The lambda value (λ-value) is a key measurement in determining the thermal conductivity of an insulation membrane. The lambda value, also known as the thermal conductivity value, indicates how well a material can conduct heat. It is measured in watts per metre per degree Celsius (W/m·K). Essentially, the lower the lambda value, the better the insulation membrane is at resisting heat flow.
Materials with a low lambda value will prevent heat from escaping in winter or entering in summer, making them more effective at insulating your home or building. Understanding this value is crucial for choosing the right membrane for your project, as it directly affects how well the material can prevent heat loss.
The lambda value plays a significant role in determining how energy-efficient an insulation membrane is. The lower the lambda value, the less heat will pass through the membrane, which helps reduce energy consumption and costs. The lambda value helps you compare different membrane options, enabling you to select the most suitable product for your specific needs.
The lambda value is measured under controlled conditions, typically in a laboratory, where the material's thermal conductivity is tested. The result is a value expressed in W/m·K, showing how much heat passes through one square metre of the material for every degree Celsius of temperature difference. The lower the value, the better the material is at insulating.
Different insulation membranes have different thermal conductivities, and their composition significantly affects their lambda value. Vapour barrier membranes and vapour control membranes each have unique lambda values, offering specific benefits depending on the application.
The density of an insulation membrane can impact its lambda value. Generally, denser materials allow more heat to pass through, increasing the lambda value. However, advanced insulation membrane technologies can achieve low lambda values while maintaining lighter weights.
Moisture can negatively affect the lambda value of insulation membranes. Wet membranes conduct heat more easily, increasing the lambda value and reducing the material's effectiveness. This is why it is essential to protect your insulation from moisture.
