Project Name: Bank of China, Zhengzhou Longxi BranchHeat Pump Unit Noise Reduction

Governance Measures: Soundproof Enclosures, Soundproof Doors, Exhaust Noise Suppressors, Noise-reducing Louvers, etc. 

Governance Result: Through the aforementioned technical measures, the noise level in the area has reachedUrban area environmental noise standard GB3096-93 Second-level standard

1. Air Noise Reduction: To effectively reduce the aerodynamic noise of fans, the installation of a silencer is recommended. A cylindrical silencer can be mounted on top of each fan, or a whole-box silencer can be installed on the top of the heat pump unit's housing.

2. Compressor Noise and Vibration Reduction: The heat pump unit compressor is mounted on the lower steel frame of the housing. Some compressors have a cavity within the intake chamber, allowing for a partial installation of a sound-absorbing hood to enclose the compressor, which can reduce noise by approximately 8dB(A). In some cases, the heat pump unit compressor cannot be fitted with a sound-absorbing hood; the noise is emitted through the intake shield plate. In this situation, the shield plate can be removed and a noise-reducing inlet baffle added, ensuring adequate airflow while reducing the compressor noise by 4 to 6dB(A).

3. Heat dissipation treatment: The heat pump unit itself requires high ventilation and heat dissipation, often placed outdoors, on rooftops, or on the main building's skirt. It has a large noise radiation area with abundant mid-to-low frequency sounds. It is necessary to adopt measures such as noise screens, noise enclosures, sound-absorbing louvers, semi-enclosed noise rooms, and noise sheds according to the local conditions to control the noise transmission from the heat pump unit while still allowing for proper ventilation and heat dissipation.

4. Soundproofing and Vibration Reduction: The technical requirements for the installation of heat pump units stipulate that rubber shock-absorbing pads should be added to the bottom of the heat pump units. If the heat pump units are installed in places particularly sensitive to vibration, strict vibration reduction measures should be taken for the heat pump units to isolate the transmission of sound caused by the units themselves.

5. Pipeline supports and suspension points equipped with shock-absorbing facilities to isolate and reduce noise transmission along the pipeline.

6. Use vibration isolation devices at the locations where pipelines pass through walls and floors to isolate the transmission of pipeline vibrations.

7. Noise Control for Heat Pump Units: Installing vibration and noise reduction equipment on the heat pump units to isolate the noise transmission from the pump body to the ground and walls.

8. Pipeline installation includes isolation and vibration reduction systems for the pump assembly, to isolate the transmission of pipeline noise. Eliminate the propagation path of the pump vibration and noise source.

9. Add soundproof windows and doors on top of the existing ones in the equipment room to ensure aerodynamic noise transmission through the doors and windows.

10. Noise Control for Heat Pump Units: Install sound-absorbing and insulating walls at the top of the equipment room and on the walls to ensure noise waves penetrate the floor transmission.

11. Surround the heat pump unit with acoustic barriers to isolate noise transmission.