free heat tunnel as exhaust from one or more of suitable heating technologies such as convection resistive electrical infra red near infra red ultra violet microwave inductive and radio frequency in further embodiments the said conduit 9 is heated by one or more heat exchangers located in the conduit 9 which heat exchangers take heat from a heated liquid fig4 shows the heat exchangers 10 within the conduit 9 however one or more heat exchangers can be located on one or more of the exterior and interior surfaces of the ignition source free heat tunnel while one conduit 9 is shown in fig4 embodiments may include one or more such conduits and such conduit or conduits can be located on one or more of the sides top bottom and around the periphery of the ignition source free heat tunnel 1 fig4 shows an opening or access door 11 to the interior of ignition source free heat tunnel 1 however the ignition source free heat tunnel 1 may include no opening or access door or more than one opening or access door fig4 shows a conduit 12 which exhausts air from inside the ignition source free heat tunnel 1 to the outside in another embodiment the conduit 12 returns cooled oil from the heat exchanger 10 to the.