I was on the "Build it Solar" website a couple of months ago and I saw this document under wood burning on the page. The author, was given the task of designing and easy to build heater that would burn efficiently
and utilize existing dead trees from the forest of Maine. the guy put some time into burning of wet wood and has a lot of great data
http://www.builditsolar.com/Projects/BioFuel/biofuels.htm#Wood
