U-value measures which aspect of glazing performance?

U-value measures which aspect of glazing performance?

• A. U-value measures solar reflectance.
• B. U-value measures resistance to heat flow.
• C. U-value measures the transmission of heat through glazing material.
• D. U-value measures sound transmission.

Answer: (C)

U-value quantifies the rate at which heat is transmitted through a glazing element. It tells you how much heat passes through per square meter for each degree of temperature difference between indoors and outdoors. A lower U-value means less heat loss or gain and better insulating performance. This measure focuses on heat transfer through the window, not on solar reflectance or sound transmission. It’s the heat that actually moves through the glazing assembly, and it’s the reciprocal of resistance (R-value) rather than a description of resistance itself.

U-value quantifies the rate at which heat is transmitted through a glazing element. It tells you how much heat passes through per square meter for each degree of temperature difference between indoors and outdoors. A lower U-value means less heat loss or gain and better insulating performance. This measure focuses on heat transfer through the window, not on solar reflectance or sound transmission. It’s the heat that actually moves through the glazing assembly, and it’s the reciprocal of resistance (R-value) rather than a description of resistance itself.