Abstract

Residential buildings use a substantial amount of energy not only during the construction but also for the operation of their heating, ventilation, and air-conditioning (HVAC) systems. The life cycle assessment methodology allows evaluating the overall environmental and economic impacts of heating systems. This study, therefore, presents the life cycle analysis of two residential heating systems, the hot water heating system with ventilation and the forced air heating system. The analysis is performed with respect to the life cycle energy consumption, life cycle greenhouse gas emissions, life cycle exergy destruction, and the life cycle costs. The total amount of material used for piping and ducting systems is estimated based on the complete design of the systems. However, there is a high level of uncertainty in the evaluation of the environmental impact of some HVAC equipment due to the absence of detailed manufacturers' data. The present study hence applies a decision model under uncertainty to analyze this situation. Using a payoff matrix model coupled with various decision criteria, the range of embodied energy and greenhouse gas emissions of such equipment is estimated.