Physics – 2.3.4 Consequences of thermal energy transfer | e-Consult

When a radiator is heated, the air in contact with the radiator gains thermal energy. This warm air becomes less dense than the cooler air surrounding it. Due to this density difference, the warm air rises. As the warm air rises, it moves away from the radiator, and cooler, denser air descends to take its place. This creates a convection current – a continuous cycle of warm air rising and cool air sinking. This movement distributes heat throughout the room. The heat is transferred from the radiator to the air, and then the air carries the heat to other parts of the room.

Factors affecting efficiency:

• Insulation: Poorly insulated walls, windows, and floors allow heat to escape, reducing the efficiency of convection heating. Good insulation minimizes heat loss.
• Air Leaks: Drafts and air leaks can disrupt the convection currents, allowing warm air to escape and cold air to enter. Sealing these leaks improves efficiency.
• Room Size: In larger rooms, the convection currents may not be as effective at distributing heat evenly. Larger radiators or multiple radiators may be needed.
• Room Layout: Obstructions in the room can block the flow of convection currents, leading to uneven heating.
• Radiator Placement: Placing the radiator near a window can lead to heat loss due to the colder air near the window.