Scaling Efficiency in New Zealand’s Largest Infrastructure Project

How Aeroseal achieved up to 99% leakage reduction for the Auckland City Rail Link (CRL)

Project: City Rail Link (CRL) – K Road & Aotea Stations
Location: Auckland, NZ
The Challenge: Inaccessible ductwork & systemic pressure loss
The Result: 99.57% peak leakage reduction; all systems brought well under compliance thresholds.

The Challenge: The “Invisible” Energy Drain

On a project as massive as the Auckland City Rail Link, ventilation isn’t just about comfort—it’s about safety and operational integrity. During the commissioning phase at the K Road and Aotea stations, several critical exhaust systems—including tunnel drainage, UPS, and emergency exhausts—showed significantly high leakage rates.

The Hurdles:

Inaccessibility: Much of the ductwork was located in ceiling voids and high-level installations where manual sealing was physically impossible.
The “Micro-Leak” Phenomenon: Initial inspections showed no major structural defects. Instead, the systems suffered from thousands of tiny gaps along the seams and joints.
Failed Traditional Methods: Conventional manual sealing (silicone and tapes) had already been attempted but failed to move the needle due to the dispersed nature of the leaks.

The Bottom Line: High leakage means fans must work harder, skyrocketing energy costs and risking non-compliance with New Zealand’s stringent building and safety standards.

The Solution: Precision Injection Sealing

LIMS deployed Aeroseal technology—a localized, internal sealing process that targets leaks from the inside out. By temporarily isolating the duct runs and pressurizing the system, we injected a mist of concentrated sealant particles. These particles stay suspended in the air until they encounter a leak, where they collide and bond to the edges, building a permanent, airtight seal.

Execution Efficiency:

Timeline: 4 days to treat multiple critical systems.
Scope: Covered duct lengths from 60m to 200m.
Versatility: Seamlessly sealed both square and round configurations (200mm to 600mm).

The Results: Data-Driven Performance

The transformation was immediate and measurable. By eliminating cumulative leakage, we restored system pressure and significantly lowered the load on the HVAC infrastructure.

Key Performance Metrics

Location	System	Initial Leakage	Post-Aeroseal	Improvement %
K Road	Toilet Exhaust	497.4 L/s	2.1 L/s	99.57%
K Road	Tunnel Drainage	459.8 L/s	4.6 L/s	98.99%
Aotea	Emergency Exhaust	322.9 L/s	5.6 L/s	98.27%
K Road	UPS Exhaust	169.4 L/s	5.4 L/s	96.81%

In every instance, leakage was brought well below the allowable threshold of ≤40 L/s.

**Before and After Report: CRL Aotea – Victoria Street West**

The Impact for Stakeholders

For the City Rail Link, the ROI of Aeroseal goes beyond just “fixing a leak.”

Reduced Operational Costs: With a near-airtight system, fans operate at design specifications, preventing the “energy bleed” associated with over-compensating for air loss.
Extended Equipment Life: Reducing the load on mechanical plants minimizes wear and tear, deferring long-term maintenance costs.
Future-Proof Compliance: As New Zealand moves toward stricter carbon-zero goals and energy efficiency mandates, Aeroseal ensures infrastructure meets the highest standards of the 2026 energy landscape.

Is your HVAC system leaking profits? Don’t let inaccessible ductwork compromise your building’s performance. Contact LIMS Aeroseal today for a technical consultation and pressure test.