This European Standard specifies the requirements and test methods for the construction, safety, classification and marking of non-domestic gas-fired overhead radiant tube systems incorporating two or more burner units with each burner under the control of an automatic burner control system, and operated by a single fan providing a single flue outlet, called system H and referred to in the body of the text as the “system”. This standard is applicable to Type B52 systems (see 4.3) intended for use in other than domestic dwellings, in which the supply of combustion air and the evacuation of the products of combustion is achieved by mechanical means. This standard is applicable only to such systems that have fully pre-mixed gas/air burners. This standard is not applicable to: a) systems designed for use in domestic dwellings; b) outdoor systems; c) systems of heat input in excess of 120 kW (based on the net calorific value of the appropriate reference test gas); d) systems having a draught diverter; e) systems that are designed for continuous condensation within the flue system under normal operating conditions; f) systems having combustion products evacuation ducts that are non-metallic. This standard is applicable to systems which are intended to be type tested. It also includes requirements concerning the evaluation of conformity, including factory production control, but these requirements only apply to POCEDs and their associated terminals. NOTE Requirements for systems which are not intended to be type tested would need to be subject to further consideration. Requirements concerning the rational use of energy have not been included in this European Standard.