A fuel gas containing 76% methane, 14% ethane, and 10% propane by volume flows to a furnace at a rate of 1250 m³/h at 23 and 250 kPa (gauge), where it is burned with 8% excess air. Calculate the required volumetric flow rate of air (m³/h) at 1 atm and 45 by assuming the air behaves ideally under these conditions.