How does thermal stratification occur in hot water cylinders?

Thermal stratification in hot water cylinders occurs when hot water, which is less dense, rises to the top while cooler water, being denser, stays at the bottom. This results in distinct layers of water at different temperatures within the cylinder. As the water heats up, the hottest water accumulates at the top, creating a warm layer, while cooler water collects at the bottom, demonstrating a temperature gradient. This phenomenon is significant in hot water systems because it affects efficiency and the way hot water is delivered. Proper understanding of thermal stratification allows for better design and operation of these systems, ensuring that hot water is readily available without excessive mixing that could lower the temperature of the hot water being drawn.