now reason if it is possible to cough up larger particles of smoke, we can surely cough up much of the fine sawdust we may inhale. (Actually I don't want to inhale any of it.) So, it seems the best thing we can do is avoid inhaling any wood dust. The small, floating parts of the sawdust are the ones we really want to trap. Air filters, home made, and commercial are a good deal. Although I don't have one of these, I do have a roof mounted whirligig vent. It works as a passive dust extractor. With a light breeze (which we always have here) will suck a piece of cardboard up to the ceiling side of the vent. The inside vent hole is 8" in diameter, so I feel it is removing a lot of the floating dust.
Irritants in some woods are another matter. I think these can only be avoided by non-use of such woods, or wearing an appropriate dust mask and proper clothing.
BTW. - Missoula has outlawed closed (glass door, etc.) fireplaces, does not allow fireplaces in new homes and requires all new stoves have catalytic converters on the flue, or otherwise proven non-polluting. These conversions must be made upon selling a home. No more gravel mixed with salt on the streets. Only salt - and I noticed that the salt water freezes and turns to very slippery ice during much of the winter. - a new hazard!
