Life Cycle Carbon Dioxide Emissions and Sensitivity Analysis of Elevators
Round 1
Reviewer 1 Report
This study determines the Carbon CO2 emissions of the life cycle and sensitivity analysis of an elevator. The article is novelty and interesting. However, it requires a strong revision. Specific recommendations to the authors are following:
The ISO 14041 standard is currently superseded by the ISO 14040 and ISO 14044 standards, which constitute the regulatory and methodological framework for carrying out a life cycle analysis. The article needs to be developed according to the phases established by the normative and methodological framework.
Phase 1: The objective and scope
Phase 2: The life cycle inventory
Phase 3: The life cycle impact assessment
Phase 4: Interpretation
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Reviewer comments: Major revision
The paper titled "Life cycle carbon dioxide emissions and sensitivity analysis of elevators" has assessed the CO2 emissions from elevators. However, there are some fundamental issues that need to be clearly addressed in this paper, as follows:
Abstract:
In line 22, please specify the life stages to make it easier for readers to understand.
What insights can be gained from this study for future investigations?
Please rewrite the abstract by focusing on the primary achievement of the study. However, more numerical results should be presented in the abstract.
In line 23, please specify the contribution percentage of each mentioned process.
Please change the keywords. "Elevator CO2 emission" should be added, and "Carbon dioxide emission" should be removed.
Introduction:
The novelty of the current study should be precisely stated in the introduction.
The introduction contains a lot of information that is not directly related to the research topic, which could make it difficult for readers to grasp the main points.
The introduction could benefit from a clearer and more specific research question or problem statement that identifies the research gap and importance of the study.
Some of the sentences in the introduction are lengthy and complex, which could make it difficult for readers to follow the argument.
Please follow the framework and address the following paper in your work: "Life cycle environmental and economic assessment of highly efficient carbon-based CO2 adsorbents: A comparative study.
Section 2:
The text does not consider the potential variability in carbon dioxide emissions across different elevators, which could limit the generalizability of the findings.
The text does not provide a detailed explanation of the specific data sources and assumptions used in the analysis, which could impact the transparency and reproducibility of the study.
The applied functional unit for the analysis must be clearly stated within the text. However, it should also be included in the explanation of Figure 1.
Methodology:
The methodology assumes that the carbon dioxide emissions are directly correlated with the size of the elevator. How can you confirm that this claim is accurate in all cases?
The methodology does not provide any information about the sources of the data or how the data was collected and used in the calculation of carbon dioxide emissions. Please provide more information about the data sources and the validation process to ensure the credibility of the results.
Please clearly mention the software used for CO2 emissions in this study, along with the applied databases.
All sections of the manuscript include redundant explanations. Please streamline them to make it easier for readers to follow.
Section 4:
The arrangement of tables is not addressed within the text.
In Tables 1, 2, and 3, how is carbon dioxide emission calculated? Furthermore, the unit of Kg is used for material name, quantity, and so on, which should be amended.
In Section 4.2, please explain how the reference data for CO2 emissions are calculated and provide appropriate references for them.
Results and Discussion:
The results and discussion section is weak and only descriptive. It should be enriched by comparing the obtained results with previous investigations.
Conclusions:
In the conclusion section, please provide practical approaches for CO2 emission reduction. Additionally, how can this study provide a framework for further investigation?
Comments for author File: Comments.pdf
Minor editing of the English language required
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
Please check the attachment for the minor revision comments.
Comments for author File: Comments.pdf
Need some revisions of English language.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 4 Report
Dear Authors,
I want to express my gratitude for the well-crafted paper you've presented. The article showcases a commendable level of writing and offers valuable insights for researchers in the field. However, I have one suggestion to make that could enhance the overall presentation:
I kindly recommend reordering the Tables as their current arrangement appears rather confusing. A more structured and intuitive sequence would undoubtedly improve the clarity and understanding of the content.
Additionally, I have a further recommendation that I believe would be beneficial to your work. It would be a great idea to link your research findings to the Sustainable Development Goals (SDGs). This linkage would not only add relevance and significance to your study but also highlight its potential impact on important global objectives.
Good Luck
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The article requires a strong revision. Specific recommendations to the authors are following:
1. The ISO 14040 and ISO 14044 standards constitute the regulatory and methodological framework for carrying out a life cycle assessment. They must be referred in to the text appropriately.
2. Authors are recommended to make use of the specific terms described in ISO 14040 and ISO 14044, especially: objective and scope of the study, system boundaries, functional unit, data quality requirements (geographical, technical, temporary), characterization factor, impact category, category indicator, assessment method, etc.
3. The authors propose “annual carbon dioxide emissions per ton·kilometer” as a new indicator to evaluate the carbon dioxide emissions for different types of elevators. For this, the product or system that is analyzed in this study, that is the functional unit, is defined in section 4, lines 382 to 391 “traction elevator with 382 energy-saving feedback mechanism manufactured by T Elevator Company…”. The technical parameters of the elevator are shown in Appendix A; however, this definition is an element that shoul be included in Goal and Scope section to complete the definition of functional unit.
4. What processes from the Ecoinvent 3.4 database have been used to create the inventory? Reference the Ecoinvent 3.4 database in the "References" section.
5. The variables and parameters that are analysed in the sensitivity analysis, as well as its purpose, are not clearly presented.
6. In tables 1, 2, 3 and Appendix, the column “Quality (kg)” would be “Quantity (kg)”?.
7. What method, impact categories, category indicators and characterisation models have been used for impact assessment?..
8. In my opinion, the article presents a compilation of emissions that constitute the life cycle inventory of the product, but the life cycle impact assessment of the product is not determined.
Author Response
Dear reviewer,
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 2 Report
No more comments have remained.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 3
Reviewer 1 Report
The article has been modified but it is necessary to correct some issues. Specific recommendations for authors are as follows:
1. This article presents the life cycle inventory (LCI) of an elevator but does not include the life cycle impact assessment (LCIA) phase. Following the normative framework established in the ISO 14040 and ISO 14044 standards, the article constitutes a life cycle inventory study (LCI) but cannot be called a life cycle assessment study (LCA) since it does not include the impact assessment phase.
Authors must specify throughout the article that a Life Cycle Inventory (LCI) study is performed and not a Life Cycle Assessment (LCA).
2. Data quality requirements (geographical, technical and temporary) are not defined.
3. As the article does not include the impact assessment phase (LCIA), the following terms do not have to be included in the article: characterization factor, impact category, category indicator and assessment method.
4. The Ecoinvent 3.4 database is LCI database supporting three system models: Allocation cut-off by classification, Allocation at the Point of Substitution, and Consequential. Which of these three system models has been used?.
5. Reference the Ecoinvent 3.4 database in the "References" section.
6. To complement the study, it is recommended that the authors continue the line of research developing the impact assessment of the life cycle
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
