Development of a Sustainable Dishwasher for Compact Living Master of Science Thesis in the Master Degree Programs, Industrial Design Engineering and Product Development SOFIE ANDERSSON JOHAN HAGEJÄRD Department of Product- and Production Development Division of Design & Human Factors CHALMERS UNIVERSITY OF TECHNOLOGY Gothenburg, Sweden 2016 Development of a Sustainable Dishwasher for Compact Living Department of Product- and Production Development Division of Design & Human Factors SOFIE ANDERSSON JOHAN HAGEJÄRD CHALMERS UNIVERSITY OF TECHNOLOGY Gothenburg, Sweden 2016 Master of Science Thesis SUPERVISOR: JOHAN HEINERUD EXAMINER: ULRIKE RAHE Master of Science Thesis PPUX05 Development of a Sustainable Dishwasher for Compact Living Master of Science Thesis in the Master Degree Programs, Industrial Design Engineering and Product Development © SOFIE ANDERSSON & JOHAN HAGEJÄRD Chalmers University of Technology SE-412 96 Goteborg, Sweden Telefon +46(0) 31-772 1000 Cover: The final concept Uniwa Print: Repro Service Chalmers Abstract Urbanisation and climate change will bring challenges to the way we design our future homes. Since the middle of 2009, more people are living in cities than in rural areas. A decline has been seen both in the average household size and floor area per person. With more people living in less area per person, there will be a growing need for more space efficient as well as energy efficient solutions. A dishwasher can save both energy and water compared to manual dishwashing. Still, many small households are without a dishwasher due to limited space. This master’s thesis project has been carried out in collaboration with Electrolux and has had the aim to develop a space efficient dishwasher concept that meets the needs and requirements of small households, while minimising the energy and water consumption related to the dishwashing process. Findings from user studies, literature studies and benchmarking indicate that there is a lack of dishwashers on the market that are adapted for smaller kitchens and households. A dishwasher designed for this segment should focus on making the most out of the already limited workspace and storage found in compact kitchens. Another finding was that user behaviour greatly affect the environmental impact of the dishwasher. This concerns for instance pre-rinsing of dishes before placing them in the dishwasher, the extent to which the dishwasher is loaded and the selection of washing program. To evaluate the possibilities of saving water and energy related to the dishwashing process, the total water consumption of the kitchen was considered. A conclusion drawn was that there is a lack of system thinking over the kitchen’s water consumption. Used tap water of relatively high quality and energy content is not taken advantage of. The final concept is a solution that handles all washing and waste management of the kitchen in one unit, where the sink unit and the dishwasher are designed to support each other. A great focus lies on flexibility of use to support the various tasks handled in the kitchen. Preface This is a report for a master’s thesis project of 30 ECTS in the Department of Product and Production Development at Chalmers University of Technology. The project has been carried out in collaboration with Electrolux, beginning in January 2016 and running until June 2016. The project idea was an initiative by the project team and the scope and content was then initiated and formulated together with the examiner. Supervisor at Electrolux Adam Szczepanowski, Global Product Line Leader – DishCare, Senior Design Manager, Major Appliances EMEA, Electrolux Group Design Examiner Ulrike Rahe, Professor, division of Design & Human Factors, Department of Product and Production Development, Chalmers University of Technology Supervisor Johan Heinerud, Lecturer, division of Design & Human Factors, Department of Product and Production Development, Chalmers University of Technology Project Team Sofie Andersson, Master’s student at Industrial Design Engineering, Chalmers University of Technology Johan Hagejärd, Master’s student at Product Development, Chalmers University of Technology Acknowledgements In this master’s thesis project there have been many people who have provided knowledge as well as support to the project team. Without them, this project would not have been possible. First of all, we would like to thank Adam Szczepanowski, our supervisor at Electrolux, who has guided us and given us valuable inputs throughout the whole project. Thank you for believing in our concept and for inspiring us with your positive spirit. We also want to thank Anna Delin at Advanced Development at Electrolux for providing us with knowledge about dishwashers and for discussing the feasibility of the concept. We would also like to thank the other employees who attended our final presentation at Electrolux in Stockholm and showed interest for our solution by asking relevant questions. Johan Heinerud, who has been our supervisor at Chalmers, deserves a great thanks for his support in this project. Our discussions about different ideas have been inspiring for our work. Finally, we want to thank our examiner Ulrike Rahe for making this project possible by establishing contact with Electrolux and communicate the idea of a project dealing with the development of a sustainable dishwasher for compact living. Contents 1. Introduction ............................... 1 1.1. Background ................................... 1 1.2. About Electrolux .......................... 3 2. Theory ....................................... 4 2.1. The dishwashing process ...... 4 2.2. The dishwasher .......................... 5 2.3. Design for sustainable behaviour ....................................... 9 2.4. Water treatment ........................ 11 2.5. Water storage ........................... 13 3. Methodology ......................... 14 3.1. Planning ......................................... 14 3.2. Data collection ........................... 14 3.3. Analysis ........................................ 15 3.4. Concept development ............ 16 3.5. Evaluation ..................................... 17 4. Initial Research and Analysis ................................... 18 4.1. Literature studies ....................... 18 4.2. Benchmarking .......................... 20 4.3. Function analysis ..................... 22 4.4. Analysis of Electrolux’s visual brand identity ............... 22 5. User study ............................ 24 5.1. User study setup ..................... 24 5.2. User study findings ................. 25 6. Basis for Concept Development ........................ 36 6.1. Main findings from initial research and user study ..... 36 6.2. Initial list of requirements ....... 38 6.3. Personas ..................................... 38 6.4. Expression .................................. 40 7. Concept development ..... 42 7.1. First concept generation ....... 42 7.2. Evaluation of concepts ......... 50 7.3. Second concept generation ................................... 50 8. Further Research and Development ........................ 55 8.1. The system – interplay between components ........... 55 8.2 Dimensions and configurations ............................ 58 8.3. Form development .................. 64 8.4. Development of the user Interface ....................................... 66 9. List of Requirements ........ 67 9.1. General requirements ............. 67 9.2. Dishwasher requirements .... 67 9.3. Sink requirements ................... 68 9.4. Faucet requirements .............. 68 9.5. Semi-tank requirements ....... 68 9.6 Recycling drawer requirements .............................. 69 10. Final Concept .................... 70 10.1. UNIWA ........................................ 70 10.2. The product and its constitutient parts .................. 70 10.3. The pre-rinsing system ....... 78 10.4. Controlling the dishwasher drawers from the interface panel ....................... 78 10.5. Form design and expression ................................ 80 11. Evaluation ............................ 83 11.1. Calculation of possible energy and water savings ........................................ 83 11.2. Implemented design strategies for sustainable behaviour .................................. 85 12. Discussion .......................... 87 12.1. Process and methods ......... 87 12.2. Final result ................................. 89 13. Conclusion .......................... 93 14. Recommendations for Further Work ..................... 94 1 1 Introduction This chapter introduces the master’s thesis project by describing the background and aim as well as the delimitations of the project. It also gives an overview of the report outline and ends with a brief introduction of the company Electrolux. 1.1. Background The world has gone through a major demographic shift with more people living in urban areas than in rural areas since the middle of 2009 (United Nations, 2010). Urbanisation is expected to continue and United Nations (2010) predicts that by 2050, the world urban population will increase to 6.3 billion, which is about the same size as the world’s total population was in 2004. Urbanisation brings both challenges and opportunities. Developed countries have historically increased the average amount of floor space available per person but today, this number is beginning to decline. With more people living in less area per person, our future homes will need to provide more flexible, smart and sustainable solutions. As living space becomes smaller, design will play an important role in developing pleasant and convenient solutions that can utilise space more efficiently. Multi-purpose functionality of products is becoming increasingly important, as well as enhanced customisation (Electrolux, 2015). Apart from the shift to urbanisation, there has also been a shift to smaller household sizes. According to Dol and Haffner (2010), European households have become smaller as a result of more older people, fewer children and more young single-person households. In 2012, single-person households accounted for more than 38% of all households in Sweden, Norway, Denmark and Germany (Euromonitor, 2013). In Sweden, the share of single-person households increased from 33% to 44% between 1981 and 2008 (Dol and Haffner, 2010). Single-person households require the same amount of household appliances as larger households, which makes it an important group to consider in the development of home appliances. It is also important to develop products that facilitate the social change while at the same time considering the environment (Electrolux, 2015). 1.1.1. Problem Description By using a dishwasher instead of washing by hand, you save not only time but also energy and water. Still, many households are without a dishwasher because of limited space in their kitchens. Most of the dishwashers that exist on the market today are suited for larger kitchens and households. The smaller variants that exist are often in the category of benchtop dishwashers. These are in many cases too bulky to fit into kitchens with limited workspace, which is typical for the compact 2 kitchen. At the same time, they can only handle limited variants of dishes and do not fully replace the standard sized machines. Therefore, there is an opportunity to explore the needs and requirements related to dishwashing in small households and develop a dishwashing machine to meet those needs. This is also an opportunity for Electrolux to explore a new market of dishwashers and promote a more sustainable way of handling dishes. 1.1.2. Project aim The aim of this project is to develop a dishwasher for small households with limited living space. The final concept should be compatible with standard measures used in kitchen modules and should also fit into Electrolux’s product portfolio. The aim is also to reduce the environmental impact of dishwashing compared to washing dishes by hand. 1.1.3. Questions posed The questions posed in this master’s thesis project is: o How should a dishwasher be designed in order to meet the needs and requirements related to compact living? o How should a dishwasher be designed in order to minimise the environmental impact of the dishwashing process? o How should such a dishwasher be designed in order to fit into Electrolux’s product portfolio? 1.1.4. Delimitations The final concept of this project is targeted to the European market, mainly focusing on Sweden. The user study have included people living in Sweden and the development work has focused on dimensions found in Swedish kitchens. This does not limit the concept from being able to reach a global market as well. The concept focuses on compact living and a sustainable use of water and energy in the kitchen, which are contributing factors to making it interesting on a global market due to the trends of urbanisation, climate change and limited resources. The target users for this project are people living in urban areas with compact living space. They have dynamic lifestyles and find chores such as dishwashing too time consuming. This target group includes a wide range of ages, from adolescents living in cramped student apartments to senior citizens who want to make the most out of their living space. The target users are living in apartments and households of one up to two people. The main focus will be people in their mid-twenties to mid-thirties who are working and spending little time at home. The final concept should be feasible to be realised within five years. The concept has therefore been based on technologies already existing on the market today. Every detail of the concept has not yet been defined and will need further development. The aim of minimising the environmental impact of the concept is mainly focused on the use phase. Materials selections, production methods and the end of life phase have therefore not been included in the scope of the project. Interior layout and interface of the concept have been considered, but not in focus of the development process. 1.1.5. Deliverables The main deliverable for this project is an academic report describing the work process, main findings from the study and the resulting concept. The project will finally be presented at Chalmers University of Technology and at Electrolux in Stockholm. 3 The presentations will include visualizations of the final concept through illustrations and CAD renderings. 1.1.6. Report outline This report consists of fourteen chapters, each starting with a short introduction to its contents. After this first chapter that introduces the background and aim of the project together with a short description of the company Electrolux, follows a theory chapter that presents information from different areas relevant for this project. Chapter 3 describes the different methods used and Chapter 4 presents findings and results from the initial research that was made in this project. Thereafter follows a chapter covering the setup and findings of the user study. Chapter 6 is a summation of the main findings from both the initial research and the user study. This chapter functions as a bridge between the study and the concept development, which is presented in Chapter 7. Chapter 8 explains the further research and development of the concept, followed by a list of requirements in Chapter 9. The final concept of this project is presented in Chapter 10 and evaluated in Chapter 11. The final three chapters includes a discussion about the methods and result of this project, the conclusions and recommendations for further work with the concept. If the reader is mainly interested in the final result of the project, this is presented in Chapter 10. To better understand the final outcome, the reader should also go through Chapter 6 until 9. Complementary material can be found in the appendices. 1.2. About Electrolux 1.2.1. The Electrolux Group Electrolux is a global leader in home appliances and bases their product development on deep consumer insight and close collaboration with professional users. They offer products such as dishwashers, refrigerators, vacuum cleaners, washing machines, cookers, air conditioners and small domestic appliances. Every year, more than 50 million of their products are sold in more than 150 markets. About 50 percent of the sales are in America, 30 percent in Europe and 20 percent in other markets. Electrolux Group consists of eight strategic brands including AEG, Electrolux, Eureka, Frigidaire, Grand Cuisine, Molteni, Westinghouse and Zanussi. The Group offer solutions to both consumers and professionals, reaching luxury, premium as well as mass markets (Electrolux, 2016a). 1.2.1. The Electrolux brand Electrolux has an impressive heritage stretching back to 1919, when it was founded by an agreement between AB Lux and Svenska Elektron AB. Since then, they have developed a variety of successful products based on their philosophy of being convenient, easy and enjoyable to use at home. A few examples of their innovative creations are the world’s first vacuum cleaner with metal runners and the world’s first benchtop dishwasher (Electrolux, 2016b). Figure 1.1 – The Electrolux logo 4 2 Theory This chapter presents the theory relevant for this project. This includes theory about the dishwashing process and the dishwasher itself. The chapter also covers theory about water treatment and storage as well as theory about design for sustainable behaviour. Figure 2.1 – Sinner’s circle describing the different factors that affects the cleaning performance of the dishwashing process 2.1. The dishwashing process 2.1.1. Factors affecting the cleaning performance Sinner’s circle (Figure 2.1) is a theory widely used to describe the washing performance for laundry as well as dishwashing processes. It was founded by Dr Herbert Sinner, who between 1932 and 1966 was employed by Henkel & Cie and worked with textile washing procedures and improving the washing result of mechanical washing devices. His theory states that the cleaning performance is determined by four individual factors: temperature, time, chemistry and mechanical action. These 5 factors operate together and if one of them is reduced, at least one other factor has to be increased to achieve the same washing result (Beringer and Kurz, 2011). 2.1.2. The dishwasher cycle The washing cycle of a dishwasher can be divided into several steps. A normal washing cycle includes at least a pre-wash, a main wash and a rinse. Water temperature, duration and how many iterations the dishwasher will perform depends on what dishwashing program the dishwasher is running. If an auto program is used, the cycle will adapt its temperature and duration to the amount of soil on the dishes. The dishwasher cycle is designed to give a good cleaning result while minimizing water and energy use. As cleaning performance is determined by temperature, time, chemistry and mechanical action, this means that an eco-program will consume less water and energy, but at the cost of a longer wash cycle (Szczepanowski and Delin, 2016). Pre-wash The pre-wash prepares dishes for the main wash phase. The purpose of the pre-wash is to soak dishes and to remove loose particles which are drained at the end of this phase. By removing loose particles, less particles will be available to dissolve and soil the water during the main wash. The pre-wash is normally performed without heating or detergent. Main wash The main wash is done to remove soil that did not dissolve during the pre-wash phase. At this stage heat and detergent are added to increase the cleaning performance. The water is then drained before the rinse phase. Rinse Rinsing is done to remove soiled water remaining from the main wash phase that include food particles and detergent. The rinsing often consists of two steps. During the first rinse, no heat is added. During the final rinse, water is heated and rinse-aid added to prepare for the drying process. Drying As the water is heated and rinse aid added during the last rinse this will not only speed up the drying process but also have a positive effect on the cleaning result. By doing so, the risk of having lime deposits on the dishes when water evaporates is reduced. Water that evaporates will either condensate on the dishwasher walls and then be collected in the sump at the bottom of the dishwasher, or be exchanged with the surroundings by venting the dishwasher. There are mainly two ways to do this, either by opening the dishwasher door or by the use of a vent fan inside the dishwasher (Szczepanowski and Delin, 2016). 2.2. The Dishwasher 2.2.1. Technical principle and construction The typical consumer dishwasher has a water circulation and filtration system to remove and collect food particles from dishes. In addition to this, heat and additives are used to increase the cleaning performance and to speed up the drying action. As described in Section 2.1.1., the cleaning performance is determined by four factors including temperature, time, chemistry and mechanical action. The different parameters may differ between different models, brands and program used but the technical principle are similar for most consumer dishwashers. 6 Figure 2.2 – Technical principle of the dishwasher The dishwasher can be described as a hydraulic system. The hydraulic system alters between working as an open or as a closed system depending on which operation the machine performs. When the dishwasher acts as a closed system, water is circulated in the machine. The main components involved at this stage includes a circulation pump, a filter unit, a heater and at least one water distributer, called spray arm. The spray arm rotates as it sprays water on the dishes that are placed in the racks. The circulation of water and the motion of the spray arm are all driven by the pressure from the circulation pump. At this stage, food particles are removed from the dishes and collected within the filter unit. As the water circulates within the dishwasher, it is heated up by the heater component. The walls of the dishwasher are insulated to maintain heat within the system. When the dishwasher acts as an open system, water is instead passing into the dishwasher and out through the drain. The water passes into the machine via an inlet valve. This allows for clean water to enter the dishwasher. After the water has circulated a number of times in the closed system, water can then be drained by the drain pump. At this stage, food particles are removed from the filter and flushed out through the drain. An overview of the different components is shown in Figure 2.2. The spray arm The standard sized and the narrow dishwashers typically uses two spray arms since they both have a two storey configuration. One spray arm is placed underneath the upper rack and the other is placed on the floor on the dishwasher. There are also models with a third spray arm mounted on the ceiling to increase water distribution on dishes in the upper rack. The benchtop or compact dishwasher typically have a one storey configuration and therefore uses one spray arm. In order to distribute the water a number of jet holes can be found on the spray arm. The circulation pump forces water into the spray arm and out through the water jet holes. The 7 nozzles on the water jet holes have a small angle so that the reaction force from the water jets causes the spray arm to rotate, this to distribute the water as much as possible over the dishes. The dishes that are convex like glasses and bowls are placed upside down to prevent collection of water. The upper spray arm sprays water upwards to clean dishes in the upper rack and downward to clean dishes in the lower rack. The lower spray arm sprays water upwards to clean dishes in the lower basket and downwards to transport soil to the drain which also helps to clean the filter unit. If the dishwasher is equipped with a third spray arm in the ceiling, the water jets sprays water downwards. The spray arm comes in different configurations with the intent to optimise the cleaning result. There are also spray arm configurations with an additional rotating part to increase the distribution of water even further. Electrolux for example uses a rotating sprinkler device called satellite in some of their dishwashers (Szczepanowski and Delin, 2016). The filter unit The main function of the filter unit is to collect food particles that are mixed with the process water. This prevents loose food particles from being repositioned on the dishes. When the particles are separated from the water they can then easily be flushed away when water is drained. Another function of the filter unit is to prevent larger particles from blocking the system and to protect the pumps from damages. If the system is blocked, the circulation will be restricted and the dishwasher will not work properly. Larger particles might clog the water jet holes on the spray arms and prevent water from reaching the dishes. The filter unit plays an important role in order for the circulation to work, which allows cleaning dishes with less water than a system without circulation would. In order to have a high filter efficiency while maintaining a high flow rate, the filter is divided into two sections: one fine and one coarse filter. The filtration is done in parallel which allows the main flow to go through the coarse filter. The coarse filter allows for a higher flow rate than the fine filter but can on the other hand not collect as fine particles as the fine filter. Correspondingly the fine filter have a lower flow rate but collects finer particles. As the water circulates several times, it will eventually pass through the fine filter as well. With a continuous flow through the fine filter, particles can gradually build up and stay in the fine section. By using two parallel filters water can pass through the filter unit with sufficient flow rate to supply the spray arms continuously. To prevent the filter from clogging, which will decrease or even stop the flow, the filter must be cleaned during the washing cycle. The coarse filter is cleaned by a water jet from the lower spray arm that rinses the particles in the direction towards the sump. The sump is where water is collected and diverted to the circulation pump. The finer filter that is placed in the sump is cleaned by back flushing water during the drain phase. Sensors In order for the dishwasher to be able to operate and to control different parameters it is equipped with a number of sensors. Type and number of sensors may vary between different dishwashers. A water level sensor makes sure that the dishwasher has enough water to run the circulation pump. A floater ensures that the dishwasher does not overfill with water. There are also sensors measuring the temperature of the process water circulating within the machine. 8 With a turbidity sensor, also called soil sensor, included in the dishwasher, the wash cycle can be adapted to the soil level of the dishes. This means that instead of running a fixed wash cycle, the dishwasher will adjust the cycle to get the dishes clean by using minimum amount of water and energy (Delin, 2016). The turbidity sensor estimates the amount of particles in the process water by using infrared light. Compared to having to run an extra wash cycle because of a poor washing result, a prolonged wash cycle determined by the sensor will save both time and water. However, the dishwasher has to be cleaned regularly for the turbidity sensor to work. Otherwise, it will continue to sense particles in the water and prolong the cycles more than necessary, leading to a higher energy and water use in the end (Parkinson, 2016). Commercial dishwashers Dishwashers that are used in commercial kitchens are effective and fast but use much more energy and water than consumer dishwashers (Szczepanowski, 2016). These types of machines are often designed specifically to handle a certain type of dishware. Except for the additives used in consumer dishwashers, some types of commercial machines also use pellets to increase the mechanical action. 2.2.2. Energy classification Household dishwashers sold in the European Union are required to bear an energy label declaring the energy efficiency of the product (European Commission, 2010a). The energy efficiency is rated on a scale from A+++ to D, with A+++ being the most efficient and D the least efficient rating. When the energy labelling was first introduced, its energy efficiency scale ranged from A down to G. As dishwashers have become more efficient, the scale has been extended up to A+++, removing the lower efficiency classes of E down to G. Figure 2.3 – The standard energy label of a household dishwasher (European Commission, 2016) Apart from the energy efficiency rating, the label includes information on the annual energy and water consumption of the dishwasher. The capacity of the dishwasher is measured by the number of place settings that it can hold, which is a defined set of tableware used by one person for a three course meal. Additionally, the label presents a rating on the dishwasher’s drying efficiency and its noise emissions (European Commission, 2010a). The energy efficiency rating is based on an index that takes several factors into account, including the capacity of the dishwasher, power consumption in ‘standby’ and ‘off’ mode, program time and energy 9 consumption. The index is calculated by comparing the annual energy consumption of the dishwasher with a reference value of a standard annual energy consumption of a dishwasher that is used 280 times a year (European Commission, 2010a). Since the implementation of the European energy labelling for dishwashers in 1999, dishwashers have become considerably more efficient. Between 1999 and 2005, the average energy consumption per cycle was reduced by almost 30 %, from 1.43 kWh to 1.035 kWh. In 1999, approximately one third of the dishwashers had a worse energy rating than class C and only about 9 % had a class A energy efficiency. In 2005, the share of class A dishwashers had increased to 90 % with no dishwashers being worse than class C (Stamminger, 2007). Since December 2013, the lowest approved rating of a household dishwasher with a capacity of 11 place settings or more is A+ (European Commission, 2010b). In 2010, The European Commission identified the best available household dishwashers in terms of the parameters included in the energy label for different dishwasher capacities. In the category of 12 place settings dishwashers, the best one had an energy consumption of 0.95 kWh/cycle and a water consumption of 9 litres/cycle. In the 6 place settings category, the best model had an energy consumption of 0.63 kWh/cycle and a water consumption of 7 litres/cycle (European Commission, 2010b). Heating is by far the most energy consuming factor in the dishwashing process. Energy is not only needed for heating the process water, but also for heating the dishware and the interior of the machine, which constitutes a large part of the total mass that needs to be heated in order to reach the desired temperature. In relation to heating, the work performed by the circulation pump demands significantly less energy and constitutes only a fraction of the total energy consumption (Szczepanowski and Delin, 2016). 2.3. Design for Sustainable Behaviour When designing for sustainability, it is important to look into every phase of a product’s lifecycle, from raw materials and manufacturing to end of life. For electronic products, it is often in the use phase where the greatest environmental impact occurs and this phase offers a great potential for improvements. When making efforts in reducing the environmental impact of the use phase, this is often done by making the product more energy efficient, with little attention paid to the user’s involvement. But the environmental impact during use is strongly affected by the way that users interact with the product (Strategic Direction, 2008). Changing user behaviour into a more sustainable way is therefore of high value. This, however, is not an easy task. Consumers are slow to adopt more sustainable behaviours (DeVries, 2006; Siegle, 2006) and even when they do so, these changes are often short-lived (Scott, 2004). Several authors have come up with different approaches on how to influence users to a more sustainable behaviour. In 1997, Jelsma applied the concept of scripting as a way of reducing environmental impact by influencing how users interact with products. He describes a script as “a kind of user manual inscribed into an artefact” (Jelsma, 1997). The design of the product should guide the way it should be used by making unsustainable behaviour difficult or impossible, while sustainable behaviour is made easy or even automatic (Jelsma and Knot, 2002). Lilley et al. (2005) made a first attempt to capture several approaches in one 10 framework, referred to as product-led interventions. The product-led interventions consist of the three following strategies: o Scripts and behaviour steering – products or systems that contain scripts for the intended use by the designer o Eco-feedback – products or systems which inform users of the impact of their behaviour in an attempt to persuade them into a more sustainable behaviour o ‘Intelligent’ products and systems – avoiding rebound effects by ceding the decision making to the product or system in order to control or block inappropriate user behaviour Bhamra et al. (2008) developed the product- led interventions framework by Lilley et al. (2005) further by splitting it up into seven design intervention strategies: o Eco-information – provides information to the users by making consumables visible, understandable and accessible in order to inspire them to reflect upon their use of resources o Eco-choice – provides options to encourage the users to take responsibility of their actions o Eco-feedback – offering real-time feedback and informs the users about the consequences of their behaviour o Eco-spur – inspiring users to a more sustainable behaviour through rewordings for good behaviour and penalties for unsustainable usage o Eco-steer – makes intended behaviour easier and unintended behaviour more difficult by embedding affordances and constraints in the product design o Eco-technical intervention – restrains unintended behaviour and makes intended behaviour automatic through advanced technology o Clever design – automatically acts environmentally without raising awareness or changing user behaviour through innovative design Wever et al. (2008) distinguish two options for reducing environmental impacts during use. Either you can adapt the product better to the actual use and thereby minimise negative side effects, or you can influence the user behaviour through design. Matching the products’ functionality to the actual use is the least intrusive of all the strategies but probably also leads to the least improvement in environmental impact. When influencing user behaviour through design, the more the product is in control, the more the intrusiveness increases, and the more effective it gets in making a sustainability improvement (Wever et al., 2008). Lidman and Renström (2011) have created a model based on previous work in the area that includes five categories of design strategies for sustainable behaviour: Enlighten, Spur, Steer, Force and Match (see Figure 2.4). The first four categories requires the user to change his or her behaviour and are ordered according to the degree of the user being in control versus the designer being in control of the behavioural change. The fifth category, Match, differs from the previous categories in the way that it requires none or little user adaptation. The categories can be described as follows: o Enlighten - motivates the user to change behaviour through information, feedback or means of reflection. Raises the user’s awareness of their behaviour and its consequences. o Spur - encourages the user to change behaviour by focusing on positive consequences or aspects apart from the environmentally related ones, through for instance incentives or competition. o Steer - guides the user through for instance constraints and affordances to 11 make the most sustainable behaviour the evident choice. o Force - restrains the undesired behaviour or limits functionality to force the user into the desired behaviour. o Match - instead of changing the user’s behaviour, the product is adapted to the current behaviour or intention of the user. At the same time it minimises its environmental impact (Lidman and Renström, 2011). Figure 2.4 – Design strategies for sustainable behaviour (Lidman and Renström, 2011) 2.4. Water treatment The process in a water treatment plant includes a series of individual processes that are effective in separating different contaminants from the water. Each individual process will be described below in the typical order they usually have in the overall water treatment process. 2.4.1. Coagulation and flocculation The purpose of coagulation is to condition the dissolved and dispersed matter of the water that do not sink to the bottom of the water container. This is done by adding chemical coagulants such as alum and iron salts or organic polymers. The coagulation process destabilised particles which means that it reduces the surface charge of particles. It also adsorbs dissolved matter into particles and forms flocculent precipitates that catch dissolved matter as it settles to the bottom. The following flocculation process aggregates the destabilised particles into larger particles that can later be removed by the subsequent processes of gravity sedimentation or filtration. The flocculation process takes around 20 to 40 minutes in general (Crittenden et al., 2012). 2.4.2. Sedimentation Sedimentation is the process where large enough particles sink to the bottom by 12 gravitational forces. This can be done by letting the water flow in a calm pace through a large basin. This gives the particles time to settle and form a sludge layer on the bottom, which can then be removed by mechanical scrapers (Crittenden et al., 2012). 2.4.3. Filtration In the filtration process, water passes through a porous medium that removes particles physically that are too large to pass. The porous medium can either be a thick bed of granular material such as sand, or a membrane which is a very thin synthetic material with tiny holes in it through which the water can pass. Rapid filtration is the most common granular filtration technology, which has a high filtration rate due to processing of the granular media into a more uniform size than what is typically found in nature. Membrane filtration is a much newer technology that rely on straining instead of depth filtration, which means that it does not require coagulation, flocculation and sedimentation for effective particle removal. Even though a membrane filtration plant demands 100 times the filter area of rapid granular filtration plant, the membrane filtration plants are often smaller due to their high packing density (Crittenden et al., 2012). Filtration membranes are classified as microfiltration or ultrafiltration membranes. Microfiltration membranes have a pore size of 0.1- µm, which captures particles, sediment, algae, protozoa and bacteria. Nanofiltration membranes has a pore size of 0.01- µm, which also captures small colloids and viruses. Both types of filtration mediums needs to be periodically cleaned from particles through a backwash cycle (Crittenden et al., 2012). 2.4.4. Reverse osmosis Another membrane treatment process is reverse osmosis, which is a pressurised system that lets water pass through the membrane while solutes are rejected. Reverse osmosis is used for desalinating seawater and brackish groundwater. It is also used for softening of water, disinfection by-product control, specific contaminant removal and advanced treatment for drinkable water reuse (Crittenden et al., 2012). 2.4.5. Adsorption and ion exchange In the processes of adsorption and ion exchange, dissolved constituents are transferred to the surface of a solid and thereby removed from the water. In drinking water treatment, the most common adsorbent material is activated carbon. The adsorption processes are used to remove synthetic organic chemicals, taste- and odour-causing organics, colour forming organics and disinfection by-product precursors (Crittenden et al., 2012). 2.4.6. Air stripping and aeration In the processes of air stripping and aeration, water and air is brought into close contact so that volatile substances like hydrogen sulphide or volatile organic compounds can be transferred from the water into the air. Likewise, substances can be transferred from the air to the water like for instance oxygen and carbon dioxide (Crittenden et al., 2012). 2.3.7. Advanced oxidation Unlike previously described water treatment processes where contaminants are removed from water, the oxidation process instead chemically transform compounds so their undesirable properties are eliminated. During the oxidation process, electrons are transferred from one reactant to another (Crittenden et al., 2012). 13 2.4.8. Disinfection Disinfection is an essential part of the process of making water safe to drink. Five different disinfection agents are common to use in the drinking water treatment: free chlorine, chlorine combined with ammonia, chlorine dioxide, ozone and ultraviolet (UV) light. The use of UV light involves the use of electromagnetic radiation while the other four are chemical oxidants. The use of chlorine is most common while the use of ozone has increased lately due to its stronger disinfecting properties and its control of taste and odour compounds. The use of UV light is not yet very common but it is expected to increase in the future because of its lack of generation of by-products and its effectiveness against protozoa (Crittenden et al., 2012). 2.5. Water storage Water stored for longer periods of time may be subjected to growth of Legionella bacteria. Legionella bacteria may cause illnesses of varied severity, from a mild febrile illness called Pontiac fever, to a potentially fatal form of pneumonia called Legionnaires’ disease (World Health Organisation, 2007). Legionella bacteria are commonly occurring in both natural and artificial water environments but its growth may be encouraged by the conditions of the storage tank. Temperature is one of the influential factors as the bacteria can multiply at temperatures between 20o C and 45o C (Health and Safety Executive, 2014). Below 20o C, there is little or no increase in numbers of legionella bacteria. At temperatures of 50o C, they are able to withstand for several hours while at temperatures above 70o C, they are destroyed almost instantly. Another factor influencing the bacterial growth is the presence of other microorganisms as they allow legionella bacteria to increase in numbers (World Health Organisation, 2007). 14 3 Methodology This chapter describes the methods and tools used in this project, divided into the areas of planning, data collection, analysis, concept development and evaluation. 3.1. Planning 3.1.1. Gantt chart A Gantt chart is useful in getting an overview of the time plan for a project. It illustrates the relationships between different activities and time. Each activity is listed on the vertical axis and illustrated by a horizontal bar in the chart. The length and positioning of the bars in relation to a horizontal axis show the start and end date as well as the duration of each activity. Gantt charts are easy to understand and communicate to others (Maylor, 2010) 3.2. Data collection 3.2.1. Literature studies The purpose of literature studies is to gain more knowledge and insight about specific areas relevant for the study. Relevant information can be found in various publications, including physical books as well as online sources (Bohgard et al., 2010). Information was collected throughout the whole span of the project and included material about dishwashing, water and energy consumption, compact living, water treatment and different technical principles. The material was retrieved from sources like e-journals, web pages and company reports (see References). 3.2.2. Benchmarking Benchmarking is a method used to investigate market trends and differences within a specific segment. It can be used to analyse the strengths and weaknesses of existing products, as an understanding of competitive products is critical to successful positioning of a new product (Ulrich and Eppinger, 2012). Benchmarking was performed at several stages of the project to gain knowledge about existing products, features and configurations. 3.2.3. Survey Surveys are useful when the aim is to collect data from a large amount of people during a short period of time or from people that are difficult to reach. They can also be used to validate the result from interviews. Surveys mainly collect quantitative data and should contain clearly formulated questions (Bohgard et al., 2010). An online survey was sent out at an early stage of the project as an explorative method to gain knowledge related to dishwashing from a varied group of people. 3.2.4. Interviews For gathering information about people’s thoughts and opinions, the most fundamental method to use is interviews. 15 Depending on the structure of the interview, the data that is being collected can be either qualitative or quantitative. In a structured interview, the interviewee is asked predetermined questions that can be answered either freely or by choosing between predetermined alternatives, providing quantitative data that can be easily analysed. In an unstructured interview, only open-ended questions are asked and the interviewee can steer the discussion into areas they find important, providing qualitative data. A semi-structured interview is a combination between the two, which allows for probing (Bohgard et al., 2010). The interviews performed in this project was of a semi-structured character, with open discussions about areas that was found interesting during the interviews. 3.3. Analysis 3.3.1. Function analysis To perform a function analysis means to translate fundamental system requirements into detailed specifications for subsystems and functions (Bohgard et al., 2010). There are several ways to perform a function analysis. The method used in this project is based on an approach by Cross (2000), which includes the following steps: First, the general function of the system is expressed as a conversion from input to output. Second, the general function is split into central sub functions. Third, the interactions between the sub functions are drawn in a block diagram. Fourth, the sub functions are allocated to components. The function analysis was performed in order to describe what is being achieved in current dishwasher systems by analysing the flow of material, energy and information as well as relations between the different sub functions. 3.3.2. KJ-analysis KJ-analysis is a method used for structuring large amounts of collected data in order to get a better overview. Quotes and comments from the study are written down on one post- it paper each. These are then placed together with related post-it’s on a board, creating several categories which can be used later as a guide when formulating requirements for the concept (Karlsson, 2007). 3.3.3. Fishbone/Ishikawa diagram A fishbone diagram, also called Ishikawa diagram, is used to structure the main and part reasons to a defined problem. This is in order to simplify the finding of a solution to the problem. The procedure starts by defining the problem. Problem categories are then identified through brainstorming and part reasons are listed. Finally, the reasons are ranked according to their importance (Bohgard et al., 2010). 3.3.4. Design Format Analysis (DFA) The purpose of a Design Format Analysis (DFA) is to identify characteristic visual elements of a brand, also known as explicit design cues. The visual elements can be found in shapes, proportions, colours, materials, textures, graphics etc. How characteristic each of the identified elements is can then be assessed by comparing them with each other and by comparing different products from the brand’s product range (Warrell, 2006). 3.3.5. List of requirements A list of requirements is a document that, based on findings from the study, formulate in detail what a product has to fulfil. It does not, however, give any solutions to how customer needs should be met or how 16 problems should be solved (Bohgard et al., 2010; Ulrich and Eppinger, 2012). The list of requirements is often not completed at one single occasion. It can be continuously updated throughout the product development process as the solutions go into more and more detailed levels (Bohgard et al., 2010). This was also the case in this project, where a very general list of requirements was created at first to allow for various solutions. As a more specific direction of the solution was chosen, more requirements were added, focusing on different parts of the concept. 3.3.6. Persona An effective way of communicating the attitudes, desires and needs of the target user it to create a persona. A persona is a fictive character who could be a possible user of the product. In order to cover a variety of users in the target group, several personas can be created (Österlin, 2010). Three different personas was created in this project. Different personalities, habits and living situations were assigned to the personas, all representing possible members of the target group. 3.3.7. Scenarios Scenarios were used to analyse and communicate different use situations and for specifying requirements of the concept. 3.4. Concept development 3.4.1. Brainstorming Brainstorming is a widely used method for idea generation. It is performed in groups during sessions with the aim of producing as many ideas as possible. Criticism is not allowed during the brainstorming session, as it has a negative effect on the creativity. All ideas are noted down and evaluation of the ideas is performed after the session (Bohgard et al., 2010). Brainstorming was performed at several stages of the concept development phase, in the beginning focusing more on general problems found in the study while the later brainstorming sessions focused on finding solutions to specific aspects of the chosen concept. 3.4.2. Sketching Sketching is an effective method for exploring, analysing as well as communicating different ideas. It can be used at different stages of a project with varied level of detail depending on what the purpose is. At the concept generation stage, sketches are made fast and simple in order to express different ideas. At the stage of further refinement and concept selection, the sketches often include more information showing design details and features (Ulrich and Eppinger, 2012). Sketching was used intensively in this project for generating ideas, evaluating different design alternatives and for communicating different possibilities both within the group and with supervisors. 3.4.3. Physical models Building physical models in foam board is a quick method that allows concepts to be expressed in three dimensions and often in full scale. These models are generally made quite rough, but provide the possibility of better evaluating concepts and making design modifications (Ulrich and Eppinger, 2012). Physical models was used mainly to evaluate the dimensions of the concept at the concept refinement stage. 3.4.4. CAD-modelling Computer aided design (CAD) tools are used to generate three-dimensional models of concepts, that can be rapidly modified and visualised as realistic images. The CAD software can also be used to generate 17 drawings and models that can be directly transferred to mechanical systems (Ulrich and Eppinger, 2012). The CAD-software that was used in this project to generate the concept model was CATIA V5. 3.5. Evaluation 3.5.1. Kesselring matrix The purpose of a Kesselring matrix is to evaluate different concepts from a number of defined criteria. The criteria are given a weight indicating their importance and the concepts a score on how well they meet each criteria. The scores and weights are then multiplied to generate total scores that can be compared between the different concepts (Johannesson et al., 2004). 18 4 Initial Research and Analysis In this chapter, the results from the initial research and analysis performed in the project are presented. The results come from literature studies, benchmarking and different tools including a function analysis and a design format analysis. 4.1. Literature studies 4.1.1. Water consumption in households According to Vattenfall (2016), the average water consumption per person and day in Sweden is 160 litres. Of these, about 30 litres are used for dishes and 10 litres for cooking and drinking. Hot water stands for about 40% of a household’s total water use and 20% of the total energy consumption. About 40% of the hot water is consumed in the kitchen (Vattenfall, 2016). As part of a study on dishwashing habits conducted by the University of Bonn, data was provided from measurements of water consumption through the kitchen tap in 81 households from Germany, Italy, Sweden and the UK. The total result showed an average consumption through the kitchen tap of almost 19 litres per person and day. However, the result differed a lot between the countries with the lowest consumption in Germany, of just 11 litres compared to 21 in Sweden and almost 24 in Italy. The activity that was found to contribute the most to the kitchen tap’s water consumption was dishwashing with an average share of 58%. This percentage includes the water used for manual dishwashing but also the water used for pre-rinsing the dishes in households with dishwasher. The pre-rinsing stood for between 14% and 25% on average of the dishwashing category of water consumption in households with a dishwasher (Richter and Stamminger, 2012). The second most tap water consuming activity in the kitchen was found to be cleaning, including activities such as rinsing out the cloth or sponge, cleaning the sink and rinsing packages to prepare them for recycling. The rinsing of packages was especially common in Sweden and the UK among the four countries. Cooking activities ended up on a third place in the study with more than half of the category’s total amount of water being used to wash vegetables, fruit or meat. The category also included filling water into a pot, rinsing pasta, plunging eggs into cold water, unfreezing and making ice cubes (Richter and Stamminger, 2012). Richter and Stamminger (2012) found a varying consumption of tap water used for the drinking category. In Sweden, the participants often left the tap running before filling up the glass or bottle so that more water than necessary was used for the actual drinking. In Germany, the participants showed the opposite behaviour as in a 19 majority of the cases, water was filled directly into the glass or bottle. Another important finding that Richter and Stamminger (2012) made was that single- person households consume around twice as much water per person as a person in a five- person household. The difference in water consumption per person between single- person and two-person households, however, was quite small with only 10% less for two-person households. Comparing single- and three-person households the reduction was as much as 40% less per person for the three-person households (Richter and Stamminger, 2012). This makes it extra important to consider small households in developing projects concerning kitchen water use. 4.1.2. Comparison between manual dishwashing and use of dishwasher Stamminger et al. (2010) performed an investigation on the environmental effects of manual dishwashing compared to dishwashing machines by letting 113 persons from seven European countries wash 12 place settings (equalling 140 individual pieces) of dishes manually. They then compared the results to two modern A labelled dishwashers running under equal conditions. They found that in average, the test persons used 103 litres of water and 2.5 kWh of energy to wash the 12 place settings of dishes. In comparison, the dishwashers used 15 litres of water and between 1 kWh for a ‘normal’ program and 2 kWh for an ‘intensive’ program. The test persons took in average 79 minutes time to finish the dishes compared to the operating time of typically between 80 and 160 minutes for the dishwashers. However, considering instead the total working time of around 15 minutes for loading and unloading the dishwasher, the user can save at least one hour’s work per load by using a dishwasher. Regarding the wash result, it was found that the dishwashers were able to reach at least the same performance as the test persons, but with significant less amount of water (Stamminger et al., 2010). Another consumer study on dishwashing was performed by Richter (2010) including 200 households with and without dishwasher from Germany, Italy, Sweden and the UK. The households were interviewed and kept diaries recording every dishwashing process for two weeks, with 82 of them participating in deeper observations including webcam recordings and resource consumption measurements. From the study, it was found that the households with dishwasher on average used 50% less water and 33% less energy per cleaned item compared to the households without dishwasher. However, the study also showed that even with the ownership of a dishwasher, a large proportion of the dishes still get washed by hand (Richter, 2010). 4.1.3. Consumer behaviour affecting the environmental impact of dishwashers Although a dishwasher has the potential to lower a household’s water and energy consumption, its environmental impact is greatly affected by consumer behaviour. In the study performed by Richter (2010) it was found that pre-rinsing of dishes was a common consumer habit especially in Sweden and Italy. This activity caused an average additional water consumption of 11 litres per dishwasher cycle in the Swedish households and 20 litres in the Italian households participating in the study. Dishwasher manufacturers recommend consumers to scrape or wipe food leftovers from the dishes before placing them in the dishwasher. If consumers do not perceive the dishes to get clean from the wash cycle without pre-rinsing them, a less water 20 consuming option is to use the dishwasher’s ‘rinse and hold’ program. Another factor affecting the energy consumption of the dishwasher is the program selection. Richter’s study showed that the majority of the participants chose the same program all the time and that in half of the wash cycles, a temperature of 65oC or higher was selected. In the Swedish households, the most commonly chosen program temperature was 50/55oC followed by 65oC. Very few of the Swedish households selected programs of either 35/45oC or 70/75oC. The extent to which the dishwasher’s total loading capacity is used also affects the water and energy consumed per item. In Richter’s study, less than 40% of all dishwasher loads were filled to the full capacity. The Swedish households, however, had the lowest proportion of only slightly filled baskets among the four countries in the study. Comparing different household sizes, Richter (2010) found that the frequency of dishwasher use and manual dishwashing is higher per person in single-person households than in bigger households. This tends to lead to higher water and energy use per item for the single-person households. Concerning the dishwasher capacity, a lower capacity did not seem to increase the dishwashing frequency in the study. Single- person households with a standard sized dishwasher was found to run their machines almost as frequently as single-person households with countertop dishwashers (Richter, 2010). 4.2. Benchmarking 4.2.1. Dishwasher configurations From the benchmarking, the project team was able to identify six different dishwasher configurations found on the market today, which are presented below and summarised in Table 4.1. Standard dishwasher 60 cm A dishwasher of standard width (60 cm) gives the highest capacity and can normally take between 12 and 15 place settings, where one place setting equals about the amount of dishes that one person generates from a three course dinner. This type can either be fully integrated with a front panel matching the rest of the kitchen, or semi-integrated, leaving the control panel to the dishwasher visible. They can also, of course, be installed without any integration, leaving the whole machine visible. The interior of a standard dishwasher commonly includes two level racks with the lower meant for large dishes like plates and sauce pans but also includes a basket for cutlery. The upper rack leaves less height above itself and is intended for smaller dishes like glasses and cups. There are also variants including three level racks, where the third and uppermost rack holds cutlery, replacing the cutlery basket from the first level rack. Narrow dishwasher 45 cm A narrow dishwasher of 45 cm has a similar layout to the standard machines but has a lower capacity of normally nine place settings, which equals about two thirds of the capacity of the standard dishwashers. Like the standard ones, this type also has the possibility to be integrated with front panels. Compact/benchtop dishwasher A compact dishwasher, also called benchtop dishwasher, are for those who do not have the possibility to install a standard or narrow dishwasher in their kitchens, or for those who only generate a small amount of dishes. A compact dishwasher is typically 55 cm wide and has the capacity of six place 21 settings, or about half the capacity of a standard dishwasher. There are a few models also from this category that can be integrated in the kitchen with a front panel. Drawer dishwasher This category of dishwashers is relatively new and was launched first by Fisher&Paykel in 1997 with their DishDrawerTM (Architecture & Design, 2008). This type of dishwasher has only very recently started to appear on the Swedish market. The DishDrawer from Fisher&Paykel comes in several configurations with either double or single drawers. The double drawers have the same outer measurements as a standard dishwasher, with the capacity of six place settings in each drawer. The separate drawers allow you to run smaller loads more frequently. The single drawers are also available in extra tall or extra wide models. Just like the above presented categories of dishwashers, the DishDrawers can be integrated as well. Sink dishwasher The principle of a sink dishwasher is to replace the sink with a combined sink and dishwasher to avoid taking up storage or workspace in the smallest kitchens. However, the sink dishwasher extends downwards and takes up more space from the sink cabinet than an ordinary sink does. A few years ago, KitchenAid launched its in- sink model Briva, with a capacity of up to five place settings and a top lid that could be used as extra workspace when closed. At the moment, sink dishwashers are not available on the Swedish market. Portable dishwasher Portable dishwashers on wheels are an option for people who do not have the possibility to install a dishwasher in their kitchens but have enough space to store a dishwasher somewhere else. When used, the dishwasher is placed beside the sink and connected to the faucet. Portable dishwashers exists in the sizes of standard (60 cm) or narrow (45 cm), but are not available on the Swedish market at this moment. Table 4.1 – Benchmarking of dishwasher configurations 22 Figure 4.1 – Function analysis of the dishwasher 4.3. Function analysis A function analysis as seen in Figure 4.1 was performed to analyse and map up the flows of material, energy and information during a normal wash cycle of the dishwasher. The information flow is marked by a dashed arrow while the material and energy flows are marked by continuous line arrows. 4.4. Analysis of Electrolux’s visual brand identity According to Karjalainen (2007), a brand’s character can be mediated through a product by using explicit and implicit design cues. The explicit values of a brand can be immediately perceived and recognised through design features embedded in the product while implicit values are more related to the overall reputation and image of the brand. 4.4.1. Design Cues To identify the explicit design cues that expresses Electrolux’s visual brand identity, several existing Electrolux products were analysed according to a Design Format Analysis (DFA). The DFA can be found in Appendix II. The identified design cues are summarised below and by Figure 4.2. o Distinct flow line (1) that balances strong angles with a little bit of smoothness. It is often symmetrical on a central axis but can also be part of other directional lines in the product. 23 o Angled surfaces and flow lines showing direction. o Sharp contrasts between surface finishes, materials and colours (2). o Common materials are shiny plastics, glass and stainless steel. The stainless steel can have both brushed and shiny surface finish. o The logotype is often in a central position on the central axis of the product (3). The logotype consists of a symbol and text, which are often placed together with the symbol above the text. A bit less common is to place the symbol and text at separate places, or with the symbol to the left of the text. o The colour of the logotype depends on the colour of the surface it is placed on. If placed on stainless steel it is often black/dark grey while if placed on a dark surface it commonly has a light silver tone. When placed on a white surface, the logotype can either have a darker silver or grey tone o Besides the logotype, silver can be found in other small details as well such as text or buttons (6) o Chamfered edges (4) together with slightly arched and angled surfaces give the products a compact, strong and robust appearance. This expression is further enhanced by the distinct split lines (5) and sharp transitions between different surfaces. Figure 4.2 – Identified design cues exemplified in the Electrolux Ultraone vacuum cleaner 24 5 User Study The setup and findings of the user study are described in this chapter. The user study deals with the use of dishwashers but also manual dishwashing, cooking habits and kitchens in general. 5.1. User study setup A user study was performed early in the project and aimed to get an understanding for habits, attitudes and thoughts as well as problems related to dishwashing. The study included both people who own a dishwasher and people who wash the dishes by hand as the two groups were believed to contribute with different perspectives on the dishwashing matter. The user study started off with a survey to provide quantitative and general information about dishwashing. Thereafter followed semi-structured interviews with people who were considered to be within the target group. These interviews aimed at getting deeper knowledge about the target users’ wants and needs related to dishwashing as well as to cooking and the kitchen in general. To get more information about customer demands when purchasing a dishwasher, a semi-structured interview was performed with the store manager of an Electrolux Home store in Gothenburg. Another interview with the administrator for rented apartments at HSB Gothenburg discussed kitchen layouts and the possibilities of installing a dishwasher in different types of rented apartments. Lastly, one short interview was carried out with the master chef in a commercial kitchen at Chalmers University of Technology for taking inspiration from the effectiveness and efficiency of a workplace kitchen handling a large amount of dishes each day. 5.1.1. Survey The survey was spread as an online version via Facebook and email. It consisted mainly of multiple choice questions that would be quick to answer but also had a few open ended questions were more information was sought for. The survey consisted of six sections where the first handled general questions about age and housing. The second part dealt with the kitchen and cooking behaviour while the third part was about environmental impact and washing effectiveness of dishwashers in relation to hand washing of dishes. After section three the respondents were sent further to two different sections depending on their answer to the question “Does your kitchen have a dishwasher?”. Finally, all respondents finished the survey with a section about dishwasher purchase. In total, the survey generated 97 responses with age distribution and type of housing shown in Figure 5.1 and 5.2. The living space of the respondents varied from less than 20 m2 to more than 100 m2 and the number of 25 people per household from one person to more than four. This diversity of respondents was desired in some of the questions, while in other questions it was more interesting to look only at what people living more compact answered, which is why a filter was added to screen out respondents living in 50 m2 or larger in some questions. This left 40 responses, of which 20 were single households, 17 households of two people, one household of three people and two households of four or more people. The last two stated to be living in student apartments of less than 20 m2, which in this case would probably mean a rented room with shared kitchen. It will be specified in the text as well as the diagrams whenever the filter is used for a result. Figure 5.1 – Age distribution of survey respondents Figure 5.2 – Living space distribution of survey respondents 5.1.2. Interviews Eight interviews were held with twelve persons from ten different households. This means that in half of the cases the participants were interviewed one by one and in the other half of the interviews there were two participants, who were encouraged to discuss with each other for generating deeper information. All interviews were of a semi-structured character meaning that some prepared questions were posed but whenever needed, the interviewees were given supplementary questions to explain more. The interviews ended with a task where the participants were asked to place the dishwasher in relation to other kitchen appliances on a diagram measuring utility versus status, and encouraged to explain their thoughts while they were doing so. After the interviews, the participants were also asked to photograph their kitchens and send the pictures to the project team. The complementary interviews with Electrolux Home and HSB Gothenburg were both held via phone while the interview with the master chef was held in the commercial kitchen at Chalmers University of Technology for being able to observe the flow and different operations handling the dishes. 5.2. User study findings 5.2.1. Cooking habits The cooking habits were found to be highly individual among the participants in the user study. In the survey, the respondents were asked how often they buy lunch and dinner during a normal week excluding the weekend. Buying lunch was in general more frequent (mean value 2.3) than buying dinner (mean value 0.9). Adding the filter of living space less than 50 m2 was found to have little effect on the result. Among those respondents, the mean values were 2 for buying lunch and 0.9 for buying dinner. Among the interviewees, the cooking 25% 43% 15% 9% 8% Age 18-24 25-29 30-39 40-49 50-60 0 5 10 15 20 25 How big is your living space in square meters? 26 frequency varied between three times a day to about once a week, not meaning that the persons would buy food for all other meals but rather that more simple meals was prepared or that they had ready meals or lunch boxes available. What turned out to be most appreciated in terms of cooking among the interviewees was either related to social aspects or to creativity and accomplishment. Some preferred cooking together while some preferred cooking alone and serving food to others. Many of the interviewees mentioned that the most boring part of cooking was to cook only for themselves and then eat alone but also to take care of the dishes afterwards. The way of handling mess caused by cooking also varied greatly. One interviewee mentioned that she would not sit down and eat before the countertop was clean while some others would usually leave the mess to be taken care of later, or another day when they would have to deal with it for being able to cook again. Some of the interviewees mentioned that they always tried to make food that would be suitable for lunch boxes while others explained that the cooking varied between weekdays and weekend, being more varied and enjoyable on the weekends. What was found to be common for the interviewees was to have a basic set of tableware they would use very frequently but that other utensils varied a lot depending on the type of cooking. 5.2.2. The kitchen Out of the survey respondents living in less than 50 m2, 40% had a separate kitchen, 42% an open plan kitchen and 18% a kitchenette. To the question “Do you feel that the kitchen is big enough for your needs?”, 22% from the same respondent group answered that it is way too small, 40% that it could have been a little bigger and 38% answered that it is adequate. From the interview with Joakim Edman, administrator of rented apartments at HSB Gothenburg, it was learned that the kitchen often take up quite a small part of the total living space, and that new apartments often are built with open plan kitchens. Also, kitchens in newly built rental apartments often have the possibility to install a standard sized dishwasher as there is usually one 60 cm cabinet that can be exchanged and a faucet adapted for standard dishwashers. However, it is the tenants themselves who are responsible for purchasing the dishwasher and making sure that it is correctly installed. Edman emphasised the importance of having a valid insurance as there is a risk of water leakage from the dishwasher. Unfortunately, water damages are not uncommon but the cause is typically carelessness, either during installation or during usage if the user leaves home while the dishwasher is running. In older kitchens, it may be more problematic to install a dishwasher due to different dimensions. Kitchens that were built until the sixties sometimes have an empty space beneath the countertop that is usually 50 cm wide, and originally meant for placing a stool. This space is too narrow for a standard dishwasher of 60 cm but can be used for a narrow dishwasher of 45 cm. Another alternative for older kitchens is to use a benchtop dishwasher. However, benchtop dishwashers today are generally wider (500-580 mm) than older ones (450 mm). As kitchens from the fifties, sixties and seventies have draining boards adapted for dish racks that are maximum 50 cm wide, part of today’s benchtop dishwashers may hang out over the sink. Another problem with benchtop dishwashers is that if the hose is connected directly to the tap, there is a risk either of the hose to come loose or, if the water is led back to through the water system, a risk of legionella bacteria. Therefore, using a benchtop dishwasher demands a special faucet adapted to this 27 kind of dishwasher. Installation of a new faucet could cost around 3000-4000 SEK, including both a new faucet and charge for approximately one hour installation work, according to Edman. HSB Gothenburg owns and administrates 1600 rented apartments. The smallest ones are in the size of 20-30 m2, which are very few and viewed mainly as short term accommodations. 30-40 m2 apartments are more common and viewed as standard one room apartments. According to Edman, there is almost always two sinks in the kitchen for the ability to do manual washing of dishes. HSB Gothenburg uses no kitchenettes for safety reasons as kitchenettes with integrated stove in the draining board poses a risk of short circuit or of electricity moving from stove to the water leading system as well as a risk of fire. From the user study, it was possible to identify four different types of kitchens: Standard kitchens, compact kitchens, older or special kitchens and kitchenettes. The standard kitchen is based on modules of 20, 40, 60 or 80 cm, with 60 being the most common dimension. It has, besides the sink unit (which is generally 80 or 60 cm), room for at least three 60 cm units including both a dishwasher, oven and cabinet/drawers. A compact kitchen is also based on standard sized modules but has, compared to the standard kitchen, only room for two 60 cm units beside the sink unit, with one of them being the oven. Those who want to install a dishwasher therefore have to sacrifice the only 60 cm unit left and thereby lose important storage. The older or special kitchens are only partly compatible with today’s standard units and often include special units with different width and height. The kitchenette has no exchangeable units and is not compatible with any of the existing dishwashers on the market. This type of kitchen exists mainly in student apartments or temporary apartments. From the interviews with the different households, it appeared that the ones living in rental apartments did not want to invest much money in their kitchens, which was in some cases one important reason for not installing a dishwasher. People who own their apartments of course have greater freedom in the way they can build their kitchens and a larger variation can therefore be found in the design of those kitchens. It was also evident from the interviews that workspace is highly valued and essential both for being able to be creative in cooking as well as for being able to socialise in the kitchen. When asked what their dream kitchen would look like, almost all interviewees answered that they would like to have a large, bright kitchen with a kitchen island in the middle providing a lot of workspace and room for several people. There should also be lots of storage and easy access to items needed when cooking. The future of kitchens was also discussed with the interviewees. Some believed that the kitchen will always be important for determining the value of an apartment and that this may be one reason for people to invest money in their kitchens, even though they may not spend much time cooking in them. It was also discussed that socializing in the kitchen may become even more important with open plan kitchens that are part of the living space. Another thought was that smaller kitchens may have to be tolerated in the future due to a lot of people moving into the cities and that the need for smaller products that can do the same job as larger kitchen appliances will then increase. The need for more energy efficient, user friendly products and better waste handling in the kitchen was also discussed. Of all the respondents to the survey, 54% had a dishwasher in their kitchen (Figure 5.3). However, of the 40 respondents living in less 28 than 50 m2, only 15% stated to have a dishwasher (Figure 5.4). Figure 5.3 – Ownership of dishwasher among survey respondents Figure 5.4 – Ownership of dishwasher among survey respondents living in less than 50 m2 5.2.3. Dishwashing frequency The frequency of which people do the dishes turned out to be quite similar for people with and without dishwasher in the survey. Most common was to do the dishes once a day followed by every other day. The main difference between the two groups was a higher number of respondents doing the dishes several times a day from the group without dishwasher and a higher number of respondents doing the dishes every third day or one to two times a week from the group with dishwasher. The participants with dishwashers were also asked how often they wash dishes by hand. It turned out that as much as 40% actually washed some dishes by hand every day. Only 4% stated to never wash any dishes by hand. From the interviews it was found that benchtop dishwashers mainly can contain a basic set of tableware and therefore needs to be run often to avoid piles of dishes on the countertop or in the sink. However, despite the larger capacity of standard dishwashers, they may need to be run almost as often since the tableware and utensils may be needed soon again. Users who have a relatively small set of tableware and utensils may therefore run the dishwasher when it is only half full. One interviewee explained that when she lived in a place where she shared kitchen with others, the dishwasher acted more as a storage for dirty dishes than an actual dishwasher as it never got full and items were taken from the dishwasher to be hand washed when they were needed. In the survey, however, only 6% stated to usually have room for more dishes when they run their dishwasher, with the rest stating that it is usually full. What people perceive to be a ‘full’ dishwasher may of course vary. It was also found in the interviews that the frequency of doing the dishes is highly individual and depends on personality as well as cooking habits. Some users cannot stand to see the dirty dishes while others leave them standing for days, or even a whole week. 5.2.4. Cleaning result When asked in the survey which option they thought provides the most effective cleaning of dishes, 19% of the respondents answered washing the dishes by hand, 58% using a dishwasher and 23% that both alternatives 54% 46% Does your kitchen have a dishwasher? Yes No 15% 85% Does your kitchen have a dishwasher? Filter: < 50 m2 living space Yes No 29 are equally effective in cleaning the dishes. However, when asked if they perceived the dishes to get clean from using a dishwasher and washing by hand, only 17% of the dishwasher owners answered “yes, always” compared to 35% of the users without dishwasher. On the other hand, only 4% of the dishwasher owners answered “no, usually there is some dirt/spots left on the dishes compared to 7% of the users without dishwasher. 50% of the dishwasher owners stated that the dishes are usually dry when the washing cycle is finished. The interviewees who owned dishwashers were in general satisfied with the washing result of their dishwasher even though the dishes did not always get completely clean and not always completely dry. They seemed to have accepted the dishwasher’s limitations and appreciated the time it saves them compared to washing the dishes by hand. To ensure clean dishes, most participants usually pre-rinsed their dishes and did not rely completely on the dishwasher to do the job. 5.2.5. Environmental impact of dishwashing In order to investigate people’s perception about the environmental impact of dishwashers in relation to washing the dishes by hand, the survey respondents were asked which of the two options they believed to be most environmentally friendly. 22% answered washing by hand, 69% using a dishwasher and 9% that both options are equally environmentally friendly. However, since the survey was answered also by employees at Electrolux, it was believed that their knowledge about dishwashers may have affected the outcome of this question. Since those people answered the study later than the rest of the respondents, it was possible to screen out the answers from the particular date when the survey was sent to them. This cancelled out 31 responses. Out of the remaining 66 respondents, 29% answered that it is more environmentally friendly to wash the dishes by hand, 61% using a dishwasher and 10% that both options are equally environmentally friendly. This shows that the result indeed was slightly affected by the employees’ participation and that there exists some confusion about how to handle the dishes in the most sustainable way. This was also the impression from the interviews, where several participants mentioned that they had low awareness of how much water and energy a dishwasher uses and did not know which the most sustainable option would be. One aspect that made some of them hesitate to use a dishwasher was the stronger detergents that are used for the dishwasher compared to the detergents used for hand washing. The survey respondents were also asked to what extent they thought that dishwashing contributes to a household’s total environmental impact, with a scale from one to five with one being small contribution and five large contribution. Of all the responses, the mean value was calculated to 2.73, which is almost in the middle of the interval. 5.2.6. Problematic items to wash There are a few items that are difficult to wash, both manually and with dishwashers. Among the users without dishwasher, the most frequent complaint were about the plastic lunch boxes. These were explained to be very difficult to get clean from all the grease sticking to them. One of the interviewees explained that she had accidentally left used lunch boxes with their lid on for several days and then found them with mould inside. The dishwashers seemed to have no problem with getting the plastic lunch boxes clean but their light weight and large area could sometimes cause the lunch boxes to flip around from the water jet in the 30 dishwasher, leaving them with the bottom down preventing them from getting clean and also getting filled with water. The same problem exists for other light items such as measuring cups, which are also small enough to fall down through the bars and end up in the sump. Another problematic item is the baking tray, which is too large to fit both in the dishwasher and in the sink. When washing it by hand, you easily splash water all over the countertop or yourself. Other large items such as oven ware, frying pans and sauce pans can be difficult to handle as well and when placed in the dishwasher, they may block the water jet from reaching other items. If they also have dried food residues left on them, they may pose a challenge to both manual washing and the dishwasher. Tall glasses and carafes can be particularly difficult to place in the dishwasher as they are often too high for the upper rack while the lower rack often lacks a secure way of placing those items. As the lower rack is meant for larger items, some interviewees explained that they hesitated to place the delicate glasses there as they felt that they could either fall or get crashed by the larger, heavier items. However, tall and narrow glasses could also pose a problem for manual washing if they are too narrow to be able to reach with a brush or a sponge. Another category of problematic items for both groups are items with small holes in them, such as the cheese grater or the garlic press. There are in particular a few categories of items and materials that the dishwasher cannot handle and need to be hand washed to avoid destroying them. These are for instance items made of cast iron like pots and pans, wooden items like cutting boards and utensils, knives and fine crystal. One of the interviewees described how she had put a brand new wooden cutting board in her dishwasher and after the program was finished, it had cracked in half. To conclude, the dishwasher cannot, as it looks today, completely replace the need for washing the dishes by hand. Nevertheless, it facilitates the dishwashing process greatly and is highly appreciated by its users. 5.2.7. Use of dishwasher Of all the respondents in the survey who had a dishwasher, 79% owned a standard dishwasher (60 cm), 11% a narrow dishwasher (45 cm) and 8% a benchtop dishwasher. The 2% that chose the option ‘other’, which equals one person, specified that it was a 60 cm dishwasher in a raised position. One to three years was the most common age of the dishwashers with 35% of the total responses, followed by four to six years (27%), seven to ten years (23%) and less than one year (11%). Only 4% had a dishwasher older than ten years. Programmes and duration The survey participants were asked which dishwasher programs they use frequently in a multiple choice question where several choices could be made. As can be seen in Figure 5.5, ‘Main/normal’ scored highest, followed by ‘eco’, ‘auto/sensor’, ‘quick wash’, ‘delicate/glass’ and finally ‘intensive’. Nobody selected the options ‘half-load program’ and ‘rinse and hold’. In general, it appeared that users often stick to the same program. 31 Figure 5.5 – Program selection among survey respondents There seemed to be a general lack of understanding why eco-programs often are significantly longer than the normal programs. Some participants felt that it was contradicting and thought that a longer program should instead consume more energy and water. The long cycle time of the eco program was frequently mentioned as the main reason for not choosing it. One interviewee had a dishwasher that took four hours to finish with the eco-program and in order to avoid having to wait for it to finish, she usually ran it at night. There also seemed to be a general lack of understanding in what distinguishes the different programs and what the different symbols indicating those means. Feedback Depending on the interface, different dishwashers give different amounts of feedback to the users. Where feedback is lacking, users can be unsure of if the dishwasher has finished or not, how much time that is left of a cycle and what is actually going on in the machine. Some dishwashers beep when they finish while others indicate the change with lamps. Some have displays while others do not. One of the interviewees that owned a benchtop dishwasher explained how she could tell from the humming sound of the dishwasher when it needed water from the tap to which the hose was attached, and when it was ‘safe’ to disconnect the hose for short periods of time if she needed the tap for other purposes. Another interviewee was unsure of what was going on in the dishwasher during the last two hours of the cycle since it then went quiet. Therefore, she would sometimes open it to let the dishes dry faster. Cleaning and maintenance Cleaning of the dishwasher was not an appreciated task among the interviewees. Especially cleaning the filter was described as very unpleasant as it gets greasy and can be difficult to reach. Some were even unaware of the need to clean the dishwasher once in a while. Others were unaware of the need to use rinse aid or salt in the machine. The frequency of cleaning the machine seemed to depend partly on the dishwashers and their self-cleaning effectiveness and partly on the users as they have different knowledge and care, but also treat their dishes differently concerning the degree to which they pre-rinse their dishes. Interior layout Regarding the inside of the dishwasher, there seemed to be highly individual needs among the users depending on their type of dishes and cooking habits. In general, flexibility and ability to customise the interior was highly appreciated. A few examples are the plate holders that can be folded down for the sake of other dishes, cutlery baskets that can be moved to different positions and second level racks that can be adjusted in height. What kind of dishes that was supposed to be placed in certain areas was not always clear and some participants explained that there 0 5 10 15 20 25 30 Which of the following dishwasher programmes do you use frequently? 32 could occur some minor disputes within the household about how the dishes should be placed. The two different variants of placing cutlery in the dishwasher, namely either in a basket or in a third rack, was mentioned frequently among the participants with some preferring the first alternative while others the second. Placing the cutlery in the third rack can be a little more time consuming than just throwing them into the basket but the rack also holds the cutlery in place while in the basket they may stand too close to each other or fall down through the bars and thereby stop the spray arm from rotating. In general, it seemed to be height rather than width of the dishwasher that was the limiting factor for what dishes that could be washed and how they should be placed. Pre-rinsing of dishes Out of all the survey respondents with a dishwasher, only 27% stated that they usually do not rinse the dishes before placing them in the dishwasher. 37% stated to pre- rinse their dishes with cold water and 36% with hot water (Figure 5.6). Pre-rinsing of dishes has a significant impact on the total amount of water and energy used for the dishwashing process and is a waste that to a large extent is out of the control of the dishwasher producers. Figure 5.6 – Pre-rinsing of dishes among survey respondents owning a dishwasher Desired improvements The participants of this user study had a few requests on desired improvements of the dishwasher. Faster washing cycles was frequently mentioned since the dishware are inaccessible during the washing cycle and may be needed for preparing food again. Another reason for having shorter programs is for the users to not feel hindered to leave home for long periods of time while the program is running. The participants also wanted a better self- cleaning function, more effective drying of the dishes and easier unloading of the dishwasher. An extra program for half- loaded dishwasher was mentioned by some participants who felt that they normally could not fill up a whole machine. Due to the different needs and types of dishes, some participants requested the ability to customise the interior even more. One interviewee gave the suggestion that different interiors could be purchased separately to be combined with different dishwasher models to enable customers to choose more freely. Other ideas from the same interviewee was a dishwasher that would evaluate its result and highlight items that may not have become properly washed to help the user detect those items before loading them into the cabinet and also to be more forgiving against the dishwasher’s shortcomings. Moreover, by enabling users to login to the dishwasher before unloading it, the dishwasher could store information about how many times each member of the household had taken out the dishes each week, for avoiding disputes about whose turn it is to take care of the dishes. This suggestion will most likely not be appreciated by everyone. 5.2.8. Manual dishwashing Of all the 45 survey respondents without dishwashers, 93% answered that they would like to have a dishwasher (see Figure 5.7). 36% 37% 27% Do you usually rinse the dishes before placing them in the dishwasher? Yes, with hot water Yes with cold water No 33 When asked which kitchen space they would be willing to sacrifice to make room for a dishwasher, 31% answered ‘none’. Of the rest, 33% would sacrifice a cabinet, 18% a drawer unit, 7% the dining area and 2% the sink. None of the respondents would be willing to sacrifice worktop area. Of the 9% selecting the alternative ‘other’, one commented ‘almost anything’, and the rest that they needed all the space they had. Figure 5.7 – Share of respondents without dishwasher wanting to have one Reasons for not having a dishwasher The main reason for not having a dishwasher was lack of space with 65% of the responses, as seen in Figure 5.8. 13% answered that it is too expensive and the rest 22% chose the alternative ‘other’. Those who chose ‘other’ specified either that they were not allowed to install one in their rented apartments, that their contract only was temporary or that it was too difficult and costly to install one. Figure 5.8 – Reasons for not having a dishwasher In one of the interviews, it was discussed that you may have only occasional use of a dishwasher, like for instance when you have had guests over for dinner. At those occasions, it would be convenient to have access to a room with dishwashers, similar to the ones used for laundry today. Another