Impact of an Innovative Solution for the Interruption of 3-D Point Thermal Bridges in Buildings on Sustainability

Round 1

Reviewer 1 Report

The topic discussed by the authors is of interest as the users of external cladding and insulating materials often neglect to consider the metallic framework used in thermal losses calculations. The paper need however to address the multiples issues described below, in addition to the typos. 

1. When variants are named in section 3.1, there is no distinction between variant #2 and variant #3 (i.e. same label). Additional details should be provided to clarify.
2. Issue with chapter and/or section numbering. Please review and correct.
3. Part of Chapter 4 (example: lines 418-422) is repeated from an earlier chapter (lines 217-221).
4. With 14 tables, this paper contains too much tables, most of them with little information. Many of these tables can (and should) be combined to improve clarity and lighten the paper. Tables 3, 4 and 5 for example could be regrouped into one, with a clear labeling of what are simulated and measured values.
5. Figures 10 and 11 could be combined into one figure as there is no overlap, as the only difference between both is the insulation thickness.
6. For Figure 7, please add a legend (/materials) for the boundary conditions. More details on the model should also be given in the text.
7. As a general remarks, results should be reorganized and expanded to avoid going through an additional paper.
8. The experimental procedure used for thermal characterization should be more explicit and ideally in a single section. In the current form, there seems to be some details in lines 250-252, and from 442 to 473.
9. When presenting your results, the standard “uninsulated” anchor should be included in any thermal comparison to highlight all changes associated with the use of an insulating material (Hilti or your patent).
10. Some experimental “raw” values should be given and explained to confirm results, as the paper only present indirect/derived values.
11. Are the Heat transfer coefficients U (simulated and measured) given for the complete wall (with/without anchor, insulant, etc…)? If so, this should be clearly mentioned and more details given.
12. Are the U values found with anchor obtained only for one anchor, or multiple? If U are for single anchors, values of U should be calculated when multiple anchors are used in the same wall section.
13. What are the hypothesis used in the economic evaluation, especially the costs of your patented approach? What is the life expectancy of your coating?
14. An English native speaker should review the paper to correct the writing style.

Author Response

Good day

I am sending an attachment with a comment. Thank you for the quality comments I accepted.

Author Response File: Author Response.pdf

Reviewer 2 Report

The article is very interesting and has significant contributions. The use of hot box systems to measure the variations in thermal bridges is an innovative aspect and there are few studies on the topic. The manuscript is well written, although there are a number of aspects that can be improved:
Include the technical specifications of the equipment.
The state of the art review should be improved. There are many studies in recent years related to the thermal characterization of the envelope.
Figures 2-4 could be merged.
A flowchart with the research steps should be included.

Author Response

Thank you for your professional comments. I tried to incorporate them all. I believe that everything will be fine.

 

Ingeli 

Author Response File: Author Response.pdf

Reviewer 3 Report

The work presented deals with the impact of an innovative solution for the interruption of 3-D point thermal bridges in buildings. The topic is current and well illustrated but the reviewer requires authors to take into account the following comments:

1) Explain in a clearer way the functioning of a ventilated wall, for not all readers it could be a known concept;

2) Specify how the economic considerations present in the paper were made: the source from which the costs were drawn, whether the costs are discounted or not, if tax relief is taken into account. This point is too lightly herringbone and should therefore be integrated.

3) Can the results on the energy needs of the building analyzed be considered as reference for other types of buildings in different parts of the world and with different climatic data or are they typical of a local case study? To specify.

4) Can the considerations and solutions discussed be considered replicable in other buildings and situations?If so, please explain in detail how.

5) The graph in figure 17 is difficult to read: improve the overall graphic rendering and make the time axis more readable.

Author Response

Thanks for sending comments. I believe that I have taken into account all the comments and the contribution will already be at the required level. Well thank you .

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Thank you for the clarification to the remarks expressed. Minor correction required for the English (some typos still are present).

Reviewer 3 Report

In the new submitted version the paper results in a more complete and adequate form.

The last recommendation that the reviewer submits to the authors is the inclusion in the introductory part of the use of insulating and superinsulating materials as a form currently used for reducing heat loss.

The inclusion of these works is suggested:

• Aerogel insulation in building energy retrofit. Performance testing and cost analysis on a case study in Rome https://doi.org/10.1016/j.egyr.2020.10.045 
• On the retrofit of existing buildings with aerogel panels: Energy, environmental and economic issues https://doi.org/10.3390/en14051276
• On the Energy Performance of an Innovative Green Roof in the Mediterranean Climate https://doi.org/10.3390/en13195163
• An Evaluation of the Environmental Payback Times and Economic Convenience in an Energy Requalification of a School https://doi.org/10.3390/buildings11010012

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

The paper presents simulations related to point thermal bridges caused by cladding of ventilated façade. The anchor and the analysis results claimed in this paper as an innovative solution were very interesting.

However, there are some reviews I would like to suggests:

Introduction

: The background of the study was described, but there are many contents that are not directly related to the study. For example, dynamic calculations or simplified calculation methods do not seem to be relevant in this study.

The purpose of the study is not clear. If the purpose of the study is to perform 3D FEM simulation simply to evaluate the steady state performance of the developed anchor, it is somewhat insufficient as a research paper.

 

Body

The description of the simulation is insufficient.

A detailed picture of the geometry modeled in the simulation is required(with dimension).

In the ventilated facade, the temperature of the hollow layer was set as the outside temperature, and the outermost shell was excluded from the simulation model. The reason for this needs to be explained.

The convective heat transfer coefficient is an important factor that cannot be ignored in the analysis of heat bridges. However, the heat resistance of the hollow layer was set to 0.04m²K/W, which generally corresponds to the outdoor surface heat resistance(h_se=25W/m²K). I think there is a serious error in applying this to the hollow layer. The convective heat transfer coefficient is related to the wind velocity (the wind velocity in the hollow layer is different due to the shell or barrier).

In order to calculate the equivalent U-value in the steady state, the indoor/outdoor temperature value corresponding to the boundary condition is not important. It was said that the temperature was set to 23.05°C / -15.22°C to match the experimental conditions, but the reason why it should be set the same as the experimental conditions should be explained. This paper does not seem to be related to experiments.

You need to check that the percentage expression for the result is correct. For example, if the result of Experiment 1 is 100 and the result of Experiment 2 is 120, the result of Experiment 2 increases by 20%, not by 16.67%.

 

(120-100)/100 * 100 =20% ; (120-100)/120 * 100=16.67%

Applying this to Table 3

(0.585-0.429)/0.585*100=26.67% ; (0.585-0.429)/0.429*100=36.36%

I hope you think about which one is right.

Equations (1) to (4) seem to explain the background theory related to the point thermal bridge, but the last equation (4) was not used directly in this study. In other words, it is not point thermal transmittance(x,chi) that is presented as a result in this study. The x value was not indicated anywhere in the paper.

Discussion

It's a good idea to mention a discussion about the results you did in this study. In this paper, the results of the simulation were studied, so it seems good not to mention the results of the experiment(Line 357~359).

Emissivity relates to the phenomenon of radiant heat transfer, and the amount of heat transferred in the form of radiation in the hollow layer is thought to be extremely small.

Conclusion

What should be stated in the conclusion does not represent an additional analysis, but summarizes the previous results and discussion. No research has been done on the economics analysis, but suddenly the conclusion mentions price.

A simpler and clearer conclusion seems to be needed.

Finally, some of the minor reviews are below.

1. Line 51~54 : It appears that a reference is needed. In particular, since this paper is about point thermal bridges, references on point thermal bridges rather than linear thermal bridges should be used.
2. Line 98 : please pay attention to the expression of the unit (Use superscript)
3. Line 108, line 104 : inhomogeneous vs. non-homogeneous. The same meaning is expressed in different terms.
4. Line 112 : please make sure the word “only” matches. There are methods such as FEM and FDM, FVM for calculating 3D modeling.
5. Line 128 : check the equation number.
6. Line 152 : linear loss coefficient. I know what is means, but the exact term is known as “linear thermal transmittance”.
7. Line 160 : there is a typo. (facades -> façades)
8. In Figures 3, 4, and 5(b), how to express L seems confused. When I first saw it, I thought it meant "minus". When looking at the text, it is understood as a meaning that corresponds to a “range”. But did you experiment or simulate by changing the length? If not, the “range” will not help to describe this paper.
9. Line 215 (ref. Line 208) : subscript and superscript
10. Line 238~239 : Not resistance through the structure (Resistance through a structure usually relates to the phenomenon of heat transfer to conduction). It seems to be resistance to indoor/outdoor surface convection.
11. Table 1 : It would be nice to express the thickness as well. This is because heat resistance is composed of thickness as well as thermal conductivity.
12. Table 3, 4, 5, 6, 7 : These are the tables showing the results, but there are overlapping contents(The table title is also the same.). It is suggested to simply organize it in one table. Also, does “Heat transfer coefficient U in W/(m²K)” in the table mean equivalent U-value?
13. Line 264 : Typo ( Psi-Therm -> PSI-Therm )
14. Line 279 : Type ( PSI Therm -> PSI-Therm )
15. Line 271 : Psi-values and Frsi-values. It seems to mean a linear thermal transmittance and a temperature factor. The exact definition of the term is necessary.
16. Figure 6, 7, 8, 9 : The geometry, which is important for modeling thermal bridges, could not be expressed, and there are many overlapping contents.
17. Line 433 and line 439 : check.

 

In addition to those mentioned above, it is too distracting to express terms.

It seems necessary to carefully check the graphs and tables.

Author Response

Response to Reviewer 1Comments

 

 

 

Point 1: Introduction

: The background of the study was described, but there are many contents that are not directly related to the study. For example, dynamic calculations or simplified calculation methods do not seem to be relevant in this study.

The purpose of the study is not clear. If the purpose of the study is to perform 3D FEM simulation simply to evaluate the steady state performance of the developed anchor, it is somewhat insufficient as a research paper.

 

Response 1: A simplified steady state calculation method is used for the given calculation. The dynamic method was not used. The computational part is mainly used for verification with the experimental model and determination of the thermal conductivity of the proposed anchor modification.

 

 

Point 2: The description of the simulation is insufficient. A detailed picture of the geometry modeled in the simulation is required (with dimension).

 

 

Response 2: Thank you for your recommendation. I added the exact geometry - Figure 6 and I added the description of the simulation.

 

 

 

 

Point 3: In the ventilated facade, the temperature of the hollow layer was set as the outside temperature, and the outermost shell was excluded from the simulation model. The reason for this needs to be explained.

 

The convective heat transfer coefficient is an important factor that cannot be ignored in the analysis of heat bridges. However, the heat resistance of the hollow layer was set to 0.04m2K/W, which generally corresponds to the outdoor surface heat resistance(hse=25W/m2K). I think there is a serious error in applying this to the hollow layer. The convective heat transfer coefficient is related to the wind velocity (the wind velocity in the hollow layer is different due to the shell or barrier).

 

 

Response 3: Thank you for your recommendation. Yes, it is true that the temperature in the air layer of ventilated facades is not the same as the exterior facade. As there is a different effect of wind and other physical parameters. Normally, with heat losses of ventilated facades, the thermal resistance on the surface is 0.08 m2.K/W, which is he =12.5 W/(m2.K). Only in this post we verify the simulation with an experiment. We did not make a ventilated structure in the experiment (Figure 15). We only needed to determine the thermal conductivity of the proposed anchor modification (Patent). In the model building (Figure 12), RSe = 0.08 according our standards was considered for heat losses.

 

Point 4: In order to calculate the equivalent U-value in the steady state, the indoor/outdoor temperature value corresponding to the boundary condition is not important. It was said that the temperature was set to 23.05°C / -15.22°C to match the experimental conditions, but the reason why it should be set the same as the experimental conditions should be explained. This paper does not seem to be related to experiments.

 

Response 4: Thank you for your recommendation. I added a separate chapter 3.1 from experimental measurement.

 

 

 

Point 5: You need to check that the percentage expression for the result is correct. For example, if the result of Experiment 1 is 100 and the result of Experiment 2 is 120, the result of Experiment 2 increases by 20%, not by 16.67%.

(120-100)/100 * 100 =20% ; (120-100)/120 * 100=16.67%

Applying this to Table 3

(0.585-0.429)/0.585*100=26.67% ; (0.585-0.429)/0.429*100=36.36%

I hope you think about which one is right.

 

Response 5: Thank you for your recommendation. I understood the query, I adjusted the values.

 

 

Point 6: Discussion

It's a good idea to mention a discussion about the results you did in this study. In this paper, the results of the simulation were studied, so it seems good not to mention the results of the experiment(Line 357~359).

 

Emissivity relates to the phenomenon of radiant heat transfer, and the amount of heat transferred in the form of radiation in the hollow layer is thought to be extremely small.

 

Response 6: Thank you for your recommendation. I added a separate chapter 3.1 from experimental measurement. We are currently analyzing the impact of the emissivity of the proposed anchor modification at the workplace. It is possible that the result will be minimal impact.

 

 

Point 7: Conclusion

What should be stated in the conclusion does not represent an additional analysis, but summarizes the previous results and discussion. No research has been done on the economics analysis, but suddenly the conclusion mentions price.

 

A simpler and clearer conclusion seems to be needed.

 

Response 7: Thank you for your recommendation. I added an economic evaluation. This is definitely better understood for the reader.

 

 

 

Point 8: A simpler and clearer conclusion seems to be needed.

Finally, some of the minor reviews are below.

1. Line 51~54 : It appears that a reference is needed. In particular, since this paper is about point thermal bridges, references on point thermal bridges rather than linear thermal bridges should be used.
2. Line 98 : please pay attention to the expression of the unit (Use superscript)
3. Line 108, line 104 : inhomogeneous vs. non-homogeneous. The same meaning is expressed in different terms.
4. Line 112 : please make sure the word “only” matches. There are methods such as FEM and FDM, FVM for calculating 3D modeling.
5. Line 128 : check the equation number.
6. Line 152 : linear loss coefficient. I know what is means, but the exact term is known as “linear thermal transmittance”.
7. Line 160 : there is a typo. (facades -> façades)
8. In Figures 3, 4, and 5(b), how to express L seems confused. When I first saw it, I thought it meant "minus". When looking at the text, it is understood as a meaning that corresponds to a “range”. But did you experiment or simulate by changing the length? If not, the “range” will not help to describe this paper.
9. Line 215 (ref. Line 208) : subscript and superscript
10. Line 238~239 : Not resistance through the structure (Resistance through a structure usually relates to the phenomenon of heat transfer to conduction). It seems to be resistance to indoor/outdoor surface convection.
11. Table 1 : It would be nice to express the thickness as well. This is because heat resistance is composed of thickness as well as thermal conductivity.
12. Table 3, 4, 5, 6, 7 : These are the tables showing the results, but there are overlapping contents(The table title is also the same.). It is suggested to simply organize it in one table. Also, does “Heat transfer coefficient U in W/(m²K)” in the table mean equivalent U-value?
13. Line 264 : Typo ( Psi-Therm -> PSI-Therm )
14. Line 279 : Type ( PSI Therm -> PSI-Therm )
15. Line 271 : Psi-values and Frsi-values. It seems to mean a linear thermal transmittance and a temperature factor. The exact definition of the term is necessary.
16. Figure 6, 7, 8, 9 : The geometry, which is important for modeling thermal bridges, could not be expressed, and there are many overlapping contents.
17. Line 433 and line 439 : check.

 

Response 8: Thank you for your recommendation. I incorporated your comments.

 

 

 

Ingeli

Author Response File: Author Response.docx

Reviewer 2 Report

The thermal bridge effect should be considered in order to ensure high thermal performance of the building envelopes. In this context, this article is very interesting, and necessary to develop the construction method for reducing thermal bridges.

I would like to give you some comments and suggestions to improve readers' understanding and support the conclusions.

1.  I recommend the abstract is revised by adding the conclusions. It is needed that both thermal and economical aspect are described briefly (quantitatively) in order to support the word "innovative solution".
2. The economical advantage of the plastic-coated anchor should be more detailed. You described it in the conclusion chapter, but I think it should be shown in the main text. 
   I wonder the total costs and the difference, the number of anchors if the three anchors apply the typical building. It can help to understand if you provide more detailed data.
3. The thermal conductivity of the plastic-coated anchor is important. So, I think it would be necessary to add the experiment and the calculation process to obtain the thermal conductivity of that anchor. The experiment is mentioned overall in the text, but it is difficult to understand because there is no specific content. 
   (In line 358, I wonder how to obtain the value "49 W/mK" from the experiment results and what is the experiment results. Is it same for the table 6-7?)

The following is minor comments.

1. Add the unit for the equation (2) to (4) 
2. Add a description of the abbreviation (ex. PE, TGIC, UV) 
3. In the table 3~5, is the heat transfer coefficient the result of the simulation (PSI-Therm)? if so, I think it would be better that "the measured values" in the table should be changed to "the simulated values" or like that. And "the sample n.1" should be changed to "the variant no.1" in order to clarify.  
4. Figure 9 is as same as Figure 8. I think it should be changed proper images. 
5. In the lines 343-345, I wonder the specific values, the thermal conductivity of the masonry wall and the total heat loss of it. I think it would be better to show the specific values if you have them.
6. In the line 345, I think you'd better clarify the standard, the regulation or the requirements and add the reference number. (also, in line 327)

 

 

 

Author Response

Response to Reviewer 2 Comments

 

 

 

Point 1: I recommend the abstract is revised by adding the conclusions. It is needed that both thermal and economical aspect are described briefly (quantitatively) in order to support the word "innovative solution".

The economical advantage of the plastic-coated anchor should be more detailed. You described it in the conclusion chapter, but I think it should be shown in the main text.

I wonder the total costs and the difference, the number of anchors if the three anchors apply the typical building. It can help to understand if you provide more detailed data.

 

Response 1: Thank you for your recommendation. I have added the economic evaluation to the abstract and to chapter 3.3.

 

Point 2: The thermal conductivity of the plastic-coated anchor is important. So, I think it would be necessary to add the experiment and the calculation process to obtain the thermal conductivity of that anchor. The experiment is mentioned overall in the text, but it is difficult to understand because there is no specific content.

(In line 358, I wonder how to obtain the value "49 W / mK" from the experiment results and what is the experiment results. Is it same for the table 6-7?)

 

Response 2: Thank you for your recommendation. I added a separate chapter from experimental measurement.

 

Point 3: Add the unit for the equation (2) to (4)

Add a description of the abbreviation (ex. PE, TGIC, UV)

In the table 3 ~ 5, is the heat transfer coefficient the result of the simulation (PSI-Therm)? if so, I think it would be better that "the measured values" in the table should be changed to "the simulated values" or like that. And "the sample n.1" should be changed to "the variant no.1" in order to clarify.

Figure 9 is as same as Figure 8. I think it should be changed proper images.

In the lines 343-345, I wonder the specific values, the thermal conductivity of the masonry wall and the total heat loss of it. I think it would be better to show the specific values ​​if you have them.

In the line 345, I think you'd better clarify the standard, the regulation or the requirements and add the reference number. (also, in line 327)

 

Response 3: Thank you for your recommendation. I added units to the equations. I have added an explanation of the abbreviations. I have completed all your requests.

 

 

 

Experimental measurement

The experimental measurement was performed in a climate chamber. We are currently verifying the impact of anchor emissivity on heat losses. Therefore, the experiment described not exactly but will be published only separately in the second publication.

 

Ingeli

Author Response File: Author Response.docx

Reviewer 3 Report

Although the manuscript deals with an interesting topic, it does not report significant and clearly explicit experimental data.  The data shown derive only from the application of a software and no experimental data are shown, although the word file not to be published shows various images suggesting experimental activities (hot-boxes, panels, sensors, etc.). The abstract is too generic, not reporting data and neither quantifying the percentage of heat losses due to anchors, described in the text.

In paragraph 3, explain better the research methodology: choice of the case study, theoretical calculation and comparison with experimental values.
-Reduce paragraph 2.1 leaving only formula (3) and integrate it with “2. Thermal bridges ". Formulas (1) (2) and (3) reported in paragraph 2.1 are well known and therefore superfluous.
- Illustrate the three variants of the design solution of the mechanical anchoring of the load-bearing gratings mentioned at the beginning of paragraph 3.1.

Figures 2 and 4 are the same; Figures 3 and 5 are the same. It is advisable to unify the figures and optimize the information in paragraph 3.1, reporting the stratigraphy of the technological solution being tested, the materials of which are shown in table 1.
The division into sub-paragraphs is excessive and involves a repetition of the same things both in the text and in the relative tables. Paragraphs 3.2.1, 3.2.2 and 3.2.3 must be unified and optimized, avoiding always repeating the data of variant 1, and represent in a single table the results of the variants analyzed (tab 3, tab. 4 and tab. 5). Furthermore in these tables the calculation of increase the heat transfer coefficient is not correct. There is no comment on the comparative calculations for the various variants.
In paragraph 3.3, the text does not explain the relationship between the number of anchors and square meters of wall, which can only be seen from the graphs. The materials corresponding to λD = 0.033 W / (m. K) and λD = 0.035 W / (m. K)) are not explicit.
The legend of the graphs in figures 10 and 11 is incomplete.

Figure 1 does not show the reference.

Regarding the references:
- they are lacking on the specific topic.
- some ones are a bit dated, see ref. [12] and [13]
- two references are repeated (ref. [10] is the same as ref [7]). 
- the UNI EN ISO standards do not report the updated dates: [6, 7] correct the date of UNI EN ISO 14683 which was updated after the first version of 2001 twice in 2008 and in 2018; to Line 433: correct the date of UNI EN ISO 10211 which was updated in 2018; the reference [9] to Line 437: correct the date of the standard which was updated in 2018
- Lacking reference of the statement in lines 52-53
- Lacking reference to the cited normative in line 208

Author Response

Response to Reviewer 1 Comments

 

 

 

Point 1: Although the manuscript deals with an interesting topic, it does not report significant and clearly explicit experimental data.  The data shown derive only from the application of a software and no experimental data are shown, although the word file not to be published shows various images suggesting experimental activities (hot-boxes, panels, sensors, etc.). The abstract is too generic, not reporting data and neither quantifying the percentage of heat losses due to anchors, described in the text.

 

Response 1: A chapter on experimental measurement has been added, which is still being worked on exactly! The abstract has been added.

 

Point 2: In paragraph 3, explain better the research methodology: choice of the case study, theoretical calculation and comparison with experimental values.

-Reduce paragraph 2.1 leaving only formula (3) and integrate it with “2. Thermal bridges ". Formulas (1) (2) and (3) reported in paragraph 2.1 are well known and therefore superfluous.

- Illustrate the three variants of the design solution of the mechanical anchoring of the load-bearing gratings mentioned at the beginning of paragraph 3.1

 

Response 2: The recommendations were accepted and modified in the text. Equation 1 was requested by one of the reviewers, so I will keep it in the text. A chapter on experimental measurement has been added, which is still being worked on exactly.

 

Point 3: Figures 2 and 4 are the same; Figures 3 and 5 are the same. It is advisable to unify the figures and optimize the information in paragraph 3.1, reporting the stratigraphy of the technological solution being tested, the materials of which are shown in table 1.

The division into sub-paragraphs is excessive and involves a repetition of the same things both in the text and in the relative tables. Paragraphs 3.2.1, 3.2.2 and 3.2.3 must be unified and optimized, avoiding always repeating the data of variant 1, and represent in a single table the results of the variants analyzed (tab 3, tab. 4 and tab. 5). Furthermore in these tables the calculation of increase the heat transfer coefficient is not correct. There is no comment on the comparative calculations for the various variants.

In paragraph 3.3, the text does not explain the relationship between the number of anchors and square meters of wall, which can only be seen from the graphs. The materials corresponding to λD = 0.033 W / (m. K) and λD = 0.035 W / (m. K)) are not explicit.

The legend of the graphs in figures 10 and 11 is incomplete.

 

 

Response 3: Figure 4 shows more detail. Figure 2 is for information only. Figure 5 has been changed. A summary table is displayed in the results. Tables 3,4,5 show only partial results. They clearly define the result for the given variant. Therefore, I would keep this breakdown. The thermal conductivity coefficient was explained and Figures 10 and 11 were added.

 

 

 

Point 4: Figure 1 does not show the reference.

 

Response 4: I have added a reference

 

Point 5: Regarding the references:
- they are lacking on the specific topic.
- some ones are a bit dated, see ref. [12] and [13]
- two references are repeated (ref. [10] is the same as ref [7]). 
- the UNI EN ISO standards do not report the updated dates: [6, 7] correct the date of UNI EN ISO 14683 which was updated after the first version of 2001 twice in 2008 and in 2018; to Line 433: correct the date of UNI EN ISO 10211 which was updated in 2018; the reference [9] to Line 437: correct the date of the standard which was updated in 2018
- Lacking reference of the statement in lines 52-53
- Lacking reference to the cited normative in line 208

Response 5: I tried to add all the quality notes into the article. For details, see article. I would like to thank the reviewer for the quality comments and his precious time. I believe that I have completed all the essential requirements and we will be able to publish the article.

Experimental measurement

The experimental measurement was performed in a climate chamber. We are currently verifying the impact of anchor emissivity on heat losses. Therefore, the experiment described not exactly but will be published only separately in the second publication.

 

Ingeli

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Many parts of the paper have been revised and seem to have been added. In particular, it seems that the direction of the paper has changed due to the addition of parts related to the experiment. That is why it is difficult and confusing to understand the paper.

First of all, the purpose(or aim, objective) and method of the paper should be explained in the introduction section, but there is no. There are no words for purpose, aim, or objective in the introduction.

This is a serious problem. I can't figure it out at all. I read the paper while guessing what the author did, how he did it, and why he did it, and I read it many times, but I can't even confirm that the guess is correct.

 Simulations and experiments were conducted, what was it done to know.? And why do you need to know it?

If the purpose of the thesis is clear, you can explore methods to achieve that purpose, and you can achieve that purpose in one or more ways depending on the logical basis of the searched methods.

For example, Line 91 in Introduction,

“The computational part is mainly used for verification with the experimental model….”

I guessed that it was done in two ways (simulation and experiment) to confirm the more conclusive results. By the way, does verifying the experimental model mean verifying the experimental results?

I again guessed that the experimental result was heat loss. And I read the following sentence,

"… and determination of the thermal conductivity of the proposed anchor modification"

In order to verify in simulation, it is necessary to know physical properties such as thermal conductivity, but determining the thermal conductivity means that the value of thermal conductivity is not yet known. Then I am immersed in the thought of what and how you have verified. Also, I don’t know why the thermal conductivity needs to be determined, and why the thermal conductivity should be determined by simulation.

Another example. Right above. Line 90.

“A simplified steady state calculation method is used for the given calculation.”

What is a “simplified” steady state calculation method? And what is “given calculation”?

Also, the connection with the previous sentence is not smooth.

It is difficult to understand because the definition of the term is not unified.

Line 152~171

In my last review, I said that the terms used in this paper should be clearly defined, but you corrected it completely wrong. Check out ISO 10211.

A method for calculating the point thermal transmission was shown, but the study results do not provide information on the point thermal transmission. Why did you include this content in the paper? This content does not seem to be related to the study. It's harder to figure out what you're talking about in this paper because of things like this.

Line 76~79

“Standard EN ISO 13786[9] requires a dynamic calculation for the evaluation of building performance but refers to Standard EN ISO 10211 [7] to do steady-state thermal bridges calculations. Martin et al. [11]. underline this contradiction.”

How does this sentence relate to what you want to talk about in this paper?

Line 276~292

3.2 Calculation analysis of individual variants

Section 3.2 introduces the simulation program, but it is confusing because information that is not relevant to this study is repeatedly displayed.

Line 397~Line 405

The location and overall composition of the additional content on the economics analysis is not good. In addition, I don't know if the contents of Table 7 are important for economic analysis (also, I don't know why you put the shape factor in). I think it is necessary to tabulate the information necessary for economic analysis and the results calculated using it.

Page 15 seems to have not yet completed the sentence. There are places where the same sentence is repeated, and the sentence is not smooth. Also, I think I should fix it to 4.1, not 3.1.

There is no mention of the experiment in Abstract. Abstract is a brief summary of the research contents, but the economic analysis part is the same as the main text (ctrl+c and ctrl+v).

Reviewer 3 Report

Below are the points that remained incomplete and further revisions regarding the new version of the paper.

There are repeated sentences (e.g. the same statement is repeated in lines 429-431; the same statement from lines 268-275 is repeated in lines 490-503).

 (lines 31-32)  These added information in the abstract do not reflect the results of the research

 

The added description of the three variants of the design solution of the mechanical anchoring of the load-bearing gratings (lines 202-204) do not explain the difference between solution 2) and 3), being the description exactly the same for both solutions.

 

Table 13 summarizes the same data of Tables 3, 4 and 5, thus the latter ones resulting overabundant. These three tables should be eliminated and substituted by Table 13 in paragraph 3.2. Table 13 should be added to Table 14, only adding a column. Furthermore, the paragraphs 3.2.1, 3.2.2 and 3.2.3 must be unified.

 

Although the paragraph “Experimental measurements” has been added, even if incorrectly referred to as 3.1, there are two paragraphs numbered 3.1 in lines 198 e 493, explaining the experimental data, it should be placed in the paragraph 3 and not in 4. In this way, the computational part and the experimental part will be consecutive for a better comprehension of the text.

(lines 388-391) The calculation method of heat demand and energy need for heating is not reported, but only input data (geometry of the building) necessary to the calculation. The calculation method has to be reported. Table 8 and Table 9 show the results of the influence of different numbers of anchoring brackets on heat losses. Justify the calculation and introduce as Annex the calculation sheet. The results in term of percentage difference of energy need for heating between the solution with and without anchors seem to be too high and not realistic. The calculation sheet is necessary.

(lines 407-409) The authors affirm: The main aim of the experimental measurement was to determine the different heat fluxes of the three variants of the design solution, but the experimental data of the Variant 2) is lacking, even if the figures 15 and 16 seem to show this variant 2). Only simulation data are provided for this variant.

 

(lines 467-469) The subject of the experiment was the experimental verification of the heat flow of the HILTI MFT-MFI M anchoring bracket without the use of a modification to break the thermal bridge (Fig.3.31).

Experimental data of this solution are missing, the reference to fig. 3.31 is wrong.

 

(lines 491-495) historical annotations on climate chambers are totally inappropriate in the research paragraph

 

Table 11 shows the same data as Table 10 except for the percentage difference. Then Table 10 could be dropped and the percentage value set into the text or in the same Table 10.

 

Table 12 reports the comparison of heat transfer coefficients between experimental measurement and simulation. These considerations should be reported in paragraph 3, being related to the verification of the experimental data, not in the discussion of the results.

 

The value of 49 W/mK in Table 1 is calculated in an unconventional way, it has to be measured by means of  thermofluximeter and eventually made a comparison with data ”Based on the percentage differences between variant no. 2 (anchor without modification to eliminate thermal bridge) and Variant no. 4 (plastic-coated aluminium anchor)”

Some references are dated and not perfectly related to the point thermal bridges. There are a lot of recent study on this matter. I recommend viewing the paper titled “Thermal bridging problems on advanced cladding systems and smart building facades panel”, by Theodoros Theodosiou, Katerina Tsikaloudaki, Stella Tsoka, Panagiotis Chastas, in Journal of Cleaner Production, Volume 214, 2019, Pages 62-69.

Some of the minor reviews are below:

- Please pay attention to the expression of the unit of measurement of U (W / (m2. K). The UNI EN ISO unit of measurement is W/(m² × K)

- References on lines 224 and 231 cannot be the same. One must refer to 2012 standard and the other to 2016/2019 standard

- Insert the references in the text to Table 2 and fig. 7

- In figure 10 divide the X axis into whole numbers