# Comparative Study of Natural Fibres to Improve Insulation in Wooden Beehives Using Sensor Networks
## 4 Discussion  
### External Heating Source  
The study's initial hypothesis--that hives insulated with specific materials would exhibit superior insulation properties compared to control hives--has been substantiated. Across various experiments and materials, insulated hives consistently outperformed control hives, with no significant differences observed between replicates. Notably, control hives showed a larger temperature variation and a higher area/thickness ratio, underscoring the enhanced insulation capability of the selected natural fibres.  
The majority of specialised literature covering hive material tests has been conducted in the field with bees, which may increase the uncertainty of the analysis due to changing environmental factors or the influence of the bees on the research. The lab results here presented align with the findings of [16]. In their study, hives with black agglomerated cork had fewer thermal fluctuations throughout the day and required less time for bees to achieve the desired temperature after opening the hive. The materials chosen in this study have demonstrated their efficacy as quality thermal insulators with low thermal transmittance. This ensures that heat within the hives is maintained at temperatures lower than the control hive throughout the entire 60 min test.  
Maintaining an optimal internal temperature is vital for hive habitability. The ideal internal temperature for the brood nest ranges between 32 and 36 \({}^{\circ}\)C [43], 34 and 35 \({}^{\circ}\)C [44], and 30.7 and 37 \({}^{\circ}\)C [45]. This temperature stability, known as homeostasis, is crucial for bee colonies. As noted by [46], prolonged exposure to internal temperatures above 38 \({}^{\circ}\)C adversely affects larval metamorphosis and brood growth and shortens the lifespan of adult bees. Therefore, in a broader context, given the escalating temperatures due to climate change, the results support the prioritisation of designing hives using natural insulators to effectively counter high summer temperatures.  
Based on the results, black agglomerated cork and rock mineral wool offer the best insulation values compared to the other materials. Nevertheless, as indicated by the ANOVA analysis comparing areas relative to the insulation layer thickness, there are no significant differences among the four chosen natural materials, which exhibit similar behaviours. However, they show marked and significant differences when compared to the control hive (as seen in Table 2 and Figure 6a). This enhanced insulation, compared to the control hive, translates to reduced energy expenditure for the bee colony in combating external temperature fluctuations. This is particularly crucial during summer when bees have to fetch water to mist inside the hive, thereby lowering the temperature through evaporation [47; 48]. This temperature-regulation process necessitates energy expenditure by the bees, which they achieve by consuming honey, which directly affects honey productivity.  
In the course of our experiments, we observed that humidity levels in the non-insulated hive approached 30% after 30 min, whereas in the hive insulated with black agglomerated cork, humidity remained at approximately 20%. While our experimental setup was not specifically designed to control or measure humidity rigorously, these preliminary findings suggest that the insulation properties of black agglomerated cork may influence internal microclimate conditions by potentially enhancing the evaporation rate and vapour loss. Further studies with controlled humidity conditions are recommended to validate these observations and explore the implications of insulation on hive humidity dynamics in detail.  
In light of these findings, it appears that any of the tested materials can significantly enhance a hive's insulation properties. Therefore, the selection of an insulation material should consider factors such as cost, mechanisation ease, and availability, with the latter varying by region.