 ## Sound generation

### Sound generation in a straight duct

Input Result
Air speed v=
Duct diameter d=
Duct width b=
Duct height h=
Sound effect Lw= dB

### Velocity

Velocity of the air flowing through the current duct, and causes the pressure drop that produces the calculated sound. To avoid that the channels will resonate which in turn would generate more noise than the speed should in a circular duct not exceed about 11 m / s while in a rectangular, the rate should be less than about 7 m / s.

### Duct diameter

Refers to the diameter of the circular duct. Circular duct is the main option in the calculations and priorities into account before the rectangular duct.

### Duct width

The width of the rectangular duct.

### Duct height

Does the height of the current rectangular duct.

### Sound effect

Shows how much the sound generated in a normal sheet metal duct. The calculation is an approximation of the more exact values ​​used ljudalstringsdiagram from the current channel manufacturer.

### Sound generation

As the air flows in a duct, it causes friction which in turn creates noise.

### Formula

Sound effect: 