Evaluation of Energy Performance and Thermal Comfort Considering the Heat Storage Capacity and Thermal Conductivity of Biocomposite Phase Change Materials

Round 1

Reviewer 1 Report

The paper " Evaluation of Energy Performance and Thermal Comfort considering the  Heat Storage Capacity and Thermal Conductivity of Bio Composite Phase Change Materials " talks about thermal cooling and heating load management. Here are the reviewer comments:

1. The whole model is a black box, basic governing equations should be described. 2. The charging and discharging profile for each case (design point) should be discussed, this will help in increasing the clarity. 3. Generally PCM deteriorates with time and cycling. A test on 100 to 500 cycles should be performed to show its stability. 4. Can you also comment on the cost and economic benefits for these pcm. 

Author Response

Thank you for kind review.

See the attached response file.

Author Response File: Author Response.docx

Reviewer 2 Report

The authors present a study on the performance of “phase change bio-materials” for energy storage, with particular reference to the building design. Two bio-composite materials have been considered, namely Bc-PCM and TBc-PCM, the latter is a modification of the Bc-PCM owing to the inclusion of Graphene nano-particles. These materials have been characterized by several techniques that include IR (infrared spectroscopy), DSC (differential scanning calorimetry), TGA (thermal gravimetric analysis) and Tci for thermal conductivity measurements. In particular, DSC and Tci allow to estimate, respectively, the latent heat of the phase change and the thermal conductivity. By means of “Design Builder” and “Energy Plus” software, energy performance and comfort analyses of the building have also been carried out for different climatic behavior.

On balance, I found the paper interesting, well written, the study quite comprehensive from the viewpoint of both material science and thermal science. The subject matter fits the scope of the “Processes” journal. However, before proceeding with publication, the authors should improve the presentation of their work according to the following points

-Since the article contains a “multidisciplinary” research where many scientific topics are involved, I suggest the authors to briefly explain the basic principle of the energy storage using PCM materials. Also, a few lines on how the “energy consumption” of the building has been estimated (quantitatively), could be useful. In this way, the paper can be made accessible also to the average reader of the journal.

-As regards Fig.4, it is stated that the curves with maxima refer to the enthalpies (scale on the left). To me, these curves seem to be representative of the changing rate of the enthalpy (energy/unit temperature or time) and the accumulated enthalpy the integral of these peaks. This point should be clarified.

-In the energy simulation, concerning the heat transport equation, eqn.1, the authors should report the boundary conditions. In particular, those at the boundary between the two materials (with KI and KE conductivities) where conservation of the heat flux should be fulfilled.

- The authors employ a simulation software for modeling energy efficiency of the building. In this context, the authors should clarify whether the physical and chemical properties determined in section 3.1 and 3.2 have been used as input parameters for the simulation.

- In page 11 line 341 and in Fig.6, the authors compare cooling and heating load reduction with respect to the reference model. From the reading of the paper, it is not clear the definition of “reference model”. Since the energetic analysis is done through computer simulations, the “reference model” should be defined.

-I suggest the authors to explain better the sentence in page 9 lines 295-298.

-In the text, there are two sections 3.2.

Author Response

Thank you for kind review.

See the attached response file.

Author Response File: Author Response.docx