Improving the Indoor Environment through an Indoor Green Curtain System

Round 1

Reviewer 1 Report

 This manuscript presented a prototype of a living green curtain to evaluate the benefits that was used as a shading device. The model was designed, built, and assessed by comparing the performance of the prototype, no curtains (control module) and external blind. This is an interesting topic, however, the writing is not professional, the analysis was not deep (only temperature, relative humidity, air quality and solar radiation). Moreover, this study can be a case study, therefore, the effect of different parameters on the performance of green curtain has the strong limitation. In addition, some comments can be seen as follows.

(1) What is the figure 3(a)? The authors did not introduce it.

(2) In the solar and heat energy flow section, the detailed expressions regarding the basic theory could be provided as this is really important to describe the effect of the plants. Instead, only boundary layer diagram as shown in the figure 5 was not sufficient.

(3) For the figure 7/8, reviewer donot think it is necessary for too many data as the variation of the air temperature lasted several months. Reviewer strongly suggests the authors present some typical comparisons by dividing the weather and indoor climate into several different periods.

(4) For some pictures that have several sub pictures, reviewer think it is necessary to introduce every sub pictures even they have the specific date and time, e.g., figure 13.

(5) Reviewer do think the section 5, conclusion, limitations, and future work can be separated into two sections including the discussion and conclusions. It is very tough to understand the too many paragraphs in one section which includes too many info.

(6) Some writings were not good, e.g., “Daily mean, Maximum daily mean and Minimum daily mean”, please proofread the whole content seriously.

(7) The discussion section requires a deep thinking regarding the variables effect, that the size of the green curtain, the weather condition, the indoor condition. Therefore, the title of this study should consider the limitation, which is “a case study in an Agricultural Glasshouse in Sydney”

Please the comments above. The manuscript requires thorough proofreading. There are many loose sentences and the English language is not correctly employed.

Author Response

We thank the reviewers for the feedback on our original research paper, appreciate the comments, and have implemented the advice given to improve the quality of the manuscript.

Author Response File: Author Response.docx

Reviewer 2 Report

After reviewing the article “Improving the indoor environment through an indoor green curtain”, I can state that the topic under investigation has novel features and is sufficiently clearly presented. However, the article has several shortcomings that must be corrected. They are listed below.

 I believe that the statement that indoor air quality and thermal comfort can be improved through an indoor green curtain (GC) can be made after investigating the performance and benefits of the GC in realistic conditions, with longer time covering all four seasons of the year. To conclude that on the results based of GC prototype testing is too ambition. Please rethink this point and make corrections in the article title and abstract as well as in discussion/conclusions of the result.

Methodology part, please explain:

Why was it decided to measure air quality only for less than a month while air temperature, relative humidity, and solar intensity were measured for several months? Why was not no curtain module equipped with air quality sensors and this indicator was not measured? Considering this, how can be understood statement giving in 134 -137 lines.

The modules were built inside the Agricultural Glasshouse, how can this influence the obtained results?

In results and analysis sections, very detailed analysis of ambient conditions, the solar radiation intensities, air temperatures, and relative humidity data are presented. However, you maintain that this study aimed to design, build, and monitor a prototype for an indoor green curtain. So where is the discussion of prototype design and building issues as can be expected, keeping in mind the aim of this particular work. Please keep the balance between the weathering conditions and issues regarding prototype design when analysing the results.

In my opinion, Figures 7, 8, 11 overload the article and should be presented as supplementary material.

The conclusions are written in an inappropriate way, please correct them.

There are technical errors: section 0 should be removed; the figures should be cantered correctly, the size of the pictures should be appropriate (especially pay attention to Fig. 2), the reference list should be numbered and formatted as required, and check for duplication (e.g., Moya et al. (2019) included twice). Also, please maintain the line spacing.

Author Response

We thank the reviewers for the feedback on our original research paper, appreciate the comments, and have implemented the advice given to improve the quality of the manuscript. 

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The current manuscript can be accepted after the serious modifications.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Thank you for the effort to correct the article “Improving the Indoor Environment Through an Indoor Green Curtain” and the responses to the comments. Unfortunately, the corrections were insufficient to improve the quality of the article. I believe that this article has scientific potential to be published, but once again I ask you to read carefully all the suggestions and make the correction or provide detailed and reasonable responses if you disagree with them. Very important – mark all corrections were made in the article.

I think not enough attention has been paid to this:

The statement “This study demonstrates that green curtains can improve air quality and thermal comfort.' (line 21) is given without testing green curtains (only prototype) under realistic conditions, within a period of time not covering all seasons of the year. In my opinion, it is necessary to avoid statements (throughout the article) that are not based on research and to highlight such moments, which scientific benefit was obtained during the conducted research.

2.  “Litmus test“ (following the therminology given of the authors) should be clearly described in the methodology part.

3. I did not find reasoning for how the obtained results could be influenced by the fact that the modules were built inside the glasshouse.

4. As I understand it, the theoretical material is given in part 3, a reference to the literature is enough if there is no scientific novelty.

5. The conclusions are written in an inappropriate way.

6. There are editing errors, line maintaining spacing not kept. There are confusing statements, for example  “The observation period was 5 months and 137 days (376 lines)' It should be given in month or days. 

Author Response

                                             REVIEWER 2

Comments and Suggestions for Authors

Thank you for the effort to correct the article “Improving the Indoor Environment Through an Indoor Green Curtain” and the responses to the comments. Unfortunately, the corrections were insufficient to improve the quality of the article. I believe that this article has scientific potential to be published, but once again I ask you to read carefully all the suggestions and make the correction or provide detailed and reasonable responses if you disagree with them. Very important – mark all corrections were made in the article.

Thanks a lot for reviewing the manuscript again. We did our best to address the previous comments and we have done the best to fix your new points carefully again. Our apologies for not marking corrections in the previous submission since there were too many major changes. In this new version, the changes have been marked in yellow and we provide detailed responses below.

I think not enough attention has been paid to this:

1.The statement “This study demonstrates that green curtains can improve air quality and thermal comfort.' (line 21) is given without testing green curtains (only prototype) under realistic conditions, within a period of time not covering all seasons of the year. In my opinion, it is necessary to avoid statements (throughout the article) that are not based on research and to highlight such moments, which scientific benefit was obtained during the conducted research.

Thanks for comment. The use of plants to improve thermal comfort and air quality is well established. What we have done in this study is applying plants in a controlled condition, in a specific context with a specific design using a prototype. This is a simple scientific method, where you test a prototype for its performance. Our claim on thermal comfort is supported with our experimental results that shows significant reduction of temperature in the GC at peat heat hours. Also, we have revised our manuscript to align of claims on air quality with the experimental results.

Line 21-22:

This study demonstrates the potential ability of a green curtain to improve air quality and thermal comfort.

Line 581-584:

Where most of the prototypes are tested on exteriors, this research is unique in developing an innovative vertical curtain within an indoor setting of a prototype room, providing full manual control to a user for allowing the sunlight to the indoor environment.

Line 558-566:

The Null hypothesis statement is that the difference in the mean of the AQ of the GC module is equal or not different from the mean of the WB-AQ. The test was done for two time frames, 0200-1600 hrs and 1600 -200 hrs. It was found that from 0200-1600hrs the p-value was 0.08 (>0.05), which means Null hypothesis was accepted but from 1600-0200hrs, the p was 0.0001 (<0.05) and Null hypothesis was rejected.  This means in the evening the difference was significant and the GC module was more effective to decrease the pollution compared to WB module.

Line 607-609:

Future developments of the research will aim to investigate the performance and benefits of the GC when applied to realistic settings in the form of larger module areas or in a building room.

2. “Litmus test“ (following the terminology given of the authors) should be clearly described in the methodology part.

Thanks for the comment. The “litmus test” is substituted by “premilitary test”. This test was done to compare the air quality of NC and WB and to confirm that both modules have the same air quality.

Line 225-230:

A preliminary test to compare the air quality of NC and WB was done for 48-hour period where two sensors were arranged for the experiment. The results were monitored online, and it was found that the values in the two modules did not differ from each other. This result was expected since the primary factor of variation of air quality is the presence of plants in the GC module. Therefore, based on those 48 hours data it was decided to install the air quality sensors only in GC and WB. Also, for comparison with GC, only one module was required as base case.

3. I did not find reasoning for how the obtained results could be influenced by the fact that the modules were built inside the glasshouse.

Thanks for the comment. The modified version did not have these lines that the modules were built in glass house. Perhaps the reviewer is referring to previous version  of the manuscript. The glass house is used as external environment, mentioning this was important because it mimics the harsh conditions the Australian outback region (high temperatures, low precipitation) were we plan to perform the experiments in the future. The glass house term is used in the manuscript as shown below.

Lines 157-164:

The exterior environment of the modules was a glasshouse. This choice allowed to test the benefit of the green curtain in indoor module (room) conditions. Indeed, the glasshouse was not equipped with any shading system, and thus the indoor temperatures are usually higher than the ones normally found in residential buildings. The temperature in the glasshouse varied considerably, which ideally resembled the extreme climatic conditions of the Australian outback region e.g., temperature has also been recorded in the summer season. Therefore, the temperature in the controlled climate of the glass house was higher than the normal Sydney ambient temperature.

4. As I understand it, the theoretical material is given in part 3, a reference to the literature is enough if there is no scientific novelty.

Thanks for comment. Section 3 is added to address the comments of the other reviewer. This section is not taken from the literature. Instead, we have tailored an energy budget model specific for the GC.  Note that the energy budget in indoors green curtains is different from the outdoor green walls so that is important to formulate the governing equations in this paper.

5. The conclusions are written in an inappropriate way.

Thanks for your comments. We did our best to improve this section appropriately and fixed grammar styles and typos. We are happy to follow further recommendations on the shape of the conclusions if needed.

6. There are editing errors, line maintaining spacing not kept. There are confusing statements, for example  “The observation period was 5 months and 137 days (376 lines)' It should be given in month or days. 

Thanks for the comment. The editor is informed about the line maintaining space issue and it will be fixed by the editorial team before publications

The statement about observation period is fixed. Only months are mentioned

Line 376:

The observation period was 5 months (Nov, Dec, Jan, Feb, and Mar).

Author Response File: Author Response.docx