The possibilities of switchable glasses in the new «daylight norms»
The Halio daylight system as part of the EN 17037
Already in 1935, the DIN 5034 gave validity to a German body of norms, which
included interior lighting with daylight. This makes it all the more astonishing that
the norm is only followed more than 80 years later, by a norm valid throughout
Europe the EN 17037 «Daylight in Buildings». On the basis of the latest scientific
findings, it provides recommendations for indoor daylighting and it is also dedi-
cated to the topics of views, tanning and glare protection. Thanks to their intelligent
control options Halio glass makes an important contribution to these important
aspects of modern daylight planning.
The functionalization of Daylight
Around 100 years ago, light came into the focus of architecture for a variety of
reasons. Modernist architecture challenged the cramped living conditions in the
backyards of the cities under the motto «Light, Air and Sun for All» and deve-
loped solutions for affordable and healthy living. Light and daylight were above all
dimensions of home hygiene. The health aspect of light was limited to the biologi-
cal effects of non-visible areas of sunlight such as infrared and ultraviolet light. It
was known that ultraviolet light killed bacteria, and sunbathing eased skin diseases,
vitamin D deficiency and rickets.
The daylighted factory created better working conditions but served primarily to
increase productivity in the early days of «Fordism». The 24-hour factory was born.
Humans, hens, plants and other living things just had to be put in the right light to
become more productive. Today’s light researchers have a different opinion.
At the turn of the millennium, a receptor in the eye
that carries the light-sensitive molecule melanopsin,
responds to the visible region of light and directly
influences our circadian rhythm, our internal clock, and
keeps bodily functions such as the immune system and
metabolism in motion.
We know that light influences us in many ways,
depending on criteria such as the time and the pe-
riod of the light exposure, the horizontal and vertical
illuminance and the light spectrum. As you know,
the high blue light content in the morning lowers the
release of the sleep hormone melatonin and stimulates
the release of serotonin when we wake up. Cold white
light in the evening delays the production of melatonin,
therefore we fall asleep with difficulty. The more time
we spend indoors, the more we isolate ourselves from
our natural internal schedule. Today it is known that an
adjustment of this clock increases the risk of certain
diseases.
Non-visual effects as a basis for daylight planning
Most properties of natural light can be reproduced with
artificial light. But why do we usually perceive the intensi-
ty and changes of daylight as much more pleasant? Why
does it have such a great influence on our moods and
helps us to perceive and classify our surroundings holis-
tically? Current researchers agree that the mechanisms
of action of light are so complex that we have still a long
way to make from standards specifications to dynamic
lighting conception in buildings. But there are directions
recognizable.
For example, in their publication “Human Centric Light-
ing (HCL): provisional appraisal in June 2019, Canazei
and others add the recommendation to include as much
daylight as possible, to supplement cold-white artificial
light. By putting a vertical proportion as high as possib-
le during the day and, in the evening, to reduce vertical
sections of the light and to use punctual light. Daylight
raises the tolerance of higher light intensities for the user,
who perceives visual discomfort significantly later, day-
light is rated higher in quality of light than any artificial
light source and, moreover, daylight is the most efficient
light source for generating increased vertical brightness,
the authors further state.
The higher is the amount of daylight, the greater is
the challenge of finding the balance between dayligh-
ting, tanning and heat input. «The daylighting market
has been tremendously creative in recent years,» says
Robert Jagger, Country Sales Manager DACH at
Halio International, a Belgian manufacturer of swit-
chable glass systems.
«Dimmable glazing automatically reacts to the weather
outside and can be programmed as needed. Intelligently
networked, Halio glasses create ideal conditions in
terms of visual quality, thermal comfort and energy
efficiency,» continues Robert Jagger.
Switchable glasses in the flashpoint between light, comfort and energy efficiency
Especially for these three criteria, EN 17037 gives designers and builders the possibility to jointly set target values for indoor daylighting. The norm
distinguishes between the levels «Low», «Medium» and «High». It introduces the concept of daylighting, which for the first time evaluates daylight quality
over a whole year and incorporates local weather data into the calculation. The individual stages are fulfilled when 50% of the area has reached the
respective target illuminance during 50% of the daylight hours and when at least 95% of the area reaches the minimum target illuminance during 50%
of the daylight hours.
Recommendations for the daylight supply through daylight openings in vertical and inclined surfaces
EN 17037 gives target values for daylight quality
Recommended level for vertical and inclined daylight openings
Target illuminanceET
Space’s proportion for the target valueFplane, %
Minimum target illuminanceETM
Space’s proportion for the minimum target valueFplane, %
Share of daylight hoursFtime, %
Low 300 lx 50% 100 lx 95% 50%
Medium 500 lx 50% 300 lx 95% 50%
High 750 lx 50% 500 lx 95% 50%
Daylight openings in façades according to EN 17037
Also, for the view from the room, the tanning and the glare protection three recommendations levels from «Low» over «Medium» to «High» were determined.
What is new is that the outward view of the location of the users in the room is used and is included in the evaluation, whether the sky and the ground are visible.
When the sun is shining, the duration of the sun’s rays (minimum recommendations of 1.5 h to 4 h) is calculated on a specific key date while exceeding a minimum,
geographically different sun altitude angle. The reference points are in the window level. Last but not least, EN 17037 recommends the value of Daylight Glare
Probability (DGP) as the value for glare protection, i.e. the probability that a person will be blinded by light. Key figures such as vertical illuminance at the eye,
luminance, as well as geometric angle and position of the glare source are included in the DGP simulation.
Only «low-transmission glazing» or «electrochromic
glazing», which allow only a very low light transmission
in the dimmed state, are recommended in addition to
conventional shading systems as a suitable glare and sun
protection.
Even if the minimum requirements for daylighting in
EN 17037 have been set very low - even on a bleak winter’s
day outdoor illuminations of 3000 lx will still affect our
eyes - it is an expression of the fact that daylight planning
is still becoming increasingly important.
Uncolored Halio glasses have a transmittance of 65%, with a color rende-
ring index of 97% in the clear state, they are completely neutral in color and
show no unnatural bluish cast or grid or erratic gradients even with increasing
gray tint. In less than three minutes Halio glasses can be dimmed to a mini-
mum transmittance of 2%, the Halio glass system is by far the fastest on the
market today. Depending on the glass structure, Halio glasses achieve
Ug values of up to 0.6 W / (m2K). «Halio’s controlled system automatically
optimizes the amount of daylight and can therefore save up to 22% on
the costs of air conditioning and heating,» explains marketing director Ka-
tia Hansen. Halio is therefore recommended for all sustainable construction
projects, no matter if it has to respect Passive House, Minergie, BREEAM
or LEED norms.
Halio dynamic glass is the future of the facade. A modern facade automati-
cally regulates, incorporating a dynamic sunscreen, providing perfect thermal
insulation and natural ventilation, all in a slimline design. The precise flowing
tint of Halio glass makes the facade smarter and more efficient. Thanks to
Halio, Smart Buildings become even smarter.
Light management is sun protection plus comfort plus energy efficiency
The high degree of automation is ensured by the Halio Cloud. It communicates with all common building
automation systems and can be addressed either via apps, voice assistants or decentralized control panels.
«The Halio Cloud is well equipped for the application of EN 17037,» adds Hansen. We can incorporate individual
preferences as well as geographic location, orientation of facades and weather conditions into our daylight
management. «
Contact:
Halio International
Katia Hansen
Marketing & Communication
Halio Europa & Middle East
Avenue Jean Monnet 4
1348 Louvain-la-Neuve, Belgium
Tel. : +32 486 89 35 16
Email : [email protected]
www.halioglass.com
Ansprechpartner:
Press Relation:
Interview International
Ingrid Hecht
15, rue Martin Luther
67000 Straßburg, Frankreich
Tel.: +33 (0)3 88 15 55 88
E-Mail: [email protected]
About Halio International
Halio is the exclusive supplier of Halio products and services to
the building industry. The joint venture between AGC, the world’s
largest flat glass manufacturer and Kinestral Technologies, Inc.,
developer and manufacturer of the Halio smart–tinting techno-
logies, consists of the two business entities: Halio North America
and Halio International. This partnership leverages the partners’
respective strengths and expertise: AGC’s reputation and
100+ years of experience in glass technologies and Kinestral’s
innovative and patented smart-tinting technologies. For more
information visit halioglass.com or follow us on Twitter or Linke-
dIn.
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