Air-cooled Chillers
(A) Noise Problems
Air-borne Noise
• Noise generated from air-cooled chillers may cause disturbance to nearby residents (see Figure 3). It mainly comes from the air flow noise resulting from air turbulence at condenser caused by the blowers and compressor noise during running and on/off compression cycle of refrigerant.
Structure-borne Noise
• Vibration from an air-cooled chiller’s operation may be transmitted through building structure at points where the chiller is connected to the structure. The situation could be particularly worse when it is rigidly fixed to the structure without proper isolation (see Figure 4). The vibration transmitted may activate the building structure to generate noise which causes noise disturbance to residents inside the building.
(B) Practical Remedies
Air-borne Noise
• Erect a barrier or partial enclosure (see Figure 5) between the plant and nearby residential buildings so as to block the noise propagation path.
(Noise Reduction Up to 10 dB(A))
• Fabricate a complete enclosure with silencers at condenser fan outlets and at air inlets of the enclosure (see Figure 6) so as to contain and absorb the noise from the chiller when there are noise sensitive receivers all around.
• Install floating floor (see Figure 6) so as to reduce air-borne noise transmission through floor slab when the floor underneath is a noise sensitive receiver.
(Noise Reduction Up to 30 dB(A))
Structure-borne Noise
• Provide vibration isolators to support an air-cooled chiller (see Figure 7), thereby isolating it from the building structure.
(Noise Reduction Up to 20 dB(A))
