Privacy is a key feature of any office interior design and #fitout. Over the years, designers have focussed in specifying partition materials with high acoustic (db) ratings.

Though a double glazed glass system or a double skin gypsum partition with high density rockwool insulation (i.e. 75mm thickness with 40kg/m3 density) can achieve great levels of sound absorption. However, the problem comes from something that the designers usually overlook i.e. the mechanical (HVAC) design of the office.

When designing the mechanical drawings for an office, the engineers are usually unaware of the client’s requirements related to sound proofing and acoustically sensitive areas.

Hence, the mechanical engineers focus of designing the HVAC system that is most economical to produce and quick to execute on site whilst providing necessary cooling.

This leads to overlooking of the fundamental concepts of sound transmission i.e. through the return ducts.

Yes, return air from the offices is sucked into the ceiling due to the negative pressure created by the FCU (Fan Coil Units) and carries with it, the sound produced inside a well insulated/partitioned office.


Following are the important points to consider when designing the HVAC system for any Interior design and Fitout for a commercial space.

  1. Position/Install FCUs in common area.
  2. Install VAVs to control the air volume of individual offices.
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Image of a VAV (Variable Air Volume) unit that can control the air flow and temperature of an enclosed space.

3. Avoid bypassing ducting between sound sensitive offices.

4. Install cross-talk attenuators to absorb any sound transmitting to common areas.

Cross talk attenuator.
Example of a straight cross talk attenuator with acoustic lining.

5. Install return plenums instead of only grills. May or may not connect with cross talk attenuators.

6. Minimize the points of failure & water leakages from CDP by keeping lower number of FCU.

At Fajr Interiors, our interior design team works closely with the engineering department to painstakingly study the furniture layout and the interior design requirements for each project. Thus, making sure the MEP design is very well aligned with our client’s requirements and fulfills all engineering parameters prior to commencement of the fitout.

To discuss an #InteriorDesign project, feel free to contact us on or visit our website

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