DIY Sand Battery Air Heaters! w/heat powered fans! no electricity needed! sand battery room heater!
• Desert Sun 02 - YouTube.com3 simple DIY "Sand Battery" Air Heaters! all w/non-electric "heat powered" fans! all 3 units run totally off-grid! the hot sand in the 'sand battery' heats the air AND runs the stove fans! no electricity is needed!