It depends a lot on the space you have. Weekend warriors often get a nice dose of whatever they are working on due to cramped quarters and low ceilings. I don't do any welding or brazing in the winter since I can't circulate the air half enough. Often the operator's face is a lot closer to the source of fumes, than a monitor. I do a lot of epoxy work, and on cramped surfaces the epoxy pot often gets virtually forced into one's face. I don't doubt the general air quality is fine, but it sucks were I am. I use a belt pack that flushes air over my face. It filters dust only, but the air coming into the pack is much fresher. They make welding hoods with airmates attached, but they are pretty expensive. I would use one if I did this a lot, welder, etc... have some nasty health problems. There are welding specific filter, presumably brazing also.