Noise and Vibration Control

Pumps, fans, chillers and other mechanical equipment are the leading source of noise and vibration in buildings. Left unchecked, that transmission shows up as occupant complaints, premature equipment wear and expensive retrofits. Acrefine’s approach to noise and vibration control is applied vibration isolation engineering for MEP equipment and building services — and it’s our busiest and most established line of work, built on close to three decades of experience with what actually holds up on site.

Why plant rooms need specialist isolation design

In taller and denser buildings, mechanical plant rooms increasingly sit close to occupied space — offices, apartments, hotel rooms directly above or beside the equipment that serves them. Transmitted noise and vibration from that equipment needs dedicated design to stay within acceptable limits, and generic isolation hardware selected without calculation routinely under- or over-specifies for the actual load and frequency involved.

Our approach

The core tools are resilient mounts and vibration isolators (springs, pads or a combination), plus spring hangers for suspended equipment and the pipework next to it. Each is selected against the equipment’s operating weight and speed and the structure it sits on: we check the isolator’s natural frequency against the equipment’s forcing frequency and set the static deflection to the floor span, following ASHRAE guidance. Getting this right isn’t a catalogue lookup; it’s a calculation against the specific equipment, its mounting and the structure.

01Equipment

Each item is checked on its own: operating weight and centre of gravity, running speed range, and the structure under it. We select the isolator type and static deflection, check the isolator’s natural frequency against the lowest forcing frequency, and decide where an inertia base is needed.

What you receive

• Isolator selection for each equipment item, with deflection and load per mount
• Layout drawings showing isolator locations and specifications
• BIM models of the selected isolators, on request

02Building services systems

Equipment is rarely the only path. Pipework and ductwork connected to isolated equipment carry vibration into the structure unless they are isolated too, with spring hangers or resilient supports along the first runs. Flexible connectors alone are not enough: they lose much of their flexibility once the system is pressurised, and the pipe still carries vibration to every hanger along the run. We design these as one system with the equipment.

What you receive

• Vibration isolation calculations for the system as a whole
• Detailed drawings for procurement and installation
• BIM models of our vibration isolation components for coordination, on request

Beyond comfort: cost and lifespan. Correctly isolated equipment is decoupled from floor resonance and from vibration coming in from neighbouring equipment, and its pipe and duct connections see less cyclic strain. That cuts wear and extends service life. Isolation does not replace balancing and alignment of the equipment itself. Getting the isolation design right at the outset is the cheaper path across the life of the equipment, not just at handover.

03Floating floors

A floating floor puts a second slab, on resilient mounts, between the equipment and the building structure. Its acoustic performance (mass, air gap, target natural frequency) is set by the project’s acoustic consultant. We select and lay out the mounts that deliver it: load per mount, spacing, deflection under the slab and the equipment on it, and the perimeter isolation that keeps the floor from touching the walls.

Standards

There’s no single mandatory code covering vibration isolation for MEP equipment; requirements are typically set by the project specification, building performance targets or the client brief. Where the specification sets an isolation requirement, such as a minimum static deflection or isolation efficiency, our selection is matched to it. Room noise criteria such as NR or NC are set and verified by the project’s acoustic consultant; our isolation design is one of the inputs to meeting them. We work to the guidance published by ASHRAE, where a member of our team is a corresponding member of Technical Committee 2.6 (Sound and Vibration), CIBSE Guide B4 in the UK and VDI 2062 in Europe.