Pacific Northwest Window Care: Managing Rain, Fog, and Interstitial Moisture

## Navigating Pacific Northwest Atmospheric Challenges From Seattle and Tacoma to Portland and Vancouver, the Pacific Northwest experiences prolonged rainy seasons with continuous high ambient relative humidity (RH). When indoor humidity generated by cooking and bathing contacts cold window panes, surface condensation forms—leading to black mold on timber sills and drywall decay. ### The Physics of Window Condensation in Maritime Climates Condensation occurs when the temperature of the indoor window surface falls below the dew point of the surrounding indoor air. In homes with old metal spacers: - Aluminum spacers create a cold perimeter ring around the glass edge. - Moisture accumulates along the lower sash edge, dripping down into wood framing. ### The Engineered Solution: Warm-Edge Spacers & Low-E Glazing By replacing conductive metal spacers with non-conductive composite or silicone foam warm-edge spacers, glass edge temperatures increase by 8°F to 12°F. This keeps the glass surface above the indoor dew point, virtually eliminating condensation droplets. Connect with ServiceFind Windows Pro for a moisture assessment and **Fair Quote**.