What happens to the efficiency of insulation when it becomes wet?

When insulation becomes wet, its efficiency decreases significantly due to the loss of its thermal resistance properties. Insulation materials are designed to trap air or a gas that enhances their ability to resist heat flow; when they absorb moisture, the trapped air is often displaced, and the insulating properties are compromised.

Moisture can also lead to conductive heat transfer as water has a much higher thermal conductivity compared to air. This results in increased heat loss in winter and heat gain in summer, making the building less energy-efficient. Additionally, wet insulation can become a breeding ground for mold and mildew, which further impacts overall indoor air quality and can lead to structural damage over time.

Thus, understanding the relationship between moisture and insulation performance is crucial for maintaining energy efficiency in buildings.