Descriptors | Air heaters, Convection heaters, Heaters, Gas-powered devices, Heating equipment, Gas space heating, Space-heating systems, Commercial, Industrial, 2nd family gases, Combustion products, Carbon dioxide, Concentration (chemical), Position, Installation, Selection, Air, Flow rates, Ventilation, Ducts (building services), Pipework systems, Flues, Inspection, Commissioning, Instructions for use, Maintenance, Mathematical calculations, Transportable |