What is the annual energy demand for a building in Denver, Colorado, if the peak heat load is \(150,000 \mathrm{Btu} / \mathrm{h}\) based on a design temperature difference of \(75^{\circ} \mathrm{F}\) ? Internal heat sources are estimated to be \(20,000 \mathrm{Btu} / \mathrm{h}\), and the design building interior temperature is \(70^{\circ} \mathrm{F}\).