When to buy new electrical/electronic products?

An environmental criterion for the determination of the usage pattern of electronic products was proposed. As such products usually have strong environmental impacts during the usage stage of their life cycles, and the impacts are generated mainly as a consequence of the power requirement, the use of energy consumption as a representative environmental indicator was justified. The model was performed on four case studies: computer monitors, refrigerators, light bulbs and induction motors. For computer monitors, liquid crystal display (LCD) was considered more environmental friendly than the cathode ray tube (CRT). However, disposing of the existing CRT and buying a new LCD might not be beneficial as the energy gained from the difference in the energy consumptions was not justified. Unlike computer monitors which were operated in periodic pattern, products such as refrigerators were mostly run continuously throughout their lives. In this case, buying a new, lower energy consumption model was often superior as the cumulative energy saving during the usage stage was significant compared with those occurred during the other life cycle stages. In general, the new product model should provide a better environmental performance, i.e. lower energy consumption rate. However, there were trade-offs between purchasing a replacement and repairing the old mal-functional one as the upgrade or repair of the old product could avoid the fixed energy consumption associated with the production stage of the new product. In the case of small electronic devices with low operating environmental impacts such as light bulbs and induction motors, the use of compact fluorescent lamps instead of incandescent lamps or new motors, respectively, were highly recommended. In particular for the case of induction motors, the maintenance such as the rewinding of old motors was proven to be beneficial.