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THE
ENERGY
FAMILY
(C) IDM Energiesysteme GmbH
Installation instructions TERRA AL Twin
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Placement and Installation
P
lac
ement
a
n
d
In
sta
lla
tion
4.6. Noise development
The effective noise pressure level at the installation
location depends on various factors, such as room
size, absorption capacity, re
fl
ection, unobstructed
sound propagation etc. It is therefore important to
ensure that the heat pump is installed beyond the
noise-sensitive area, in so far as possible. The heat-
ing room should be furnished with a noise-insulating
door.
By a night-time reduction of the fan speed the noise
development can be lowered by up to 4 dB. The noise
pressure level at the outlet opening is furthermore
reduced by up to 4 dB if air shafts are used.
The noise pressure level can rise as a result of a
superposition of noise pressure waves if the system
is surrounded by walls. This superposition can lead to
an increase in the noise pressure level of up to 3 dB.
4.7. Sound propagation
The farther away one moves from a source of sound,
the "thinner" the noise energy gets, thus reducing the
immission values. Depending on the source type the
effect of the reduction of these immission values will
be higher or lower.
If the noise source is directly on the ground, a equal
hemispherical reduction of the noise pressure level
can be assumed. The noise pressure level at various
distances can be derived from charts. In the diagram
below you will
fi
nd the reduction rates for the noise
pressure level for TERRA AL Twin.
Due to noise re
fl
ection respectively noise absorption
depending on the on-site situation, deviations will oc-
cur.
4.8. Sound pressure level
The sound pressure level depends on the sound
power level, on the distance to the sound source and
on the type of installation (re
fl
exion-surfaces). Follow-
ing picture shows the sound radiation on a facade.
Sound power can be calculated. This calculated re-
sults can be used for
fi
rst approximitation.
