In Texas, builders commit a cardinal engineering sin: they locate the home's most sensitive cooling equipment (the evaporator coil and thin plastic ductwork) directly inside the hottest environment in the entire house—the attic.
The 140°F Oven Effect
When your AC compressor turns on, it generates crisp 55°F air. That air is pushed through flexible plastic ducts suspended in a 140°F attic. Even with minor R-6 duct insulation wrapped around them, the sheer radiant heat of the wood roof deck bakes the ducts. By the time that 55°F air reaches your master bedroom ceiling register, it has often warmed up to 64°F. That 9-degree loss is pure wasted money.
Attic Temperature Reduction
Installing a pure aluminum Radiant Barrier stapled directly to the rafters physically reflects the sun's radiation away from the attic interior. This instantly drops the ambient temperature of the attic by 25°F to 30°F.
Faster Cooling Times
Because your flexible ductwork is now sitting in a 110°F environment instead of a 140°F oven, that 55°F air doesn't bake en route. It hits your bedroom register at 58°F. The room cools down twice as fast, and the compressor shuts off 30 minutes earlier.