Sound-Proofing Calculation Sheet (Example - Sanyo SGP-E70J2GU2 User Manual

Design
Table 1 Sound-proofing calculation sheet (filled in example)
Frequency
1)Operating sound of outdoor unit
2) Distance attenuation
3) Refraction attenuation
4) Increase for reflections (wall
surface)
5) Increase for reflections(ground
surface)
6) Sub-total
7) Overall A characteristic correction
factor
8)A characteristic
When the calculation in Table 1 is completed, the overall A characteristic is calculated.

(8)Sound-proofing calculation sheet (example)

Frequency
1) outdoor unit operation sound
2) distance attenuation
3) Refraction attenuation
4) Additional sound due to reflection
(wall surface)
5) Additional sound due to reflection
(ground surface)
6) Sub-total
7) Overall A characteristic conversion
factor
8) A characteristic
When the calculation in the above table is complete, the overall A characteristic is calculated at the reception point.
(calculate in order of largest sound level). When the overall A characteristic is calculated, combine this with the
background noise level to obtain the total sound level at the reception point.
Hz 63 125
From the operating sound characteristics diagram in the outdoor unit manual
dB
69 66
dB
From Figure 1, attenuation of unit operating sound –22
dB
-3.5 -5
Figure 6 additional sound due to reflections (wall)
dB
By calculation or the simplified method, the combined two sounds MAX value is +3
Figure 7 additional sound due to reflection (ground surface)
dB
By calculation or the simplified method, the combined two sounds MAX value is +3
dB 49.5 45
dB
-26 -16
dB(A) 23.5 29
Hz 63 125
From the operating sound characteristics diagram in the outdoor unit manual
dB
dB
Distance attenuation value:
Refraction attenuation sound path difference d=A+B d
dB
dB
By calculation or the simplified method, the combined two sounds MAX value is +3
Figure 7 additional sound due to reflections (ground surface)
dB
By calculation or the simplified method, the combined two sounds MAX value is +3
dB
dB
-26 -16
dB(A)
D - 27
6. Sound-proofing measures
250 500 1000
62 59 56
From distance attenuation
Figure 2 Refraction attenuation quantity,
sound path difference d=A+B-d
-6.5 -9 -12
39.5 34 28
Conversion factors for A characteristic
-9 -3 0
30.5 31 28
250 500 1000
Distance attenuation
-
Additional sound due to reflections (wall)
Conversion factors for A characteristic
-9 - 3 0
2000 4000 8000
49.5 45 41.5
δ:0.5
-15 -18 -21
18.5 11 4.5
+1 +1 -1
19.5 12 3.5
2000 4000 8000
δ:
+1 +1 -1