Thanks Rod. So I am getting the impression then that "Exempt" units can, in fact, be as clean, or even cleaner burning, than units which meet EPA Phase II. Just because a unit is "Exempt" does not mean it is, by definition, a polluter in comparison.
But you are also saying (if I am understanding you correctly) there have at times arisen some technicalities where certain units, which are in fact, clean burning, could not -- due soley to technicalities -- get the "EPA" Certified Exempt label. And in certain areas, like yours, the lack of that EPA label means the local authorities won't approve for install.
Thanks all, for all the answers and links. Not a simple business, I can see!! And I just started out thinking about a new house and "wouldn't it be nice to just have a nice fire to enjoy and take the chill off".
Happy Fourth all.
builderbob