Why Micro Angle Chromatic Solutions is the natural evolution of spectrally selective coatings in the architectural glass industry



When German inventor Rolf Groth in 1971 filed the “heat-reflecting window pane” patent, he probably was not aware that this technology would become the leading solution in high-performance glass for the next 40 years. If someone could have told this from looking in their crystal ball and secured all possible patent variations, you would probably have been able to find them comfortably positioned among the absolute top of Fortune 500 companies today. Knowing that history has a tendency to repeat itself – we should always be on the look-out for technologies that hold the promise of disrupting the glazing industry.

However, disrupting technologies or quantum leaps rarely present themselves when existing technology has not yet reached its limits. Since the 1970’s there has been both strong and stable improvements in performance of spectrally selective coatings on glass roughly up until the year 2000 when the performance of selective coatings with close to neutral colour rendering approached its physical limitation. Since then, the industry has made only minor improvements to the performance of the selective coatings.

Today, the global architectural glass industry is presented with the paradox of seeing a growing demand for advanced glazing, while at the same time being painfully aware that it is impossible with the current neutral spectrally selective coating technology to truly gain an edge in terms of differentiation - nor can the platform deliver on the rising demands with regards to energy, indoor climate and overall well-being of the people inhabiting the buildings. The result is an explosion of a new shading solution industry, that since the mid 1990’ties has grown to be substantially larger than the façade glazing industry for commercial buildings in Europe with mature regions following globally. This industry, focuses mainly on exterior façade shading solutions which block the sun or selectively modify the incidence angle of light to achieve an energy performance well beyond that of neutral selective coatings on glass.

Examples of such façade shading solutions are many and include dynamic venetian blinds, fixed external lamellas and dynamic screens which are integrated as a part of the architecture. All these systems are thermally effective and offer an improved indoor climate as they provide an effective shading of the direct solar beam while to varying extent allowing diffuse light to enter the building. Shading systems using optically opaque lamellas can be characterised as classic examples of Angle Chromatic Solutions - or ACS. The basic principle of the ACS is to shade more solar irradiation from high than low incidence angles and herewith protect against the burning sun standing high in the sky.

Unfortunately, the benefit in energy saving and indoor climate of the classical ACS comes with a negative consequence in terms of reduced view out of the façade – not to mention the complexity and cost added to installation and maintenance as well as the high lifetime cost. Furthermore, they are unpredictable as their performance is dependent on configuration, wind and weather as well as manual overrides from tenants.

It seems as if the construction and real-estate industry is ready for yet another quantum leap, like the one we saw with the introduction of coatings in the 1970’ies. Ideally, it should be a solution, which combined all the positive characteristics of the coating as well as the ones from the ACSs – but without the drawbacks.

Enter the Micro ACS. This new platform for high-performance glazing products introduces new ways of manipulating the solar irradiation falling on glazed facades and roofs. In many ways Micro ACS works in similar ways to classic ACS, except the use of microscopic lamellas and other optical structures bring benefits to the solution that has not been seen before. Firstly, the microscopic structures can be made invisible to the human eye while maintaining the same shading effect as classical exterior ACS. This means that the shading element can be made invisible and that the users will have permanent view to the exterior through the Micro ACS. Secondly, microscopic structures easily fit inside the glazing cavity and can be protected by the glass resulting in long service life of the Micro ACS.

The range of MicroShade® products is an example of a micro ACS. In addition to the above qualities, glazing with MicroShade® delivers effective g-values as low as any exterior shading solution and due to the passive nature of the product the effect is fully predictable and requires no cabling and configuration.

  Laurits Macs Billede  

In effect, glazing with MicroShade® the Micro ACS manages to combine the best of the performance attributes from classical ACS with those of spectrally selected coatings on glass – it is not only efficient, but also simple, durable and predictable. As such, MicroShade® represents an example of a Micro ACS that constitutes a complete technological disruption, as the performance levels by far supersede the requirements of any façade demand in buildings today and expectedly the next couple of decades.

Energy and light performance are not the only parameters on which the Micro ACS eclipses the performance attributes of other solutions. In fact, Micro ACS is a technology platform which can be adapted to address specific challenges in a given location and building as well as it can service the demands of the complete façade addressing glare protection, light redirection, beam shading effects - all while maintaining view to the outside. In future versions it could also be possible to add photovoltaic features into the MicroShade® and thereby enable active harvesting of solar energy from the façade.

Such flexibility is of course primarily attractive to the users of buildings, but the technology is also well-suited to the requirements of building owners and contractors as the Micro ACS glazing is not only able to meet the regulatory demands for modern and future buildings, it is as simple to install as normal glazing and requires no mechanical configuration. Finally, it is a dream come true for the architect, as Micro ACS offers artistic freedom with fewer compromises on light and façade aesthetics, it enables a complete elimination of external shading systems and keeps the façade ‘clean’. Also, Micro ACS is compliant with shaped and even curved glazing - and sizes up to jumbo is a possibility if that is the architect’s vision for a building.

So, it would seem that evolution has brought about a new era in façade design where classical Angle Chromatic Solutions are currently dominating - but also that this will likely be very temporary as significantly superior performance can be introduced inside the glazing with both current and future Micro ACS technologies. 

By Laurits Bach Sørensen – CEO, MicroShade A/S

 

In summary:

7 reasons why Micro ACS will be the future in high-performance glass solutions:

  1. It outperforms existing technologies
    With its invisible 3D structures Micro ACS redefines the performance obtainable by technologies contained inside a glazing cavity and boasts very low effective g-values, while delivering a very high quality of daylight experience with plenty of useful daylight. It is also neutral in colour and gives a more uniform distribution of the light into the room.

  2. It is a complete “mass customizable” façade solution
    Micro ACS is not just a glass product - it is a configurable platform for the entire façade that can cater to the specific needs of the customer and not only deliver on the needs for bringing down energy penetration but can also be customized to a building for superior daylight experience, glare protection, light reflectance and view to the outside.

  3. It is durable
    Just like coatings, Micro ACSs are fully passive and lie protected within the cavity of the glazing allowing long lifetime and due to its passive nature it is also 100% predictable.

  4. It is simple
    Producing Micro ACS glazing units is easy and very cost effective like manufacturing of coatings on glass. A simple IGU line upgrade will allow for mass production of units. Furthermore, the simplicity extends also to the installation process of the glazing in the building which is similar to any other passive glazing; no configuration, just install and forget.

  5. Its performance is in demand
    Building certifications such as BREEAM and LEED, as well as regional building and energy regulations are constantly driving the demand up for energy efficient solutions and the reality is that most European countries demand facade performance on new builds today is below effective g-value 0.15 already; a performance level where the Micro ACS is the only simple and passive alternative which also delivers high quality daylight.

  6. The alternatives are complex and with significant compromises on light and view out.
    The most significant challenge with the classical Angle Chromatic Solutions, such as external shading systems, is not only its high investment cost, the complex installation, very large lifetime cost or unpredictable and maintenance heavy operations, but the trend towards true daylight simulations. The reason is that all these systems, unlike Micro ACS, achieve its low energy performance by impacting the daylight experience.
    It is a fact that that most building codes today do not include shading devices in their light specifications, but with LEED and BREEAM converting towards true daylight simulations and with most of the large architectural firms such as Henning Larsen choosing to simulate the actual daylight experience (also taking into account the influence from shading systems) - knowing the true impact on view out capability and daylight from these solutions will slowly disqualify them.

  7. It has a very compelling proposition across the full value chain
    The range and potential of Micro ACS is vast. The Micro ACS technology platform can be configured to meet different requirements depending on the customer needs and will offer completely new possibilities for façade design. It also reduces risk and complexity for the contractor and building planners while at the same time outperforming all other existing alternatives on energy, light, view out, building design effectiveness, installation simplicity, lifetimes cost and sustainability. In essence, all influencers and decision makers in the long and complex building industry value chain will benefit substantially by Micro ACS solutions compared to alternatives.