AHU Soundproofing
Air handling plant is loud, runs all day, and sits one slab away from people trying to work. The fix has to work while the building keeps running.
The problem is rarely only the wall
AHU noise arrives three ways at once: airborne through the partition, structure-borne through the slab from the unit's own vibration, and duct-borne straight down the supply into the ceiling void of the room you are trying to protect.
Treat only the wall and you will spend a great deal of money for a small improvement, because the other two paths are still open. That is the single most common reason a previous attempt did not work.
What a complete system includes
- Spring or neoprene isolation under the units, sized to the running speed
- Flexible connectors so the ductwork does not become the path
- Acoustic enclosure across all six surfaces, not just the shared wall
- Stone wool infill and a mass layer where the frequency needs it
- Acoustic access doors that still allow maintenance
- Acoustic louvres so the room can still breathe
- Duct lagging and in-duct attenuation where the path is airborne
- Every penetration sealed — and photographed before it is covered
Working in an occupied building
Most of this work happens in buildings that cannot shut down. We sequence around occupancy, agree access and shutdown windows before we start, and keep the site clean enough that the floor below does not know we are there. Tell us the constraint at audit stage and it goes into the programme.
| Untreated AHU room | 75–90 dB(A) |
| Target at the occupied space | < 45 dB(A) |
| Achievable reduction | 30–45 dB |
| Building code reference | NBC 2016 |
| Vibration assessment | ISO 2631 |
- Measure in the plant room and in the affected space
- Separate the airborne, structure-borne and duct-borne shares
- Design to the target at the occupied space, not in the plant room
- Install in agreed windows, building stays live
- Re-measure and issue the report
Asked before you ask.
Can you work in a building that is already occupied?
Yes, and most of our commercial work is exactly that. Plant rooms, DG yards and party walls are normally dealt with while the building keeps running — sequenced around working hours, with dust control and access agreed in advance. Tell us the constraint at audit stage and it goes into the programme rather than becoming a surprise later.
What do STC, IIC, NC and RT60 actually mean?
STC is how well a wall, floor or ceiling blocks airborne sound — speech, TV, traffic. IIC is the same idea for impact: footsteps, a dropped chair. NC describes how quiet a finished room is when nothing is happening in it, which is what makes a cinema feel expensive. RT60 is how long sound takes to die away inside the room.
A wall can have a high STC and the room can still sound wrong. They are different numbers, solved by different work, and a proposal that only mentions one of them is incomplete.
Do you give a report after the work is done?
Yes. We measure again after installation and hand over the readings with the as-built detail. It is the only honest way to sell acoustic work: the claim made at the start should be checkable at the end.
How much does soundproofing cost in India?
It depends on three things: how much reduction you need, how big the surface is, and whether the building is finished or still open. The same 12 dB improvement costs very differently on a bare stud wall and on a finished bedroom with a marble floor.
As a rough order of magnitude, a single residential room treated for insulation typically starts around ₹80,000, and a dedicated home theatre acoustic build usually falls between ₹3–8 lakh. AHU and DG enclosures are priced after measurement, because the target is set by law and not by taste. We give an itemised proposal, not a lump sum.
Request a plant survey.
We measure in the plant room and in the space that is complaining, then tell you which of the three paths is actually costing you the decibels.
- We call you back within one working day to understand the problem.
- We visit and measure — baseline dB levels and frequency profile, at no charge.
- You get a written proposal with performance targets, materials and costs, itemised.
Hyderabad, Telangana – 500033