The future of windows –
Material innovation for energy efficient
building envelopes
Martin Schröcker
CTO, GlassX AG, Zurich, Switzerland
Exploitation manager project HarWin
03-2015 MS
Agenda
 Windows – cultural heritage
 New materials for windows – why are they
needed?
 EU-granted Smart Windows Projects
 Detailed view: HarWin project
 Case study: Phase change materials in windows
03-2015 MS
Windows – cultural heritage
Blick-ins-Grüne-immo-mitula
Evian, Genfer See
03-2015 MS
Mattias Klum - National Geographic
Windows – cultural heritage
 Historical role: facade opening for lighting and
ventilation of buildings
 Windows as cultural heritage

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Religious buildings
Prestigious buildings
Art objects
 Windows as technical achievement
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03-2015 MS
High performance buildings
Increased living comfort
Science & IT
Materials innovation for windows
Reduction of energy demand in buildings necessary
 Energy consumption in
building sector larger than
in transportation and
industrial processing sectors
storepet-fp7.eu
03-2015 MS
 Reducing building energy
consumption is key to
meeting EU greenhouse gas
reduction targets
Materials innovation for windows
Windows and frame influence over 50% of
energy demand in residential buildings
100%
90%

Exploitation of energy
saving potential  better
windows

Balancing of building
energy consumption
through energy harvesting
 smart windows

Focus on new materials
for intelligent windows
offering enhanced energy
control
Window solar
gains
80%
70%
60%
Window
conduction
50%
Infiltration
40%
Internal gains
30%
20%
Roof/Foundation/Walls
10%
0%
Heating
Cooling
Source: US DoE, 2010 Buildings Energy Data Book,
Aggregate Residential Building Component Loads
03-2015 MS
Materials innovation for windows
Functionality of new materials for windows

Weight reduction through utilization of strengthened thin glass
panes, polymer-glass composites and fiber reinforced materials
PV-Glazing

Energy conversion solar-electrical,
solar-thermal, solar-photonic

Radiation control in visible, IR and
FIR spectral range
BIPV-window, Wilson, 2012
Sunlight
Outer
IR-reflected
Colorless UVabsorbing PE-foil
Inner
Heat
Outer
Inner
Heat
Metallized PE-foil as
IR reflctor
Coloured UVabsorbing PE foil
g-Value
PV-window shades, apep.uci.edu
03-2015 MS
Visible radiation
Source: multifilm.de
[email protected]
g-Value
EU-granted Smart Windows Projects
 Goals of Smart Windows Programme
 Energy savings over life cycle up to 20%
 Weight reduction up to 50%
 Insulating window with u-value down to 0,3 W/m²/K
at VLT > 50%
 Projects funded under EeB Smart Windows
Programme EeB.NMP.2012-5
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03-2015 MS
Mem4Win
WinSmart
SmartBlind
EELICON
HarWin
EU-granted Smart Windows Projects
 Glazing concepts for Smart Windows


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Vacuum-Insulated Glazing, VIG
Multiple glazing up to 4 panes
Laminated thin glass pane glazing as multiple glazing
Glass particle
reinforced
laminate: HarWin
VIG: WinSmart
03-2015 MS
4-panes: Mem4Win
EU-granted Smart Windows Projects
 Energy conversion principles in Smart Windows

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Photo-chrome
Electro-chrome
Integrated OPV
WinSmart, SmartBlind
Solar-thermal
LDC (luminescent down conversion)
PCM (phase changing materials)
WinSmart, SmartBlind, EELICON
 Radiation control in Smart Windows (g-value)

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03-2015 MS
Low e-coatings
AR-coatings
IR-filters
Micro-mirrors
Micro lamella
Micro-mirrors
Mem4Win
MicroShade
HarWin Project
Goals of project HarWin
Materials
innovation
Polymer-glass
composite materials
for lightweight frames
Solar energy harvesting
with PCM* and UV to
visible light conversion LDC**
Glass-polymer composite
foils for lightweight
laminate glazing
03-2015 MS
Components
Glazing with
added
functionality
Technical feasibility and LCEA
Performance
modeling and
building
simulation
Life Cycle Environmental Analysis
* Phase Change Materials,
** Luminescent Down Conversion
Dissemination
& Exploitation
HarWin Project
Harwin Consortium
*
*Partner left the consortium in 02-2014
03-2015 MS
HarWin Project
HarWin material concept for glazing
VLT- or PCM-functionality of
glass particles
Low-e-coated thin glass pane
Inside
 Glass-particle reinforced
polymer foil: acoustic
damping and thermal
insulation, stiff and
transparent
Outside
AR-coated thin glass pane
 Problems to be solved upon
reinforcement with glass
particles: avoidance of haze
along with adjustment of high
toughness and acoustic damping,
as well as low heat conductivity
Relative thickness of different layers is not to scale
03-2015 MS
HarWin Project
HarWin light weight material concept for frame
Integrated
glazing-frame
element
Glass fiber reinforced
polymer tape on a
polymer foam core
(both PP based)
Basytec Broschure
Polymer foam with glass fiber reinforced topcoat as lightweight material for window
frame for significant weight reduction at low Uf-value and high acoustic damping
03-2015 MS
HarWin Project
HarWin preliminary results
Results
UGlazing
(calculated)
SoA Design
Weight SoA
0,48 W/m²/K
4mm/4 mm low e/4 mm low
e
30 kg/m²
HarWin Design
VSG 1,5-1,5/2mm low e/2
mm low e
Weight HarWin
17,5 kg/m²
Weight reduction
[%]
VLT [%]
LDC- und PCMfunctionality
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41,7%
S
74,3
G
Proven on lab scale
t
Case study: PCM in windows
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Case study: PCM in windows
15mm of PCM
03-2015 MS
200 mm of concrete
Case study: PCM in windows
GLASSX®store
GLASSX®crystal
Summer
Polycarbonate
containers
Polycarbonate
containers
Solar protective
prism
PCM
Winter
strengthened
glass
« Translucent
thermal mass for
lightweight
structures »
03-2015 MS
Inert gas filling
PCM
«Sun protection,
thermal insulation
and thermal mass in
one package »
Case study: PCM in windows
Winter
With PCM
Tint=29°C
Sun
Sun
Internal loads
Sun
Internal loads
Without PCM
Ventilation
Ventilation
Internal loads
Tint=24°C
PCM
Heating
Ventilation
03-2015 MS
Internal loads
Heat cond.
Heat cond.
Heat cond.
Tint=24°C
Tint=24°C
Heating
Ventilation
Heat cond.
Case study: PCM in windows
Summer
Internal loads
With PCM
Internal loads
Without PCM
Tint=26°C
TGX=
24°C
Sun
Air conditioning
Heat conduction
Ventilation
Sun
Heat conduction
Sun
PCM
Tint=26°C
Air conditioning
Ventilation
Note: Heat is released through free
night cooling
03-2015 MS
Case study: PCM in windows
Example - Office building
• Daylight concept: Elements allow the use of
unobstructed daylight in summer without risking
overheating
• Climatisation concept: No active cooling or
heating installed, building is cooled by passive
night air flow and heated by the sun
• Installation: GLASSX®crystal elements installed as
part of the outer façade, covering approx. 30% of
the south-facing building shell
• Ventilation system: Comfort ventilation with some
degree of underground heat storage installed
Object:
Marché International, Office building
Location:
Kemptthal, Switzerland
Architecture: Beat Kämpfen
Volume:
120 m2 GLASSX®crystal
03-2015 MS
Case study: PCM in windows
Example - School
• Daylight concept: Compared to massive walls the
rooms receive much more daylight
• Climatisation concept: Small-sized air conditioning
and passive cooling elements
• Installation: GLASSX®store elements are mounted
5-10 cm behind the curtain wall, architect has full
freedom to design outer façade
• Ventilation system: Grills in the floor release air
that streams along both sides of the GLASSX
element
Object:
‘Centre professionelle’, School
Location:
Fribourg, Switzerland
Architecture: Butikofer de Oliveira Vernay Sarl
Volume:
120 m2 GLASSX®store
03-2015 MS
Case study: PCM in windows
100%
10 – 30%
reduction
on average
80%
20 – 40%
reduction
on average
60%
Up to
100%
reduction
possible
40%
Up to
100%
reduction
possible
20%
0%
Heating energy demand
Reference building
03-2015 MS
Use of PCM storage
Note: Standard use in up to 30% of building façade
Source: GlassX project experience and simulations
Cooling energy demand
Optimised use of PCM storage
Conclusion
 Future windows will acquire additional technical and
aesthetic functionality
 New materials for windows – glazing and frame – can
enable implementation of light weight technologies
into architecture
 Energy harvesting through technologies like Phase
Change Materials can help to offset building energy
demand
 EU regulations support the development of smart
windows in the area of glazing as well as the frame
03-2015 MS
 Acknowledgement
 Financial support within the European Union Seventh
Framework Programme (FP7/2007-2013) for project
HarWin, No 314653.
 For your attention; further information is provided on
our homepage: www.harwin-fp7.eu
 With questions, feel free to contact me directly:
[email protected]
+41 44 389 10 72
03-2015 MS