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Example 1: Gym lighting design – The glazed openings must also have a good energy perfor-
The objective here is to achieve maximum homogeneity in the
gym’s lighting, while minimising the risk of its users getting
dazzled.The architect tended towards polycarbonate on ac-
count of its interesting light diffusion and transmission proper-
ties. Despite the gym’s high degree of openness, the idea was
for it to achieve high thermal performance, thus preventing it
becoming a weak point in the building’s envelope.The selected
polycarbonate wall elements (Ug = 0,99 W/m²K) achieve a
light transmittance rate of 40%, while the 55 m² of roof lights
achieve a rate of 38%.
The simulation results 4 obtained are as follows:
Average daylight factor 5: 4.47 %
Maximum daylight factor: 7.68 %
Minimum daylight factor 2.59 %
Uniformity factor: 58 %
The results show that, to gain 458 lux (the amount of artificial
lighting planned and determined by Dialux©) of lighting, the
natural lighting obtained is sufficient to dispense with artificial
lighting for 70% of standard usage hours (8:00 - 18:00). [Fig. 4]
Example 2 Natural lighting for the rooms looking out over the patios
Several factors influenced the architect’s choice of installing
ponds in the patios. Water has a reflection factor close to 80%,
almost twice as high as a conventional roof with a bitumen
membrane. [Fig. 5] Apart from this aspect, there are other favour-
able, though less quantifiable, factors such as adiabatic cool-
ing. In the summer half of a year, air crossing the patios comes
into contact with the water in the ponds and takes up humidity,
thereby providing cooling due to the latent energy resulting
from the evaporation of water.
Fig. 5: Visualisation of the results – daylight factor
(Autodesk Ecotect Analysis©)
Fig. 6: Example of zones specifically subjected to dynamic thermal
simulation (using the Trnsys© software package) in order to assess
annual energy requirements and solar input on the facades.
Final positioning of the solar protection (yellow: outside screens;
orange: perforated steel sheeting).
mance 6, making the most of sunlight.
Dynamic simulations of target zones were used to determine en-
ergy requirements in terms of heating and cooling; net solar input
at right angles to the building’s windows was used as a guide
for choosing the way to manage/exploit this free input.The solar
factors and the positioning of the outside sun protection devices
followed the conclusions of these simulations.
On Levels 3 & 4, the facades most exposed to the sun are pro-
tected by motorised outside louvres, as well as by the envelope
of perforated steel sheeting with its 50% transparency factor.The
solar gain factors (g) 7 of the windows are between 0.5 and 0.6,
with the exception of the windows on the outer edge of the build-
ing, where it is 0.4.The aim here is to ensure, when necessary, that
these glazed surfaces have a combined (glazing and protection)
factor (gtot) lower or equal to 20%.
Patios: glazed with “AGC planiclear” (Ug = 1.1; W/m²K, g = 0.64)
combined with Helioscreen white mobile solar protection (g = 0.24:
gtot = 0.15).
Windows on the outside edge of the building: glazed with “AGC
planistar sun” (Ug = 1.0 W/m²K, g = 0.38) combined with fixed solar
protection (g ≤ 0.5: gtot = 0.19).
The dynamic simulations show that the use of solar protection
results in a gain exceeding 46% over the cooling energy otherwise
needed to ensure comfort in rooms facing south. [Fig. 6]