I have read all the posts that I can find on the subject of putting a vent free propane insert in a wood burning heatilator box and it sounds like it is OK. On the Heatilator website, they say that the NA36 can accomodate a vented gas log set up to 100,000 BTU per hour. The propane set I have is a 36,000 BTU vent free set. When I install it, should I be concerned about anything? Also, should I run it with the vent flue open or shut?