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Condensation on window glass

Window Condensation

Managing condensation on windows and other cold surfaces.

Why Condensation Happens

Condensation forms when warm, humid indoor air hits cold surfaces like windows or exterior walls. The moisture turns into liquid water, which can feed mold if it stays wet.

Where Condensation Commonly Appears

  • Window glass and frames
  • Exterior walls and corners
  • Cold water pipes
  • Behind furniture on exterior walls
  • Basement walls

How to Reduce Condensation

Lower Indoor Humidity

  • Run bathroom and kitchen exhaust fans
  • Use a dehumidifier in damp rooms
  • Avoid drying clothes indoors
  • Keep lids on pots while cooking

Warm the Surface

  • Improve window insulation or add storm windows
  • Open blinds to let warm air reach glass
  • Seal air leaks around frames
  • Add insulation where possible

When It Becomes a Mold Risk

  • Condensation that drips or pools daily
  • Water staining or peeling paint around windows

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Quick Response Steps

  • Wipe up condensation daily
  • Dry window sills and frames

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