Acoustic Fa├žade Ventilators for City Centre College

Acoustic façade
ventilators for
City Centre College

New life is being breathed into a
1960s college building in the
heart of London through
innovative ventilation techniques.
City & Islington College needed to upgrade
its four-storey Centre for Business, Arts &
Technology in line with changing
vocational courses, but had a limited
budget with which to achieve the mix of
accommodation from specialist studios for
dance, fashion and printing through to
engineering workshops and recording
suites, and additional requirements such
as a library, administration facilities, a
nursery and café.

Wilkinson Eyre Architects’ solution was to
redesign the interior to take into account
student movement, cutting out long
corridors and creating a central courtyard.
To ensure compliance with DfES
requirements to utilise sustainable
solutions as far as possible, the ventilation
strategy focused round a natural
ventilation chimney, a 100m long double
skin glass buffer zone on the façade
fronting the busy adjacent main road and
Passivent Aircool® ventilators.

Buffer Zone

The buffer zone, which runs from the firstfloor to enable adequate access to the
building and movement round the
communal areas at ground floor level,
allows fresh air to enter the building whilst
minimising noise penetration and
optimising external temperature changes.

The central chimney provides continuous
air movement drawing ‘used’ air out of the
building by the buoyancy effect by which
warm air rises, with extraction boosted by
a roof-mounted turbine.
As the buffer zone could not include the
ground floor, a solution had to be devised to provide natural ventilation to that area.
As a result, 27 acoustically treated Passivent Aircool® ventilator units have been installed to draw the fresh air through the building facade and circulate it throughout the rooms, with each unit providing an average geometric free ventilation area of 0.375m2.

Bespoke façade ventilators

Passivent has developed bespoke versions
for the College, including a double bank of
acoustic chevrons in each Aircool unit.
Working closely with the acoustic
consultant and using Passivent’s testing
results for the standard acoustic product
range, the unit was calculated to achieve a
noise attenuation of 30dB.

The thermostatically controlled Aircool® units open automatically to draw replacement, fresh air into the building achieving penetration depths of five times the floor-to-ceiling height. Daytime heat build-up is also automatically dissipated via the units at night. Stafford Critchlow, architect for the project at Wilkinson Eyre, commented,
“It is a DfES requirement to utilise natural
ventilation as far as possible. The buffer
zone effectively provides this from the first
floor, but we needed a means of extending
the natural ventilation strategy throughout
the building ie including the ground floor.
Passivent helped us achieve that.”

To download the Case Study PDF click here