The Gas Furnace is build up by an iron framework and is insulated with mineral wool. The furnace is covered with steel sheets on the inside and with coated steel sheets on the outside. Natural gas burners heat up the furnace. The hot air is guided from the burners to the fan units for circulation of the air in the furnace. The furnace has fan units containing circulation fans and motor driven dampers. It is also provided with a fan unit for cooling and for removing exhaust gases. The gas heated furnace can be used for drying of welding electrodes. sing electricity prices have made gas-fired furnaces an economical choice for heating applications. Gas furnaces are grouped according to power combustion efficiency at 80-82% annual fuel utilization efficiency (AFUE) and have a condensing efficiency of at least 90%. While traditional furnaces lose heat during operation, a condensing furnace has a second heat exchanger that makes use of the potentially lost heat making a gas furnace more efficient.