Experimental and Simulation Research on the Energy-Saving Potential of a Sunspace—Taking an Apartment in Qingdao as an Example
Round 1
Reviewer 1 Report (Previous Reviewer 1)
Authors have addressed all the comments.
Author Response
Point 1: Authors have addressed all the comments.
Response 1: We appreciate the time and effort that you dedicated to provide the insightful feedback and valuable improvements on our manuscript.
Reviewer 2 Report (Previous Reviewer 2)
My comments are addressed
Author Response
Point 1: My comments are addressed.
Response 1: We appreciate the time and effort that you dedicated to provide the insightful feedback and valuable improvements on our manuscript.
Reviewer 3 Report (Previous Reviewer 3)
The authors improved the paper by following reviewers' suggestions. In my opinion, some numerical results should be added in the conclusion section. Furthermore, given that the authors affirmed that they did not consider visual comfort "Because the bedroom is mostly used at night", it is not clear if the calculation (e.g. of the energy saving) and the measurements were performed by considering 24h or a specific schedule.
Author Response
Point 1: The authors improved the paper by following reviewers' suggestions. In my opinion, some numerical results should be added in the conclusion section. Furthermore, given that the authors affirmed that they did not consider visual comfort "Because the bedroom is mostly used at night", it is not clear if the calculation (e.g. of the energy saving) and the measurements were performed by considering 24h or a specific schedule.
Response 1: We appreciate the time and effort that you dedicated to provide the insightful feedback and valuable improvements on our manuscript.
We have added some numerical results in the Conclusions section.This study focuses on the energy-saving potential of the sunspace. Visual comfort is another research direction, which is not considered in this study.The calculation and the measurements were performed by considering 24 h.
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
This paper explores the energy saving potential of a sunspace in a residential building in six modes of user behavior. Thermal performance of the sunspace in winter and in summer was investigated. Both experiment and simulation were used. The paper has a good structure, and results are discussed well. However, some key simulation parameters are missing. My comments are below:
Line 142:
Simulation details are missing !
How was the sunspace modelled? Which algorithms were used? Was Airflow network used?
How many nodes did you choose?
How were the values of parameters chosen?
This section Must be explained in detail!
Line 125: Please explain why the initial temperature difference was set to 3 °C, and the final 1 temperature difference was set to 1. Any references to support this?
Only 31 papers were reviewed in the paper. More relevant papers must be reviewed. It is highly important to properly acknowledge and review previous works.
A flow chart is suggested to show the structure of the paper.
Reviewer 2 Report
For simulation, what is the material of the door between sun space and bedroom ?
Line 105. It is not a house but an apartment.
Section 2.2. Did you simulate only the bedroom, or the whole apartment, or the whole building ?
I suggest fig 4-12 using the same scale of y axis
DT (Delta Temperature) is equal to the inlet air temperature minus the outlet air temperature. It is better to use supply and return air temperature.
Please give more information on the ventilation system, such as the type of the unit, and the location of the unit, heating/cooling load, inlet, and outlet.
The initial temperature difference was set to 3 °C. How can you set the temperature difference ?
DT controller was used to control the air supply between the sun space and bedroom. Please tell the air supply direction. It is from sun space to bedroom, or inverse. What is the purpose of this fan ?
Table 2 was not clear in column of Mode of user behavior. You only provided part of information. For example, when using DT-controlled ventilation, how about door and window status ? In 2021/12 and 2022/4, how about window status ? I suggest using three column: DT-controlled ventilation, door status and window.
What is FR (flow rate) in Table 7 ? Is it the ventilation volume of the fan was set to 78 m³/s in line 126 ?
Fig 3 the simulated sunspace is different from the actual one in fig 1. In the apartment, there is no slope angle of the roof.
Why did you use depth with 0.6-1.5m ? As far as the reviewer knows, 0.6-1m is unreasonable. Please check the normal depth or building standards and code
Table 10. Please consider using some optimization algorithms or programs to find optimal designs, such as Genetic Algorithm, GenOpt, JEPlus. There were so many parameters in the model and they were interactive. You cannot change one by one to find optimal.
Reviewer 3 Report
This paper deals with the analysis of the thermal performance and energy-saving potential of the sun-space of an old apartment building in Qingdao through actual experiments and software simulation. The topic is interesting, but in my opinion, the paper has many lacks.
Many other studies investigated the same topic. The results obtained from similar studies should be reported and the novelty of this work has to be underlined.
References for Vantage Pro2, TC96-V DT, testo-174H and, other instrumentation should be included.
Monitoring schedules considered a very short period and it could be a lack for the study. This problem should be solved or underlined in the manuscript.
More information about the climate conditions has to be given.
It is not clear how the authors calculated the energy savings. Is there a “baseline case”? Which are its characteristics?
The term “heating energy consumption” is too generic.
Section “methodology” has to describe more in detail the methodology applied to conduct the research. The description of the case study is very poor. The schematic figure is not enough. It is very difficult to understand the advantages to use this system without including more important information. Furthermore, the description of the method used to evaluate “comfort conditions” should be included. In this regard, it has to be underlined that visual comfort conditions should be investigated.
