Internet of Things (IoT) as Sustainable Development Goals (SDG) Enabling Technology towards Smart Readiness Indicators (SRI) for University Buildings

Round 1

Reviewer 1 Report

Line 42 to 45: was this also reflected in the same reference #3 mentioned in the following sentence? Need to clarify.

Line 62: use and instead of y for the directives.

Line 102 to 104: rewrite sentence

Author Response

Dear Reviewer,

The authors of the manuscript (ID: sustainability-1263348) thank you for your time taken and the suggestions provided, which follow improving the overall quality of our article. We went through each of their recommendations as indicated following:

Line 42 to 45: was this also reflected in the same reference #3 mentioned in the following sentence? Need to clarify.

Thank you for the comments. The entire text (updated lines 41 to 46) has been rewritten by remarking (at the beginning of the paragraph) the European strategy referenced by [3] and repositioning the rest of the sentences.

Line 62: use and instead of y for the directives.

This sentence has been removed because the entire manuscript has been revised with the help of a native translator. In this updated version of the manuscript the language is more accurate, avoiding over-statements and too long sentences, and reducing Introduction section by better adjusting it to the aim of the article in an international scope. Even so, two new paragraphs with literature review both specific scope of IoT smart buildings and SRI evaluation have been included.

Line 102 to 104: rewrite sentence

The sentence has been rewritten (marked in green color in the manuscript) as: “IoT is one of the technological paradigms destined to exponentially increase the connectivity of various devices. A main strength of IoT is its high impact on the daily behaviour of potential users”.

The authors thank again the comments because these suggestions (within your  have contributed to improve the overall paper and we hope that this new proposed version of the manuscript will meet the quality standard of MDPI in order to be definitely accepted.

Author Response File: Author Response.docx

Reviewer 2 Report

The manuscript provides an interesting internet of things (IoT) ecosystem for a smart campus (focused on NZEB, air quality monitoring, energy saving, etc.). The methodology uses a “measure – analyze – decide and act” approach resulting in a three-level IoT model: information acquisition, interoperable communication, and data-driven decision. The study also defines and details two conceptual spaces (users and infrastructure) and two dimensions (physical and digital). The results section is well detailed and provides a clear demonstration of how the developed theoretical models can be applied in real life for the attainment of sustainability development goals (SDGs) in buildings. Finally, the paper provides real-life data from the application of the proposed model, proving its benefits in terms of cost effectiveness and energy conservation.

Some possible areas of improvement are the following:

The introduction section seems too long and too general. For example, the first two pages mainly discuss the SDGs in Europe, related laws and regulations, and the Strategy for Energy Rehabilitation in the Building Sector in Spain (ERESEE). Although they offer useful knowledge about the prominence of SDGs in the EU, the provided information can be summarized since the particulars do not greatly impact what is later discussed in the paper.

Moreover, since the introduction section is too lengthy the authors are advised to divide it into sub-sections. This facilitates understanding the prominent sub-ideas discussed and allows forming a more solid view about the interrelationship between these ideas. 

In line 113, the authors discuss some of the advantages of the “proposed approach”. However, the reader is not introduced yet to their purpose nor approach. Thus, the benefits discussed are irrelevant. This description should thus be moved until after the proposed approach is described.

The paper includes no literature review. The authors did not mention any previous similar work in literature. How different is the proposed model from previously built models for smart buildings? What was missing in previous similar efforts which was addressed in this paper?

The paper is well written. However, sentences seem to be too long. Many sentences are also overloaded with information in parenthesis which results in more clutter and distracts the reader from the main idea.  Some edits could be done to minimize long sentences in the paper, such as reducing the use of wordy phrases and replacing long sentences with shorter ones that enable the communication of ideas more effectively.  Moreover, some sentences include wrong usage of words. These should be revised for meaning. Example lines 554 – 558 (too many ideas in one sentence) and 177-181 (long and word usage):

“This article proposes a “measure – analyze – decide and act” methodology to quantify the SRI from a holistic perspective (research group includes Architecture and several specialties of Industrial, Mechanical, Design, Thermal, Electrical, 179 Electronic, Computer and Telecommunication Engineering) for University buildings as reference environment of measuring, testing, study and researching for energy efficiency and COVID-19 prevention models.”

“On the other hand, the “measure - analyze - decide and act” methodology applied to spaces has remarked the importance of quantitative knowing the use and occupation of university spaces (classrooms, offices, laboratories, etc.) and detecting unnecessarily air-conditioned areas outside their work hours, unnecessarily illuminated empty areas, among other examples of energy inefficiency.”

Author Response

Dear Reviewer,

The authors of the manuscript (ID: sustainability-1263348) thank you for your time taken and the suggestions provided, which follow improving the overall quality of our article. We went through each of their recommendations as indicated following:

Some possible areas of improvement are the following:

The introduction section seems too long and too general. For example, the first two pages mainly discuss the SDGs in Europe, related laws and regulations, and the Strategy for Energy Rehabilitation in the Building Sector in Spain (ERESEE). Although they offer useful knowledge about the prominence of SDGs in the EU, the provided information can be summarized since the particulars do not greatly impact what is later discussed in the paper.

Moreover, since the introduction section is too lengthy the authors are advised to divide it into sub-sections. This facilitates understanding the prominent sub-ideas discussed and allows forming a more solid view about the interrelationship between these ideas. 

We fully agree: The Introduction section has been reduced as suggested by removing paragraphs 2 (page 2), 5 (page 3) and 7 (page 4) by better adjusting Introduction to the aim of the article in an international scope.

In line 113, the authors discuss some of the advantages of the “proposed approach”. However, the reader is not introduced yet to their purpose nor approach. Thus, the benefits discussed are irrelevant. This description should thus be moved until after the proposed approach is described.

We agree: The sentence (marked in green color in the manuscript) has been moved to Discussion section as “Furthermore, the proposed approach is committed to open science in order to foster verifiable scientific knowledge subject to scrutiny and critique, the reproducibility of the experimental results, and robust decision-making processes”.

The paper includes no literature review. The authors did not mention any previous similar work in literature. How different is the proposed model from previously built models for smart buildings? What was missing in previous similar efforts which was addressed in this paper?

Thank you for the valuable suggestion. In Introduction section has been included the following paragraph with literature revision in this scope (marked in green color in the manuscript): “Since this research area is an emerging field, the available literature is still limited. Nonetheless, some related word can be highlighted. In [17], assuming this scope is a relatively new development, a comprehensive review was detailed by analysing the potential of connecting Building Information Modelling (BIM) and smart buildings with IoT-based data sources. In [18], several examples of IoT implementation (within the last five years) in residential and commercial buildings were reviewed. Compared to the reviewed literature, the approach in this paper advances in the integration of open-source tools, open data and open hardware with ultra-low consumption technologies, such that this knowledge can be available to the population. Even so, several works have been published on open-source IoT devices in academic buildings. In [19], a hardware IoT infrastructure was proposed for monitoring school buildings in Greece. A study by [20] developed an IoT lab system to monitor the overall activities of the lab. The differential value of the contributions of this paper is that the entire buildings (not only researching labs) become an experimental testbed for the teaching/learning of current and future generations. Thus, the methodology proposed constitutes a reference model for direct application in academic works, re-searching projects and institutional initiatives, extendable to professional environments, healthy buildings and cities.” Furthermore, a new paragraph about SRI evaluation have been included (marked in green color in the manuscript) as: “Previous work on the application of the SRI has been sought. Only one has been found [24], the authors evaluated the SRI of two buildings and detected some weak points in the methodology. This paper advances in this line, evaluating the SRI of the university build-ings and especially taking advantage of this useful tool to propose ideas for retrofitting actions”.

The paper is well written. However, sentences seem to be too long. Many sentences are also overloaded with information in parenthesis which results in more clutter and distracts the reader from the main idea.  Some edits could be done to minimize long sentences in the paper, such as reducing the use of wordy phrases and replacing long sentences with shorter ones that enable the communication of ideas more effectively.  Moreover, some sentences include wrong usage of words. These should be revised for meaning.

Thank you for the comments. Following the suggestion, we have revised the entire manuscript with the help of a native translator to make language more accurate and avoid over-statements. Furthermore, many long sentences have been replaced with sorter ones and several wrong words have been corrected: all changes are directly updated in the manuscript.

Example lines 177-181 (long and word usage): “This article proposes a “measure – analyze – decide and act” methodology to quantify the SRI from a holistic perspective (research group includes Architecture and several specialties of Industrial, Mechanical, Design, Thermal, Electrical, Electronic, Computer and Telecommunication Engineering) for University buildings as reference environment of measuring, testing, study and researching for energy efficiency and COVID-19 prevention models.”

We agree. The ideas have been divided into short sentences as: “This article proposes a “measure – analyse – decide and act” methodology to quantify the SRI from a holistic perspective. The research group includes architecture and several specialities of industrial, mechanical, design, thermal, electrical, electronic, computer and telecommunication engineering. This transversal perspective is intended to serve as a reference environment of measurements, testing, study and research for energy efficiency and COVID-19 prevention models”.

Example lines 554 – 558 (too many ideas in one sentence): “On the other hand, the “measure - analyze - decide and act” methodology applied to spaces has remarked the importance of quantitative knowing the use and occupation of university spaces (classrooms, offices, laboratories, etc.) and detecting unnecessarily air-conditioned areas outside their work hours, unnecessarily illuminated empty areas, among other examples of energy inefficiency.”

We agree. The ideas have been divided into short sentences as: “On the other hand, the “measure – analyse – decide and act” methodology applied to spaces has shown the significance of situations of energy inefficiency. Some examples include the effective occupation of university spaces, detection of unnecessarily air-conditioned areas outside working hours and unnecessary illumination of empty are-as, among others”.

The authors thank again the detailed comments because these suggestions (within the other reviewers, marked in green color in the manuscript) have contributed to improve the overall paper and we hope that this new proposed version of the manuscript will meet the quality standard of MDPI in order to be definitely accepted.

Yours sincerely,

authors of manuscript sustainability-1263348 (MDPI)

Author Response File: Author Response.docx

Reviewer 3 Report

see the comments attached.

Comments for author File: Comments.pdf

Author Response

Dear Reviewer,

The authors of the manuscript (ID: sustainability-1263348) thank you for your time taken and the suggestions provided, which follow improving the overall quality of our article. We went through each of their recommendations as indicated following:

Comments and Suggestions for Authors

see the comments attached. peer-review-12502812.v2.pdf

1. Page 2 Paragraph 2: What is the purpose of this paragraph? It does not have a direct link with the topic, and it is recommended to remove/summarize it.

Following the recommendation, the paragraph has been removed. Moreover, Introduction section has been reduced as suggested in comment #3 and the entire manuscript has been revised with the help of a native translator to make language more accurate, avoid over-statements and too long sentences: all changes are directly updated in the text.

2. Page 3 Figure 1: Please add reference.

Figure 1 has been originally created for this manuscript. Anyway, as included ideas come from ERESSE strategy, the [7] reference ([14] before revision) has been added in the caption as: “Figure 1. ERESEE strategy. Milestones towards climate neutrality, adapted from [7]”.

3. The introduction section is too long, and there are a lot of information that are not directly related to this paper. Please consider reduce/summarize some of the contents.

We fully agree: The Introduction section has been reduced as suggested by removing paragraphs 2 (page 2), 5 (page 3) and 7 (page 4) by better adjusting Introduction to the aim of the article in an international scope. Furthermore, two new paragraphs with literature review both specific scope of IoT smart buildings and SRI evaluation have been included. Finally, in the Materials and Methods section some preceding methodologies and theoretical basis have been added, including 3 new references.

4. Page 6 Section 2.1.1: What are the sensors/equipment details for monitoring different parameters?

Thank you for the question. These details are added in section 3.2 within the following new paragraph (marked in green color) including 3 new references: “With these premises, meaningful variables were real-time monitored from wired and wireless sensors. Wired sensors (over 300) were connected to the SCADAs to provide the air-quality parameters detailed in [31]. Wireless LoRAWAN sensors (46) were ad-hoc in-stalled to provide temperature, humidity, barometric pressure and CO2 level. The selected sensors were SenseCAP AU915 [32] and Aranet 4 Pro [33]. Their features, technical speci-fications and device details are summarized in [32] and [33] respectively. Figure 6 shows several examples of their real installation in the three buildings of sensoriZAR: 15 in Ada Byron, 12 in Torres Quevedo, 19 in Agustín de Betancourt”.  

5. In the methodology section, a few figures were presented to show the benefits of the sensor systems. However, how did you collect the data? Most importantly, how will you analyze the data with which big data analysis method?

Following the comment, the details of each step of the measure and analysis methodology has been updated in section 3.1 as “This project, specifically for the heterogeneous features of the collected data, combined several big data analysis technologies, including Amazon Web Services (as tools and services set for cloud computing), Amazon S3 (as a specific service for se-cure objects management in the cloud), Ceph (as an open analysis system, defined by software, specific for large amounts of distributed data) and influxdb (as a reliable management system to visualise data time series, specific for IoT), among others”. Furthermore, to improve this explanation, several sentences (in green color) have been added through section 2.2.

6. Page 9 Figure 4: Are you putting the figure in the methodology section or results section? Since you discussed the Figure 4 in the results section, so it should not be the methodology.

Sorry for the layout mistake: Figure 4 (updated to Figure 5) has been moved to Results section in page 10.

7. Page 10 Section 3.1: Do you have any photos of the real IoT systems installed in the building, and the building pictures as well?

We do. A new photograph has been added in Figure 5 (updated to Figure 6 in page 12) to show the real IoT systems installed in a classroom.

8. Page 12 Figure 6: Is this CO2 sensor selection criteria supposed to be put on the methodology section?

Following the suggestion, Figure 6 (updated to Figure 4) and its corresponding explanation (previous lines 467 to 479, updated lines 293 to 305) has been moved to Materials and Methods section as can be seen in green color in page 8.

9. Page 14 Figure 10: How did the energy consumption measured should be explained in the methodology section clearly. Otherwise, it is not able to know how Figure 10 was built up.

Thank you for the suggestion. We provide further explanations about the measurement methodology (marked in green color in page 14) including a new reference as: “The use of intelligent systems allows to detect in real time inefficiencies that condition the operation of buildings, and that taking measures allow to make their management more efficient. Figure 10 shows a comparative analysis of the energy consumption (electricity in blue and gas in red) of the different university buildings. As Figure 10 illustrates, the diversity of construction and facilities of the university's building is very wide. Until the implementation of intelligent monitoring systems, the consumption data of the buildings were obtained from the energy billing and the information provided from the general electrical totalizers of the buildings. Current real-time monitoring is automatically integrated with SCADA through Siemens Sentron Pac 3200 digital energy multimeter [35]”.

10. The discussion is too short.

Thank you for the recommendation. We have added further ideas and reflexions, as it is remarked (in green color) in the manuscript, about how proposed approach is committed to open science; how proposed methodology allows to fulfil the SRI perspective that EPBD recommends; and how the use of this methodology is currently providing improvement actions, as the recent evaluation of SRI in a building of the smart campus.

11. This article did not show what is the benefits of applying these IoT system into the smart building. It does show a lot of features/advantages, but it does not clearly show how all these would achieve.

Thank you for the comment. The updated revision remarks how this paper advances in its integration proposals of open source tools, open data and open hardware with ultra-low consumption technologies to ensure that the value of this intelligent knowledge can be universalized to the population. Furthermore, the “measure – analyse – decide and act” methodology, applied to the entire buildings (not only isolated researching labs), achieves the differential value of contributing to become smart campus in an experimental test bed for teaching-learning of current and next generations.

12. It feels like this paper wants to cover too much, but it does not go deep for either one approach. Maybe the author could consider break the paper into a few papers, and only talk about one/two features of IoT systems. E.g., CO2 monitoring or Energy consumption monitoring and control, and reduction.

After the initial contribution of conceptual spaces (physical and digital) within two dimensions (users and infrastructures) over a three-level IoT model (data, information and knowledge), the aim of the authors is to focus the results in CO2 and energy consumption monitoring. To underline this approach and highlight it in the manuscript several sentences has been added:

• In abstract: “Focused on CO₂ and energy consumption monitoring, the results showed effectiveness through real installations, demonstrating the IoT potential as SDG-enabling technologies.”
• In Introduction: “The Results section shows several success stories, focused on CO₂ and energy consumption monitoring, through real installations as a proof-of-concept of IoT as SDG-enabling technologies.”
• In Results (first paragraph): “This work details the obtained results, focused on CO₂ and energy consumption monitor-ing, during the recent design, development, implementation and technical validation of sensoriZAR.”
• In 3.3 section: “The first examples are focused on energy consumption monitoring and, derived from the COVID-19 situation, CO₂ evolution as analysed in a specific classroom.”

13. Recommend for major revision.

The authors thank again the detailed comments because these suggestions have contributed to improve the overall paper and we hope that this new proposed version of the manuscript will meet the quality standard of MDPI in order to be definitely accepted.

Yours sincerely,

authors of manuscript sustainability-1263348 (MDPI)

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Thank you for revising the paper

Reviewer 3 Report