What does "R-value" measure in insulation?

R-value measures thermal resistance in insulation, which indicates the material's effectiveness in resisting heat flow. A higher R-value signifies better insulating properties, meaning that the material can better resist the transfer of heat, keeping spaces warmer in the winter and cooler in the summer. This measurement is crucial in energy-efficient building practices, as proper insulation can significantly reduce energy consumption for heating and cooling.

It's important to note that while insulation materials can provide some degree of moisture resistance, sound resistance, and airflow resistance, these characteristics are not what R-value quantifies. R-value focuses solely on how well a material can insulate against thermal energy transfer, making it a critical factor in the effectiveness of insulation used in HVAC applications and overall building performance.