<p>Background: The most energy efficient houses today are so called passive houses. These houses achieve high energy-efficiency partly by having well insulated walls. U-value describes the amount of heat transfered through a building element, the more insulation, the smaller U-value. A typical passive house wall have a U-value of 0.10 W/m2,°C. The passive houses are primarily made as small family houses and not as a block of apartments. This is partly because the bigger houses often are made of prefabricated walls, which at present times are not made with enough insulation. One construction method common in prefabrication is a sandwich-construction with two layer of concrete surrounding a core of cellular plastic. Skanska is making this type of walls in a factory on Gotland. </p><p>We wanted to combine the energy efficiency of passive housing with the efficiency of </p><p>prefabricated sandwich-walls. </p><p>Aims: To present a suggestion of a sandwich-construction made with concrete and cellular plastic with a U-value below 0.10 W/m2,°C, that could be implemented in the factory on Gotland. </p><p>Methods: By analyzing systems of today we developed two different models that have a U-value below 0.10 W/m2,°C. The first system was developed from a system used in Skanska’s factory on Gotland and the second one was based on a system delivered by Halfen DEHA. This was made through empirical tests and theoretical calculations. We compared the developed systems in terms of the conditions in Skanska’s factory on Gotland. </p><p>Result and discussion: The system based on Halfen DEHA needs a larger amount of shackles, than the system developed from Skanska’s present system. This leads to the need of thicker insulation to achieve the desired U-value. The reason is that the Skanska-based system uses a combination of shackles and cellular plastic to carry the loads of the coating layer while the Halfen DEHA depends on the shackles alone. We believe that the first of our two developed systems is the best in terms of the ease in adopting to the production method in Skanska’s factory. The second system is safer in terms of controlling the production and has the possibility to have an air gap. </p><p>Conclusion: In the rapport we present a sandwich-construction system that has a U-value below 0.10 W/m2,°C, that we believe would work for prefabrication of wall structures and could be easily adopted in Skanska’s factory on Gotland.</p>

Background: The most energy efficient houses today are so called passive houses. These houses achieve high energy-efficiency partly by having well insulated walls. U-value describes the amount of heat transfered through a building element, the more insulation, the smaller U-value. A typical passive house wall have a U-value of 0.10 W/m2,°C. The passive houses are primarily made as small family houses and not as a block of apartments. This is partly because the bigger houses often are made of prefabricated walls, which at present times are not made with enough insulation. One construction method common in prefabrication is a sandwich-construction with two layer of concrete surrounding a core of cellular plastic. Skanska is making this type of walls in a factory on Gotland. We wanted to combine the energy efficiency of passive housing with the efficiency of prefabricated sandwich-walls. Aims: To present a suggestion of a sandwich-construction made with concrete and cellular plastic with a U-value below 0.10 W/m2,°C, that could be implemented in the factory on Gotland. Methods: By analyzing systems of today we developed two different models that have a U-value below 0.10 W/m2,°C. The first system was developed from a system used in Skanska’s factory on Gotland and the second one was based on a system delivered by Halfen DEHA. This was made through empirical tests and theoretical calculations. We compared the developed systems in terms of the conditions in Skanska’s factory on Gotland. Result and discussion: The system based on Halfen DEHA needs a larger amount of shackles, than the system developed from Skanska’s present system. This leads to the need of thicker insulation to achieve the desired U-value. The reason is that the Skanska-based system uses a combination of shackles and cellular plastic to carry the loads of the coating layer while the Halfen DEHA depends on the shackles alone. We believe that the first of our two developed systems is the best in terms of the ease in adopting to the production method in Skanska’s factory. The second system is safer in terms of controlling the production and has the possibility to have an air gap. Conclusion: In the rapport we present a sandwich-construction system that has a U-value below 0.10 W/m2,°C, that we believe would work for prefabrication of wall structures and could be easily adopted in Skanska’s factory on Gotland.

Detta examensarbete fokuserar på utveckling och utvärdering av en ny metod för att räkna dubbelriktade personflöden inomhus med hjälp av Ultrasonic Time-of-Flight teknik. Projektets huvudsyfte är att skapa en kostnadseffektiv, strömsnål och integritetsvänlig lösning som är i linje med lagar som GDPR. Studien börjar med en kort genomgång av tillgängliga tekniker för personflödesmätning, men det blir tydligt att dessa tekniker brister i kraven för den önskade tekniken. Mot denna bakgrund framstår Ultrasonic Time-of-Flight som en lovande kandidat på grund av sin förmåga att detektera objekt och rörelseriktningar utan att samla in personligt identifierbar information. För att realisera detta projekt har ett utvecklingskit baserat på sensorn CH201 från Chirp Microsystems använts. Sensorns låga strömförbrukning och förmåga att mäta avstånd i ett brett synfält är det som är lovande i tekniken. Ett akustiskt hölje optimerar sensorernas synfält och minimerar störningar. Experimentdelen av arbetet inkluderar uppbyggnaden av en testmiljö där sensorernas förmåga att korrekt räkna individer och bestämma deras rörelseriktning testas. Resultaten från dessa tester visar på hög noggrannhet i detektering av enskilda individer som passerar, men har lägre noggrannhet då flera personer passerar samtidigt. Vidare diskuteras potentialen för att vidareutveckla systemet för att även kunna hantera större personflöden och mer komplexa scenarion, som flera personer som rör sig bredvid varandra i olika riktningar. En kritisk granskning av systemets prestanda under längre tidsperioder och i olika miljöer föreslås som framtida forskningsarbete för att ytterligare validera och förbättra tekniken. Sammanfattningsvis demonstrerar detta arbete potentialen hos tekniken som en säker och integritetsvänlig lösning för effektiv övervakning av personflöden. Med ytterligare utveckling och anpassning förväntas tekniken kunna uppfylla en ännu högre noggrannhet. / This thesis focuses on the development and evaluation of a new method for measuring bidirectional indoor people flows using Ultrasonic Time-of-Flight technology. The main purpose of the project is to create a cost-effective, low-power, and privacy-friendly solution that complies with laws like the GDPR. It begins with a short review of existing techniques for measuring people flow, concluding that these technologies do not support the goal of the new technology. Ultrasonic Time-of-Flight emerges as a promising candidate due to its ability to detect objects and directions of movement without collecting personally identifiable information. To realize this project, a development kit based on the CH201 sensor from ChirpMicrosystems has been used. The sensor’s low power consumption and ability to measure distances in a wide field of view are what made the technology promising. An acoustic enclosure optimizes the sensors’ field of view and minimizes interference. The experimental part of the work includes the construction of a test environment where the sensors’ ability to accurately count individuals and determine their direction of movement is tested. The results from these tests show high accuracy in detecting individual passersby but encounter more problems with multiple individuals simultaneously. Further discussions will explore the potential for developing the system to manage larger crowds and more complex scenarios, such as multiple people moving side by side in different directions. A critical review of the system’s performance over longer periods and in different environments is proposed as future research work to further validate and improve the technology. In conclusion, this work demonstrates the potential of the technology as a secure and privacy-friendly solution for effective monitoring of people flows. With further development and adaptation, the technology is expected to offer significantly better accuracy.