Transfer unit


Reduction number unit	D_n,e=	dB
Wall area	A=
Reduction number wall	R_vägg=	dB
Resulting reduction number	R_res		dB

Explanations

Wall area

The area of the wall to be calculated.

Resulting reduction number

The summed noise reduction number for the total wall.

Reduction number unit

The reduction number for a unit (D_n,e) is calculated on a 10m² wall. An alternative value used is the R value for other standard wall areas. Correction figure for R value to D _{n, e} depending on the wall area used to determine the value can be made according to the table below.

Area	10	2	1	m²
Correction	0	7	10	dB

Reduction number wall

The noise reduction value of the current wall.

Formula

Transfer unit:

Transfer unit

Calculates how much an overhead device degrades a wall in terms of sound.