Radiative heat transfer
= Radiative heat transfer
{title2=$P_{\rm net}=\epsilon\sigma A(T_s^4-T_e^4)$}
Transfer of <energy> by <thermal radiation>. A diffuse grey surface of <area> $A$ and <emissivity> $\epsilon$ completely enclosed by isothermal black surroundings has net outward <power> $\epsilon\sigma A(T_s^4-T_e^4)$. This subtracts absorbed environmental radiation from emitted radiation. Other geometries require exchange factors; a gross emitted <power> is not a net cooling rate.