Zbornik - SDR

“Lighting Control Systems To Improve energy performance…” R-5
of free contributions shall be taken into account and daylight availability in buildings can
significantly contribute to improving energy performance of electric lighting installations.
The European Committees for Standardisations (CEN, CENELEC and ETSI) are currently
working on implementing methodologies to calculate the integrated energy performance of buildings.
As far as energy consumption related to electric lighting is concerned, the CEN TC169 is preparing a
standard (prEN 15193: Energy performance of buildings – Energy requirements for lighting) [8]
devised to establish conventions and procedures for the estimation of annual energy requirements of
lighting in buildings. The standard can be used for existing buildings, newly designed or renovated
buildings and it takes a “dynamic” use of electric light into account, considering both daylight
availability and space occupancy. According to European Directive guidelines, the TC 169 is
implementing a method that - despite maintaining the simplification necessary to guarantee design
applicability - sharpens the calculation of energy consumption concerning use of artificial light
management systems based on the integration of natural light or user presence. Once obtained, the
estimate of energy consumption of the lighting plant contributes to defining world energy
performance regarding certifying the building.
Still within the overall framework of tools to implement the indications in the European
Directive, a technical procedure is included that establishes the provisions and methods for
estimating the impact of “building automation” systems on energy performance and energy use in
buildings (prEN 15232: Calculation methods for energy efficiency improvements by the application
of integrated building automation systems) [9]. The standard underlines the role of building
automation systems in increasing functionality and energy efficiency systems, including obviously
artificial lighting plants and screening systems of direct sun radiation.
In addition to indications emerging on energy certification of buildings, greater awareness about
adopting lighting control systems is also due to indications published in a recent technical set of rules
disseminated in lighting-technique circles. The standard CEN 12464 “Light and lighting – Lighting
of work places – Part 1: Indoor work places” [10], in the section Criteria for lighting technique
design at point 4.9 – energy saving – cites that a lighting plant must correspond to lighting
requirements of a particular area without wasting energy. While in the section Lighting requirements
for indoor, visual tasks and activity, use of equipment with adjustable light flow is recommended for
school buildings facilities (school classrooms, evening classrooms and reading rooms).
4 Limits to the popularity of lighting control systems
Despite the potential benefits of using lighting control systems to reduce lighting energy and
enhance lighting quality, their application on a large scale has not yet been achieved, and this lack of
diffusion is particularly true in Italian buildings. Furthermore, it is quite common to come across
buildings where the controls have been disabled because of occupants’ complaints against their use.
Going further into the analysis, it is possible to outline the most relevant aspects that may have
had a negative influence on the use of lighting controls [11]. Often architects or lighting designers are
not well informed about existing control technologies (features and potentials of different solutions,
operating characteristics of each component, etc.). Lighting controls must be compatible with
existing lighting equipment (luminaires, lamps, ballasts and wiring) and since lighting and control
components can be obtained from multiple vendors, the designer must be knowledgeable about their
interactions. Lack of awareness implies a difficulty in choosing and designing appropriate solutions
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