Radiant Heat Calculator:
Enter the values of Stefan-Boltzmann constant, σ(W/m2K4), temperature raised to the power of 4, T(K) and surface area, A(m2) to determine the value of Radiant Heat, H(W).
Radiant Heat Formula:
Radiant heat is the energy emitted by a surface in the form of electromagnetic waves, primarily infrared radiation, due to its temperature. This form of heat transfer does not require a medium and can occur in a vacuum. Radiant heat plays a crucial role in applications like thermal insulation, radiative cooling, and heating systems, as well as in understanding the energy balance of the Earth and other systems.
The amount of radiant heat emitted by a surface is directly proportional to its temperature raised to the fourth power, surface area, and a constant known as the Stefan-Boltzmann constant (σ). This relationship is described by the Stefan-Boltzmann law, which applies to blackbody radiation a theoretical concept where a surface emits the maximum possible radiation.
In practical scenarios, real objects are not perfect blackbodies, and an emissivity factor (ε) is often included to account for deviations. However, for simplicity, the standard formula assumes an ideal blackbody.
Radiant Heat, H(W) in Watts is calculated by the product of Stefan-Boltzmann constant, σ(W/m2K4) in Watts per square metre per Kelvin to the fourth power, temperature raised to the power of 4, T(K) in Kelvin and surface area, A(m2) in square metres.
Radiant Heat, H(W) = σ(W/m2K4) * T(K) * A(m2)
H(W) = radiant heat in Watts, W.
σ(W/m2K4) = Stefan-Boltzmann constant in Watts per square metre per Kelvin to the fourth power, W/m2K4 (5.67 * 10-8W/m2K4).
T(K) = temperature raised to the power of 4 in Kelvin, K.
A(m2) = surface area in square metres, m2.
Radiant Heat Calculation:
1.A metal plate with a surface area of 2m2 is at a temperature of 500K. Calculate the radiant heat emitted.
Given:σ(W/m2K4) = 5.67 * 10-8W/m2K4, T(K) = 500K, A(m2) = 2m2.
Radiant Heat, H(W) = σ(W/m2K4) * T(K) * A(m2)
H(W) = 5.67 * 10-8 * 500 * 2
H(W) = 0.000056W.
2.A surface emits 500W of radiant heat with a temperature of 400K. If σ is 5.67 * 10-8W/m2K4, calculate the surface area.
Given:σ(W/m2K4) = 5.67 * 10-8W/m2K4, T(K) = 400K, H(W) = 500W.
Radiant Heat, H(W) = σ(W/m2K4) * T(K) * A(m2)
A(m2) = H(W) / σ(W/m2K4) * T(K)
A(m2) = 500 / 5.67 * 10-8 * 400
A(m2) = 34.44m2.