I just came across this article about a Crimean
Oven used in the U.S. Civil war of 1860's. They have something going on with the trench through the tent creating a draft to pull the heat through. According to the article it made very diffused heat that was equally felt throughout the tent.
Perhaps the concept can be applied to create radiant floor heating with a Rocket heater? Interesting history and tech anyway!
You can read the article here:
http://www.notechmagazine.com/2014/03/crimean-ovens.html