Heck, w/ good DRY wood split small and a "teepee" fire, I can even have a nearly (visible) smoke free fire in my old masonry FP. Even so, I'm sure there are a lot more particulates in the non-visible smoke from my FP than a properly functioning EPA stove would generate. Of course, if I throw on a couple big splits w/o enough "supporting" fire (smaller wood buring under or around the larger wood), the chimney looks like it's from a little kid's picture of a house in winter time (i.e. lots of puffy smoke coming out). And if the wood is at all green, furggitaboutit.
Peace,
- Seqouia
Peace,
- Seqouia