I revamped a free 1980's nightwatch insert by adding a bigger baffle, three secondary combustion tubes ducted to one air inlet and a air wash duct over the loading doors attached to the other air inlet. I aimed a video camera wired to my TV at my chimney. It takes at least 10 to 15 minutes for the smoking to subside unless I open one loading door slighty. After that I close the door and see no smoke. Much better than the continuous grey plume I used to create. If anyone with a non cat epa stove has observed their chimney during several warm up cycles I would like to know what they are seeing. Do they need to heat up before they run clean ? I live in a densely populated area and I like my neighbors. Thanks for any comments.