Comparative analysis of global consumer behaviour in the context of different manual dishwashing methods

Abstract

AbstractThis laboratory study presents an overview of the global manual dishwashing behaviour. The focus of the investigation was to analyse individual attitudes towards manual dishwashing and to determine the amount of water and energy used, as well as the cleaning performance achieved. Additionally, manual dishwashing was compared with automatic dishwashers. Two hundred eighty‐nine participants from 29 countries took part in this investigation. Each consumer had to wash up a complete soiled dishwasher load consisting of 12 place settings based on both international and local performance test standards for automatic dishwashers. Country‐specific aspects such as tableware, food residues or washing up equipment were considered. In order to analyse individual consumer's behaviour, each participant was recorded on video and had to fill out a questionnaire. The resource consumption for washing up dishes was measured during the tests. At the end of each trial, the cleaning result of the washed up tableware was assessed. To compare manual with automatic dishwashing, country‐specific dishwasher models were tested in parallel with three different programmes with the same soiled dish samples. The study provides comprehensive data about the average resource consumption for manual dishwashing for a specific load for each country. The average water consumption per country reached 34.7 l up to 160.1 l, and individual values ranged from 18.3 l to 472.8 l. The lowest used average heat quantity accounted for 0.9 kWh per country, while the highest amount was five times higher. The cleaning results did not differ much between the countries: the average test results were between 2.2 and 2.8 on a scale between 0 and 5. The automatic dishwasher tests showed differences between both the machines and the programmes. All machines achieved lower water consumption values than the average consumers with about 9.6 l to 26.7 l of water on average. The energy consumption ranged from 0.5 kWh on average up to 2.0 kWh. The cleaning results of the dishwasher tests varied highly ranging from 1.1 in a quick programme to 4.4 in an intensive programme. The study comes to the conclusion that automatic dishwashing is more superior as compared with manual dishwashing in terms of performance and resource consumption under the tested conditions. Furthermore, it points out that washing up dishes under running tap water is the most water‐consuming manual dishwashing method of all investigated ones. A high lack of knowledge about the benefits of automatic dishwashing compared with manual dishwashing can still be identified among consumers.