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Innovation for insulation: the ins and outs of polisocyanurate or PIR foam in retrofitting


PIR foam is one of the top performing insulation materials on the market. Its lambda value - insulating capacity - is good, and enables relatively thin layers of insulation for walls and roofs of buildings. It also happens to be easy to install and there are many types and sizes.

By incorporating phase-changing materials (PCM) microcapsules, PIR foam can increase thermal inertia, meaning it can store excess energy. In PCM, the energy is adsorbed when the material changes in state, from solid to liquid, and it is released when the materials changes in state back from liquid to solid. PIR insulation with PCM embedded can be used to limit energy loss.

This savvy combination of PIR foam and phase-change materials was put to the test in a world first for a public building - an engineering college in the Belgian city of Liège. The building was an energy-eater and needed a serious overhaul of its façades, ceilings and roof. Today with the PIR foam and PCM microcapsules, the building boasts new thermal storage and smart temperature control capabilities, accomplished as part of a European project called BRICKER.

For four and a half years, the 18-strong consortium has been putting together a set of energy-saving measures specifically for retrofitting non-residential public buildings. The overall goal of the BRICKER project (Energy Reduction in Public Building Stock) is to develop a scalable, adaptable and highly energy-efficient system for refurbishing non-residential public buildings in order to radically reduce energy consumption and greenhouse gas emissions.

“What was innovative with BRICKER at the Liège building was the merging of PIR foam and PCM material as this kind of solution isn’t yet available on the market”, explains Marta Pieńkowska of Polish company Purinova which specialises in PIR applications.

PCM microcapsules were produced at the Acciona Spray Drying pilot plant facility, following patented production system. These were then sent to the Purinova production facility where PIR+PCM insulation foams where produced according to Purinova’s optimized synthesis process.

PIR foam was used in Bricker project to provide high quality, durable insulation that can be fitted into existing architecture at the engineering college. For Pieńkowska, “the technical challenge was to develop a PIR system to work with PCM; a high amount of solid PCM needed to be introduced into the foam without affecting its mechanical properties.”

There was a regulatory challenge too. During the PIR-PCM foam production stage, local fire restrictions caused some delays in final panel design, as it was necessary to fulfil all fire requirements according to the obtained test results. This was overcome by using and additional layer as a flame barrier.

The main drawback with PIR foam is indeed its relatively higher flammability compared to other insulation materials such as mineral wool. However at the Liège building, a solution was found to ensure compliance with building regulations and the benefits of PIR foam, especially with embedded PCMs, look set to play a major role in building retrofitting.


27 March 2018