# Empirical Modeling of Seasonal Cooling Performance Based on Test Devices Using Zinc Oxide/Low-Density Polyethylene Passive Cooling Membranes

## TL;DR

This paper presents a climate-adaptive cooling material using zinc oxide and polyethylene that reduces temperatures in outdoor structures across different seasons.

## Contribution

The study introduces an empirical model linking cooling performance to seasonal solar irradiance and specific volume for passive cooling materials.

## Key findings

- ZnO/LDPE membranes achieved maximum temperature reductions of 12.55°C in summer, 8.02°C in autumn, and 2.90°C in winter.
- Cooling efficiency varied with seasonal solar irradiance, showing quicker responsiveness in summer and reduced in winter.
- An empirical correlation between temperature reduction and specific volume was established for standardized performance assessment.

## Abstract

Outdoor structures, such as vehicles, buildings, and outdoor equipment, are prone to overheat due to prolonged exposure to solar irradiation, which could affect their service life or user experience. To address this urgent issue, we developed a climate-adaptive thermal management solution using zinc oxide (ZnO)/low-density polyethylene (LDPE) hybrid membranes. The cooling performance of the membrane was examined across different seasons, achieving maximum temperature reductions (∆T) of 12.55 °C in summer, 8.02 °C in autumn, and 2.90 °C in winter. Our results demonstrated that the material’s cooling efficiency varied with seasonal solar irradiance, showing quicker responsiveness in summer and reduced in winter, effectively preventing overcooling. Moreover, the enclosed specific volume (SV) was identified as another critical parameter affecting cooling performance. We established an empirical correlation between ∆T and SV to quantify passive cooling performance across different seasons. This standardized method for assessing the cooling effect enables comparison between different materials, which is essential for determining climate-adaptive thermal management. Notably, the ZnO/LDPE membranes exhibited stable and balanced performance year-round, highlighting their potential for substantial energy savings in outdoor applications. This research provided valuable insights for designing climate-adaptive passive cooling materials that optimize thermal management across seasonal variations while contributing to sustainable energy conservation.