Development of a method for calculating the environmentally optimum lifespan of electrical household products

Abstract

This paper considers the idea that for many products there is a particular length of lifespan for which the environmental impact of the item is at a minimum. It is suggested that for some types of product this ideal lifespan is not, as is often believed,`as long as possible' but until the performance of a new product justi®es replacing the existing one. Electrical household appliances are identi®ed as a product group for which this issue is particularly relevant. It is proposed that the improvement over time of use-phase energy consumption shown by many products in this group means that at a certain point it is environmentally bene®cial for the customer to replace their existing machine with the latest model. The paper suggests that it is possible to calculate this point in the life of the product when replacement is most bene®cial from information about new and existing machines. The development of a method for calculating this optimum lifespan from energy consumption data is described, using a dishwasher to demonstrate the technique. Using the equation devised, the environmentally optimum lifespan of a dishwasher is found to be 8.1 years in 2003. Keywords: product lifespan, environmentally sensitive design, domestic appliances NOTATION A, B constants from the equation of the energy consumption graph b build energy (kW h) E energy consumption (kW h/year) m gradient of the energy consumption graph (kW h/year 2 ) n length of lifespan (years) t time from the beginning of the energy consumption graph (years) T start year (years) V variable energy (kW h/year)

Integrated Assessment of Water Conservation Practices For Sustainable Management Strategies

“…Chalkley et al (2003) proposed a method for estimating optimal lifespan to keep the environmental impacts of a product at a minimum. The method considers the environmental impacts of energy consumption from production and end-use stages of a product.…”

“…The method considers the environmental impacts of energy consumption from production and end-use stages of a product. The optimized lifespan of a product is important to reduce overall environmental impacts by regular replacement of old appliances while allowing new products to be designed with appropriate level of durability (Chalkley et al, 2003).…”

“…For a product with short lifespan, it would be beneficial to upgrade its design to use environmental friendly materials that will cause less impact upon disposal. For a product with long lifespan, the major effort should be placed for improving its reliability and maintenance (Chalkley et al, 2003).…”

L’obsolescence des produits électroniques : des responsabilités partagées

“…de recherche sur la durée de vie, par exemple les stratégies visant à optimiser la durée de vie des appareils (Chalkley et al, 2003), les approches en design permettant d'allonger la durée de vie (Van Nes, 2010, Van Nes andCramer, 2005), l'étude des relations usager/objet (Chapman, 2005) et les stratégies défiant l'obsolescence (Park, 2010, Park, 2005.…”

The eco-efficiency of reuse centres critically explored – the washing machine case

“…In literature some publications can be found concerning life time optimisation of washing machines [5] [6]. The Öko-institut conducted a study about washing machine utilisation in Germany [7] [8].…”