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DANC Dai-Dan Active Noise Control System: Overview
DANC Dai-Dan Active Noise Control System
Active Noise Control System
Active Noise Control System
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.
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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