Rainer Stamminger

University of Bonn | Uni Bonn · Institute of Agricultural Engineering (ILT)

Despite the fact that dishwashers have been optimised in recent decades in response to policy requirements, consumers still use more energy and water than necessary. This has been deeply investigated by two research groups with complementary approaches and published in this journal. When translating these scientific findings into recommendations, i...

Routine household tasks, such as laundry or dishwashing, are complex socio-technical systems in which a variety of factors and actors interact, including manufacturers, technologies, regulators, consumer practices, cultural norms and infrastructures. A deep understanding of these socio-technical systems is necessary to find the right recommendation...

The laundry process is energy-intensive and an important target for reducing residential environmental impacts. Category life-cycle analysis (LCA) studies show the primary environmental impact is due to the energy consumed during the use phase, mainly for heating water. However, doing the laundry is a complex socio-technical system, where addressin...

Automatic dishwashers combine capital, energy, and water to provide a relevant household service, namely dishwashing. Consumer behaviour in using the automatic dishwasher influences to a great extend the environmental impact of such a device. But what simple and intuitive recommendation can be given to consumers to save energy and water while maint...

Automatic dishwashing has been optimised in manifold ways during the last decades: new dishwashing devices (e.g. optimised for best class in energy labelling) and innovative dishwashing detergents (e.g. with advanced enzyme technologies). However, the usage of the automatic dishwasher in consumers’ home may not be adequate to gain all the benefits...

Ecodesign and Energy Labelling Regulation of domestic cooking appliances entered into force in 2015. Since then, the market has evolved and new technologies are available. The implementing measures contain review clauses that are already due. Energy classes also need rescaling. Therefore, the Commission launched the revision of this Regulation. The...

Every day, dirty dishes and cutlery have to be cleaned in millions of households worldwide. From a scientific point of view, the question of “how” is particularly interesting, because everyday household chores hold great potential for saving resources. This review summarises the current state of knowledge about dishwashing. In general, electric dis...

Consumers and users of household appliances nowadays increasingly require information on the energy performance and other performance parameters of these products. The test methodologies from which this information is obtained subsequently need to have certain characteristics to be accurate and reliable. They need to be repeatable and reproducible...

The parameters required to calculate the energy efficiency of household refrigerating appliances (i.e. refrigerators, freezers and their combinations) are determined by standard measurements. According to regulations, these measurements are carried out when the appliances are new. It is known from previous studies that various technical aging mecha...

The current state of knowledge about hygiene (efficacy testing) in commercial dishwashers will be collated in this review. Therefore, studies about hygiene in commercial dishwashing are summarised and existing standards, guidelines and the legislative basis described. Finally, examples of information available from the market, for example, detergen...

Domestic refrigeration appliances are standard household commodities. Although policies, such as the energy labelling, prompted technical improvements and decreased appliance energy consumption throughout recent decades, important parameters were disregarded. These refer to the efficiency loss over time and the consumer behaviour. The objective of...

The requirements for commercial dishwashers differ fundamentally from those for domestic dishwashers. For commercial dishwashers, capacity and programme duration are the main factors. Accordingly, different designs are offered for the different types of requirement. Comprehensive data on the usage behaviour of commercial dishwashers is scarcely ava...

Vegetables lose quality after harvest mainly due to water-related weight loss. In households, vegetables are usually stored in refrigerators, typically providing temperatures from 0 – 14°C and relative humidity ranges from 20 – 100 %. Weight loss is related to the storage humidity conditions. As a consequence, storage systems providing humidity-con...

Near infrared (NIR) measurements have been used for several years to examine the processes taking place in the dishwasher during dishwashing. It is possible to differentiate between the soil components butterfat, oatmeal and egg-yolk and to determine their concentration in the dishwashing liquor quantitatively. Consequently, time-consuming dishwash...

There are over 80 countries in the world that currently use some kind of energy label for electric household appliances. In Europe, as an example, a lot of appliances are obliged to have an energy label when shown for sale, including online. Energy labels give relevant information to the consumers to help them make an environmentally beneficial cho...

The 'Recommendations for the Quality Assessment of the Cleaning Performance of Dishwasher Detergents" provide detailed procedures to assess the performance of a household dishwasher detergent using a standard test programme of a standard dishwasher. As such, they are a de facto standard for a whole industry. Consequently, it is relevant to ensure t...

The aim of this study was to establish a simple model describing the microbial reduction of a cleaning process by only using physical parameters of a given cleaning process (time and temperature) together with microorganism-specific inactivation parameters. The \Microbiological Inactivation Equivalent (MIE) unit" representing the time-temperature i...

Since perishable food in private households is usually stored in refrigerators, both consumer knowledge of correct storage parameters and food handling have a major impact on food quality retention. Today’s refrigerators provide features, such as climate-controlled compartments, to improve chilled storage performance, but former studies have shown...

The increase of the thermal conductivity of PUR foam in the insulation of the cabinet is an important cause for aging processes of household refrigerating appliances. To determine the influence of the PUR foam aging on energy consumption, the development of a new measurement method is necessary because current methods influence the aging behavior o...

Poor hygiene when handling food is a major cause of foodborne illness. To investigate whether hygiene practices visible in television cooking shows influence viewers’ kitchen hygiene, a study on the adoption of demonstrated hygiene behavior was conducted under controlled, experimental conditions. In a study ostensibly on cooking by following recipe...

The presented results are published in the following article: Brands B, Schulze Struchtrup S, Stamminger R, Bockmühl DP (2020) A method to evaluate factors influencing the microbial reduction in domestic dishwashers. Journal of Applied Microbiology.

One of the global challenges of our economy is to meet the demand of a growing population while reducing resource consumption and waste production. This means moving from a linear to a more circular economy model, in which the design of more durable products plays a key role. From a technical perspective, product design needs to be supported by sou...

During the last decades, the strive for energy efficiency lead to lower washing temperatures in laundering processes. In this regard, there is a rising need to measure the antimicrobial action of laundry detergents and additives, since chemistry must be considered an important means to compensate for the loss of temperature. Although there is an ex...

Despite the omnipresence of household refrigeration appliances, there is still a lack of knowledge about their age-related efficiency loss over time. Past studies provide basic evidence for increasing electricity consumption of cooling appliances with ageing but fail to investigate the associated technical wear. Concentrating on the degradation of...

Aims: To develop a method that is able to determine the microbial reduction of different dishwasher cleaning cycles and differentiate between different program parameters used. Methods and results: Stainless steel biomonitors were contaminated with Micrococcus luteus or Entereococcus faecium and cleaned in a specially programmed household dishwa...

Automatic dishwashing is a process which takes enormous amounts of resources (energy, water, chemicals). However, most of the dishwashing programs are designed and tested to clean the worst scenario for a certain kind of load items (glass, porcelain, etc.) and do not or only partly adapt to the actual load and soiling conditions. Thus, resources ar...

Automatic dishwashing is a process which takes enormous amounts of resources (energy, water, chemicals). However, most of the dishwashing programs are designed and tested to clean the worst scenario for a certain kind of load items (glass, porcelain, etc.) and do not or only partly adapt to the actual load and soiling conditions. Thus, resources ar...

The aim of this questionnaire survey study is to find out if the three socio-demographic aspects gender, age and household size have any influence on washing-up behaviour and whether people's washing-up behaviour changes due to them. The data was collected via a questionnaire created and carried out by “Forum Waschen” that could be answered by Germ...

The European energy label was established to reduce energy consumption in Europe. All classes and values on the energy label are stated by the supplier. The task of market surveillance is to ensure correct labels and to validate their values through compliance tests. However, this can only be done for a small fraction of all models on the market, s...

Purpose More than 50 per cent of all German households own a freezing appliance and so far the market of frozen foods is constantly increasing (1 per cent from 2017 to 2018). Despite frozen foods playing an important role in our everyday life, little is known about the consumer’s habits at home. The purpose of this paper is to uncover gaps in the k...

In dishcleaning automatic dishwashers do clearly win over manual cleaning when it comes to efficiency: Resources can be saved without compromising on hygiene. But mistakes in the usage behaviour can equalize saving advantages. Consumers in nine countries, covering different regions of the world, were asked about their dishcleaning behaviour to iden...

The ubiquitous finding of microplastic in the abiotic and biotic environment has gained a lot of attention recently in the media, scientific community and among the general public. One of the known sources of microfibres is the washing of textiles. It would be a conceivable option to install filters in domestic washing machines that would sift out...

There is a large influence of consumer behaviour on the resource consumption of owners and non-owners of automatic dishwashers. Therefore, it was the task to explore what kind of habits and intentions of consumers in Europe can be identified which restrict the consumer from using an automatic dishwasher, either not buying one or not using it, altho...

The private household sector utilises a large contribution of the global energy and water resources. Household appliances have been developed to be increasingly efficient and resource saving. The efficiency of the appliance itself and consumer behaviour have an influence on the real-life usage of resources. A calculation module was created to help...

The purpose of this study was to utilize NIR spectrometry to develop a novel method to detect and determine concentrations of different soils in dishwashing liquor during automatic dishwashing in real-time. If it is possible to differentiate between soils, this could be an opportunity to react specifically to them (e.g. by increasing the water temp...

Product testing is widely used to assess the characteristics, e.g. performance and energy consumption of a product. The procedures for executing the tests, including measurements and processing of measurement results, can be contained in standards. Standards should produce results that are repeatable, reproducible and valid at a reasonable cost. A...

Designing more durable products is a key strategy of the Circular Economy to save materials and reduce the amount of waste to handle at the End of Life of the product. However, the design of more durable products needs to be supported by methods for assessing and verifying durability aspects. Although internal protocols are typically implemented by...

Even though the duration of usage of large household appliances is found to be an average of 13 years in Germany, the data also shows that the proportion of large household devices which are already defective within the first five years has increased in the last decade. Material, functional, psychological and economic obsolescence are defined and d...

Since the introduction of the energy label for household dishwashers in the EU, manufacturers have been incentivised to reduce resource consumption and increase the energy efficiency of their appliances. Technological progress has led to very efficient programmes with cleaning cycles of 3 to 4 h or longer. The European Commission recently initiated...

Water and energy dissipation is a remaining problem in the world and dishwashing is contributing to this. The correct cleaning technique can help to save resources, but needs to be promoted, as consumers tend to clean without thinking a lot about their technique. A global consumer survey was carried out and helped to identify common mistakes in dis...

Each consumer is entitled to have hygienically clean processed dishes and cutlery. Consequently, restaurants, caterers, canteens, nursing homes, kindergartens and hospitals are very concerned to avoid infecting their customers and patients. They are afraid of the spread of diseases by inadequately washed dishes, glasses and cutlery. This study deal...

Insufficiently decontaminated textiles could lead to transmission of infections. Thus, laundry hygiene is of particular interest and investigated in numerous studies. However, laundering experiments that use microorganisms to investigate the reduction of microbial loads on textiles are particularly time-consuming and material-intensive and the hand...

Since a few years, cooking shows have enjoyed great popularity in Germany. Currently, about 60 different formats are broadcasted on German television. In the field of food preparation and nutrition, they represent a significant passive source of information. This study aims to assess food safety practices in German TV cooking shows and to identify...

Durability plays a key role in enhancing resource conservation and contributing to waste minimization. The washing-machine product group represents a relevant case study for the development of a durability test and as a potential trigger to systematically address durability in the design of products. We developed a procedure to test the durability...

Reducing water temperatures in the wash phase of a washing programme and increasing the overall cycle durations are the latest trends in decreasing energy consumption of washing programmes, particularly for the so-called Standard programmes. This paper discusses the importance of saving energy in laundry washing, reasonable cycle duration for consu...

Energy Labels are an instrument supporting on-going market transformation towards higher energy efficiency by motivating consumers to select more energy-efficient products. Since the purchase decision can be influenced by the consumers' understanding of the Energy Label, this paper addresses the clarity of the Energy Label of washing machines from...

Energy Labels are an instrument supporting on-going market transformation towards higher energy efficiency by motivating consumers to select more energy-efficient products. Since the purchase decision can be influenced by the consumers' understanding of the Energy Label, this paper addresses the clarity of the Energy Label of washing machines from...

The continuing rise of greenhouse gas (GHG) emissions is leading to catastrophic damage in many parts of the world over the coming decades unless GHG emissions can be controlled quickly. The objective of reducing GHG emissions can only be accomplished when all the sectors contributing to GHG emission act responsibly. The contribution of the househo...

This publication is a Technical report by the Joint Research Centre (JRC), the European Commission’s science and knowledge service. It aims to provide evidence-based scientific support to the European policy making process in the framework of the Ecodesign Directive 2009/125/EC

Over recent decades, water conservation have become increasingly an utmost important issue for debate, and this includes the domestic sector. Reducing demand water by improving the efficiency of water use in domestic sector requires an understanding of how water is used and in what ways water savings can be realized. The focus of this global, web‐b...

Commercial dishwashers are used in community facilities such as hospitals, refectories, nursing homes or food services. In this area, kitchen and food hygiene is of great importance to ensure consumer health. The aim of this study was to verify the hygienic performance of commercial dishwashers with a water-change system by use of bioindicators. Th...

In times of low-temperature washing, laundry hygiene gains importance, as microbial contaminations on textiles can cause infection transmission and malodour formation. This study systematically investigated the antimicrobial effect of laundry detergents (solid and liquid market detergents) with regard to time and temperature in domestic washing mac...

While the energy generation system is changing towards the use of more renewable energies, the problem of how to deal with fluctuating energy supply is increasing. Smart appliances in households are often referenced as one possible solution, as their operation may be shifted in time and, thus, used to balance an unstable energy supply. The potentia...

Several different approaches are commonly used to obtain information about the performance of laundry systems, e. g. washing machines. The evaluation of washing performance with soiled test fabrics is commonly done by measuring the reflectance of the washed test specimen. The absolute reflectance readings may be used if the results are only compare...

To further reduce energy consumption of dishwashing programmes and still obtain satisfying cleaning results, water temperatures in the programme steps are decreased and running times are prolonged. To which extent the cleaning factor duration is able to compensate for temperature has been insufficiently researched until now. This study quantifies t...

Since the washing performance of household washing machines must comply with certain limit values, like the ecodesign requirements in Europe, the method of washing performance evaluation is crucial. Today, the washing performance is defined as an overall washing performance in IEC 60456:2010, constituting an calculation of the average sum of reflec...

Washing machines should not only deliver good removal of stains, but also take care of the garments. Mechanical action produced by the washing machine has a twofold impact: It supports the removal of stains, but it also influences the structure of the textiles negatively and is, therefore, critical to textile care. Most washing machines are current...

A literature review was executed to collect data on the resource consumption connected to domestic laundering processes. Data from literature on water and energy consumption were collected. The study focussed on Europe, as for Europe enough date could be collected for a thorough analysis. However, the limited data available for Japan and the USA we...

Lowering water temperatures in the cleaning step of a dishwashing program to 30°C leads to reduced energy consumption and decreased cleaning performances on persistently soiled dish- and cookware and of fatty soilings on hydrophobic surfaces. This study focusses on the question if the observed decline of the cleaning performance can be compensated...

Obsolescence is the wearing out of technical appliances. Planned obsolescence is often seen as an economic strategy to improve sales by reducing the lifespan of these appliances. Although there are a lot of public discussions about planned obsolescence, there is a lack of data available to support or contradict this hypothesis. The objective of thi...

To identify key features in the perception of consumer satisfaction of washing performance, a survey among detergent users from five European countries was run. Respondents from each country were volunteers recruited through the Internet without previous selection criteria. The size of the sample (over 4,000 participants) and the wide geographical...

Washing machines sold for private households are increasing in capacity. The aim of this study was to assess how these higher capacities are utilised by consumers. A consumer survey was conducted in eleven European countries with more than 5,000 participants who are substantially involved in washing laundry. Questions were asked about their washing...

The proper cleaning of used dishes provides an essential means to maintain a sufficient hygiene level on food contact surfaces. However, little is known on the microbiological quality of domestic dishwashers themselves, especially in relation to consumer habits. This study investigated dishwashers in German households to analyse the number and comp...

Washing machines in Europe have to comply with regulations fixed in the Energy Label and Ecodesign legislation. They require declaration of the specific consumption and performance values which are deduced as average values from tests on three different treatments. Detailed data about the individual tests are normally not available to the public bu...

The aim of this study was to assess consumers' behavior in home hygiene with particular attention paid to hygiene in laundering. In this way, the applications of washing temperatures and detergents on textiles are evaluated. The data were obtained by using a questionnaire distributed at the ' Action Day Sustainable Washing" arranged annually. The r...

Decreasing resource consumption concerning electricity, water and detergents in the framework of automatic dishwashing is not only determined by technical improvements. First and foremost, the use phase, in other words, the consumers and their choices, for example, the type of dishwasher, the kind of dishwashing programmes selected and the method o...

Im Jahr 2010 identifizierte der Wissenschaftliche Beirat Verbraucher- und Ernährungspolitik beim damaligen Verbraucherschutzministerium (BMELV) eine "kleine, aber wachsende Gruppe" verantwortungsvoller Verbraucher: Diese übernehmen "Verantwortung für sich selbst, für die Umwelt und für andere. Doch wie übernimmt man Verantwortung? Welche Möglichkei...

Megatrends are global changes in individual, social and technological structures that shape our lives. The aim of this paper is the identification of trends that will shape laundry washing by 2030, and their effects on it, based on the expert judgment of the members of the Board for Washing Excellence. The conclusions indicate that the demand for w...

Appliances and energy-using products are getting more energy efficient, but they also tend to become more and more sophisticated with a multiplication of programmes and auxiliary features. The way they are set and used becomes a critical determinant of their real life energy consumption, which can vary greatly depending on a single initial setting...

Amid a wide array of fruits available in the international market, strawberry has gained high praise among consumers for its unique taste and health benefits. Today’s consumers are more knowledgeable and they are in demand of high quality, nutritionally versatile, and safer plant produce. This has forced both researchers and manufacturers to monito...

In order to simulate the usage of washing machines by the consumer, a concept of a "virtual washing household" is developed that, to some extent, behaves as a real life household. As essential part of this virtual household is the virtual washing machine in which washing cycles are conducted in dependence of the washing parameters, household size a...

In the past years some researches were conducted to model laundry washing in the automatic washing machine. The most studies, however, were focused to some aspects of the automatic laundry washing (e.g. spinning cycle) and not on the washing process as whole. In this paper a model of a washing machine is presented that is based on measured data of...

The aim of this study was to develop a repeatable method for the measurement of microbial load reduction factors after hand and machine dishwashing processes that meet the requirements associated with consumer studies, based on non-pathogen test strains. Microorganisms were isolated from tableware, identified and cultured for this purpose, mixed wi...