Technical information
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VBE- and AQ-index
Human index for the room's lighting experience and the lighting's total quality index
VBE index
Through research we now know that light aects us not just visu-
ally, but also non-visually. Traditionally lighting quality was only de-
scribed visually within a space by stating the illuminance within the
working area and its immediate surroundings. However, research
has shown that ambient lighting, the lighting of walls and the ceil-
ing, has a signicant eect on us both biologically and emotionally
(non-visually). The level of ambient light is important for our alert-
ness and therefore our ability to perform over time.
The VBE index is a model that describes a way to interpret the
lighting experience within a room visually, biologically and emotion-
ally. The aim of the VBE index is to describe the subjective lighting
experience – where all parameters have signicance and can be
weighted dierently depending on the type of room and the activ-
ity. The model aims to be a support and communication tool in the
dialogue between the buyer and the lighting planner and can be
used for dierent types of environment, e.g. work, restaurant and
care environments. The template can also be used as a basis for
evaluating the existing facility.
The model for the evaluation of the quality of the lighting solu-
tion, with man in the centre, is based on a subjective evaluation
of the visual, biological and emotional aspects where the overall
perception of a lighting solution is taken into consideration. The dif-
ferent parts are individually evaluated and the sum gives a total VBE
index through the use of certain assumed parameters and the value
of these. The better the correspondence with the input parameters,
the higher the overall points for VBE.
The parameters for the VBE index are presented in a triangle. Each parameter is
valued on a scale of 1–5, where 3 corresponds to the normal value. The total VBE
index can therefore be a maximum of 15. The higher the total index, or the filling of
the triangle, the better the total lighting experience. As an example for workplaces –
work surfaces – the visual aspects have the greatest significance.
Emotional
Biological
Visual
AQ index
There are ever increasing demands on the reduction of energy con-
sumption, for both economic and environmental reasons. The need
to be able to value the overall light quality in a room, both with
respect to the lighting experience and the operating cost, was the
inspiration behind the AQ index.
The AQ index (Application Quality Index) is a model that describes
a way to interpret the lighting experience together with parameters
which show energy consumption and operating costs for a specific
room.
The lighting solution's quality index is based on ve dierent
parameters with the aim of showing the total quality of a light-
ing installation for a specific room. The operating cost parameter
takes the energy consumption, product eciency, illumination and
the recommended maintenance of the lighting within a room into
consideration.
The value of all the parameters is based on the dierent crite-
ria, which are shown in the form of a table. The final presentation
which appears in the pentagon should be seen as a value of system
solutions within the room – the room's lighting experience together
with the energy consumption and operating cost of the lighting.
The evaluation is normally made by a lighting planner at the design
stage, but can also be carried out by an inspector on an existing
installation.
Product
eciency
Total lighting experience
Energy
consumption
Recommended
maintenance
Light control
The criteria for the AQ index is shown in a pentagon. Each criterion is valued accord-
ing to a scale of 1–5. The higher the total index, or the filling of the pentagon, the
better the system solution's index for the room. The Lighting Concept Tool shows
how the AQ index changes when wall lighting and lighting control is added.
Aspects of the VBE index
The visual aspects
include the more traditional fundamental values such as the visibility of an object,
visual comfort, contrast, glare etc. over time.
The biological aspects
are primarily due to our biological clock – the body's endocrinal hormone secretion and
its influence on our alertness, wellbeing and performance both during the day and for
the dierent seasons. Research shows that the body is mainly aected by the level of
ambient light and its spectral composition.
The emotional aspects
are the most subjective – how we generally perceive the light in a room, the colour of
surroundings and the light's colour, dynamic and comfort over time.
Parameters for evaluation of the total AQ index
Lighting experience
is based on the total VBE index, i.e. a subjective evaluation of the visual, biological and
emotional parameters within the room.
Energy consumption
describes the energy consumption and is valued according to the room's calculated
LENI figure in accordance with EN 15193. The calculated LENI index describes the
room's energy consumption expressed in kWh/m² per year.
Product eciency
for luminaires including light sources – stated as an LLE index for all luminaires in the
room. The calculated LLE value is expressed in lm/W.
Lighting control
describes which type of control system is used in the room.
Recommended maintenance
is the interval for maintenance of the lighting in the room, with regards to cleaning,
servicing and changing light sources, recommended by the lighting planner.
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