Sanyo ECO G SGP-EW120M2G2W, Технические данные инструкция

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System Design
6. Sound-proofing measures
D-29
(6) Converting from octave band levels to overall A weighting
Table 1. Correction factor for converting from octave bands to A weighting
Octave band Hz 63 125 250 500 1000 2000 4000 8000
Conversion factor dB
－
26
－
16
－
9
－
3 0 +1 +1
－
1
Using the above table, the A weighting is obtained by adjusting the calculated value for each band by its
conversion factor. These values are then combined in order of magnitude, as shown in the following example, to
obtain the overall A weighting.
<Calculation example>
The octave band levels (dB) are obtained from the frequency analysis table (the operating sound level at the
center frequency of each octave band). These values are corrected with the A weighting correction factor to
obtain the A weighting. The following calculation determines the operating sound level.
Octave band Hz 63 125 250 500 1000 2000 4000 8000
Octave band
level
dB 69 66 62 59 56 49.5 45 41.5
Conversion correction
f t
dB
－
26
－
16
－
9
－
3 0 +1 +1
－
1
A weighting dB(A) 43 50 53 56 56 50.5 46 40.5
These A-weighting values are combined one-by-one in order of magnitude (in the same away as combining
different operating sounds).
56 56 53 50.5 50 46 43 40.5
The overall A weighting is thus calculated to be 60.95 dB(A).
(7) Designing sound-proofing countermeasures
<Calculation example>
In the installation drawing at the right, a scheme to suppress operating
sound at the reception point is required.
First, determine the operating sound level of the outdoor unit at each
frequency. By applying this information to Table 1, the sound-proofing
calculation sheet, sound attenuation and additions are calculated for the
installation.
Difference
= 0
56+3.0
=59
Difference = 6
59+0.95
=59.95
Difference = 9.45
59.95+0.45
=60.4
Difference = 10.4
60.4+0.35=60.75
Difference = 14.75
60.75+0.1=60.85
Difference = 17.85
60.95
No further calculation necessary
60.85+0.1=60.95