家庭洗濯における衣類乾燥の環境負荷低減のための評価

抄録

Sales of household machines combining both washing and drying functions have increased rapidly in recent years due to an increasing number of women working, an increasing number of single-person households, and the appeal of these machines in terms of reducing the burden of housework. In this study, we examined ways to reduce environmental and economic effects by applying social LCA to the entire life cycle, including clothing-related factors, by comparing the new type of washer-dryer incorporating a heat-pump unit with traditional type of washer-dryer and separate gas dryer. The mechanical action of washer-dryers was evaluated by measuring the unraveling of MA test pieces and the rate of shrinkage of shirt collars as an indication of the effects on clothing. Electric power and water consumption were measured for each washer-dryer cycle. The unit prices for washer-dryers, detergent, and clothes were obtained via market research. The social LCA results indicated that CO₂ emissions were higher for machine usage than for manufacture, for all types of washer-dryer. The results also showed that greater damage to clothing was caused during the drying process compared to washing alone, and the drying process also greatly increased overall CO₂ emissions. The study also showed that heat-pump washer-dryers with short, low-temperature drying cycles were effective in reducing CO₂ emissions by approximately half due to their lower energy consumption and mechanical power compared to conventional washer-dryers. The Life cycle costing (LCC) results showed that using heat-pump washer-dryers for both washing and drying reduced costs compared to conventional washer-dryer or gas dryer.