nozzles upper and lower opposing nozzle arrays are provided with each nozzle in the lower array except for an end nozzle positioned between two nozzles in the upper array i e the upper and lower nozzles are staggered with respect to each other suitable nozzles also include direct impingement nozzles such as direct impingement nozzles having a plurality of apertures such as a hole array bar or direct impingement nozzles having one or more slots which provide a higher heat transfer coefficient for a given air volume and nozzle velocity than a flotation nozzle as between the hole array bar and the slot bar the former provides a higher heat transfer coefficient for a given air volume at equal nozzle velocities although maximum heat transfer is obviously a goal of any dryer system other considerations such as air volume nozzle velocity air horsepower proper web flotation dryer size web line speed etc influence the extent to which optimum heat transfer can be achieved and thus the appropriate design of the direct impingement nozzle in certain embodiments the top surface of the direct impingement nozzle may be crown shaped approaching a central apex at about a 5 degree angle this design encourages the return air to flow over the edges of the nozzle after impingement on the web the angle of the crown can vary from about 0 degrees to about 10 degrees in general the closer the nozzle is to the web the larger the angle of the crown in certain embodiments one or more nozzles 20 is an elongated member having one or more discharge openings 21 for emitting air see fig1 such as an elongated slot or a plurality.