Towards More Sustainable Dishwashing Behaviour. A User Research Study with Design Strategies to Modify Unsustainable Practices

Abstract

Dishwashers have become part of the modern home and when used correctly can lead to significantly less water and energy consumption than the alternative of manual dishwashing. Manufacturers are constantly improving the efficiency of these appliances with better mechanical components, lower cycle temperatures and increases in capacity. However, an aspect which has received less attention is how the behaviours of users impact the efficiency. This project investigated unsustainable behaviours in automatic dishwashing by studying previous research as well as conducting new research, through user studies in a lab environment complemented by a diary study in a home context. Six unsustainable behaviours were identified: (1) inefficient programme choice, where users choose to run a dishwashing programme which is either too intensive or too gentle, resulting in increased water and energy consumption or unclean dishes. (2) inefficient loading, not utilizing the full capacity of the dishwasher or overloading the dishwasher resulting in unclean dishes; (3) pretreatment of dishes, rinsing dishes under running water before placing them in the dishwasher; (4) inefficient detergent use, using more detergent than necessary for a good result; (5) manual dishwashing, households with dishwashers washing some dishes manually and (6) poor maintenance, not doing the maintenance needed for effective cleaning and along lifespan of the appliance. The study found that these behaviours depend on several factors among users, where the most critical ones were a lack of information, a lack of trust in the dishwasher and convenience. The next part of the project consisted of investigating how design could be used to address the unsustainable behaviours. Which resulted in the six design recommendations: sustainability sheet, programme costs, Auto Dose text, tips & tricks, scraping off tool and filter warning. These recommendations in addition to the insights from the research are aimed to serve as inspiration for dishwasher manufacturers on how they can improve the sustainability of their appliance by employing a user behaviour point of view.