Elta STDL315-1EC-R Twinflow Centrifugal Box Fan Single Phase EC - 315mm (rectangular spigots)

The Elta STDL315-1EC-R is a Twinflow duty/standby centrifugal box fan for 315mm duct systems, with rectangular spigots sized 348 x 378mm. Two backward curved fans sit side by side in one acoustically lined case: one runs, the other waits on standby. At full speed it moves up to 2207 m³/h free air, about 1998 m³/h at 100 Pa, and still delivers 871 m³/h against 500 Pa.Each fan has an IP44 EC external rotor motor (220 to 240V single phase, 50/60Hz) with sealed for life bearings, and the case is 1.2mm galvanised mild steel. An auto changeover panel (149-ACO1/EDV) is fitted as standard, switching to the standby fan if the duty fan fails and sharing run hours between the two. Speed is set by the built in commissioning potentiometer or a 0-10V signal, and Elta give a 12 month (1 year) manufacturer warranty. 1 Phase EC Motor Up to 2207 m³/h Speed Controllable What it is best used forLarger commercial extract on 315mm ducting where the system must stay running: whole floor office toilet extract, commercial kitchen general ventilation (not the canopy), hotel and student accommodation risers, school dining halls and library ventilation. It gives 2207 m³/h free air and about 1750 m³/h at 200 Pa.At 61 kg and 759 x 866mm (A x B on the datasheet drawing) it needs a strong fixing and a decent void. It is not for grease laden canopy extract, corrosive or explosive atmospheres, or air above +60°C.Why choose this over alternativesThe point of a twin fan is resilience. A single fan such as the Elta SSDL315-1EC-R Singleflow moves more air in the same duct size (2376 m³/h free air against 2207 m³/h here, and 1008 m³/h at 500 Pa against 871 m³/h), but when its motor fails the extract stops until someone replaces it. The STDL315-1EC-R keeps running on its standby fan, the panel gives normally open fail and run contacts for a BMS or alarm, and the duty share means neither motor does all the hours. Choose it for windowless toilets, risers and any system where a dead fan means a complaint or