| DANC Dai-Dan Active Noise Control System: Overview |
| DANC Dai-Dan Active Noise Control System |
| Active Noise Control System |
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| DAI-DAN Active Noise Control System (DANC) reduces noise of ducts for air conditioning use by emitting
a reverse-phase sound from the speaker against the sound transmitted through the ducts. This system can reduce
the low-frequency (63 to 250 Hz) noise by 10 to 20 dB. |
 Overview of the System
General passive noise reduction system absorbs the energy of noise by means of nose absorbing material like glass wool and
effective to reduce middle to high-frequency noise. Meanwhile, this active noise control system reduces noise by generating
a sound-wave interference through emission of reverse-phase sound wave and effective to reduce low-frequency noise.
As soon as the microphone installed inside the duct catches the transmitted noise, the speaker emits the reverse-phase sound
based on the digitally calculated value. The reverse-phase sound emitted from the speaker causes a sound-wave interference,
reverses the sound waves of the noise transmitted the ducts and reduces noise. The system is effective for long-wave noise
i.e., low-frequency noise. |
Features
Energy saving of the fan: This system has no parts protruded into the ducts and reduces resistance against air transfer,
which result is reduction of the fan load.
Flexibility of the installation: The system can be installed anywhere if a microphone and a speaker can be installed whether
on a straight duct path or on a curved one. This system can be installed additionally to the existing duct.
Safety: Fail-safe function is incorporated to prevent the system from being out of control. |
| [Patents]: No. 2544899, No. 2544900, No. 2610393, No. 2620050, No. 2923476, No.3327812
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