A tunnel oven using air impingement as the heat transfer mechanism is constructed for significant reduction of energy consumption and minimal labor required for cleaning. The oven is designed so that the number of airflow direction changes is minimized, and that there are no narrow ducts and no narrow spaces in the air circuit. The initial placement of thermal energy is optimized to maximize efficiency while minimizing unnecessary heat losses through exterior oven panels. The air impingement nozzle elements are on plates supported by rails and/or feet for very easy maintenance. The easy fast-out and fast-in nozzle plates are removed through access openings, and without removing the conveyor or the front of the oven. No downtime for cooling off is required. Therefore, one unskilled worker of minimal strength can disassemble the oven extremely quickly and easily for routine cleaning.