Analysis of Microclimatic Comfort Conditions in University Classrooms

Round 1

Reviewer 1 Report (Previous Reviewer 1)

The manuscript titled "Analysis of Microclimatic Comfort Conditions in University Classrooms" appears to be an intriguing study aimed at evaluating the efficacy of different methods for assessing people's thermal comfort within an academic building. However, certain aspects, particularly regarding the methodology, require clarification for a better understanding.

Methodology

1) The author should explain more detail of the class room such as it is an open or closed classroom, and the use of air conditioning within the room.

2) The author should control the parameter that should be affect the result such as   student density, room type and size. Moreover, room type should be categorized in order to clearer explanations.

3) The author should show evidence or references to support that a temperature difference of approximately 5 degrees Celsius (the maximum variance between temperatures in April and May) does not significantly impact the results.

4) the type of clothing worn should be controlled for the student participating in the questionnaire.

5) I observed that the room temperature was increasing with each replicate of measurement. I am not sure that it may impact to the result from the questionnaire. Is the author control the time of taking the questionnaire for all rooms?

6) Table 1, the student density (number of students per area) should be indicated.

Result and discussion

1) Table 3, an error in the recorded of wind speed and relative humidity for Room 7.

2) the author should present the result in the format of mean ± standard deviation (SD).

3) Table 6, No equation for PMV and PPD calculation according to EN-16768.

4) Table 7, the header of column 1 is room no.? Is it necessary to calculate the total of “Location” category?

5) Statistical method should be used to present the result to enhance the clarity and rigor of the study.

6) Figure 7, a bar chart should be used instead of a line chart for better understanding.

7) The author should compare the study result with other studies that related with your study for the accuracy and strong discussion.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report (New Reviewer)

The study is relevant since it deals with the relevant problem of microclimatic conditions in university classrooms in St. Petersburg by experimentally measuring the values of microclimatic parameters in classrooms and calculating comfort indices by applying the Fanger method as well as comparing them with the actual human thermal comfort sensations. Since microclimatic parameters have a significant impact on the efficiency of learners, the relevance of the topic is obvious, but I have a few observations:

1.     It is appropriate to indicate the measuring ranges of the devices used for the experiment.

2.     Explanation as to why April, May and September have been chosen for making measurements would be appropriate. It is not clear whether the measurements have been made only one day or entire month during the specified period. It would be also appropriate to explain at what time the temperature was measured outside. Have indoor and outdoor temperatures been measured at the same time of day on different days? Why was only the ambient temperature but not the relative humidity measured outside.

3.     Table 1 is confusing and overloaded with redundant information.

4.     There is a reference to Figure 13 in the row 225, but the paper does not contain such figure.

5.     In rows 240-241, the authors state that the mean thermal dissipation rate of a person at rest is equal to 90 W. Since W is the unit of power, this should be clarified.

6.     It would be appropriate to calculate temperature gradient in a room in order to find out how the indoor air mixing occurs since the authors have measured the temperatures at different heights.

7.     In rows 268-269, it has been explained that the temperatures have been measured at 0.6 m, 1.0 m and 1.7 m height from the floor, while the table contains the temperatures obtained at 0.1 m, 0.6 m and 1.7 m height.

8.     The results of the survey about the microclimatic conditions in the studied classrooms are doubtful since the authors themselves claim that the answers could have been given by the respondents dishonestly or without thinking (361-364 rows).

9.     There is a lack of discussion for the data provided in Figure 6 and Table 10.

10.  There is a lack of deeper insights and more detailed analysis with the discussion of the obtained results of the study by the authors.

11.  Some references have been provided not in accordance with the requirements of the journal.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report (Previous Reviewer 1)

congratulations

Reviewer 2 Report (New Reviewer)

The quality of the article has been significantly improved when the supplements and amendments were made to the article manuscript.

It is great that the authors have taken into account a part of observations and amended the article manuscript according to the comments.

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

Materials and Methods

1. the author should write the method of study such as measurement procedure and equipment detail in the form of sentences instead of bullet form.

2. The author should indicate the total number of interviewees. the number of interviewees was very small in some rooms such as 19 people (room 1) and 8 people (room 4). It may impact on the precision of the result. 

3. No Figure 11 and 12 but they was indicated in the main text.

4. Table 17., the name of parameters need to be indicated in the table.

Result and discussion

1. With insufficient references, the author should compare the result and discussion with other studies in order to ensure the accuracy of the study. the references from other studies are strongly requested for the result and discussion section.

2. the author should discuss the impact of each parameter on the microclimate and people's real thermal sensations.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

This study discussed the impact of microclimate on well-being and productivity. The study also evaluated the role of microclimate parameters from an architectural design perspective and focused on the methods of regulating these parameters. The article showed that the indoor microclimate was generally favorable, and the PMV value obtained from the real thermal comfort survey was higher than the calculated PMV value. Generally, the topic seems interesting; however, some fatal problems exist. 

Originality, application, and creativity of this study are unclear.

The findings and discussion are rather weak.

The authors should indicate the number of devices used for measurement, including CO₂ concentration, air flow rate, temperature, relative humidity, and radiant temperature instruments.

Explain whether the experiment was monitored at different locations simultaneously or in batches. How to compare the differences in monitoring values ​​between the locations at the same time?

The authors should explain the comparison results between the thermal sensor and the numerical simulations. How to simulate the generation of actual heat sources at different locations?

The authors should carefully describe the impacts of CO₂ emissions and temperature from human body on the microenvironment.

Improve use of English throughout the text.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

The paper entitled “Analysis of microclimatic comfort conditions in university classrooms” has serious flaws that undermine its validity and reliability. I am sorry to say that this paper is not suitable for printing. Some comments:

-        The structure of the manuscript is not correct and may cause confusion. The first paragraph defines the objective of this study and just the next section includes background information. Table 2 shows results obtained from field measurement, and it is include in the methodology section.

-        The document that the authors have submitted has the appearance of a technical report rather than a manuscript. The authors present the equations and substitute the value of the variables (without indicating the units), showing results in the methodology section (e.g., page 7).

-        There are some sentences that do not make sense in the manuscript. Line 62: “Povl Ole Fanger, Director of the International Centre for Indoor Environment and Energy at the Technical University of Denmark, a leading expert in the field of thermal comfort and perception of the indoor environment.”

-        Authors stated that (Line 27): “The goal of the study consisted in determining the comfortable microclimate of classrooms in educational institutions during the cold season.” However, in the methodology section, the authors did not define essential aspects: How did they select the sample size? Are six classrooms enough? Why were the classrooms selected from a single building (Institute of Civil Engineering at Peter the Great St. Petersburg Polytechnic University) and not from different representative buildings? The authors did not justify whether it was possible to infer the results obtained from this sample of classrooms.

-        The authors do not provide enough information on the measurement procedure: Why did the authors measure at 1 m and 0.1 m height from the floor? If students in a classroom are seated during lessons, why did the authors decide to measure at these heights? Figure 4 shows the points where data were collected, why the authors did not collect environmental data from a point in the middle of the classrooms?

-       Line 170: “In view of this, we measured the following parameters of the microclimate in the rooms: Air temperature, °C; Air speed, m/s; • Relative humidity, %;” Was the radiant temperature not measured? How then have the authors evaluated the indoor thermal environment from the PMV model?

-        Did the authors consider the influence of radiant temperature in the analysis of thermal comfort? The authors do not provide measured values of radiant temperature in Tables 2, 3, 4, 5, 6 and 7. Radiant temperature is crucial for assessing indoor thermal conditions.

-        The authors provide inconsistent information. For example, (Line 185): “The three rooms selected for measurements were of approximately the same size, …” However, at line 155 authors indicate that: “We selected 6 classrooms…”.

-        (Line 268): “Only 93 people who were in one of the three classrooms participated in the survey. …” Only three classrooms? (Earlier the authors indicated that they selected 6 classrooms). Why did only 93 people participate? How were these participants selected? What was the procedure chosen by the authors? Is this sample size sufficient? None of these aspects is explained by the authors in the document.

-        The sample selected by the authors is insufficient and cannot be used to infer the results and support the conclusions they provide.

I regret to inform that I cannot recommend this article for publication. The manuscript has serious flaws in its logic, its methodology, and its results. The authors have not provided sufficient and credible evidence to support their claims and conclusions.

Minor editing of English language required

Author Response

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Author Response File: Author Response.pdf