Thermal resistance of a glazing system expressed ft2/hr/°F/BTU (m2/W/°C). The R-value is the reciprocal of the U-value. The higher the R-value, the less heat is transmitted through the glazing material.
Thermal resistance of a glazing system expressed ft2/hr/°F/BTU (m2/W/°C). The R-value is the reciprocal of the U-value. The higher the R-value, the less heat is transmitted through the glazing material.