Using the Degree-Day Method to Analyze Central Heating Energy Consumption in Cities of Northern China
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsDue to the large amount of built surface in the cities selected for this study in northern China with cold and very cold climates, which represent millions of GJ to heat living spaces, this study plans a simplified method to know the relationship between variables associated with heating energy consumption and elucidate the characteristics of central heating in northern Chinese cities. This is presented as a macro study, and it is understood that it guides later on carrying out more specific studies considering other variables such as the envelope of the buildings, facilities, among others.
It addresses serious problems of consumption and lack of energy efficiency, which is increasing due to population growth in some places in the world, as well as the growth of built infrastructure whose tendency will increase, therefore, the problem requires timely attention.
Most of the articles published in this field address specific or very localized and small-scale case studies, be it a building or a city, and use simulation software. In this case, the contribution is the analysis of a large region, with a urgent problem in the energy need for supply, providing a proposal based on information and large-scale statistical management, recognizing that the problem must be addressed in a more specific way. Although it is true that the method is simplified and already exists, it has been applied to analyze a large amount of data from official sources obtained for analysis and give the world an idea of what is happening in those regions in a macro view.
The conclusions are short, but they reflect the main idea.
The references are appropriate, it contains references to studies that consider this technique, as well as other types of similar, somewhat different case studies and other evaluation methods that help to place oneself in the context of the topic.
If there is a hypothesis that is clearly expressed in the article
Author Response
Thanks for your comments, please view my replies in the word file.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe work carried out by the authors presents an analysis of energy consumption for heating during the cold season in the case of 60 cities located in cold areas and areas with severe cold, using the degree-day method.
After a careful reading, I would recommend the authors to highlight better the importance and the novel elements of the work, to identify in the established specialized literature, works in which this topic was addressed (either in the introduction or in a separate section of review of specialized literature), to highlight better the implications of the undertaken study.
I also recommend that the source used be mentioned under each figure/table and that a clearer interpretation of the data be provided - it is not ok for the sections/subsections of a work to end with a figure or table without an interpretation being made of the data.
The discussion part should be developed through the mirror presentation of other results of similar researches. Likewise, the part of the conclusions - it's a bit rushed by the authors.
Author Response
Thanks for your comments, please view my replies in the word file.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe topic of improving the energy performance of the built environment in terms of savings is extremely topical. However, the simplified stationary method used, which considers standard parameters that in reality are not standard, and indeed can vary the building's performance by a great deal, is a purely theoretical value, useful for comparing the performance obtained with the regulatory limit or for placing the building in an energy class, but certainly not for defining the building's real consumption. Only "dynamic simulation" accurately and reliably analyzes the energy performance of a building.
The scientific relevance of the contribution can exert influence on the scientific community only at the national level (China) because of the particular boundary conditions not elsewhere widespread.
Not considering piping losses during heat transfer and the energy efficiency of building terminals limits the effectiveness of the evaluation.
The methodology is well described.
The conclusions are obvious, with no particular evaluation needed. The central issue to be handled is not to reduce indoor temperatures in heating perides, but to eliminate leakage and plant efficiency, in case by meeting the minimized demand with renewable energy sources.
The data shown in Tables s1, S2, S3, s4 are not controllable
Regarding the bibliographical references, it is unclear how references No. 1, 2, 4, 7, 18, 20, 21, 25, 32, 33, 41, and 42 contributed to the work.
Author Response
Thanks for your comments, please view my replies in the word file.
Author Response File: Author Response.pdf
Reviewer 4 Report
Comments and Suggestions for Authors1. The paper presents a comprehensive overview of the study's objectives and methodology; however, the literature review appears to be somewhat limited. While the authors reference the use of the degree-day method and its application in various fields, a more extensive review of existing literature on central heating characteristics in northern regions could enhance the foundation for the study. A more thorough exploration of prior research, especially studies related to energy consumption, heating models, and the specific climatic considerations of northern cities, would strengthen the contextual background and demonstrate the current state of knowledge in this area
2. Authors need to explicitly articulate the specific research gap they intend to address. While the introduction mentions the application of the degree-day method in analyzing central heating characteristics in northern regions, a clearer identification of the existing knowledge gaps or unanswered questions in the literature would provide readers with a better understanding of the novelty and significance of the study
3. The authors should elaborate on why they chose the degree-day method. While its simplicity and historical use are clear benefits, a concise rationale aligning its advantages with the study's specific goals is needed. Additionally, acknowledging and discussing the method's limitations would enhance transparency and strengthen the justification for its application.
4. The authors should explicitly outline the limitations of their study. A transparent discussion about the potential constraints, assumptions, and challenges inherent in the research would enhance the credibility of their findings and provide readers with a comprehensive understanding of the study's boundaries
5. The authors frequently cite Chinese codes, such as the 'Thermal Design Code for Civil Building.'. Authors need to provide a brief overview or explanation of the key principles and specifications outlined in these codes for reader who are not familiar with them.
6. Figure 1: define x-axis and y-axis with units
Comments on the Quality of English Language
The quality of English in the manuscript is commendable. The language is clear, and the content is effectively communicated.
Author Response
Thanks for your comments, please view my replies in the word file.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors respected the recommendations received, thus improving the work. The arguments presented and the additions made by them allow me to recommend the publication of the article in its current form.
Reviewer 3 Report
Comments and Suggestions for AuthorsThe arguments in response to the comments are convincing and the changes sufficient
Reviewer 4 Report
Comments and Suggestions for AuthorsI am pleased to note that the comments have been addressed. The manuscript's level of clarity and credibility is much better now. I recommend accepting the manuscript. Good luck!
