After the 2010 Florida Building Code went into effect last March 15th, 2012, owners of new construction projects were required to comply with new energy-consumption guidelines, including maximum U-factor and Solar Heat Gain Coefficient (SHGC) values. This post is written from the perspective of specifying and selecting the right glazing makeup of impact windows and doors that meet the Code.
- R values rate one single material versus U-values measure entire components.
- R-values rate how much heat loss the material resists from passing through it.
- U‐values rate how much heat the component allows to pass through it.
- R-values measure how much heat loss passes through fiberglass insulation. On the other hand, U-values rate how much heat can pass through a window component (glass, air, aluminum frame).
- The relationship between r-values and u-factors is R = 1/U.