Evaluation of the Thermal Performance of Two Passive Facade System Solutions for Sustainable Development

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper is interesting. However, there are some suggestions for more comprehensive, as follows.

1) There should be a Nomenclature, as many terms appear first without any explanation, such as BW (page 3), MLW (page 3), OPF (page 5), HF (page 6)...

2) It is confused about the studied subjects, as the terms of MLW-OVF and LWS-OVF used for them alternatively. It should be consistent.

3) The novelty and the purpose of the study is not clear and not consistent. In the title, the abstract, and conclusion, it seems about evaluation of two green solutions of LWS/MLW and OVF, but in the introduction, it is also about a measuring method.

4) To understand the measurement, a sketch of sensor locations in the room is necessary, also to understand the boundary conditions of the model.

5) In figs. 8-10, the term "power on/off" needs an explanation.

6) The validation of output data in Tables 2-4 is presented, but it is not clear, such as the standard deviations of R. It is better to present the comparison between the measure data and predicted data in time sequences (similar to Figs. 8-10). 

Comments on the Quality of English Language

There are some typos, such as "whit" (page 17), "one of the main reason" (page 18)...

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Very interesting article. However, it is necessary to introduce some improvements for its publication.

Both in the introduction and in the experimental part, it should make references to the different types of living walls that exist and justify why it has taken container systems instead of geotextile systems.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This study evaluated the thermal characteristics of two passive façade systems (i.e., living wall system and open ventilated façade). The research objectives are meaningful and the methodology, especially the application of PASLINK cell, is clearly stated and appropriate for this study. However, the results were not clearly presented and some discussions/explanations were missing. The following detailed comments might help the author to revise the article:

Title:

1.     It’s better to add “façade” or “envelope” in the title, such as “evaluation thermal performance of two passive façade systems for sustainable development”.

Abstract:

2.     The structure of the abstract is lack of logic. The first two sentences are about background, which is good. However, the third one is about “the model”, which model did the authors refer? Then, “the Greybox RC model” was mentioned, and another comment on the model (“This model makes it possible to quantify how passive surfaces influence energy flux compared to bare surfaces”) was given, which is similar to the third sentence (“allowing the energy flux dynamics of untreated, bare facades to be contrasted with those of ventilated and green facades”). This is confusing. The aim and design of this study is missing. A possible structure could be 1) background; 2) the overall purpose/aims of the study; 3) the basic design/methodology; 4) major findings; and 5) conclusions and implications. Please rephrase the abstract.

1. Introduction

3.     Please avoid repetition. For example on page 1 line 38-42, “The aim is to create residential communities that are architecturally and urbanistically integrated with a strong focus on minimizing carbon emissions and energy consumption, while adhering to the principles of sustainable development.[1]. Reducing energy consumption is therefore a major concern in the fields of architecture and engineering”. The second sentence is not necessary. And please remove the “.” Before “[1]”.

4.     Pay attention to the abbreviations. Lots of abbreviations were used in this paper. Some of them are very similar (such as VG, VGS, GF, LWS, MLW…), which is confusing. Perhaps some of them are not necessary, e.g., VG and GF, since it was only used once or twice, you can use the full names directly. What’s the difference between LWS, VGS, and MLW? It seems that they referred to the same thing in this study. Besides, some of them were not given a full name (e.g., VG), some of them were given two full names (e.g., BW, base wall and building wall), some of them were introduced twice (e.g., VGS in section 1 and section 2.1), and some o them were not introduced when it first appeared (e.g., MLW and BW). Please carefully check all the abbreviations and add a list of abbreviations at the end of this paper.

5.      Line123, what is the  “opposite approach”?

2. Experimental set-up

6.     Line 155, “the first section is the test room, which has a length of 5 meters long and a square in shape, with each side measuring 2.7 meters”. The expression is not clear, perhaps you could just mention the length, width, and height separately, such as “the first section is the test room (5.0 (L)*2.7 (W)* 2.7 (H))”.

7.     For the description of the three facades in section 2.1, the “layer” and  “surface” should be exchanged.

8.     Lines 204-209, please be precise for the monitoring periods. For period A, did you include July? (seems not according to Figure 8)? For period C, which month did you monitor?  Why there is such a large time gap between the three monitor periods? How could you make sure the PASLINK test cell was the same after two years? Was there any natural destruction of the building materials (such as the roof)?  Please explain the reason and mention this as a limitation in the discussion section.

9.     Table 1, the unit of heat flux should be W/m2.

3. Methodology

10.  Line 254, what is “RC”?

11.  Line 268, please explain all the parameters used in the equations under the equations.

12.  Line 277, What's the LORD program? related reference and introduction should be provided.

13.  Line 281, please remove”,” after the “grey box parameter models”.

14.  Line 305, “The PRBS sequences from July 8th to July 16th, 2014 were used for the calculation of the thermal parameters of the MLW”, if this was introduced for data pool C, then it’s better to mention them for the other two datasets in sections 3.1 and 3.2 respectively.

4. Results and discussion

15.  Figure 8, It's better to give subtitles to these figures (i.e., a)...b)...c)...), so that they can be precisely referred to in the text. Besides, please check the unit of solar radiation. Moreover, it was confusing for the PRBS. According to section 3, PRBS is “used to obtain data sets containing the low frequency response information on the device under test”. For the PRBS shown in Figure 8 a), it seems that it was off sometimes (e.g., on the 22 Jun and 30 Jun),  however, the data still could be obtained. Please also explain the PRBS data shown in Figure 8 in the related text.

16.  Line 347, “The heat pulses of the PRBS cycle performed cause an immediate response in the temperature of both the inside of the PASLINK cell and the first layer”. Do you mean the change happened at 12:00, 23 Jun? No such impact of PRBS was identified later. In other words, no related cycle was identified in the temperature of the inside of the PASLINK cell nor the first layer.

17.  Lines 362-365, “The high inertia of the wall during the night prevents the temperature of the last layer from falling below the ambient temperature. For example, between June 25 and June 28, layer 4 and layer 3 recorded temperatures above 40 ℃, while the ambient air temperature was at most 34 ℃”,  does the example correspond to "during the night"? Does the "ambient temperature" mean outdoor temperature? it was far below 34, especially during the night.

18.  line 370,  “maximum of 30℃..., reaching 40℃” this is confusing…

19.  Figure 9, why do the temperature measured on layers 1-4 vary differently from the temperature measured on layers 5-8? Besides, Ago should be Aug; check the legend of layer 5 and 6.

20.  Line 379, “It can be seen that the indoor air temperature reacts quickly when the heating is activated”, when was the heating activated? why the heating was activated during summer?

21.  Line 382, this information should be mentioned earlier in section 3.2, similar to the "The PRBS sequences from July 8th to July 16th, 2014 were used for the calculation of the thermal parameters of the MLW" in section 3.3.

22.  Line 384, “several aspects can be determined, on the one hand…”, what are the other aspects?

23.  Line 401, “during the periods without solar radiation, that is, hour’s night this value becomes positive reaching values of 5 W/m2”, please check the English.

24.  Line 406, “The comparison of the exterior and interior surface temperatures with the outdoor air temperature shows that the surface temperature can be up to 10 ºC cooler than the outdoor environment during the hottest hours of the day”, which surface do you mean by saying “the surface temperature can be up to 10 ºC cooler”?

25.  Line 409, it seems not true. Do you mean the differences in temperature measured on layers 1 and 9?

26.  Line 413, what is “LW”?

27.  Figure 10, layer 9 seems missing. Besides, "The PRBS sequences from July 8th to July 16th, 2014 were used for the calculation of the thermal parameters of the MLW" (line 305). However, in Figure 10, the dates were from 9 to 17 July. Please carefully check the date. Additionally, The temperatures during July in Spain were too low (the highest temperatures on several days were lower than 20), which was not consistent with the climate data searched online. Please check the results.

28.  Line 419, “The highest temperature observed within a 24-hour period is greater in the BW (ranging from 40-43 ℃) compared to the MLW”, were they comparable? The outdoor climate were different for these two measurement periods. The outdoor temperatures for BW situation was higher than it for MLW. For example the Te of the third day during the period for MLW situation was less than 20 (Figure 10 b)), while it was almost 30 for BW situation (Figure 8 b)). The outdoor climate should be considered.

29.  Line 436, “In July, the average temperature of the air in this space is 5 ℃ lower than the ambient air temperature”, please mention the specific layers, e.g., “see layers 5 and 6 in Figure 10 a)”.

30.  Line 458“the error committed is less than the precision error of the signals”, what is the error of the signals? were these validation methods (fitting the data sequence or checking the residuals) used before?

31.  Line 476, please check the English.

32.  Line 485, “This proves that the OVF is beneficial for indoor comfort, since its use has a positive effect on the thermal balance of the facade in summer”, the positive effect on A is observed thanks to B, since B improves A???  This is not an explanation...It just repeated the result.

33.  Lines 500-503 repeated the above paragraph.

34.  Line 505, “Therefore, if an enclosure needs to be renovated to minimize heat loss, it is recommended that the BW be insulated before installing the vegetated system”, how did the author get this conclusion?

5. Conclusions

35.  Line 515, “The aim was to characterize the heat flows through the modules and the vegetation itself”, the aim was different from the aims mentioned in the introduction "evaluate thermal performance of two passive facade systems, a MLW and an OVF, in comparison to a conventional building solution BW for building rehabilitation".

36.  Line 517, “It should also be noted that by adding, for the ventilated facade, 5 cm of rock wool to the base wall (1.59ºC m2/W), the modular living wall would achieve a quantitative increase in insulation capacity”, is this an assumption? adding wool to the MLW? Is there any proof? It was never mentioned in the results and discussion part. Please provide more discussions about this conclusion.

37.  Line 524-525, please add a unit for the absorptivity.

38.  Line 530, “Future developments will focus on evaluating initiatives that offer multiple benefits such as waste reduction, reduced energy consumption, and improved environmental quality”, was this relevant to the present study?

Comments on the Quality of English Language

Some sentences are not clear, please check the above-mentioned comments.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Thank you for your kind responses. I found the revised manuscript more comprehensive, and it can be considered for publication.

Author Response

Thank you all for the comments that have helped us to improve our manuscript

Reviewer 3 Report

Comments and Suggestions for Authors

Thank the authors for patiently answering the questions. Most of them were addressed properly. I think the revised version is now in much better shape. However, to make it clearer and easier to be followed by the readers, some improvements still need to be done.

1.       It's better to avoid using abbreviations in Highlights

2.       For the abbreviations, did you use "GR" in your manuscript? For green facade, it was first mentioned on page 4, "Green facades involve the development of climbing plants", please mention the abbreviation there and use the abbreviation to replace "green facade" in the following text. In addition, please mention the full name when the abbreviation was first mentioned in the main manuscript.

1. Introduction

3.       the first section is the test room, (5.0 (L)*2.7 (W)* 2.7 (H)) meters”, please move "meters" inside the "()" and remove the ",".

2. Experimental setup

4.       “The Base wall (BW) (see Fig. 2) have is constructed of the following surfaces; Layer 1: thick cement mortar (1.5 cm). Layer 2: double hollow brick (32 cm x 14 cm x 6.4 cm thick)”, please change ";" to ":" and change "." to ";".

5.       For Figure 2, first, please change the labels in the figure (S1-S4 should be L1-L4, Layer 1/2/4 should be surface 1/2/4). Second, the legend should be "Surface1: the internal surface of layer 1; Surface 2: external part of layer 2; Layer 3: not ventilated air chamber; Surface 4: external part of layer 4”. Third, please add subtitles for each figure, for example: a) the appearance of the base wall, and b) the detailed structure of the base wall. Please revise the corresponding parts in Figures 3 and 4.

6.       "It is important to note that an additional PRBS experiment was conducted in July", if it's important to the results shown in this paper, then you should present related data. Otherwise, it's better not to mention it. You said it's important to note that another experiment was conducted, however, no related result was given, which will confuse the readers.

7.       “the article focuses on a single dataset for two reasons”, do you mean “specific period (i.e., 8-16 July, 2014)” by saying “a single dataset”? If so, please revise it accordingly. If not, please provide more information, since three datasets were used in this study.

8.       “The Paslink test room is highly insulated”, please use capital letters for the abbreviation.

4. Results and discussion

9.       “Fig. 10” or “Figure 10”, please keep the format the same. Please also check other similar expressions.

10.   “this value .. reaches values of 5", please check the English.

11.   “temperature difference between the outside air temperature and the last layer of the MLW, the vegetation layer, at night is only 2°C”, do you mean “layer 9” in Figure 10 a) and “T air, e” in Figure 10 b)? If so, the maximum difference between them seems larger than 2°C. For example the last points of these two lines. Besides, it's better to mention the exact line in the text. Such as, "outside air temperature (i.e. T air, e in Figure 10 b))and the last layer of the MLW (i.e., layer 9 in Figure 10 a) )".

12.   “The highest temperature observed within a 24-hour period is greater in the BW (ranging from 40-43 °C) compared to the MLW (ranging from 31-34°°C)”, first, please check the unit. "within a 24-hour period"? which 24-hour did you mention? The figures are all about 7 days. Do you mean 26 July 2012 for BW and 17 July 2014 for MLW? Please provide the precise information. In addition, the highest temperature within 24 hours should be one value, why did you provide a range?

13.   Table 3, please change surface to layer, and Layer 6 should be 5cm instead of 10 cm, according to the previous Figure.

14.   Table 4, Layer 5 should be “Ventilated …”.

15.   “Therefore, if an enclosure needs to be renovated to minimize heat loss, it is recommended that the BW be insulated before installing the vegetated system”, thank you for your explanations, however, no information was added in the text. 'Therefore' is usually used as a conjunctive adverb to show causation. You should first mention a sentence that is the causative factor, then you use "therefore,..." to mention the results. An explanation sentence before this one is missing, please provide it.

Comments on the Quality of English Language

Some sentences are not clearly expressed and please check the singular and plural of some nouns. 

Author Response

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Author Response File: Author Response.pdf