►► Proposed Updates to Jet Fan Test Standard EN ISO 13350 ◄◄
Working Group 13 has been working on two updates to jet fan test standard EN ISO 13350, both related to situations where such fans are installed close to solid surfaces such as tunnel soffits and walls. The first update aims to provide guidance on testing jet fans where the inlet silencer is located close to one or more surface, such that choking of the inlet flow (and thereby a reduction in jet fan thrust) can be expected. The second update relates to the measurement of thrust for jet fans with deflection devices such as nozzles, deflection vanes and slanted silencers intended to overcome the Coanda effect. Such deflection devices affect the horizontal component of thrust, due to reaction forces and aerodynamic friction. The proposed update to the standard will propose means of measuring the total thrust, or alternatively to measure both the horizontal and vertical components of thrust. This presentation will describe the reasons for the proposed changes, detail the current proposals, and invite feedback from the conference delegates.