Optimization of the Thermal Insulation Level of Residential Buildings in the Almaty Region of Kazakhstan

Round 1

Reviewer 1 Report

Language and expression

The manuscript was altered in many segments however one of the biggest problems, that we have discussed in our last review remained: there are several grammar mistakes that can be found almost in every chapter of your new manuscript. Here are some of the examples that stuck out:

The essential points made in chapter 2.1 Methodology for determination the optimal thermal insulation level are not comprehensive – the grammar in points 3. And 4. has to be improved in a manner that the sentences are put together correctly – especially through using tenses and interpunctuation correctly, so the readers can understand the sentences and the methodical steps that you are trying to display.

For example, point 3., line 146 says:

Calculating the optimal level of thermal insulation of the external partitions, heat losses

through the longitudinal thermal bridges formed at the joints of the partition elements were

not evaluated. However, the influence of these bridges was evaluated calculating the energy

characteristics of insulated reference buildings.

 

This statement is unclear due to grammatical errors and there is not much sense in mentioning what has not been done and what has not been evaluated.

 

Point 4. Line 150 Says: 

The total cost of each thermal insulation improvement was calculated as the sum of the initial investment, maintenance and replacement costs, if declared live cycle of the structure is shorter when calculating period, and deducting residual value if declared live cycle is longer when calculating period. 

This statement, as well, is unclear due to poor sentence building and also has a relevant typing error “live cycle” (instead of correct “life cycle”).

Chapter 2.2.5. begins with a sentence which is not comprehensible due to wrong expression language-wise: “The initial investment for the implementation of thermal insulation for building envelope is calculated by summing up all the costs that were up to the moment the building is ready for use and is handed over to the user.” 

Altogether, the manuscript has got to be reviewed once again when it come to the language and expression, in order to make sure that the ideas and statements of this work are displayed correctly in a comprehensible manner and do not get misinterpreted or misunderstood. The points mentioned above are just some of the chosen examples, the work should be thoroughly analyzed as a whole one more time, perhaps by someone with professional skills and knowledge of scientific English language.

 

Content and layout

The alterations that we suggested were implemented well – the structure is overall better, as you have combined and connected some of the chapters as recommended.

The new manuscript also contains graphics, as we suggested which are presentable and make your results more comprehensive.

The tables that the old manuscript contained have been optimized aesthetically, however, the formatting could perhaps be optimized in certain places e.g. in the Table 4 in chapter 2.2.5 – we would recommend avoiding the splitting of the words in a manner that leaves the word looking like it is spelled wrongly (which is confusing at first sight and has to be observed closely in order to grasp your intended usage of the word).

g, ggl....

 

It is common knowledge that you should respond to all reviewer comments and mark all changes. in the revised scriptum nothing has been marked so it is difficult to follow the changes. Please always mark everything new and answer all questions.

Author Response

Comments to the authors	Answers to the reviewer 1
Reviewer 1
Language and expression   The manuscript was altered in many segments however one of the biggest problems that we have discussed in our last review remained: there are several grammar mistakes that can be found almost in every chapter of your new manuscript. Here are some of the examples that stuck out:   The essential points made in chapter 2.1 Methodology for determination the optimal thermal insulation level are not comprehensive – the grammar in points 3. And 4. has to be improved in a manner that the sentences are put together correctly – especially through using tenses and interpunctuation correctly, so the readers can understand the sentences and the methodical steps that you are trying to display.   For example, point 3., line 146 says:   Calculating the optimal level of thermal insulation of the external partitions, heat losses through the longitudinal thermal bridges formed at the joints of the partition elements were not evaluated. However, the influence of these bridges was evaluated calculating the energy characteristics of insulated reference buildings.   This statement is unclear due to grammatical errors and there is not much sense in mentioning what has not been done and what has not been evaluated.   Point 4. Line 150 Says:   The total cost of each thermal insulation improvement was calculated as the sum of the initial investment, maintenance and replacement costs, if declared live cycle of the structure is shorter when calculating period, and deducting residual value if declared live cycle is longer when calculating period.   This statement, as well, is unclear due to poor sentence building and also has a relevant typing error “live cycle” (instead of correct “life cycle”).   Chapter 2.2.5. begins with a sentence which is not comprehensible due to wrong expression language-wise: “The initial investment for the implementation of thermal insulation for building envelope is calculated by summing up all the costs that were up to the moment the building is ready for use and is handed over to the user.”   Altogether, the manuscript has got to be reviewed once again when it come to the language and expression, in order to make sure that the ideas and statements of this work are displayed correctly in a comprehensible manner and do not get misinterpreted or misunderstood. The points mentioned above are just some of the chosen examples, the work should be thoroughly analyzed as a whole one more time, perhaps by someone with professional skills and knowledge of scientific English language.	Thank you for the comment. We agree that our scientific English is imperfect. We ordered a language correction for MDPI. They corrected the article.                                       A new version has been submitted:   The annual energy consumption was calculated as heat losses through 1 square meter of the enclosure element during two heating seasons of different duration. Heat losses through walls and roofs were calculated as heat transfer through these structures, through windows - as difference of heat transfer and solar heat gains through windows, and through floor – primarily for the whole floor of reference building and for optimization as an average value per 1 m2 of floor area was used. The influence of thermal bridges was evaluated in calculation of energy characteristics of reference buildings with optimized thermal insulation (Table 7). (See lines 160-167).               A new version has been submitted:   The total cost of each thermal insulation improvement was calculated as the sum of the initial investment, maintenance and replacement costs, if declared life cycle of the structure is shorter when calculating period. For envelope structures, of which declared life cycle is longer when calculating period, the total cost was calculated as the sum of the initial investment and maintenance cost, and residual value of structure was deducted. See lines 168-172).                 A new version has been submitted: The initial investment for each step of thermal insulation of building envelope element is calculated by summing up all the costs that are needed to finish the building.(Lines 272-273).
Content and layout The alterations that we suggested were implemented well – the structure is overall better, as you have combined and connected some of the chapters as recommended.   The new manuscript also contains graphics, as we suggested which are presentable and make your results more comprehensive.   The tables that the old manuscript contained have been optimized aesthetically, however, the formatting could perhaps be optimized in certain places e.g. in the Table 4 in chapter 2.2.5 – we would recommend avoiding the splitting of the words in a manner that leaves the word looking like it is spelled wrongly (which is confusing at first sight and has to be observed closely in order to grasp your intended usage of the word).   g, ggl....   It is common knowledge that you should respond to all reviewer comments and mark all changes. in the revised scriptum nothing has been marked so it is difficult to follow the changes. Please always mark everything new and answer all questions.	Thank you for the note. Based on your comments, Table 4 was formatted avoiding the splitting of the words. We have also marked all changes in the manuscript.

Reviewer 2 Report

The paper is original, the authors touch on an important topics such as energy efficiency of residential buildings and the validity of standards.However, the study looks unfinished, no solution proposed. If the authors are ready to finalize rationale for improving standards and propose an improved methodology that is suitable for Kazakhstan or other countries now, then the article can be published. The conclusions given by the authors in the article are also insufficiently substantiated from a scientific point of view.The list of references contains many normative documents. More scientific sources are recommended. Also, the article is perceived as rather local and is not of due interest to international readers. It is recommended to expand the geography of the article, since now it may be of interest to Kazakhstan, but there are other countries with a similar cost of energy resources for which the results of the study and calculations could be of interest.

Author Response

Reviewer 2

Answers to the reviewer 2

The paper is original, the authors touch on an important topic such as energy efficiency of residential buildings and the validity of standards. However, the study looks unfinished, no solution proposed. If the authors are ready to finalize rationale for improving standards and propose an improved methodology that is suitable for Kazakhstan or other countries now, then the article can be published. The conclusions given by the authors in the article are also insufficiently substantiated from a scientific point of view. The list of references contains many normative documents. More scientific sources are recommended. Also, the article is perceived as rather local and is not of due interest to international readers. It is recommended to expand the geography of the article, since now it may be of interest to Kazakhstan, but there are other countries with a similar cost of energy resources for which the results of the study and calculations could be of interest.

Thank you for the comment.   The main proposal of this study is the calculation-based optimal levels of thermal insulation of residential buildings, which, when validated in the Almaty region, do not increase or only slightly increase the total costs over a period of 30 years.   Other proposal is presented as conclusion: To reduce long-term thermal energy consumption and improve thermal conditions in buildings, their energy efficiency must be higher than calculated in this study. It is recommended partly to redistribute the energy subsidies for implementation of energy efficient measures in residential building sector. (Lines 481-482).   The following proposal is included in the new conclusion: The validation of the building's optimized insulation levels according results of this study would slow down the increase in the demand for thermal energy in the region due to the intensive development of residential construction (lines 488-490).   The analysis of the dependence of total costs and the scenarios of changes in energy prices and the value of money was also performed (See lines 425-436).   An additional analysis of subsidies for energy efficiency improvement measures has been made (See lines 437-445).   Five additional scientific sources related to the subsidization of energy saving measures have been analysed (sources 35-39).   Conclusions and recommendations are provided for the transition from artificial reduction of energy prices to subsidization of innovative energy efficiency measures in order to achieve long-term goals of reducing dependence on fossil energy and reducing environmental pollution. (See lines 491-496 ).

Author Response File: Author Response.docx

Reviewer 3 Report

Minor spell check is required. Check the abstract at line n.27 Check, also, the paper layout, especially at page n.9 control the line spacing between text and figure 1. Check all the pages of the paper 

Author Response

Reviewer 3	Answers to the reviewer 3
Minor spell check is required. Check the abstract at line n.27 Check, also, the paper layout, especially at page n.9 control the line spacing between text and figure 1. Check all the pages of the paper.	Thank you for the remark. We ordered a language correction for MDPI. All grammar and sentence punctuation mistakes were corrected.

Author Response File: Author Response.docx

Reviewer 4 Report

The authors presented a case study of optimizing the building insulation from the cost analysis, which has been an important subject of the energy study. However, their manuscript needs further improvement before the acceptance.

• The objective of the study should be stated in the introduction section. 
• The originality of the study should be stressed in the introduction section.
• The Roman numbers in Table 1 and 2 seem absurd.
• Please check the number formats in Table 5. The commas and periods are used at once.
• No description on how to calculate annual energy cost is found in the manuscript.
• Detail estimation process of how the shift of insulation thickness affects the energy cost is not clearly outlined.
• The format of decimal point changes between comma and period in the manuscript.
• The thermal network schematics for their model is necessary.
• The results are simple descriptions of the figures. More physical interpretation is needed.

Author Response

Reviewer 4

Answers to the reviewer 4

The authors presented a case study of optimizing the building insulation from the cost analysis, which has been an important subject of the energy study. However, their manuscript needs further improvement before the acceptance.   The objective of the study should be stated in the introduction section.               The originality of the study should be stressed in the introduction section.           The Roman numbers in Table 1 and 2 seem absurd.   Please check the number formats in Table 5. The commas and periods are used at once.     No description on how to calculate annual energy cost is found in the manuscript.                           Detail estimation process of how the shift of insulation thickness affects the energy cost is not clearly outlined.       The format of decimal point changes between comma and period in the manuscript.   The thermal network schematics for their model is necessary.   The results are simple descriptions of the figures. More physical interpretation is needed.

Thank you for the comment.               Supplemented as follows: The objective of this work is to find out the impact of increasing the thermal insulation of partitions on the total energy consumption and total costs of residential buildings over a period of 30 years and to provide recommendations for the thermal insulation of new construction residential buildings in the Almaty region. In most investigations in this area, building thermal insulation is optimized using global energy market set prices for energy, construction work and building materials. (Lines 57-60).   Supplemented as follows: In Kazakhstan, energy prices are artificially reduced and the prices of construction works and materials, especially innovative ones, are left to the market regulation. The study of this situation will provide new results and will help to clarify the impact of artificial regulation of energy prices on the energy consumption of buildings in the long perspective. (Lines 62-65).     Table 1 (lines 221-222) and Table 2 (lines 230-231) were formatted changing the Roman numbers to names of months.   The numbers were corrected in Table 5 (line 318). There are all numbers with periods now.     Supplemented as follows: The annual energy consumption was calculated as heat losses through 1 square meter of the enclosure element during two heating seasons of different duration. Heat losses through walls and roofs were calculated as heat transfer through these structures, through windows - as difference of heat transfer and solar heat gains through windows, and through floor – primarily for the whole floor of reference building and for optimization as an average value per 1 m2 of floor area was used. (Lines 160-165).   The annual energy consumption was calculated as heat losses through 1 square meter of the enclosure element during each heating seasons of different duration. The annual energy cost was calculated for particular year taking into account different heating energy sources and scenarios of increase in energy prices (see Table 5).  The total energy cost during period of 30 years is a sum of annual energy cost. (Lines 341-344).   We have inserted Table 6 (Line 358), which is part of the data set of the whole optimization process. This table shows how increasing the insulation thickness affects the energy parameters and costs of the ceilings. Because the particular numbers are less important for the study than the trends, all the results hereafter are presented in graphs.   The format of decimal point was made the same in whole manuscript.   A graphical presentation of the building insulation optimization model is presented in Figure 1 (See lines 183-189).   The analysis of the dependence of total costs and the scenarios of changes in energy prices and the value of money was also performed (Lines 425-436).   An additional analysis of subsidies for energy efficiency improvement measures has been made (Lines 437-445).   Conclusions and recommendations are provided for the transition from artificial reduction of energy prices to subsidization of innovative energy efficiency measures in order to achieve long-term goals of reducing dependence on fossil energy and reducing environmental pollution. (Lines 485-496). .

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Dear author thank for the improving of the article in accordance of my previous comments. The article became more better. 

Author Response

Thank You for revision and comments !!!

Reviewer 4 Report

The manuscript was revised reflecting all the reviewers' comments.

However, the citing style should be checked and corrected for the references [12-24]. 

Author Response

Thank you for the comment.

The citing style for the references [12-24] is amended and additional analysis of published investigation results is performed (lines 97-157)

Author Response File: Author Response.docx

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

A topic of this paper is indeed interesting and relevant for the readers. The researches in this field and on similar topics were made before, as stated in introduction, so this research represents a good follow-up. However, there are some certain points in the paper, as well as the overall formatting of the paper, that could be slightly or significantly improved. To start with, this journal does not have strict formatting requirements, but all manuscripts must contain the required sections: Author Information, Abstract, Keywords, Introduction, Materials & Methods, Results. This manuscript does actually contain all of the previously stated information, yet I believe that some parts should be reformatted, and some sections could be put in one. For example, sections 3, 4, and 5 could be examined again. When it comes to English language proficiency and the overall style, changes are needed. There are not too many typing or spelling mistakes, however there are quite a few places where the logic of the sentence cannot be understood, due to the poor sentence building and missing words. For example, in line 292: “The building will be built in a 9 point seismic zone.” According to this sentence, the building is about to be made, but in the text before is mentioned that the model is actually older building. This and similar points in text may lead to misunderstanding and lack of clarity. Therefore, I suggest examining and verifying the text and also using more scientific English. Furthermore, the manuscript does not contain any graphics, diagrams or photos. I suggest adding some photos in order to improve the understanding of the paper and show where the measures were made. Charts or diagrams comparing the results of this research and previous researches, or just results on different types of buildings or different windows types, could improve the overall representation of the results and measurements. When it comes to tables, this paper includes quite a few of them, and all of them are mentioned and explained in text. However, some tables don’t seem to be formatted well. For example, pages 10 and 11 are occupied totally by tables, without margins, which should be corrected and reformatted. Due to the significance of the Abstract and Conclusion of the paper, I believe that in this paper too these parts should be checked again and improved. As a suggestion, in line 405: “see column t = +12oC, r = 4” is not actually making thing clear, I believe that authors should explain it better, without referring to tables in the conclusion section.

Reviewer 2 Report

This paper is essentially a building energy performance study for the region of Almaty in Kazakhstan.

Abstract: The text in the abstract is more appropriate as an introduction to the problem.  The abstract should summarize the objectives, methodology and results. The building typology addressed is not mentioned anywhere.

 Section 2: Evolution of Energy Performance of Buildings and Methods of Optimisation; this section does not provide the reader with a clear overview of the existing methodologies aiming to combine building energy saving measures with economic analysis. A list of potential measures specifically for Kazakhstan, linked to the local building typologies is missing. It would be easier to follow if the authors included a table with measures and potential economic impact.

Detailed comments:

Line 46-49: Text is not easy to understand. Needs improvement. Explain – give example of strict limits set by current law in Kazakhstan

Line 51-71: This historical review of building energy efficiency is not necessary

Line 72-76: Very poor review of methods for assessing energy performance taking into account economic factors.  Needs significant revision

126-`127: Where is the review of LCA/LCEA/LC-ZEB/LCC papers? For what type of building is the review performed?

 

Section 3. Methodology for Determination the Minimum Optimal Insulation Level According to EU 163 “Cost optimal” Methodology; What is the motivation for applying the cost-optimal methodology in Kazakhstan? There are plenty of guideline documents on how to implement the “cost-optimal” method (e.g. http://bpie.eu/publication/implementing-the-cost-optimal-methodology-in-eu-countries/

Detailed comments:

Line 165-196: Very poor description of “cost-optimal methodology”. It is better to include a flow chart to describe the steps of the methodology.

 

Section 4. Initial Data for Calculation of Optimal Energy Performance Indicators of Buildings

What type of buildings is the study addressing? Residential, public, offices, hotels? New or renovated? What type of construction?

Detailed comments:

Line 250-252 and Table 3: Why are calculations made for 1m2 of 5cm thermal insulation layer? How is the energy consumption taken into account? The prices quoted in Table 3 are of the order of ca. 1000 KZT which correspond to ca. 2 Euros. Is this correct? The same applies for all the quoted prices (e.g. for windows etc). They seem to be extremely low.

Line 270: Table 4: what is the time period over which the total costs are calculated? Please explain “Tif” and “r”

Line 284: Table 5: Again prices seem to be very low

Section 5. Reference Buildings and Structures of Their Envelope

Detailed comments:

Line 286-292: Provide a plan view of the reference building. Is it an apartment? Which are the boundary conditions? What are the special requirements in building construction to address the local seismic activity? How is the building reinforced? Provide tables with materials/systems considered in the reference building. What is the building orientation?

Section 6. Technical and Economic Indicators of the Envelope Elements and Calculation Procedure Used for Optimization of Building Insulation

This section needs significant revision. It is not clear how the results of Table 7 relate to Tables 3-6. The energy saving calculation method and corresponding cost calculation method are unclear. How were the calculations performed? Did the authors use commercial software?

It is stated that the reference building has a monolithic frame work with concrete masonry and brick wall partitions.  There are no details about the envelop configuration and the used material properties.

Section 7. Results and Discussion

It is very difficult to assess the results due to the previously missing information.

Detailed comments:

Line 386- 395: How ere the values in Tables 8 and 9 obtained?

Section 8. Conclusions

The key outcome of the work is as stated “the current relationship between energy prices and the cost of introducing energy saving measures is holding back the introduction of innovative energy-saving measures in the Almaty region”. This requires further analysis. What do the authors propose? Increase of the energy prices? Not to adopt energy saving measures? What about the life cycle perspective of such buildings?

 

Overall comments:

The authors implement a cost-benefit approach for new residential reference building in the Almaty region. Comparisons with other regions are missing. The particular characteristics of the region which might make the work attractive (e.g. seismicity, extremely low cost of energy) are not properly described and analysed. The work, in its current form, is of limited innovation.  The authors are urged to re-structure their arguments in the discussion section, in order to emphasize on their findings and highlight the added value of their work. 

The work is very poorly written and needs thorough rewriting and significant improvements in the analysis and substantiation of the results. The English language should also be improved. The paper cannot be published in its present form.

Reviewer 3 Report

The authors presented the optimization of the building energy performance in a certain area in Kazakhstan. The title seems to be interesting, but the contents were not.

The manuscript seems to be mere a report of calculation sheets. This reviewer could not find any original contribution. It should be clearly stated in the introduction part.

The citation style seems not consistent with the journal's standard. 

The first paragraph in the beginning of section 3 (line 165-180) is not clear and totally unreadable. 

Eq. (1) is weird.

The Roman numbers in Tables 1 and 2 seem strange.

Some superscripts and underscripts are not printed correctly.

Some part of contents in Table 7 could be better presented in figures.