Tailoring rooftop HVAC system noise breakout solutions; includes heavy duty, to lightweight options suitable for outdoor applications.

The new Harold Park precinct in inner-city Glebe, Sydney has recently undergone a radical transformation. The former Rozelle tramsheds and surrounding area are now to enter a new era as a world class, industrial styled venue including several modern apartment buildings. As a Sydney icon, developers and local council were conscious of preserving the historical significance of the site while still focusing on sustainability and providing the highest quality standards of modern living.

Three of the luxury apartments needed an aesthetically viable solution to prevent breakout noise from the air conditioning units and ventilation systems on top of the buildings. After issues recognised with the first building, Pyrotek consultants stepped in with a more efficient solution for the remaining two Harold Park apartments. 

Initially Pyrotek recommended Viterolite® 300, durable outdoor sound absorbing tiles. The proposed solution was to seal off the HVAC systems by installing the tiles along the perimeters of the rooftop providing an enclosed wall. 

After discussion with Mirvac and subcontractors, it was clear an urgent solution was a factor to meet onsite deadlines. As such Pyrotek offered a Sorberpoly 2D GC system in order to address the breakout noise issues. The system ticked every box in terms of look, noise absorption, durability, cost efficiency and delivery.

An extremely lightweight, compressible polyester acoustic insulation, Sorberpoly 2D provides superior sound absorption and thermal insulation combined with exceptional durability, even in outdoor applications. Made from 100% polyester fibres, the product is recyclable and will not emit odours as it contains no resin binders. Sorberpoly 2D is completely non‐toxic, contains no irritants, features self‐draining hydrophobic properties that repel water and eliminate mildew smells, and won’t degrade or crumble over time. The glasscloth (GC) facing was ideal to complement the high performance and finish off the look and requirements for the rooftop application.

Pyrotek’s 30+ year reputation for providing the highest quality acoustic soundproofing products, along with previous working relationships, gave Mirvac the confidence to specify Sorberpoly 2D GC for the final two Harold Park apartments. 

Additionally, Mirvac specified Soundlag® 4525C pipe lagging for the buildings’ waste water pipes and duct work, to reduce disruptive noise transfer between apartments. Featuring 25mm flexible convoluted foam and a fire retardant aluminium facing, Soundlag 4525C is easily cut to size and taped around even the smallest pipes to create a noise‐tight seal.

The supply of 130 Sorberpoly 2D GC panels were fixed to the frame surrounding the HVAC units, facing the noise source. Capped with a u‐cap to send rainwater away from the material as a precautionary measure for the longevity of the product. An air gap behind the polyester further improves noise containment.