Arthur Street Building

TYPE: Corporate Office


When it opened for occupancy in 2008, the Arthur Street luxury office high rise in North Sydney, Australia was designed to be high-performance. Unfortunately, the building never came close to meeting expectations. Tenants were never happy with the AC, and energy costs were well beyond initial design levels. So when it was time to sell the iconic building, its owners knew they had to resolve the problem.

The Problem

Consulting engineers told the owners that without sealing leaks in the ductwork, the building’s state-of-the-art chilled beam system would never operate efficiently. However, the owners were told that manual duct sealing would cost $3 million and include a year of disruptive work — and so they put off the project until the impending sale required an immediate fix.

Project Overview
Building Arthur Street Building
Location North Sydney, Australia
Aeroseal Contractors Clean-Air Australia Pty Ltd.
Contract Engineer Seed Engineering
Goal Reduce energy costs, Improve AC effectiveness
Before Aeroseal 427 CFM of leakage
After Aeroseal 15 CFM of leakage
Results Certified 5-Star rated for building performance; 10% the cost of manual sealing. 18 month estimated ROI

The Aeroseal technology allowed us to seal the entire 23-story duct system in a matter of days, without disrupting the existing tenants. We estimated that a job that was once cost-prohibitive would now pay for itself in less than two years. We now recommend Aeroseal to most of our clients. We have yet to find a building that meets today’s standards for duct leaks and, in most cases, Aeroseal is the only sensible, cost-effective means of fixing the problem.

Rob Lord
Managing Director
Seed Engineering

The Solution

It was then that the engineers learned about Aeroseal duct sealing technology. By sealing from the inside of the duct system, workers avoided the usual disruptions that come from the demolition typically required to access and re-seal ducts. After a highly successful trial project, the Aeroseal team at Clean-Air was given the green light to seal the ducts throughout the entire building.

Clean-Air mapped out the project and coordinated efforts to minimize tenant disruption. They had two months to seal the ductwork that served 23 different air handling units – including 20 vertical shafts and hundreds of square feet of horizontal ducts branching to individual offices. Working on weekends only, the Clean-Air team partitioned off the entire duct system into more than fifty individual sections. Each section was sealed using Aeroseal — showing results as they were happening.


It took Clean-Air three weekends – a total of about 9 days to effectively seal the entire duct system. The final cost was about 10% of the estimated cost for manual sealing. When finished, the building surpassed all code requirements for top ratings. By eliminating virtually all leakage, the engineers were able, for the first time, to turn down A/C power while increasing the comfort of the entire building. By calculating the cost of conditioning the “lost air” engineers estimated an ROI of fewer than two years.

To Learn More About Improving The Comfort, Indoor Air Quality, and Energy Efficiency Of Your Building
CALL: 937-428-9300 or EMAIL: