Honeycomb Attenuator Book


The Honeycomb Attenuator has been designed to overcome the conflicts between natural ventilation and acoustics. The Honeycomb Attenuator allows the flow of air into and through a building, whilst reducing the passage of sound. This product can easily be incorporated into the facade of a building, allowing for natural ventilation on all sites, irrespective of environmental noise levels. The Honeycomb Attenuator can also be used to prevent cross talk issues when implementing cross ventilation to atria and corridors.

It is a flexible product and can easily be customised to comply with the criteria associated with BREEAM, BCO, HTM, BB93 and other standards.

The concepts and design specifications for the Honeycomb Attenuator have come from MACH Acoustics’ consulting experience. Our experience has shown that many current products have a limited acoustic performance, are inflexible, costly, and lacking in technical innovation. Using knowledge and insight, the Honeycomb Attenuator has been designed, developed and produced by MACH Products.

The Honeycomb Attenuator is formed from W shaped tiles manufactured from acoustic foam. These elements are then tessellated and stacked together to form the Honeycomb Attenuator. The result is a lightweight, simple and flexible product which can be fitted into bulk heads to allow for cross ventilation, or incorporated into the facade of a building to prevent noise break-in.

The key features of the Honeycomb Attenuator are its patented technology based around the honeycomb structure; its novel W shaped splitter arrangement; and the materials from which it is made. A simple manufacturing process delivers a cost effective, lightweight product, which is exceptionally flexible and therefore can be made to fit into a wide range of spaces and locations.

The Honeycomb Attenuator is designed and manufactured on a bespoke basis for individual projects. It is then tested using MACH Acoustics’ in-house test facilities, thus ensuring the  acoustic specification meets the project requirements.

Honeycomb Attenuator Book

1. Honeycomb Attenuator located under planter.
2. Honeycomb Attenuator incorporated above a suspended ceiling, providing an air exhaust path.
3. Honeycomb Attenuator used as a cross talk attenuator.
4. Honeycomb Attenuator installed under a play box.
5. Honeycomb Attenuator built into the building envelope.
6. Honeycomb Attenuator integrated under a window and above a veiling line.
7. Honeycomb Attenuator placed under a parapet roof.
8. Dogleg Honeycomb Attenuator built into the building envelope.

Honeycomb Attenuator Book
Example of cross vented building.

Honeycomb Attenuator - Facades

When naturally ventilating a building on a noisy, or moderately noisy site the acoustic design of the facade is fundamental. The ability to provide high levels of sound resistance within a limited depth is often a requirement for an attenuator in the facade of a building. Due to the honeycomb structure and the performance of the acoustic foam, the Honeycomb Attenuator is an exceptionally slim product with an outstanding acoustic performance. The size and depth of the Honeycomb Attenuator is dependent upon 2 main factors.

The free/open area specified by the M&E consultant or engineer. This governs the required face area of the attenuator and its percentage free area. A large face area will transmit a greater level of sound into a room, hence the attenuator can be made longer to compensate.

The second factor affecting the depth of the attenuator is the required level difference between the environmental noise and the internal noise limit. The greater the difference, the longer the attenuator.

To design and test the Honeycomb Attenuator, MACH Products has an in-house test rig calibrated to BS EN ISO 7235:2003. This test facility enables MACH Acoustics to design and test a range of options at any stage of a project. TheHoneycomb Attenuator is then manufactured to fit into a given location, as well as meeting the building’s ventilation and acoustic requirements.

See Chapter 2 for further details.

Honeycomb Attenuator - Cross Vent

It is generally accepted that cross ventilation is the most effective form of natural ventilation. Acoustics plays a key role in the design of a cross ventilated building as air must flow freely through the building whilst maintaining privacy across partitions. To allow cross ventilation and maintain privacy, cross talk attenuators are required within partitions adjacent to circulation spaces.

One of the key design benefits of the Honeycomb Attenuator is the simple implementation of cross ventilation through a corridor wall, while still maintaining the acoustic integrity. Furthermore, this product enables cross ventilation to vertically stacked rooms, vented through a single stack. In other words, vertically stacked spaces no longer require independent chimneys to maintain the acoustic separation between rooms, resulting in a significant recovery of floor area and a considerable cost saving.

One of the drawbacks of ventilating through the corridor wall is the requirement for an exceptionally large bulk head to accommodate large, heavy attenuators. The Honeycomb Attenuator has been designed to provide exceptional levels of cross talk separation. MACH Acoustics has undertaken extensive research to understand the required levels of acoustic separation across these partitions. Depending upon the air flow and the required level of acoustic separation, the Honeycomb Attenuator can be as slim as 600mm deep. In some instances, this is required to be increased to 1200mm, depending on the required acoustic performance.