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Sound-Attenuated AHU System Mounting

In the 2026 engineering landscape, achieving a "Silent Office" environment (typically NC 30-35) is a core requirement for Grade-A developments in Kuala Lumpur. Under the Energy Efficiency and Conservation Act (EECA) 2024, sound attenuation must be achieved without increasing static pressure to the point of violating Specific Fan Power (SFP) limits.

At EKG (Malaysia) SDN BHD, we treat the mounting of an AHU as a critical acoustic decoupling exercise. If a unit is not correctly mounted, mechanical vibrations will bypass even the best internal silencers, traveling through the building structure as "Structure-Borne Noise."

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1. The Multi-Layered Isolation Strategy

To ensure a silent and vibration-free installation, we utilize a three-tier mounting protocol:

Tier 1: Inertia Bases

For large-scale Chilled Water AHUs, we install concrete-filled steel inertia bases.

• Engineering Logic: The added mass of the concrete lowers the natural frequency of the system.

• Benefit: This makes the vibration isolation much more effective against the low-frequency thrum produced by large fans, ensuring the floor below remains undisturbed.

Tier 2: High-Deflection Spring Isolators

The inertia base (or the AHU chassis) is supported by engineered spring isolators.

• Static Deflection: We specify springs with a minimum static deflection (typically $25\text{--}50\text{ mm}$) based on the fan's lowest operating RPM.

• Vibration Efficiency: Our mountings are designed to achieve 95% to 99% isolation efficiency, effectively "floating" the unit away from the building's structural slab.

Tier 3: Flexible Connectors (Hydronic & Air)

A silent mount is useless if the pipes and ducts act as "noise bridges."

• Braided Connectors: We install stainless steel braided flexible connectors on the chilled water supply and return lines.

• Canvas/Rubber Flanges: Duct connections utilize heavy-duty flexible canvas or rubber flanges to prevent fan vibrations from entering the air distribution network.

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2. Aerodynamic Sound Control (Duct Side)

The way the AHU is mounted in relation to the ductwork determines the level of "regenerated noise."

• Laminar Transitions: We model AHU-to-Duct transitions in LOD 400 BIM with a maximum slope of 15° to 20°. This prevents air turbulence at the fan discharge, which is a primary cause of mechanical "whining."

• Integrated Silencers: Rectangular or circular sound attenuators are mounted directly to the unit's outlet. These are specified to provide the required "Insertion Loss" across the octaves where the IE5 EC Fan Wall is most active.

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3. Sterile & Statutory Requirements (EECA 2024)

Mounting is not just about noise; it is about hygiene and energy compliance.

Component	Installation Standard	Purpose
Precision Leveling	1:100 slope toward drain.	Ensures Sterile Drainage and prevents mold growth—a mandatory DOSH (JKKP) safety requirement.
Airtight Sealing	Class L1 Casing Leakage.	Prevents "energy theft" from air bypassing the sound-attenuated panels.
SFP Verification	< 1.1 kW/m^3/s	Proves that the sound attenuation has not compromised the unit's efficiency for the Energy Commission (ST) audit.

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4. Why Partner with EKG (Malaysia) SDN BHD?

• Acoustic Integrity: We are mechanical engineers who specialize in the physics of sound and vibration in tropical HVAC systems.

• Zero-Clash Modeling: We coordinate the mounting heights in the virtual world to ensure that the inertia bases, isolators, and sloped drainage all fit within your mechanical room's height constraints.

• EECA 2024 Readiness: We ensure your "Silent" unit is also a "High-Efficiency" asset, protecting your building’s Energy Intensity Label.

Is your AHU mounting engineered for silence or just "sitting" on the floor? Contact EKG (Malaysia) SDN BHD today for a specialized Sound-Attenuated Mounting assessment.

Would you like to review the vibration isolation calculations for your specific floor-to-floor height and equipment weight?