Twinflow STDL

The Elta Twinflow STDL is a twin centrifugal box fan for external mounting — two fans in one casing with an Auto Changeover Panel included as standard, so if one fan is stopped the other takes over. That built-in run/standby resilience makes it the sensible specification for extract systems that cannot be allowed to fail.

We offer seven sizes from 125mm to 500mm (single-phase EC across the range, with a three-phase EC option at 500mm), delivering air volumes up to 1.740 m³/s and static pressures up to 730 Pa.

• Advanced backward-curved impellers in a redesigned casing for improved efficiency and lower energy use
• EC external rotor motors (IP44) with stepless speed control via potentiometer or BMS
• Auto Changeover Panel for twin-fan operation included
• Acoustic internal lining; 1.2mm galvanised mild steel casing; impellers balanced to ISO 1940-1
• Connects directly to standard flexible or rigid circular ducting (optional rectangular spigots); ambient up to +60°C
• 12-month warranty

If you only need a single fan, the Singleflow SSDL is the matching one-fan unit. See the full box fan range — lead times are shown on every product page.