This is a very interesting way of heating. Paul Wheaton12 shows how a rocket mass heater works and tells how his took him from burning 4 cords of firewood per winter down to one cord per winter and provided warm mornings too. Kind of amazing.
The second video is him showing a couple different builds of rocket mass heaters. I will also post his article if you would like to read it.
The article is at the link below.
http://www.richsoil.com/rocket-stove-mass-heater.jsp
wood stove vs. rocket mass heater
12 rocket stove mass heaters – efficient wood heat
Rocket Mass Heaters: Superefficient Woodstoves YOU Can Build
The Book of Masonry Stoves: Rediscovering an Old Way of Warming
