Note:

This calculator determines the overall thermal transmittance (U) of a multi-layer structure. You do this by entering the thermal resistance values for each layer in m²·°C/W.

Input Fields:

• Resistance R₁: Represents the thermal resistance of the first layer (e.g., an air film on the exterior surface). This value indicates how well the layer resists heat flow.
• Resistance R₂: Represents the resistance of the second layer (e.g., a condensate film). Enter the value in m²·°C/W.
• Resistance R₃: Represents the resistance of the third layer (e.g., a scale film on the steam side). Provide its value in m²·°C/W.
• Resistance R₄: Represents the resistance of the fourth layer (e.g., a metal wall). Enter its thermal resistance in m²·°C/W.
• Resistance R₅: Represents the resistance of the fifth layer (e.g., a scale film on the water side). Input its value in m²·°C/W.
• Resistance R₆: Represents the resistance of the sixth layer (e.g., a water film). Provide the value in m²·°C/W.

If your structure has fewer layers than six, you may leave the extra fields blank or enter zero. The calculator sums these resistance values and calculates the overall U-value as the reciprocal of the total resistance. A lower U-value indicates better insulation (less heat flow), while a higher U-value indicates more heat transfer.

Real-Life Application: In a building wall composed of layers such as exterior brick, insulation, and interior plasterboard, each layer’s resistance contributes to the overall thermal performance. By entering these resistance values, you can determine the wall’s U-value, which is crucial for assessing energy efficiency and maintaining comfortable indoor temperatures.