Table of content 1. Foreword ............................................................................................................................................... 2 2. Nomenclature ....................................................................................................................................... 3 2.1 Notations ....................................................................................................................................... 3 2.2 Abbreviations ................................................................................................................................ 3 3. Introduction .......................................................................................................................................... 4 3.1 Background ................................................................................................................................... 4 3.2 Purpose ......................................................................................................................................... 4 3.3 Delimitations ................................................................................................................................. 5 3.4 Method ......................................................................................................................................... 5 3.5 Stakeholder analysis ..................................................................................................................... 6 4. Frame of reference ............................................................................................................................... 8 4.1 Joule heating ................................................................................................................................. 8 4.2 Thermal efficiency ......................................................................................................................... 9 4.3 Heat transfer in a toaster .............................................................................................................. 9 4.4 Infrared heating .......................................................................................................................... 11 5. Method ............................................................................................................................................... 13 5.1 Getting to know the products ..................................................................................................... 13 5.2 Ideation ....................................................................................................................................... 30 6. Specifications ...................................................................................................................................... 41 6.1 Specifications for the toaster ...................................................................................................... 41 6.2 Specifications for the water kettle .............................................................................................. 42 7. Results ................................................................................................................................................. 43 7.1 Electric water kettle concept ...................................................................................................... 43 7.2 Toaster concept IR ...................................................................................................................... 44 8. Conclusions ......................................................................................................................................... 50 8.1 Water kettle ................................................................................................................................ 50 8.2 Toaster ........................................................................................................................................ 50 9. Discussion ........................................................................................................................................... 52 9.1 Future work ................................................................................................................................. 53 10. References .......................................................................................................................................... 54 1 11. Appendix A: Energy performance study of water kettle .................................................................... 55 12. Appendix B: user survey ..................................................................................................................... 57 13. Appendix C: Qualitative user study .................................................................................................... 68 14. Appendix D: QFD toaster .................................................................................................................... 72 15. Appendix E: QFD water kettle ............................................................................................................. 73 16. Appendix G: Energy performance test with IR-prototype .................................................................. 74 17. Appendix H: IR-emitter ....................................................................................................................... 75 1. Foreword In this chapter the people assisting in the project are acknowledge The main purpose of this project was to investigate the energy usage of small domestic appliances and develop concepts with less energy usage during the usage stage. Investigation of improvements and redesign of toaster, water kettle and coffee maker were made on behalf of the division Small domestic appliances at Electrolux AB. The project was conducted at a primary development phase where new technical solutions are the main focus. Firstly, thanks to the entire primary development team for aiding in idea generation and supplying interesting input. Special thanks to my supervisor Henrik Eriksson for supplying instruments and material and taking time to discuss the project and show of interest. My steering group, Johann Zita, Martin Andersson, Mathias Belin and Marianne Heydari for taking time to discuss the decisions making and helping the project steer into an interesting approach. Secondly, a survey over the internet was conducted with 55 answers and a qualitative investigation with four people. Thanks to everyone who participated in these user studies. Johan Jannung Stockholm, October, 2011 2 2. Nomenclature In this chapter the abbreviations and notations are stated 2.1 Notations Symbol Unit Description ̇ [W], [J/s] Power [J] Energy [J/gK] Specific heat capacity [K] Kelvin 2 [m ] Area [m] Meters [kg] Mass 3 [m ] Volume 3 [kg/m ] Mass density [V] Volt [ ] Resistance [A] Current [s] Time [m] Wavelength [1] Emissivity [Pa] Pressure [m/s] Speed 2.2 Abbreviations Abbreviations Description CAD Computer aided design IR Infrared NIR Near Infrared MIR Mid Infrared FIR Far Infrared SEK Swedish krona 3 3. Introduction The project is presented and the background explained. Delimitations and methods are made clear and a stakeholder analysis for the thesis is communicated. 3.1 Background In kitchen appliances, many products heat food or beverages to make them warmer and tasteful. Electrolux AB sells kitchen appliances in the breakfast line; electric water boilers, drip coffee makers and toasters. These products are common in many kitchens and sold in millions, every year. These products are used on daily basis and mostly used during breakfast. The concerning appliances have not been experience much energy saving innovations. Moreover, Electrolux have not been conducting much research and development on these products before. 3.2 Purpose The objective was to investigate the energy efficiency for these products. To clarify the function and purpose of the product and by this identify changes, to make them more energy efficient. Furthermore, identify where the energy losses was located and develop solutions to optimize the energy consumptions. The purpose was to develop new ways of heating water, toasting bread and making coffee that consumes less energy than the standard products on the market. The target was to develop concepts, technical solutions and test them against current appliances. The goal was to make technical feasible and verifiable solutions and prototypes. The main goal of the project was to - Develop prospective energy reducing concepts for the breakfast line products The targets were - Significantly reduced energy consumption, during usage phase, for at least one of the products in the breakfast line - Ensure that consumer demands as taste, safety and usability are satisfied Vision - “Develop a feasible energy efficient products making them 100 % efficient” Project deliveries - Energy efficiency test of current products - Functional prototypes 4 - Documentation and evaluation of developed concepts - Proposed improvements for the entire range of products - Visualizations of aesthetical, user friendly and improved products 3.3 Delimitations The total environmental impact of a product derives from the entire life cycle, from cradle to grave. However, this project focused on the usage phase of the products. When looking at the quantity of these products sold the usage phase contribute to emissions. The system boundary is seen in Figure