Cold-Chain Challenges Explained
Insulation works by slowing the transfer of heat which can move in three ways: conduction, convection and radiation.
Understanding the influence of these three methods allows one to make better and more informed choices.
Heat transfer through fluids (liquids/gases) by movement of warm particles rising and cool particles sinking.
Controlling convection is the most overlooked element in cold-chain shipping. Often taken for granted, closing the lid on an EPS cooler traps a certain amount of air within the container. By reducing the air space in a container you reduce convection and improve performance.
Heat transfer between objects in direct contact, where heat moves from warmer to cooler areas.
Slowing conduction is the primary role of insulation. Most thermal shipping materials (EPS, FPF, PET, denim, rock wool, etc) have comparable performance slowing conduction.
Heat transfer through space in the form of electromagnetic waves, like sunlight. No medium needed.
Radiation is the least influential method of heat transfer when it comes from thermal shipping. Even in the most extreme environments, heat gain comes primarily from the convection currents of air around the package conducting heat on to the surface of the package.
