206 Daylighting: Natural Light in Architecture
Digital multiplex controller A sophisticated electronic controller used
to monitor and vary circuits in a lighting system, such as might be used in
a theatre.
Dimming Dimming controls are exactly what the name implies, a
device by which the intensity of a light source can be reduced. All fila-
ment sources, both mains and low voltage can be controlled by simple
dimmers.
Intelligent luminaires Light fittings with inbuilt sensors programmed
to vary the light intensity, generally related to the amount of available
daylight or occupancy.
Noise attenuation Noise reduction.
Passive building A building which by its configuration eliminates the
need for mechanical ventilation, and reduces the need for daytime elec-
tric lighting
Photocell Measures illuminance at any position. When placed exter-
nally the photocell allows internal light control systems to react to
changes in the weather, an element of ‘daylight linking’.
Photovoltaics External panels on the southern exposure of a building
designed to convert solar energy into useful electricity, a developing
technology.
Scene set The use of more complicated electronic controls using a
microprocessor, to permit different room appearances to be available at
the touch of a button, with a number of scenes being ‘present’; which can
subsequently be changed automatically.
Stack effect The way in which hot air will rise in a chimney.
Thermal shutter An electrically operated mirror which tracks the sun,
and redirects its rays to cope with low or high angle sun, at different
seasons of the year.
Wind turbine A ‘windmill’ designed to generate electricity.
- ARCHITECTURE
Atrium The courtyard entrance to a roman house, with an opening in
the centre through which rainwater was collected. This opening also
provided light to the courtyard and surrounding rooms. The word has
now taken on the meaning of multistorey spaces which are daylit from
overhead glazed roofs.
Barrel vault A continuous structural vault of semi-circular section, used
from Roman architecture to the present; nowadays formed of reinforced
concrete.
Brieze soleil Large vertical louvres externally designed to control the
heat and glare from the sun. These are most used in hot climates.
Casemate A vaulted chamber built into a fortress for defence. Often
used as a battery, or barracks.