(C) IDM ENERGIESYSTEME GMBH
Installation instructions AERO SLM
7
acoustic evaluation
Relevant place of immission
The sound immission have to be determined 0.5 m
in the middle in front of the open window (outside the
building) of the most a
ff
ected rooms, which need par-
ticular protection. According DIN 4109:1989 rooms
needing particular protection are:
- Living- and bed rooms
- Children room
- Work spaces / o
ffi
ces
- Classrooms / seminar rooms
Rating level L
r .
The rating level corresponds to an equivalent conti-
nuous sound pressure level associated with a speci
fi
c
period. The rating level is determined for both rating
periods „day“ (6 am-10 pm) and „night“ (10 pm-6 am)
separately. The operation time of the heat pump has
particular impact on the resulting equivalent conti-
nuous sound pressure level. Reducing the operation
time from 16 h per day to 4 h per day the rating level
is reduced by 6 dB(A).
But the equivalent continuous sound pressure level
alone is not su
ffi
cient in order to determine the distur-
bing e
ff
ect of noise. In general noise is perceived very
disruptive, if individual tones are clearly discernable
or the noise is irregular (impulsiveness). These noise
characteristics will be taken into account by applying
a surcharge. Additionally, daytimes with increased
sensitivity are taken into consideration. According the
„TA Lärm“ the following corrections are applied:
Information incorporation
3 or 6 dB(A)
Impulsiveness
0,3 or 6 dB(A)
Daytimes with increased
sensitivity
6 dB(A)
The rating level L
r
shall be obtained by summing the
calculated immission level and the applied correc-
tions of the speci
fi
c periods.
Finally, the determined rating level can be compared
with legal limit values (e.g. „TA Lärm“).
Standard Immission Values (SIV) - relevant place of
immission outside the building:
Territory
SIV-day
SIV-night
Industrial area
70 dB(A)
70 dB(A)
Business park,
commercial areas
65 dB(A)
50 dB(A)
Village areas and mixed
areas
60 dB(A
45 dB(A)
Settlement area
55 dB(A)
40 dB(A)
Residential area
50 dB(A)
35 dB(A)
Spa area, hospitals
45 dB(A)
35 dB(A)
In case of sound propagation inside buildings or
structure-borne sound transmission the Standard
Immission Values for the rating level of rooms nee-
ding particular protection are as following:
SIV-day:
35 dB(A)
SIV-night:
25 dB(A)
For the calculation of the rating level according „TA
Lärm“ a calculation tool is provided at the hom page:
http://www.idm-energie.com
Tips for installation of heat pumps
- Sound re
fl
ections areas should be kept as low as
possible
- The installation on acoustically hard ground and
areas with depression in the terrain should be avo-
ided
- The distance from the heat pump and the relevant
place of immission should be as big as possible
- In case of outdoor installation the blow out of air
in direction to the neighbour or relevant receiver
location should be avoided
- The air
fl
ow should not be blown directly against
walls as sound re
fl
ections lead to increased sound
pressure levels accordingly
