Introduction: Villas built before 1960 make up about 45% of the housing stock in Sweden. With the average U-value of their walls around 0.5 W/(m²·K), and the average U-value for a horizontal attic floor in single-family houses is 0.33 W/(m²·K), there is significant concern about improving these values. Sweden's energy and climate goals aim for a 50% improv in energy efficiency by 2030 compared to 2005. Purpose: The purpose of this project is to explore potential energy efficiency measures for an older single-family house built in 1953. Specifically, the goal is to align the heat transfer coefficient of individual building components with the requirements outlined in BBR when modifying the building envelope. By doing so, the authors aim to contribute to and encourage the renovation of existing villas, which can lead to reduced energy usage. Moisture control, cost considerations, and examining insulation proposals for the Slab on grade are not included in this study. Method: This work is based on a case study of a single-family house from 1953 located in Ale, Västra Götaland in Sweden. The research uses a hybrid approach that integrates bothquantitative and qualitative methods to comprehensively investigate energy efficiency in older single-family houses. Quantitative methods include numerical measurements such as U-value calculations and heat demand analysis, while qualitative methods involve expert discussions on insulation requirements and heating system improvements. The methodology includes interviews to gain a deeper understanding of existing conditions and to propose ways to utilize the materials currently available on the market. It encompasses case studies and material analysis, with key calculations including U-value determination, average heat transfer coefficient (Um), and primary energy demand (EPpet). Energy-saving measures such as additional insulation and ventilation upgrades are central to the methodology, along with TMF calculations for heating system transitions. The method is consistently guided by predefined research questions to ensure coherence and clarity in the investigative process. Results: The study revealed that the original exterior wall of the case study had a U-value of 0.54 W/m²K, much higher than the current recommended value of 0.18 W/(m²·K), and the average U-value for a horizontal attic floor is 0.33 W/(m²·K) much higher than the current recommended value of 0.13 W/(m²·K). Through renovation, U-values of 0.17 W/(m²·K) for exterior walls and 0.1 W/(m²·K) for the ceiling were achieved. Option F, the best proposal, included a ground-source heatpump with an inverter, mechanical exhaust ventilation, and various insulation improvements, leading to energy savings of approximately 36 MWh/year. The average heat transfer coefficient (Um-value) of 0.29 W/(m²·K) was below the recommended 0.30W/m²K. Option F resulted in an energy classification of B. The improved EPpet value for Option F was 52 kWh/m², well below the recommended 90 kWh/m². Simply adding insulation to walls and roofs and upgrading windows yields slightly better results than only replacing the heating system.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:du-48928 |
| Date | January 2024 |
| Creators | Kherfan, Rashid |
| Publisher | Högskolan Dalarna, Energisystem i byggd miljö |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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