I built this Rocket Mass Heater on my back porch. It is one of the most efficient wood burning heaters known to humans. 

Timelapse version of this project here:    • Rocket Mass Heate...  

I modeled the design based on this book: "The Rocket Mass Heater Builder's Guide: Complete Step-by-Step Construction, Maintenance and Troubleshooting". By Erica Wisner (Author), Ernie Wisner (Author)