General Assist Customer Information
My Outdoor Unit Seems Too Noisy
Understanding normal sound levels and local council noise requirements
Guidance for residential outdoor air conditioning units in Australia and New Zealand
Outdoor air conditioning units generate sound during normal operation. Whether a particular installation complies with local noise requirements depends on the unit, its operating conditions, the installation location and the rules that apply at the property.
1. Understanding noise ratings
Sound is commonly expressed in decibels using an A-weighted scale, shown as dB(A). The A-weighting reflects how the human ear responds to different frequencies.
Illustrative guide only. Perceived loudness and measured results vary with distance, surroundings and measurement conditions.
Typical operating range: Many residential outdoor units have published sound pressure levels in the approximate range of 45–60 dB(A), depending on the model, capacity and test conditions. Always refer to the product’s technical data for the applicable published value.
Published sound ratings are obtained under defined test conditions. A reading taken at a home may differ because the microphone position, distance, operating load, surrounding surfaces and background sound may not match those test conditions.
2. Council and environmental noise requirements
Noise requirements are established by the relevant state, territory, regional or local authority. Assessment methods can differ and may consider the sound level at a property boundary, at a neighbouring residence, during particular hours, or relative to the existing background sound level.
Important: A product’s published sound rating does not, by itself, confirm that every possible installation will comply with a council requirement. Compliance is site-specific and is influenced by unit selection, placement and installation design.
Some night-time limits or background-noise-based criteria can be very low. Larger systems, units installed close to neighbouring properties, or installations surrounded by reflective surfaces may require additional noise-control measures.
3. Why the same unit can sound different
| Factor | Potential effect |
|---|---|
| Distance and direction | Sound normally reduces with distance, while the discharge direction and position of the fan can influence what is heard. |
| Walls, fences and hard surfaces | Sound can reflect between surfaces and become more noticeable in narrow side passages or enclosed areas. |
| Background sound | The unit may appear more prominent at night or in a quiet neighbourhood than during the day. |
| Operating mode and load | Fan and compressor speeds can change with outdoor temperature, room demand, heating, cooling and defrost operation. |
| Mounting and vibration | Poorly supported pipework, panels, brackets or mounting surfaces can transmit vibration into the building structure. |
4. What can be done
- Confirm the sound is not abnormal. Ask the installer to check for loose panels, damaged components, pipe vibration, debris, restricted airflow or an installation fault.
- Check the mounting arrangement. The unit should be securely supported and, where appropriate, installed with suitable vibration isolation.
- Maintain clear airflow. Obstructions or recirculated discharge air can increase operating load and fan noise.
- Review the location. Relocating the unit away from bedrooms, boundaries or reflective corners may reduce the impact on neighbouring properties.
- Consider a purpose-designed acoustic solution. A screen, enclosure or barrier must maintain the clearances and airflow required by the installation instructions. Poorly designed screening can reduce performance or increase noise.
- Obtain professional assessment where required. A qualified acoustic consultant can measure the site under the applicable regulatory method and recommend suitable controls.
Do not fully enclose the outdoor unit. Any acoustic treatment must allow adequate intake and discharge airflow and must not obstruct service access or required clearances.
5. Summary
- Outdoor units generate sound as part of normal operation.
- Published product ratings are based on specified test conditions and may differ from an on-site reading.
- Council compliance is site-specific and cannot be determined from the unit rating alone.
- Placement, reflective surfaces, operating load and vibration transmission can materially affect the result.
- The installer should first check the installation, with an acoustic consultant engaged where a formal compliance assessment is required.
Support
Assist Technical Support
Australia: 1300 364 484
New Zealand: +64 4 568 8761
Australia: 1300 364 484
New Zealand: +64 4 568 8761
This information provides general guidance only. The installing contractor remains responsible for unit selection, installation location and compliance with applicable planning, environmental noise and building requirements. Refer to the current product installation instructions and the requirements of the relevant authority.