Gas-fired overhead radiant tube heaters and radiant tube heater systems for non-domestic use. Safety and energy efficiency|Stability, Single, Ignition systems (heat engineering), Time, Flames, Testing conditions, Flow rates, Marking, 2nd family gases, Ignition, Leak tests, Fire safety, Heating equipment, Combustion products, 3rd family gases, Radiant heaters, Protective coatings, Commercial, Gas space heating, Safety measures, Temperature rise, Maintenance, Safety devices, Conversion, Fire tests, Performance testing, Design, Classification systems, Control devices, Heaters, Pilot flames, Thermal testing, Burners, Flues, Identification methods, Gases, Gas valves, Installation, Gas-powered devices, Safety valves, Test pressure, Wear tests, Overhead, Flued heaters, Formulae (mathematics), Gaseous fuels, Instructions for use, Electrical safety