Black Bodies Heat Exchange by Radiation Calculator

Formula

The formula to calculate the Heat Transfer by Radiation is:

\[ q = \epsilon \cdot \sigma \cdot A \cdot (T_1^4 - T_2^4) \]

Where:

\(q\) is the Heat Transfer (W)
\(\epsilon\) is the Emissivity
\(\sigma\) is the Stefan-Boltzmann Constant (5.670367E-8 W/m²K⁴)
\(A\) is the Area (m²)
\(T_1\) is the Temperature of Surface 1 (K)
\(T_2\) is the Temperature of Surface 2 (K)

Definition

Heat transfer by radiation between black bodies is the process of energy transfer through electromagnetic waves emitted by the surfaces of the bodies.

Example Calculation

Let's assume the following values:

Emissivity (\(\epsilon\)) = 0.95
Area (\(A\)) = 50 m²
Temperature of Surface 1 (\(T_1\)) = 101 K
Temperature of Surface 2 (\(T_2\)) = 151 K

Using the formula:

\[ q = 0.95 \cdot 5.670367E-8 \cdot 50 \cdot (101^4 - 151^4) \]

Evaluating:

\[ q = -1119.99370862799 \text{ W} \]

The Heat Transfer is -1119.99370862799 W.

Conversion Chart

Emissivity (ε)	Area (A, m²)	Temperature of Surface 1 (T1, K)	Temperature of Surface 2 (T2, K)	Heat Transfer (W)
0.9	50	101	151	-1,061.046671331780
0.91	50	101	151	-1,072.836078791022
0.92	50	101	151	-1,084.625486250264
0.93	50	101	151	-1,096.414893709506
0.94	50	101	151	-1,108.204301168748
0.95	50	101	151	-1,119.993708627990
0.96	50	101	151	-1,131.783116087232
0.97	50	101	151	-1,143.572523546474
0.98	50	101	151	-1,155.361931005716
0.99	50	101	151	-1,167.151338464958
1	50	101	151	-1,178.940745924200