Heat Transfer: Heat from junction box to surface

[Paosy27]

Homework Statement

Calculate the surface temperature of a stainless steel junction box that is in a 35C ambient temperature environment. There are electrical "boxes" that generate 30W of heat inside of this box.

Homework Equations

(1) Q_dot_total = Q_dot_conv + Q_dot_rad
(2) Q_dot_conv = hA(T_s-T_∞)
(3) Q_rad = εσ(Ts⁴ - Tsurr⁴)

The Attempt at a Solution

After combining equations 2 and 3 into 1 and solving for Ts, I get a 4th order equation. When entering this equation into a solver, it gives me ridiculously high numbers (like 21000 degrees C). Any help would be appreciated.

 

[SteamKing]

It would help anyone commenting if you could show your work. It might be something like a mistake in arithmetic, or it might be something conceptual.