Optimum operational lifespan of household appliances considering manufacturing and use stage improvements via life cycle assessment

To lessen the residential sector environmental burdens from the energy consumption of household appliances, notable efforts have been directed to replace existing energy-consuming appliances by new energy-efficient equipment. However, less attention has focused to understand the optimum operating period of households so reduced greenhouse gas emissions can be achieved. Conventional household appliances should be preferably replaced with new designs featuring improved energy efficient models, along with reduced environmental burdens associated with the manufacturing of the new products. Such studies, to the best of our knowledge, have not been extensively investigated. To address this gap, the global warming potential during the life cycle of three representative household appliances, a microwave oven, a dishwasher and a washing machine is analyzed using a cradle-to-grave life cycle assessment. To provide guidelines towards impact reduction, the current situation and four new scenarios focused on material efficiency, recycled material, renewable electricity and responsible consumption are analyzed. Depending on the scenario, impacts of 84-261, 317-1330, and 533-1375 kg.CO2 eq/lifetime are obtained for a microwave, a dishwasher and a washing machine, respectively. Balancing energy efficiency and life- time when replacing a class A appliance, operating periods of 3.4-30, 2.7-26.2 and 4.6- 33.9 years for microwaves, dishwashers, and washing machines, render the lowest CO2 footprint. These results may assist manufacturers, policymakers and citizens to promote environmentally sustainable production and consumption patterns. (C)22 The Authors. Published by Elsevier Ltd on behalf of Institution of Chemical Engineers.

Automated summary

To reduce the environmental burdens caused by household energy consumption, replacing energy-consuming appliances with energy-efficient models is important. However, determining the optimal operating period of households to reduce greenhouse gas emissions has received less attention. This study analyzes the global warming potential of three household appliances and provides guidelines for impact reduction through different scenarios.