Deep Dive into the AS2047 Air Infiltration Test: Why Airtightness Matters

When people think about window testing, they usually picture shattering glass or heavy rain spray. However, one of the most consequential aspects of window validation happens quietly, without any water or broken components: the AS2047 Air Infiltration Test.

As Australia targets sustainable, energy-efficient building envelopes, airtightness has moved from an afterthought to a core performance requirement. In this technical deep dive, we explore how the air infiltration test is executed, how it is scored, and why it is critical for modern sustainable architecture.

How the AS2047 Air Infiltration Test Works

The air infiltration test measures the volume of air that leaks through a completely closed window assembly over a set time period.

1. The window or door specimen is installed tightly onto a pressurized testing chamber.
2. The testing machine applies a constant, uniform air pressure of 75 Pascals (Pa) to the exterior face of the window (simulating a consistent breeze against the building).
3. Precision airflow meters calculate the total leakage rate in liters per second ($\text{L/s}$).
4. This total leakage value is divided by the total surface area of the window unit ($\text{m}^2$) to establish the final metric: $\text{L/s/m}^2$.
5. The process is then reversed to apply negative pressure (suction) to ensure the window seals operate properly in both directions.

Passing Criteria: Air-Conditioned vs. Non-Air-Conditioned

AS2047 divides buildings into two operational environments with distinct allowable limits:

                  ┌──────────────────────────────┐
                  │ AS2047 Air Infiltration Test │
                  └──────────────┬───────────────┘
                                 │
         ┌───────────────────────┴───────────────────────┐
         ▼                                               ▼
[ Air-Conditioned Buildings ]               [ Non-Air-Conditioned ]
 Max Limit: 1.0 L/s/m²                       Max Limit: 5.0 L/s/m²
 (Stricter sealing required)                 (Standard residential)

To achieve an “Air-Conditioned” rating, the window must demonstrate exceptional sealing capability, allowing minimal draft bypass.

Why Airtightness Matters for Your Project

1. Meeting 7-Star NatHERS & NCC Section J Targets

A building envelope can feature high-end insulation, but if the windows leak air, energy efficiency plummets. Drafty windows cause conditioned indoor air to escape, forcing HVAC systems to work harder. Certified low-infiltration windows are essential to hitting the 7-star energy efficiency ratings mandated under the updated National Construction Code (NCC).

2. Acoustic Performance & Noise Reduction

There is a direct correlation between air infiltration and sound transmission. If air can pass freely through a window assembly, acoustic vibrations (traffic noise, sirens, wind howling) will follow. High-integrity seals that ace the AS2047 air infiltration test also provide superior sound dampening for urban projects.

3. Dust, Pollen, and Moisture Control

Infiltration testing ensures that dust, regional allergens, and airborne moisture stay outdoors. Effective sealing safeguards internal indoor air quality (IAQ) and eliminates micro-drafts that can introduce hidden moisture into wall frames, preventing mold growth.

Engineering for Low Infiltration

Low air leakage requires high-precision manufacturing tolerances. At MEICHEN Windows & Doors, we utilize multi-point locking hardware that pulls window sashes tight against structural frames, combined with premium, UV-stable EPDM continuous compression gaskets. Our window systems comfortably exceed the strict air infiltration standards for air-conditioned spaces.

Contact our technical sales team to learn more about how our low-infiltration systems can optimize your building’s thermal performance.