Quantitative Perturbation Analysis of Plant Factory LED Heat Dissipation on Crop Microclimate

Round 1

Reviewer 1 Report

In this research "Quantitative Perturbation Analysis of Plant Factory LED Heat Dissipation on Crop Microclimate", the design of this experiment is interesting, however, there are some minor issues. Overall, I hope that the authors will solve these issues in the manuscript, improve the quality and make it suitable for publication in Horticulturae.

·                You should better to write keywords without numbering.

·                It is better to write the best result obtained from the results of this study as well as your suggestion in a paragraph at the end of "Discussion section".

Comments for author File: Comments.pdf

·                Delete "plant" on page 3, line 123

·                On page 3, line 132, "an" replace with "a" in "we established a energy"

·                On Page 4, line 151 please delete to in "Compared to to latent"

Author Response

Dear Reviewer #1,

Thank you for your valuable comments and suggestions on our manuscript. We appreciate the time and effort you have taken to review our work, as well as the critical insights you have provided. Your feedback has been very helpful in revising and improving our paper, and it also carries significant guidance for our future research.We have thoroughly reviewed your comments and made the necessary revisions to address each of the concerns you raised. The revised portions of the manuscript are highlighted in red for your convenience. Additionally, we have taken great care to polish our manuscript by correcting any grammatical errors, improving style, and fixing typos.

1. Response to comment: (You should better to write keywords without numbering.)

Thank you very much for your suggestion. We have removed the numbers from the keywords as recommended.

2. Response to comment:(It is better to write the best result obtained from the results of this study as well as your suggestion in a paragraph at the end of "Discussion section".)

• Thank you very much for your suggestion. Our results showed that with the increase of LED light intensity (PPFD), the microclimate uniformity decreased significantly while the disturbance coefficient increased significantly. This study is a quantitative analysis article. Based on our findings, the optimal lighting scheme should be to use lower intensity lighting modes as much as possible while meeting the growth requirements of the plant growth area.We have revised the conclusion section of the manuscript between lines 369-399 based on your feedback and added our recommendations. The revised content has been highlighted in red.

Based on the findings of this study, the regulation of lighting modes in plant factories should consider the photosynthetic physiological needs of different stages of plants. Appropriate lighting can better avoid excessive heat dissipation of LED light sources and reduce the electricity cost of removing these heat losses. 

3. Response to comment: (Delete "plant" on page 3, line 123.)

We apologize for the transcription error. We have removed the word "plant" as suggested.

4. Response to comment: (On page 3, line 132, "an" replace with "a" in "we established a energy".)

We apologize for the transcription error. We have corrected "a" to "an" as suggested.

As shown in Figure 1, we established an energy balance equations for each environmental factor of the crop canopy microclimate.

5. Response to comment: (On Page 4, line 151 please delete to in "Compared to to latent".)

• Thank you for your suggestion. We have made the requested correction and deleted the duplicate "to" in line 151, so it now reads as "Compared to latent".

Compared to latent heat, sensible heat increases with increasing transpiration rate. 

Thank you again for your valuable revisions. We hope that our revised manuscript meets your expectations.

Author Response File: Author Response.docx

Reviewer 2 Report

The present manuscript investigates 'Quantitave perturbation analysis of plant factory LED heat dissipation on crop microclimate'

I raise the following comments regarding the manuscript:

ligne 97: why you ignore the heat exchange caused by solar thermal radiation.

ligne 120:plant factory as closed systems, how??

ligne 123:the word plant is repeated twice!!

ligne 151:"to" is repeated twice.

*why u didn't take into consideration the exchanges between the soil and the plantation?? also between walls and plantation???

ligne 188: why u used specially k-epsilon turbulence model?

*what type of regime you used in simulation?

*what type of solar radiation you used DO or what?? and why?

u should improve it

Author Response

Dear Reviewer#2,

Thank you for your decision and for taking the time to provide constructive comments on our manuscript. We appreciate your insightful feedback, which has helped us to improve the quality of our work. We have carefully considered each of your suggestions and have made several changes to the manuscript.

1.Response to comment: (ligne 97: why you ignore the heat exchange caused by solar thermal radiation.)

Thank you very much for your suggestion. As the plant factory is located inside a building, the walls are within the building and it is an independent room inside the building. The outer walls of the Jilin University Plant Factory are not exposed to solar radiation, so we do not consider the heat transfer between the sun and the wall.

2. Response to comment:(ligne 120:plant factory as closed systems, how??)

Plant factories are often referred to as "closed environments" due to their ability to control all aspects of the growing environment, including temperature, humidity, light, and nutrients. This control is achieved through the use of various technologies such as artificial lighting, hydroponics, and environmental sensors. In a plant factory, the growing environment is completely enclosed and isolated from the external environment, allowing for precise control over factors that can affect plant growth and development. This closed environment also provides protection from pests, diseases, and other environmental stresses that can impact plant health. Overall, the term "closed environment" describes the highly controlled and regulated growing conditions in a plant factory, which enable plants to grow more efficiently and with higher yields compared to traditional methods.

3. Response to comment:(ligne 123:the word plant is repeated twice!!)

We apologize for the typographical error in our previous communication. The extra word "plant" has been removed.

4. Response to comment:(ligne 151:"to" is repeated twice.)

Thank you for your suggestion. We have made the requested correction and deleted the duplicate "to" in line 151, so it now reads as "Compared to latent".

Compared to latent heat, sensible heat increases with increasing transpiration rate. 

5. Response to comment:(why u didn't take into consideration the exchanges between the soil and the plantation?? also between walls and plantation???)

Thank you for your question. In our study of the plant factory environment, we did not consider the heat and mass transfer between the soil and plants or between the walls and plants. This is because we focused on the controlled environmental factors that can be manipulated in a plant factory, such as temperature, humidity, light, and airflow. In our numerical model of the plant factory, we simplified the wall material as an insulating material and did not consider soil-plant interactions. This is because the plant factory in our study utilized hydroponics, where plants are grown without soil.

6. Response to comment:(ligne: 188: why u used specially k-epsilon turbulence model?)

We used the k-epsilon turbulence model in our simulation of the plant factory because it is a widely-used and well-established model that has been shown to provide accurate predictions of turbulent flows in various engineering applications. The k-epsilon model is a two-equation model that solves for the turbulent kinetic energy (k) and its dissipation rate (epsilon). It is a relatively simple model that can handle a wide range of flow conditions, making it a popular choice for industrial applications. Moreover, the k-epsilon model has been extensively validated against experimental data, which gives us confidence in its ability to accurately predict turbulent flows within the plant factory. In addition, the k-epsilon model has been successfully applied in previous studies of plant factories, making it a suitable choice for our research as well. Overall, we chose the k-epsilon turbulence model because it is a reliable and well-validated model that can capture the effects of turbulence on the heat and mass transfer within the plant factory.

7. Response to comment: (what type of regime you used in simulation?)

In our simulation of the plant factory, we used the finite volume method to discretize the space. This numerical method divides the space into small control volumes and computes the fluxes of mass, momentum, and energy across the boundaries of each volume. The finite volume method is a widely-used numerical technique for solving partial differential equations that arise in fluid mechanics, heat transfer, and other areas of engineering. It is known for its ability to handle complex geometries and non-uniform grids, making it a suitable choice for simulating the flow and heat transfer phenomena that occur within a plant factory. Overall, the finite volume method allows us to accurately predict the temperature, humidity, and other important parameters within the plant factory, which can help inform the design and operation of these systems for improved crop production and energy efficiency.

7.Response to comment: (what: type of solar radiation you used DO or what?? and why?)

Thank you for your comment. Our study was based on the artificial light type plant factory at Jilin University, where LED lighting was used exclusively for illumination. Since there was no solar radiation within the facility, we did not use a DO (discrete ordinate) model to simulate the direct and diffuse solar radiation. Instead, we focused on modeling the LED lighting and its interactions with the plants and the surrounding environment. By simulating the LED lighting using numerical methods, we were able to predict the distribution of light intensity and spectrum within the plant factory, which is important for optimizing plant growth and development. Our study aimed to investigate the effects of various lighting parameters on the energy efficiency and crop yield of the plant factory, and we hope that our findings can contribute to the development of more sustainable and efficient indoor farming systems.

Thank you again for your valuable revisions. We hope that our revised manuscript meets your expectations.

Author Response File: Author Response.docx

Reviewer 3 Report

The article presents previously unpublished data and the overall research, and findings presented by the authors are good. Authors have taken the efforts to prove their hypothesis and given a direction to the research in this field to develop the crops as a plant factory with LED. In my view the article could be accepted for publication in this journal after some corrections and substantial revision in its current form.

Some comments and recommendations are listed below:

1)      In abstract, authors denoted the CFD abbreviation, what does it mean?? it should be written in full form and then use abbreviation. For other words also firstly denote it in full and then use the abbreviations for the same for e.g., LED.

2)      Remove the numbers in the keywords.

3)      The article is poorly written, English needs to be improved. Check for grammar spacing between words, overlapping of words, punctuations, and use proper spacing between the square bracket of references and citation text in the MS.

4)      In line 55, Luuk et al., has not been found in reference list.

5)      In line 60, H.F. and colleagues has not been properly cited.

6)      In line 69, citation Kitaya and Goto et al. are two different references, so cite them properly.

7)      In line 70, Z Y et al… I have not found this reference in list. Correct it and rewrite.

8)      In introduction, Line 90-93 is look like a concluding remark, there authors should write the aim of study and place these sentences in conclusion section.

9)      In Line 141, “In the present work, the value of is zero throughout the computational domain since..” what does it mean? Sentence is unclear.

10)  Authors should remove the extra sentences given in format of the journal, that are for understanding and preparation of statements accordingly. I observed that authors let these statements in the subsequent sections for e.g., Data availability statement, Acknowledgment, and so on.

11)  Authors should have to check all the references for their correctness regarding authors name and last name also format as per journal guidelines.

12)  Authors should correct all the references for their DOI. I have not found a single reference with the DOI provided by the authors. So, correct all the references for DOI and format them as per journal template and guideline as the MS is not formatted.

13)  MS needs thorough revision so the authors should carefully check the MS and revise accordingly it has lot of typo-graphic errors.

14)  The authors should have to identify the errors by themselves and make through revision before resubmitting the MS.

Review comments:

 The manuscript could be accepted for publication after substantial revisions and corrections in its current form. Thoroughly revise the MS and resubmit. 

The article is poorly written, English needs to be improved. Check for grammar spacing between words, overlapping of words, punctuations, and use proper spacing between the square bracket of references and citation text in the MS.

Author Response

Dear Reviewer#3,

Thank you for reading our manuscript and reviewing it, which will help us improve it to a better scientific level. We revised our manuscript, and quite a lot of changes have taken place. So we have sent the revised manuscript, and a version containing all the changes to be visible.

1. Response to comment: (In abstract, authors denoted the CFD abbreviation, what does it mean?? it should be written in full form and then use abbreviation. For other words also firstly denote it in full and then use the abbreviations for the same for e.g., LED.)

Thank you for your comment. We apologize for the oversight. CFD stands for Computational Fluid Dynamics. We will ensure to write out the full form and then use the abbreviation for all technical terms, including LED, as per your suggestion in future publications.

Although LEDs (Light-Emitting Diode) are called cold light sources, more than 80% of the heat is still emitted into the surrounding environment. 

CFD (Computational Fluid Dynamics) is used as the main technical tool to simulate and optimize the environment of agricultural facilities. 

2. 2. Response to comment: (Remove the numbers in the keywords.)

Thank you for your comment. We apologize for the mistake and have removed the numbers from the keywords as requested.

3. Response to comment: (The article is poorly written, English needs to be improved. Check for grammar spacing between words, overlapping of words, punctuations, and use proper spacing between the square bracket of references and citation text in the MS.)

We apologize for the poor quality of our English, which resulted in these issues in our article. We invited a native English-speaking Ph.D. from our team to proofread and make revisions to the entire text, including correcting grammar and spelling errors, adjusting spacing, and fixing punctuation issues.

4. 4. Response to comment: (In line 55, Luuk et al., has not been found in reference list.)

We apologize for the misunderstanding. We had referenced the names of the authors in the references based on the names given under the title of the cited articles. However, we discovered that there were some discrepancies between the author names in the body of the text and those in the references. Following your suggestion, we have revised the spelling of the author names in the entire manuscript according to the reference format. Thank you for bringing this issue to our attention, and we will continue to strive to improve the quality of our articles.

Graamans et al. developed a crop transpiration model to study the relationship between sensible and latent heat exchange and corresponding vapor flux in lettuce production within closed systems using LED as the only heat source. The model considered the plant's transpiration, crop canopy microclimate, and thermal buoyancy of the air caused by the LED as a heat source, which could aggravate uneven microclimates in the crop canopy [20].

5. 5. Response to comment: (In line 60, H.F. and colleagues has not been properly cited.)

We apologize for the mistake and have made the necessary modifications. The updated content is now as follows.

Fang H. et al. used a computational fluid dynamics (CFD) model to analyze the airflow pattern on crop canopy in a single cultivation bed under different ventilation modes, by inputting LED heat dissipation parameters into the simulation model [21].

6. Response to comment: (In line 69, citation Kitaya and Goto et al. are two different references, so cite them properly.)

Thank you very much for pointing out our mistake. We have reorganized the references and made the necessary modifications. The revised content is now shown below.

Kitaya et al. found that a uniform and stable airflow field can effectively improve plant tip burn by promoting plant transpiration [25,26].

8. 8. Response to comment: (In line 70, Z Y et al… I have not found this reference in list. Correct it and rewrite.)

Thank you very much for pointing out our mistake. Regarding the names of the authors in the cited references, we have made the following revisions.

Zhang Y et al. evaluated five different air distribution system designs for indoor workshops and found that arranging the inlet and outlet alternately in rows can eliminate heat dissipation in lighting, but it does not improve average airflow velocity or uniformity [27]

9. 9. Response to comment: (In introduction, Line 90-93 is look like a concluding remark, there authors should write the aim of study and place these sentences in conclusion section.)

Thank you very much for your suggestion. We have removed this part of the content in the introduction section.

10. Response to comment: (In Line 141, “In the present work, the value of is zero throughout the computational domain since..” what does it mean? Sentence is unclear.)

We apologize for the lack of clarity in our statement. We have revised it as follows.

In this study, there are no additional volumetric heat sources or sinks besides the LED lights. 

11. 11. Response to comment: (Authors should remove the extra sentences given in format of the journal, that are for understanding and preparation of statements accordingly. I observed that authors let these statements in the subsequent sections for e.g., Data availability statement, Acknowledgment, and so on.)

Thank you for your comment. We apologize for the oversight and have revised the subsequent sections, including the Data Availability Statement and Acknowledgments, to remove any extra statements that were provided for understanding and preparation of the manuscript in accordance with the journal format. Thank you for bringing this to our attention, and we will make sure to review our article thoroughly to ensure compliance with the journal's guidelines.

12. 12.Response to comment: (Authors should have to check all the references for their correctness regarding authors name and last name also format as per journal guidelines.)

Thank you for your comment. We appreciate your feedback and agree that it is important to ensure the accuracy of all references, including authors' names, last names, and formatting in accordance with the journal guidelines. We will review our references carefully to ensure their correctness and compliance with the journal's guidelines. Thank you for bringing this to our attention, and we will strive to improve the quality of our article.

13. 13. Response to comment: (Authors should correct all the references for their DOI. I have not found a single reference with the DOI provided by the authors. So, correct all the references for DOI and format them as per journal template and guideline as the MS is not formatted.)

We apologize for the inconvenience caused. We used the MDPI citation style provided by Zotero, which does not include hyperlinks for DOIs. However, in response to your feedback, we have revised the MDPI reference settings and set the DOIs as hyperlinks to enable automatic redirection. Thank you for bringing this issue to our attention, and we will continue to improve our manuscript to meet the journal's requirements.

14. 14. Response to comment: (MS needs thorough revision so the authors should carefully check the MS and revise accordingly it has lot of typo-graphic errors.)

Thank you for your comment. We appreciate your feedback and agree that our manuscript needs a thorough revision to ensure accuracy and readability. We will carefully review the entire manuscript and make necessary revisions, including correcting any typographical errors. Thank you for bringing this issue to our attention, and we are committed to improving the quality of our article.

15. 15.Response to comment: (The authors should have to identify the errors by themselves and make through revision before resubmitting the MS.)

Thank you for your comment. We appreciate your feedback and agree that it's the responsibility of authors to identify any errors in their manuscript and make thorough revisions before resubmitting to the journal. We will carefully review our manuscript again and work towards addressing any issues and ensuring its accuracy and clarity. Thank you for bringing this to our attention, and we are committed to improving the quality of our article.

16. Response to comment: (Comments on the Quality of English Languagehe article is poorly written, English needs to be improved. Check for grammar spacing between words, overlapping of words, punctuations, and use proper spacing between the square bracket of references and citation text in the MS.)

Thank you for your comment on the quality of English language in our manuscript. We apologize for any errors or shortcomings and will take steps to improve the language throughout the manuscript. We recognize that clear and concise language is essential for effective communication, and we appreciate your feedback on how we can achieve this goal. We will carefully review the manuscript and make necessary revisions to ensure its readability and accuracy.

Thank you so much for taking the time to review our manuscript. Your revisions were incredibly detailed and helped me make targeted revisions, greatly improving my efficiency in the revision process. Once again, thank you for your thorough review, and we will do our best to optimize the quality of our manuscript to meet the publication requirements of the "Horticulturae" journal.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

thank you for your clear answers.