Life cycle energy analysis of a green building in Vietnam

The paper presents the life cycle energy analysis (LCEA) of an office green building in Hanoi, Vietnam to prove the advantages of green buildings regarding energy efficiency and environmental effects. The case study building is a concrete structured one, which consists of 3 basements, 17 floors, and 1 attic with a gross area of 14,112 m2. In the study, the building’s embodied energy is determined based on the contained energy coefficient of the ith material and its quantity needed. Whereas, the operating energy is computed according to the annual energy consumption of the building, which is stimulated by the EnergyPlus simulation software. Relying on the relative share of the demolition energy with the life cycle energy that has been proposed by previous publications, this category will be estimated. Results showed that the initial embodied energy contributed the largest share to the life cycle energy (61.37%), followed by operational energy (27.61%). It also indicated that the percentage share of the operational energy of a green building is much lower than that of other buildings. The primary reason for this is associated with the usage of environmentally friendly materials and energy-saving equipment in the design option of the green building. Therefore, it can be convincing evidence that may help to change the mindset of decision-makers in Vietnam about green buildings.

Life Cycle Energy Analysis and Evaluation of Retreaded Engineering Tires

In this paper, energy consumption models of retreaded engineering tires were constructed based on life cycle analysis, theoretical calculation model, and energy consumption method during the four stages of retreaded engineering tires, i.e., production, transportation, usage, and recycling stage. The energy substitute model and energy evaluation index during the recycling stage, which involves one of five classical retreaded engineering tire recycling methods, i.e., secondary retreading, mechanical smash, low-temperature smash, combustion decomposition, and combustion power generation, were presented. Life cycle energy analysis of retreaded engineering tires was conducted, and the energy consumption during the different life cycle stages was quantitatively analyzed, thus obtaining the energy restoration rate of the five classical recycling stages of retreaded engineering tires. Energy consumption analysis and energy evaluation at different stages were performed. Main conclusions indicate that the energy consumption during the production stage is the highest, and energy consumption during the transportation stage is the lowest. The energy recycling result of the secondary retreading or combustion decomposition of retreaded engineering tires is obtained.