Cross Ventilation
Core Applications
One of the key benefits of the Honeycomb Attenuator is its simple implementation of cross ventilation through a corridor wall, while still maintaining acoustic integrity. It also enables cross ventilation to vertically stacked rooms, vented through a single stack.
This means that vertically stacked spaces no longer require independent chimneys to maintain the acoustic separation between rooms, resulting in a significant recovery of floor area and considerable cost savings.
Design
A dog leg attenuator is one way to minimise the presence of the attenuator. Experience has shown that it may even be the only feasible method for it to fit into a building’s design. The 90 degree bend also increases the acoustic performance, allowing for an even smaller unit.
Installation
Quick, simple and adaptable installation is one of the key benefits of the Honeycomb Attenuator. The process is broadly the same for most applications. The tessellating foam is arranged into honeycomb pairs by alternating orientation, then simply slid into the duct. Since the foam is malleable and can be cut, fitting around building services or any on-site alternations can be easily achieved. Installation generally takes under one hour – saving money and construction time.
For a dog leg installation, the attenuator is placed between the wall partition, supported by the metal frame.
Case Studies
Ebbw Vale school featues a range of Honeycomb Attenuator ventilation methods, including a 90 degree dog leg style cross ventilation between floors.
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Design
A simple, clean bulkhead containing the Honeycomb Attenuator is the most common way to install and achieve BB93 performance requirements.
Its lightweight design allows the MF system to be the supporting structure but equally, a purpose built bulkhead can be used, with plasterboard, timber, metal ducting etc. Please see the inspiration section for examples of how the Honeycomb Attenuator bulkhead can be used.
Install
Quick, simple and adaptable installation is one of the key benefits of the Honeycomb Attenuator. The process is broadly the same for most applications. The tessellating foam is arranged into honeycomb pairs by alternating orientation, then simply slid into the duct. Since the foam is malleable and can be cut, fitting around building services or any on-site alternations can be easily achieved. Installation generally takes under one hour – saving money and construction time.
Rogiet Primary School features classroom cross ventilation bulkheads, which not only naturally ventilate the building, but also add to the classrooms’ visual design. The design uses a plasterboard duct, with CNC cut alphabet lettering rather than a standard architectural grill.
Download the Case Study
Cross Ventilation Inspiration
Performance
Cross ventilators are often used in combination with passive/natural air movement and a forced air system which provides heat recovery. The acoustic performance of the Honeycomb Attenuator is rated between 34 dB Dne,w and 39 dB Dne,w.
Research shows that cross talk attenuators with an acoustic resistance of 34 dB Dne,w provide an equal performance to that of a solid partition containing an acoustically rated door (30 dB Rw).
The Honeycomb Attenuator can be designed to meet BB93’s requirements of 39 dB Dn,e,w with a face area of 2m² and a free area of 50%, plus a length of 1100mm.
The Honeycomb Attenuator frequently performs better on-site. Attenuators are usually tested in accordance to BS EN ISO 10140-1:2010 however this is limited to attenuators with an opening of less than 1m2. Typically on site an attenuator has an opening in the order of 1.2m2, though this can vary in size for different applications.
Rogiet Primary School is a timber frame building located between the M4, M48 and the main rail link between Swansea and London. Such a site is acoustically challenging before even considering natural ventilation. By performing an environmental survey of the site, MACH Acoustics successfully implemented natural ventilation though careful consideration of building placement and well executed cross ventilation – meeting BB93 39Dnew requirement.