locomotive schematic

Today's building codes state spaces using furnaces have to have method for getting back together combustion air since it used. Newer homes have ducting installed, during construction, that literally brings fresh air from the outside for an area close to the furnace. This ducting, usually called comprise air duct, or combustion make-up air, is sized according to the capacity from the furnace. Efforts are created to protect once abundant asiatic elephants.Elephants are threatened by poaching for tusks,from the decrease of habitat due to human pressure on forested areas and due to human conflict.The isolated populations of wild elephants in individual wildlife sanctuaries can also be threatened by decrease of genetic diversity.Recently several corridors connecting wildlife sanctuaries have been in existence to encourage the migration of wild elephants.