Proceedings of the International scientific and practical conference ―Multidisciplinary approaches in science, technology and culture‖ (September 5-7, 2025) / Publisher website: www.naukainfo.com. – Oxford, United Kingdom, 2025. - 124 p.

119 During the day, the PCM absorbs heat and melts, preventing overheating; at night, it solidifies and releases heat, maintaining thermal comfort [3]. Experiments show temperature increases of 1–7.5 °C in greenhouses using PCM. To ensure optimal performance, the PCM‘s melting point should align with the desired indoor temperature range (e.g., 18–25 °C for greenhouses) [4]. Paraffin is favored due to its chemical stability, non-corrosiveness, and reversibility. PARAFFIN T3: PROPERTIES AND SUITABILITY AS A PCM Paraffin wax is one of the most accessible and cost-effective phase change materials (PCMs) for thermal energy storage. It consists of a mixture of saturated hydrocarbons (CnH₂n₊₂), with melting point and latent heat depending on the chain length. Paraffin T3, a technical-grade petroleum wax with minor oil content (~3%), melts at approximately 50–55 °C [4]. While this temperature is higher than typical indoor conditions in greenhouses, it becomes practical when used with solar collectors or concentrated heat sources. Key thermophysical properties of paraffin T3 include :  Melting point: ~50–55 °C;  Latent heat of fusion: ~190–200 kJ/kg;  Specific heat capacity: ~2.1 kJ/(kg·K);  Thermal conductivity: low, ~0.15–0.21 W/(m·K);  Density: ~800 kg/m³ (solid), ~750–770 kg/m³ (liquid);  Chemical stability: non-toxic, inert, non-corrosive, safe for agricultural use. Despite its low thermal conductivity, which limits heat transfer rates, paraffin T3 is widely regarded as a reliable PCM due to its stability, safety, reversibility, and affordability. These characteristics make it suitable for large-scale thermal storage systems in agricultural applications. CASE STUDY: THERMAL STORAGE CAPACITY OF A PARAFFIN T3-FILLED TUBE Problem setup :