The Evolution of Energy-Efficient Glazing
PPG introduced the Solarban glass name in 1964. Now, as PPG celebrates the
brand’s 50th anniversary, it remains synonymous with industry-changing
advances in energy-efficient glass technology, included today’s most
sophisticated triple-silver-coated low-emissivity glasses.
The timeline below plots the technological advances associated with PPG and
Solarban glass, including two significant developments that predated the
debut of Solarban glass.
1934: The First Heat-Absorbing “Environmental Glass”
Formulated with high-iron content that resulted in a slight green tint,
Solex® glass (now Solexia® glass) by PPG was designed to absorb solar heat
and create more comfortable work environments in the new glass-and-steel
skyscrapers of the time. The most historic installation of Solex glass was
on New York City’s historic Lever House Building, which is often cited as
launching the era of the glass-clad modernist building.
1945: The Beginning of the Insulating Glass Unit
PPG first mass-produced dual-pane insulating glass units (IGUs) for
sound and temperature control in Pullman railroad cars before adapting the
technology to create Twindow® dual-paned residential windows. A
first-of-its-kind product, Twindow foreshadowed the green building movement
by promising to keep “homes warmer in the winter and cooler in the summer.”
The introduction of multi-pane IGUs marked a significant advance in window
performance and energy efficiency that continues to be refined today.
1964: The Introduction of Solarban Glass
In 1963, PPG adapted the wet chemical deposition coating process, which
had been primarily used to make mirror glass, to produce PPG LHR
(Light-Heat-Reflective) glass, the world’s first energy-efficient coated
architectural glass. One year later, PPG perfected the wet chemical
deposition process to create Solarban Twindow glass, launching the historic
Solarban brand name.
The double-pane configuration of Twindow glass, together with the reflective
Solarban coating, revolutionized solar control performance – producing a
0.25 solar heat gain coefficient (SHGC) that was significantly improved over
the 0.62 SHGC of tinted Solex glass. However, the mirror-like coating of
Solarban glass cut visible light transmittance (VLT), a critical measure of
transparency, from 77 percent to 20 percent.
1983: The Dawn of Low-E Glass
Almost 20 years later, PPG combined transparency with solar control for
the first time when it successfully deployed the magnetron-sputtered vacuum
deposition (MSVD) process to create its first low-emissivity (low-e) glass.
Coated with a single layer of heat-reflecting, light-transmitting silver,
the original low-e glass did more than offer a more desirable balance
between VLT (73%) and SHGC (0.51); it also ushered in a new technology
platform that has since become the basis for many of today’s most advanced
solar control, low-e coatings.
2000: Double-Silver-Coated Low-E Glass
PPG further refined MSVD coating technology creating the first temperable
double-silver glass for the automotive glass market. Ultimately refined for
the architectural glass market, this technology led to the launch in 2000 of
Solarban 60 glass, a double-silver-coated, solar control low-e glass that
outperformed PPG’s first low-e glass by dropping the SHGC from 0.51 to 0.39
while maintaining visible light transmittance of more than 70 percent.
2005: Triple-Silver-Coated Low-E Glass
PPG debuted triple-coated Solarban 70XL glass at the GreenBuild
International Conference and Expo. With visible light transmittance of 64
percent and a SHGC of 0.27, Solarban 70XL glass produced an unprecedented
light to solar gain (LSG) ratio of 2.37 that approached the theoretical
performance limits for low-e coatings and set a new standard for
2005-2015: A Decade of Progress
Over the past decade, PPG has continued to build on its technical
leadership, launching a variety of new products to meet the diverse
aesthetic and performance needs of architects and building owners. They
2007 – Solarban z50 glass: a double-silver MSVD-coated glass on Optiblue
glass, a unique tinted glass developed to optimize coating performance
2010 – Solarban R100 glass: an enhanced double-silver MSVD-coated
neutral reflective glass
2012 – Solarban 72 glass: a high performing triple-silver MSVD-coated
glass on ultra-clear glass
2013 – Solarban 67 glass: an enhanced double-silver MSVD coated glass
2014 – Solarban z75 glass: a high performing triple-silver MSVD-coated
glass on Optiblue glass
As PPG celebrates the 50th anniversary of Solarban glass, it continues to
refine glass coating technologies, enabling architects to tune solar control
performance to specific climates and project requirements, while offering an
ever-widening array of colors, tints and aesthetic options.