Beautiful ** orrery (model of the solar system) available at:. Www.orrerystore.com This is a video of passive solar heating system in use at www.envirosponsible.com in Whitby, Ontario, Canada. It provides a large amount of heat, and the installation program, Chris, will make it more effecient by the addition of a second computer fan to push hot air at the top, by painting the inside better and taping the duct work. Moreover, the work carried out will be directed to the office where the door can be closed and used in a sort of minor mass.This air heater is ideal for urban survival and interceptions, it does not require power input and is cheap and easy to do . It is not just for strawbale, COB, cabins, houses, ships or land companies. They can be installed on a home, and look great when done well. Ragnar Benson would be proud. Visit our website or call 905-666-2002 envirosponsible.com.