A standard gas convection oven has 30 percent energy efficiency and a 18,000 Btu/h, or British thermal unit per hour, idle energy rate. An Energy Star-certified gas convection oven is required to have 44 percent energy efficiency and a 13,000 Btu/h idle energy rate.
The energy efficiency relates to cooking, indicating how much energy a food item absorbs in relation to the total amount of energy used by the convection oven. The idle energy rate indicates the amount of energy used by the convection oven while the appliance maintains a constant operating temperature. An energy-efficient convection oven can cut energy use by a third, which saves money on energy bills.