What Makes a Window Energy Efficient in Climate Zone 4A?
How Climate Zone 4A Shapes Window Performance A window that performs well in a hot, dry climate can be a poor fit for Climate Zone 4A, where homes deal with humid summers, cold snaps, shoulder seasons, and plenty of temperature swings. That is why window ratings matter so much. The frame, the glass package, the air seal, and the installation all work together. If one part is weak, the entire window underperforms. For homeowners comparing ENERGY STAR windows for Cli