Radiant tube gas heaters heat the space principally through infrared radiation. Special burners with blowers – usually operating with gaseous fuel and in a few instances with oil – create inside the radiant tube (with typical diameters of 80 bis 100 mm – some types up to 400mm) a long laminar flame and the resulting exhaust gasses. The tube surface temperature is heated to temperatures of 200 bis ca. 600 °C. The hot tube surface emitts infrared heat radiation.

By reflector designs – some with insulation – above and to the side of the radiant tube radiation is directed to the occupied area. The combustion gases are discharged to the outside via an exhaust system.

Radiant tube gas heaters are decentralized heat generators and heat transfer systems in one unit. The use of radiant tube gas heaters therefore begins with installation heights of about 3 m, devices with high heat output require heights of at least 8 m. The heat up time is very short. No more than 5 minutes after turning on the full radiation intensity is reached

Burner and flame of a tube space heater, by special mixing devices flame lengths of up to 6 m inside the radiant tube are produced to achieve uniform heat distribution.