BCD SPECIAL REPORT ON
HISTORIC CHURCHES
21ST ANNUAL EDITION
41
Light Perceptions has a reputation for providing
a
highly personalised design service for lighting
projects in significant heritage buildings.
Wakefield Cathedral Carlisle Cathedral
L
IGHT
P
ERCEPTIONS
Lighting Consultancy and Project Management for Historic Buildings
Unit 4 Cressex Enterprise Centre, Lincoln Road, High Wycombe
Bucks HP12 3RL
8,
,
01494 614540
Work for 2014 includes projects in eight UK cathedrals, Tewkesbury Abbey
and many other places of worship of all denominations.
Metalwork Fabrication,
Restoration & Repair
Waltham Forest Engineering Ltd
020 8502 0337
Metalworkers by
Appointment to
HM Queen Elizabeth II
to his services by subtly raising the brightness of the light on the altar
area at appropriate times using a remote control hidden in his pocket.
Some places of worship have a scene set control system that
is not altered after it has been installed and set up. Others like to
change the scenes and modify them as the uses of the spaces change.
Depending on the type of control system, modifying lighting scenes
can require some technical ability. Some churches may have staff
or volunteers who particularly enjoy getting their hands on an
iPad and setting up a lighting scene for a special event. It’s always
important that the control system matches the needs and capabilities
of the place of worship and its staff, both now and in the future.
Alternatively, the lighting can be controlled by dimmer knobs or
sliders. This means that the levels have to be set each time the lights
are used, but this system is intuitive, cheaper and completely flexible.
LEDs
Recently, lighting has been revolutionised by improvements in light
emitting diodes (LEDs). These fittings have a number of advantages.
LED lamps can last for up to 50,000 hours. If they are used for 40 hours
each week they should last for around 20 years. Furthermore, LEDs use
less electricity than conventional light sources so they save energy. They
can also be dimmed very well and are generally smaller than other types
of light source. However, they do have a major disadvantage: although
there are many cheap, poor quality LED fittings on the market, good
quality LED fittings are expensive. It is essential to use only fittings from
known, reliable manufacturers. The extra cost of good quality fittings is
off-set by their longer lifespan. The savings in maintenance and energy
make LED light fittings the favourite choice for many churches.
Because good quality LED lamps last so long, they can be
installed in less accessible, and therefore less visible, locations. It
is now possible to have light fittings hidden high up among the
ceiling rafters. The fittings can be maintained when the church is
redecorated or when high level repairs or inspections are carried out.
LIGHT QUALITY
Like fluorescent tubes and other energy-saving light sources, different
LEDs produce light in different shades of white, and quality may vary
considerably. Selecting the wrong type may result in a very unnatural
effect, so quality is just as important as brightness. Light quality is
defined by two measures: colour temperature and colour rendering.
Colour temperature
Light can be a cool, bluish white or it
can be a warm white like a domestic tungsten lamp, or anywhere
in between. The colour is precisely defined by a colour temperature
rating. This is a non-intuitive number – the higher the temperature,
the cooler the light appears. Colour temperature is measured in
degrees Kelvin (K). A warm domestic light is 2,700k, while a cool,
bluish white would be around 4,000k. If the light from a fitting is only
described as, for example, ‘warm white’, this could mean anything and
this type of fitting should be avoided. As a rough guide, 3,000k is a
good compromise colour temperature for most church buildings.
Colour rendering
The other measure of the quality of light is the
Colour Rendering Index (CRI). This is a measure of how accurately
the light can render colours using a scale of 0 to 100. The higher
the number, the better the light source’s colour rendering accuracy.
A modern, good quality light for church use should have a CRI of 90
or above. Unfortunately, fittings with higher colour rendering tend to
be more expensive and less efficient at converting electricity into light.
The only advantages of old-fashioned tungsten filament lamps were
that they had a fixed CRI of 100 – the highest possible – and the limited
choice of colour temperature made choosing fittings much simpler.
In view of the current trend towards broadening the function
of historic churches to suit the needs of local communities, recent
developments in lighting technology are invaluable. Many churches
which have installed new flexible lighting systems are able to host
a much wider range of events and activities than previously. Often
only relatively modest changes to improve the functionality of
their interiors can provide the key to securing their future.
MARK SUTTON VANE
established independent lighting design
consultancy Sutton Vane Associates (
) in 1995.
The practice has designed interior and exterior lighting for many
places of worship ranging from small chapels to cathedrals.
