Discreet Flowbar crucial for RIBA award winner

A discreet, but effective ventilation system became a key part of the design for the revolutionary educational building that went on to win this year’s RIBA North West Award.

The new St John Bosco Arts College state secondary school was a D&B project by A&B Engineering who undertook the design and installation of the mechanical services (see their case study) and was built by Vinci Construction as a massive ‘hangar’ style open plan facility. It has become a landmark in the surrounding Liverpool housing estate because of its size, bright colours and unusual design. Inside, it offers a tremendous feeling of space with few physical barriers between teaching and activity areas.

As well as the building’s own award, the RIBA regional Client of the Year prize went to the college’s head teacher Anne Pontifex, who played an active part in specifying its revolutionary ‘circular motion’ teaching space.

Clearly, such a large open space presented major challenges to the ventilation designers, particularly as they had to remain true to the overall vision of minimal physical structures in order to keep lines of vision and movement clear.

The original idea was to use floor standing displacement ventilation terminals, but the architects felt this would be too intrusive. A second proposal involved multiple jet nozzles to ventilate the space, but again the architects were unhappy because of their unsightly appearance. At this point, the team turned to Ruskin, who proposed slot diffusers.


Ruskin’s Flowbar Jet Throw linear diffuser offers a performance that is not too dissimilar to a jet nozzle so is able to ventilate very large spaces, but without the unsightly appearance. They can also be plastered into the walls so, not only are they discreet, their subtle lines can also be a feature of the architect’s interior design without any loss of ventilation performance.

“So we were able to offer a solution that both looked good and worked well – the classic win win.”

Each of the slots, which are manufactured in the UK by Air Diffusion, were 2m long with varying sizes of plenum boxes behind. The slots ventilated the large open spaces while the individual classrooms also benefited from fixed blade swirl diffusers.  The dance studio also has high level swirls providing ventilation air from 6m above the floor.

Air Diffusion’s FlowBar diffusers are suitable for either ceiling or sidewall applications. They are available in straight lines or curves to blend with other architectural elements. Standard slot sizes are 25mm, 38mm, 51mm, 63.5mm and 76mm with single section lengths available up to 2,400mm.

The Jet Throw (JT) Flowbar models used at the St John Bosco college come with pattern flow controllers to allow the airstream to be jetted in a horizontal direction (sidewall mounted) whilst fully integrating into the wall system. Jet throw pattern controllers allow extended throws in typical high bay applications for heated and/or cooled air.