Box Fans

Box fans put a centrifugal or mixed flow impeller inside a square, duct-mounted casing, giving you higher pressure development than an axial fan in a unit that is easy to install, maintain and — in the insulated versions — keep quiet. They are the workhorses of commercial kitchen extract, office and classroom ventilation, and any ducted system where resistance from long runs, bends and filters demands more than a simple axial fan can deliver. All of our box fans are genuine Elta units, supplied with UK support and datasheets on every product page.

Which box fan do I need?

• Singleflow SSDL — externally mountable centrifugal box fan with acoustic lining as standard, in eight sizes from 100mm to 500mm. A strong all-rounder for general extract.
• Twinflow STDL — twin-fan version with an Auto Changeover Panel included, giving run/standby resilience for systems that must not stop. Seven sizes, 125mm to 500mm.
• Qube SQU — double-skinned, insulated multi-discharge box fan in four case sizes from 500mm to 1020mm, ideal for commercial kitchens, offices, schools and industrial buildings.
• Multiflow SMB — mixed flow box fan whose blade geometry packs high airflow into a compact casing, in six sizes from 400mm to 700mm.
• Hideaway SH — low-profile box fan designed for very shallow ceiling voids, in six sizes from 100mm to 315mm.

Buying box fans from Alpha Air

Most ranges are available with energy-efficient EC motors offering stepless speed control, and AC alternatives where you prefer transformer control. If your extract runs hot — kitchen canopies, process air — look at the high temperature versions of the Qube, rated to 120°C with the motor out of the airstream. Alpha Air is a Leicester-based UK supplier: lead times are shown on each product, and orders over £400 ex VAT get free UK mainland delivery.