Installation manual

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Air-to-Water Heat Pumps 2.12
2.12 Acoustic Emissions of Heat Pumps Installed Outdoors
Fig. 2.17 on p. 71 shows the four main directions of sound
propagation. The air inlet side is indicated by direction “1” and the
air outlet side by direction “3”. Directional sound pressure levels
of the air-to-water heat pumps can be determined using Table
2.8 on p. 71. The values at a distance of 1 m are actual measured
values. The values at a distance of 5 and 10 m are calculated on
the basis of hemispherical propagation in the open air.
Deviations are possible in actual use on account of sound
reflection and/or sound absorption due to local conditions.
Fig. 2.17: Determination of sound directions
NOTE
Basic principles of sound can be found in Chap. 5 on p. 144.
Table 2.8: Directional sound pressure level in relation to distance, in dB(A).
For example:
Sound pressure level LA 11AS in the direction of the air outlet at
a distance of 10 m: 33 db(A)
Type LA 11MS / LA 11AS
LA 16MS / LA 16AS /
LA 11PS
Dir. 1 2 3 4 1 2 3 4
1 m 49 46 50 46 50 47 51 47
5 m 38 35 39 35 39 36 40 36
10 m 32 29 33 29 33 30 34 30
Type LA 20AS / LA 17PS LA 24AS / LA 28AS
Dir. 1 2 3 4 1 2 3 4
1 m 52 48 54 48 56 50 58 50
5 m 41 37 43 37 45 39 47 39
10 m 35 31 37 31 39 33 41 33
Type
LA 22PS / LA 26PS
LA 22HS / LA 26HS
LA 8AS / LA 9PS
Dir. 1 2 3 4 1 2 3 4
1 m 56 50 58 50 49 49 49 49
5 m 45 39 47 39 38 38 38 38
10 m 39 33 41 33 32 32 32 32