A flat metal wall of a storage tank has a thickness \(d\) and thermal conductivity \(k_{\text{metal}}\). Thermal energy transfers through the wall at a rate \(H_0\) when a constant temperature difference \(\Delta T\) is maintained across its inner and outer surfaces. To reduce heat transfer, a layer of fiberglass insulation of the same thickness \(d\) and thermal conductivity \(k_{\text{fiber}} = \dfrac{1}{4}k_{\text{metal}}\) is added directly to the outer surface of the wall, while maintaining the same overall temperature difference \(\Delta T\) across the combined two-layer boundary. What is the ratio \(H_{\text{new}} / H_0\) of the new rate of thermal energy transfer to the original rate?