**4. Discussion**

A proposed model was made based on the emulation of the characteristics of the Saharan ant employing a high reflectivity coating applied to the buildings' roofs and the contrasted stripes of the Zebra by applying the reflective coating in a segmented distribution. All this is using the Designbuilder software in which the microclimatic data were taken for the dynamic simulation carried out in the ENVI-met software. From the simulation results obtained, the following could be highlighted:


the reflective and non-reflective segments was 7.5 ◦C, while buildings with strategies have 3.75 ◦C less (colder) without applied strategies;


Although the operative temperatures reached lower values than the base case, results from the SHNV indicator confirm the thermal unconformity recorded inside the buildings during the occupancy periods in passive mode, which is considered significantly low just as in [47].

Moreover, the proposed case performed better than the base case and the base case when implementing the reflective coating over all roof constructions in terms of indoor operative temperature values and electricity consumption for cooling. The average reduction in electricity consumption for cooling of 5.07% (about 505 kWh) when using microclimate data as in [8], compared to the average reduction of 3.13% (8.8 MWh), here in the proposed case, might not represent high enough energy savings to undergo the microclimate data generation process from standard weather data or in situ data collection for simulation purposes only, as suggested in [8,49]. However, the use of microclimate data could strengthen the evaluation-verification process of new urban designs [49] before implementation at a real scale by giving more precise values for energy needs forecast.

Furthermore, the difference in the roofs with the applied Zebra-stripes biomimetic strategy is comparable as it occurs with the Zebra, which through its black and white coloration, obtains a temperature differential that causes convective currents that accelerate heat dissipation [26]. The effectiveness of this biomimetic strategy is also observed at the surface temperature at the roof west slopes of both cases for both months (Figures 11 and 12). For instance, above the park on the left (surrounding with trees), the buildings' roofs west slope without the reflective coating (color yellow in Figure 12a) appeared 5 ◦C lower than the same slopes in Figure 11a (in orange). The same can be spotted on the buildings' roofs above the cathedral and those on the righthand side (below the park).

To corroborate, the 2D transient heat transfer simulations helped realize that the heat flow perturbance at the surface of the body (heat flow lines in Figure 15) caused by the stripes allows a faster temperature drop than the surface with homogenous heat flow. However, the impact of this strategy could be enhanced by combining different patterns since the latter may be as fundamental as the stripes' pattern distribution and shape [25]. It is worth highlighting, based on the study [25] that denies the fact that Zebra stripes do not have a significant effect on the decrease in body temperature, our study is based on biomimetics, which does not take the behavior of the analogy directly. Rather, it is adapted to the applications and needs of the design, for example, the reflective coating that also promotes heat dissipation. Finally, using a commercial coating with a reflectivity value of 0.92 [44] on roofs limits the Saharan ant reflectivity value of 0.96, which brings an opportunity for future coating developments. Although significant energy saving for cooling was attained with the combined biomimetic strategy used here, a cost-effective analysis of retrofitting the roofs' construction contrasted with energy saving costs, needs to be performed, as in as in [21], before implementation.

## **5. Conclusions**

The main objective of this research was to evaluate the indoor thermal comfort and energy efficiency of buildings in an urban area in the Casco Antiguo of Panama City through biomimetic strategies from a previously carried out study. Among the findings this

investigation provided, the following can be retained: The functionality of Zebra stripes, together with the reflective characteristics of the Saharan ant, provide better performance for buildings' thermal regulation and energy needs for cooling. Further investigation through experimental studies might support the effectiveness of this combined biomimetic strategy, but a cost-effective analysis of retrofitting the roofs' construction contrasted with costs energy saving needs to be performed before implementation.

It is important to highlight that biomimetics has been applied throughout history by nature without generating negative impacts on the environment. That is why it must be learned from, and we must seek alternatives to solve the challenges currently faced by society through the application of different approaches so that they may be solved sustainably.

A recommendation for future work would be to conduct more in-depth studies verifying the effectiveness of the strategies applied in this study, such as convective currents that influence heat dissipation through experimental tests. The evaluation of the application of biomimetic strategies in walls added to the strategies of this study.

**Author Contributions:** Original concept, formal analysis, and editing by M.C.A., P.P., K.A. and K.R.M. Introduction, figures and writing of most of the manuscript by M.C.A., K.A. and P.P. Supervision and funding by D.M. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by a Panamanian Institution Secretaría Nacional de Ciencia, Tecnología e Innovación (SENACYT) https://www.senacyt.gob.pa/ (accessed on 30 November 2021), within the projects FID18-056, together with the Sistema Nacional de Investigación (SNI).

**Institutional Review Board Statement:** Not Applicable.

**Informed Consent Statement:** Not Applicable.

**Data Availability Statement:** Not Applicable.

**Acknowledgments:** The authors would like to thank the Technological University of Panama and the Faculty of Mechanical Engineering for their collaboration, together with the Research Group ECEB (https://eceb.utp.ac.pa/, accessed on 30 November 2021).

**Conflicts of Interest:** The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
