Sorry, I haven't kept up with some great posts. I'll try not to write a book here, and bore everyone to tears. Lots of good info above. Some of it repetitive from other threads, but a few things for me to ponder over.
1st off, I've mentioned before, I "do" have a baro, "and" an MPD. And I have set the baro to the manufacturers spec of -.04. When the weather is 20 something and higher, the heat exchanger temp will go to 400* and keep us warm. When the temps are lo-teens and less, this little stove has a hard time keeping our living space warm. But I don't want to get into a discussion on required BTUs per sq/ft, cause I know I'm below my requirements. ("supplemental stove")
But back to my original question or dilemma. (And trying not to be redundant). It seems there is still some conflict of opinions, as to whether a closed MPD is retaining heat in the stove or not. This is the way I'm viewing it, so please correct me if I'm wrong. The manometer measures a flow, or airspeed/velocity. But not amplitude or quantity. If our stoves are at full speed and we were to measure the amount of "exhaust" or heat coming off the top of our chimneys, I'm willing to bet a closed MPD will reduce the amount of exhaust flow out the stack. By doing this, it must mean that some of the heat is still "trapped" in the stove, which should equate to more heat being radiated. In the case of "only" a baro installation, altho the draft will be consistent, it still is a wide open 6" hole all the way to the chimney cap. Sure you can adjust it to a higher pressure for a hotter burn, but isn't it still blowing out the chimney at an alarming rate? (Compared to a closed MPD?) Once again, what I'm trying to do is get my stove temp. up higher than a medium heat of 400*. It'll go 500, but not easily. I can get a bed of coals to be bright yellow to almost "white hot", but still the heat exchanger temp only creeps, if at all. I didn't want to drag this out, and it appears I did anyway. Sorry. My next question is, "what color is HOT?". But I'll save that for another thread.