Press Release
RGPR 107
September 2009
How new rooflighting developments are helping to
reduce carbon emissions
Richard Cliffe, Director of Roofglaze Limited, explains how advances in
rooflight design are meeting demands for ever-lower U-values as part of
the drive towards buildings with lower carbon emissions.
Today’s increasing emphasis on energy efficiency and reduced carbon emissions
has placed rooflight manufacturers in the spotlight, amid growing awareness of
the positive role rooflights can play in meeting the new efficiency targets.
Research recently carried out by De Montfort University, concluded that with
today’s low-U-value rooflights, increasing rooflight areas has a beneficial effect
on carbon emissions by reducing the demand on artificial lighting. This is
contrary to the previously widespread view that increasing rooflight areas
equalled greater heat loss and consequently higher energy usage. The fact is,
advances in rooflight technology have changed the balance in favour of larger
rooflight areas.
Design improvements and increased thicknesses of multiwall polycarbonate
sheet; triple and quadruple wall glazing elements on modular rooflights;
advances in thermal performance of glass glazing and further improvements in
kerbs, upstands and ventilation systems are all contributing to greater energy
efficiency, with U-values for modular and continuous polycarbonate glazed
rooflights typically around 1.3 W/m2k. This is well inside the required standard as
stated in Part L of the Building Regulations. However the increased performance
allows greater design freedom in other aspects of the building envelope.
As awareness of these developments is increasing amongst specifiers, another
innovation is making an important contribution in this respect: the introduction of
rooflights incorporating nanogel-filled multiwall polycarbonate glazing.
Nanogel is a free-flowing translucent granular material that consists of silica
based particles made up of 5% solids and 95% air. Nanogel’s unique structure
creates superior insulating properties as well as excellent light transmission and
other properties that make it ideally suited for use in architectural daylighting
systems. For example, a leading UK supermarket chain is installing Nanogelfilled rooflights at their new ‘low carbon’ superstores.
With a U-value of just 0.89 W/m2K, Nanogel-filled rooflights provide a twofold
contribution to reducing carbon emissions. Firstly, heat loss is minimised, as the
thermal performance of the rooflights is virtually the same as the surrounding roof
construction. Secondly, excellent light transmission and reduced solar gain allow
the use of large glazed areas. This in turn minimises the requirement for artificial
light, thereby further reducing energy consumption.
Compared with conventional insulation materials, Nanogel (Aerogel) provides
more than double the insulation value (see table below).
Another outstanding advantage of Nanogel-filled rooflights, is the quality of light
provided to the building interior. Nanogel®-filled glazing provides high levels of
diffused lighting with minimal shadows or ‘hot spots’ – to create a pleasant and
comfortable internal environment.
Nanogel®-filled glazing also provides superior acoustic performance, with a 25%
noise reduction at 1,000 Hz. This property makes a further contribution to the
quality of the internal environment.
From a practical point-of-view, Nanogel-filled rooflights score highly, too.
Weighing under 4 kg/m2, compared with over 30 kg/m2 for a typical double
glazed glass system, they are suitable for a wide range of roof constructions and
are ideal for retrofits and upgrades. The glazing elements are delivered to site
pre-assembled, so installation is quick and simple – as with any multi-wall
polycarbonate rooflight.
In conclusion, the variety of current rooflight technologies available to the
specifier, provides solutions suitable for every kind of building. Importantly,
thanks to the ingenuity of materials manufacturers and rooflight designers,
today’s rooflight specifier has greater design freedom than ever before, despite
tightening legislation relative to energy performance.
Based in St Neots, Cambridgeshire, Roofglaze Limited is one of the UK’s leading
providers of rooflights and skylights, offering a complete range from modular
domes and pyramids, to continuous barrel vaults, ridgelights, lantern lights,
bespoke designs and Nanogel-filled rooflights.
For further information, visit www.roofglaze.co.uk
Ends - 626 words
Photo captions:
Nanogel performance table:
Nanogel has more than double the insulation value of conventional insulation
materials
Nanogel rooflight:
Nanogel-filled glazing provides high levels of diffused lighting with minimal
shadows or ‘hot spots’.
For editorial information, please contact Paul Bennett on 01280 821400 or email
paul@bennettandpartners.co.uk