In this study, the life cycle assessment and life cycle cost were applied for comparison with lighting bulbs and the economic and environmental valuations of the effect of converting traditional lighting bulbs to low-carbon-type lighting bulbs. When an incandescent bulb was converted to a LED lighting bulb, CO2 emission was decreased by 78%. However, when a fluorescent bulb was converted to a LED fluorescent bulb, there was no decrease in CO2 emission. Next, the effect of both types of conversion on the household′s CO2 emission and cost was calculated. As a consequence, annual CO2 emission per household decreased from 73 to 41 kg, and the annual cost decreased from 3,800 to 2,160 JPY. Further, sensitivity analysis was performed by shortening the time for which an occupied compartment was used. The results showed that the effect of converting an incandescent bulb on the reduction in CO2 is higher than the effect of converting a fluorescent bulb.
