U-value (thermal transmittance) is the rate of heat transfer through a structure per unit area per degree of temperature difference. Lower U = better insulation. Units: W/(m²·K). U = 1/R_total.

How is wall heat loss calculated?

Q = U × A × ΔT, where Q is heat flow (W), U is thermal transmittance (W/m²K), A is wall area (m²), and ΔT is temperature difference between inside and outside.

R-value is thermal resistance: R = thickness/conductivity for each layer. Total R = R_si + ΣR_layers + R_se (including surface film resistances). U = 1/R_total. Higher R = better insulation.

What are typical wall U-values?

Uninsulated brick wall: U ≈ 2.0 W/m²K. Insulated cavity wall: U ≈ 0.3-0.5 W/m²K. Well-insulated wall (modern code): U ≈ 0.15-0.25 W/m²K. Passive house: U < 0.15 W/m²K.

What are surface film resistances?

R_si (internal surface) ≈ 0.13 m²K/W and R_se (external surface) ≈ 0.04 m²K/W account for the thin boundary layer of still air at each surface. They are included in the total thermal resistance calculation.

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ಗೋಡೆಯ ಮೂಲಕ ಶಾಖ ನಷ್ಟ ಕ್ಯಾಲ್ಕುಲೇಟರ್

ಸಂಯೋಜಿತ ಗೋಡೆಗಳ ಮೂಲಕ ಉಷ್ಣ ನಷ್ಟ Q = U × A × ΔT ಅನ್ನು ಲೆಕ್ಕಿಸಿ. ವಸ್ತು ಪದರಗಳನ್ನು ಸೇರಿಸಿ, ತಾಪಮಾನಗಳನ್ನು ಹೊಂದಿಸಿ ಮತ್ತು U-value ಹಾಗೂ ಉಷ್ಣ ಹರಿವು ಪಡೆಯಿರಿ.

Q = U·A·ΔTಬಹು-ಪದರ#176

Results

ಉಷ್ಣ ನಷ್ಟ Q

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U-Value

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ಒಟ್ಟು R-Value

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ಉಷ್ಣ ಫ್ಲಕ್ಸ್ q

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ಸಂಯೋಜಿತ ಗೋಡೆ ಉಷ್ಣ ವರ್ಗಾವಣೆ

R_si = 0.13 m²K/W (ಆಂತರಿಕ ಮೇಲ್ಮೈ), R_se = 0.04 m²K/W (ಬಾಹ್ಯ ಮೇಲ್ಮೈ).

Heat Loss Through Wall Calculator | Free U-Value Tool

Published by Nikolai Shelkovenko on ಫೆಬ್ರವರಿ 15, 2026 ಏಪ್ರಿಲ್ 5, 2026

Results

ಸಂಯೋಜಿತ ಗೋಡೆ ಉಷ್ಣ ವರ್ಗಾವಣೆ

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