This European Standard specifies the requirements and test methods for the safety and efficiency of non-domestic gas-fired air heaters having a fan to assist the transportation of combustion air and/or flue gases, hereafter referred to as "appliances". This includes appliances having forced draught burners. This European Standard applies to Type B12, B13, B14, B22, B23, B42, B43, B44, B52, B53, C12, C13, C32, C33, C62 and C63 appliances with a heat input not exceeding 300 kW (based on net calorific value) intended for use in other than single unit residential dwellings. It also applies to appliances intended for outdoor installation. Provision of the heated air may be by means of ducting or may be directly into the heated space. For Type C62 and C63 appliances, this European Standard only applies when such appliances are intended for final installation in a similar manner to Type C3 appliances. This standard does not apply to: a) appliances intended for use in a single unit residential dwelling; b) appliances of the condensing type; c) appliances with atmospheric burners without a fan to assist the transportation of combustion air and/or flue gases; d) dual purpose air conditioning appliances (heating and cooling); e) appliances where the air is heated by an intermediate fluid; f) appliances fitted with manual or automatic flue dampers; g) portable or transportable forced convection appliances; h) appliances having multiple heating units with a single draught diverter; i) appliances fitted with more than one flue outlet; j) appliances that are designed for continuous condensation within the flue system under normal operating conditions; k) appliances having combustion products evacuation ducts, POCEDs, that are non-metallic.