单甲板只能上下调节风向，双层甲板可以上下调节风向。但在实际使用中，双层出口存在噪声问题、清洗困难等缺点，中央空调的通风口一般不需要调节风向。
Double shutter tuyere: 1, double adjustable blade, different air supply distance and diffusion Angle.
2. The double shutter tuyere can be used as air outlet
3. The preparation of aluminum or iron.
4, double shutter tuyere is to use single shutter and control valve
Single louvers tuyere
Available: 1, the single adjustable blade, the spread of different air supply distance and Angle.
2. It can be used as outlet and return air
3. The preparation of aluminum or iron
4. For used with air outlet regulating valves.
5. To return to vent, it can be made into an open structure, and used together with the filter screen.
Single deck only up and down to adjust the direction of the wind, double deck can adjust up and down the wind. But in actual use, double export noise problem and the difficulty of cleaning, faults, central air-conditioning vents generally do not need to adjust the direction of the wind.