Masonry Heater: Again SunRay puts his own twist on an old idea. Masonry or mass heaters have been built in Europe for centuries and are now becoming more popular in the U.S. because of their great efficiency. The well-insulated firebox, fed with air from outside the house, burns so hot that little smoke is released. The flue gases travel up from the firebox until they hit the soapstone floor of the oven where they are directed down past copper coils heating water for the radiant floor heat and domestic hot water. The flue gases then travel around the bench heating the stone mass of the heater itself before finally traveling up through the chimney. Only a few hours of fire are required to charge this elegant heat BATTERY and heat the concrete floor, both radiating the heat for hours after the fire is out. SunRay's is currently designing a masonry heater that will have a steam drive alternator that will charge the batteries for an electric vehicle as well. Watch for up coming video links on the progress this latest project.