Modern Building Services
Xpelair redefines the performance of inline duct fans
Published:  08 December, 2007

Xpelair’s XPress range of duct fans is said to provide very high pressure development, volume and efficiency — enabling significantly smaller ductwork to be used than with conventional inline fans.

The design is based on a dynamically balanced mixed-flow impeller and bellmouth entry with minimised clearances to ensure optimum pressure development. Air is transferred through a meridian channel and then enters a static 3-dimensional guide vane.

This dihedral twist retains a third of the pressure build up, which would otherwise be lost. Efficient air management virtually eliminates air-turbulence noise and vibration that is associated with typical centrifugal inline fans.

Richard Farrow, product manager for Xpelair, says, ‘We believe XPress redefines inline fan performance. Although all the theory for high-efficiency design exists, XPress was optimised through virtual prototyping using a computational-fluid-dynamics program.

‘The results have been remarkable. For example, an XPress 250 mm delivering 1400 m3/h at 200 Pa has a volume output double that of an equivalent-diameter centrifugal inline fan and 50% higher than a 315 mm. This impressive performance means that smaller ducts can be chosen with an efficiency that provides economy associated with EC/DC fans of the same performance. Better air management through the unit means that much of the low-frequency noise associated with circular inline is eliminated.’

XPress is the same size as the ductwork in which it is mounted, using flexible connections. A mounted foot is fitted in the factory. These fans can be run at any angle.