Experimental and Numerical Energy Assessment of a Monolithic Aerogel Glazing Unit for Building Applications
Round 1
Reviewer 1 Report
While the topic is very interesting, the introduction is long and largely descriptive (e.g. the research question or objectives of the paper is not clear). We CANNOT have 100% WWR in real buildings due to having window frame, etc. The standard daylight illuminance on the working plain is different among countries. Which standard are the authors refer to when saying “the daylight illuminance on the working plane is higher than the recommended value (500 lux)”? The paper is well structured and organized but the limitations of the study have not been addressed in the conclusion properly. Some of the limitations have been explained in the method section but they could be expanded in the conclusion or a discussion section. I would strongly recommend improving the introduction section to make the aims of the paper clear, as well as adding a discussion section explaining the limitations and what can be done in further investigations about monolithic aerogel.Author Response
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Author Response.pdf
Reviewer 2 Report
The authors measure the thermal resistance of a monolithic aerogel glazing unit. Energy modelling is carried out and the performance of the aerogel unit is compared to that of commercially available glazing systems. The annual energy demand for buildings in cold or moderate climates is evaluated to be less for the aerogel glazing unit than for the commercially available units. The results are good and of interest, but a number of points should be addressed before the paper can be recommended for publication.
Four thermoresistances were installed on each surface - at what location on the surfaces were these installed? It is recommended that additional experiments should be carried out to measure the thermal resistance for the following cases (1) one float glass, (2) two float glasses, and (3) float glasses with 15 mm of air between them. This will provide for a more direct comparison to determine the benefits of the monolithic aerogel. The following sentence in Section 2.2 needs clarification: "The thermal resistance (R) of the sample is composed by the monolithic aerogel pane contribution and by toe one of the two clear float glasses" - why does only one of the two float glasses contribute to the thermal resistance? Can more justification be provided for assuming the fT value is similar to that of granular aerogel. For example, are the densities similar? The authors should comment on the sensitivity of the results to the value of fT. In some parts of the paper the grammar need to be corrected. The sentence "It has not external walls and is kept at a constant temperature thanks to the HVAC system" needs to be clarified. In the results and discussion section the authors state that "only the most significant results are shown with both the temperatures". The authors need to clarify what is meant here by "most significant" - It could be interpreted that the authors selected the data they wanted to report. The reported results should be an average of multiple tests - how many times were the tests repeated ? [311] - the air temperature trends are not found in Figure 4.
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Thank you for addressing the comments. Not sure what the authors mean by tracked version in their response. I have checked both the PDF file and the word file (in both all markup and simple markup modes) and could not find the responses in those lined that the authors mentioned. The first comment has not been addressed properly. The aim of the study is still not clear!!!! Additionally, the authors could have explained using a 100% WWR as one of the limitations of their study. Regarding the third comment, the authors should have explained the standard in the content of the article rather than just simply citing that.
Overall, the paper is well-written but still have lots of grammar mistakes.
Author Response
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Author Response File: Author Response.pdf
Reviewer 2 Report
The authors have addressed most comments and the manuscript is improved.
To increase confidence in the results it is recommended that each test be performed multiple times. It is also recommended to perform a reference test, where float glasses are separated by 15 mm of air between them. This will provide for a more direct comparison to determine the benefits of the monolithic aerogel.
There are still some grammatical errors in the paper.
Author Response
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Author Response File: Author Response.pdf
