MechChem Africa January 2018

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Smart windows that channel magnetic fluids

O ur future selves might look back and wonder howwe ever handledhaving just plain old glass in our windows. Curtains or blindsmight get theflick in favour of a variety of smart windows that can tint themselves or turn opaque on command, and now a team of German engineers has demonstrated a new design. Dubbed Large- Area Fluidic Windows (LaWin), the system usesironparticlessuspendedinliquidtoblock sunlight at different levels and harvest heat energy from the sun. Most of the smart window systems we’ve seen in the past are electrochromic, mean- ing they change tint or opacity in response to electrical signals passing through wires embedded in the glass. That lets users cloud the window over if they want both privacy and natural light, or darken the glass to keep the house cool. This new system has similar applications but takes a completely different approach. To make a fluidic window, magnetic iron nanoparticles are suspended ina liquid, which is contained inside vertical channels in the glass itself. These particles cloud up the win- dow, blocking light to different degrees and

Altair Engineering.................................................................... IBC Cape Union Mart.......................................................................IFC Flexicon......................................................................................OBC Hahn & Hahn............................................................................ OFC Marthinusen & Coutts..............................................................19 Multotec Group...........................................................................11 Omron.............................................................................................27 productOne...................................................................................22 Rose Foundation........................................................................... 3 SEW-EURODRIVE......................................................................17 SKF....................................................................................................35 SMC Pneumatics.........................................................................43 Vega Controls.......................................................................37, 39 Zest WEG Group.........................................................................13 Index to advertisers info@miningindaba.com www.miningindaba.com Africa Energy Indaba 20-21 February Sandton Convention Centre, Johannesburg +27 11 463 9184 bette@energyindaba.co.za www.africaenergyindaba.com March 2018 FILTECH 2018 13-15 March Cologne, Germany Suzanne Abetz +49 2132 93 57 60 info@filtech.de www.filtech.de Industry diary February 2018 Mining Indaba 2018 5-8 February Cape Town International Convention Centre +44 07 779 8890 Extracted from a New Atlas article by Michael Irving. Original Publication: Heiz, B. P. et al. (2017): A Large-Area Smart Window with Tunable Shading and Solar-Thermal Harvesting Ability Based on Remote Switching of a Magneto-Active Liquid, Advanced Sustainable Systems, DOI: 10.1002/ adsu.201700140. ing to the developers these windows should continue to function for as long as thebuilding is in use. While the current prototypes were manufactured in batches measuring 200 m², the researchers say the technology should be scalable to standard sizes of window frames, including double- and triple-glazing frames. The endgoal is to cut backonenergy costs, particularly in terms of heating and cooling of buildings, which canmake up a huge percent- age of energy consumption. The design has already been funded to the tune of several millionEuros andcommercial applications are apparently planned for later in 2018.

soaking up heat as needed. When you want to make it transparent, switching the LaWin on triggers magnets to pull these particles out of the liquid. “Our project’s key feature is the use of liquids in windows and façades, for example, as heat carriers or to enable additional func- tions,” says Lothar Wondraczek, coordinator of the project. “To this end we develop new glassmaterials, intowhich large-area channel structures are integrated. These are used for circulating functional fluids. Dependingon the number of the iron particles in the liquid, the liquid itself takes on different shades of grey, or it will even turn completely black. Then, it becomes possible to automatically adjust the lightortoharvestsolarheat,whichcanthenbe put to further use within the building.” In terms of heat gainby area, the research- ers say the system is as about as efficient as solar thermal facilities. The team also says that no electrical connection is needed at the windows because toggling the particle capture system happens in a separate tank. The LaWin system might be fiddlier to produce, since the specialty channels need to be built right into the glass, but accord-

A prototype of the Large-Area Fluidic Windows (LaWin), which can control shade and harvest heat using magnetic nanoparticles suspended in liquid. Photo Credit: Jan-Peter Kasper/FSU.

Power & Electricity World Africa 2018 March 27 to 28, Sandton Convention Centre Power & ElectricityWorld Africa 2018 celebrates its 21 st anniversary this year. The show welcomes over 8 000 attendees and hosts along with solution providers spanning four halls and thousands of square metres. Power & Electricity World Africa is Africa’s longest running and largest power and energy show. For 21 years it has helped shape the regional energymarket through sharing knowledge, educating the market and facilitating influential meetings. The show’s mission is to maintain this forum as the industry meeting place where industry professionals come and learn how to develop sustainable, clean and bankable world class energy generation projects throughout the African continent. Cecilia Braxton: +27 11 516 4049; cecilia.braxton@terrapinn.com

44 ¦ MechChem Africa • January 2018