Two black surfaces, AB and BC, of lengths 5 m and 6 m, respectively, are oriented as shown. Both surfaces extend infinitely into the third dimension. Given that view factor F₁₂ = 0.5, T₁ = 800K, T₂ = 600K, T_surrounding = 300K and Stefan Boltzmann constant, σ = 5.67 × 10⁻⁸ W/(m²K⁴), the heat transfer rate from Surface 2 to the surrounding environment is ________ kW.