How does insulation thickness affect energy losses in a house, and what principle explains it?

• A. Thicker insulation reduces heat transfer, explained by higher resistance to heat flow (R-value).
• B. Thicker insulation increases heat transfer.
• C. Insulation thickness has no effect.
• D. Insulation only affects sound, not heat.

Answer: (A)

Thickness of insulation affects energy losses by changing how hard heat has to work to move through the wall. Heat flows from hot to cold, and the rate of this flow depends on the barrier’s resistance. More insulation thickness increases the thermal resistance (higher R-value), so the same temperature difference pushes heat through much more slowly. Because heat transfer is inversely related to this resistance, thicker insulation lowers the amount of heat lost (or gained) each hour. In simple terms, thicker insulation keeps the inside warmer in winter and cooler in summer by making it harder for heat to pass through. When multiple layers are present, their resistances add up, giving an even larger overall resistance and less heat flow.