There’s a particular kind of neighbourly tension that builds up over a humming compressor. Maybe it’s your own outdoor unit copping complaints from next door, or maybe you’re the one lying awake listening to a neighbour’s air conditioner drone on past a reasonable hour. Either way, outdoor unit noise is one of the more common sources of neighbourhood friction across Melbourne, and it’s governed by rules that surprisingly few homeowners actually know exist.
Here’s what Victorian regulations actually say about air conditioner noise, how Melbourne councils enforce it, and what you can do if your own outdoor unit is louder than it should be.
Who Actually Regulates Outdoor Unit Noise in Victoria
Residential noise, including noise from air conditioners, is governed by the Environment Protection Act 2017 and the Environment Protection Regulations 2021. EPA Victoria develops the guidelines and standards, but it’s your local council that handles day-to-day enforcement and investigates noise complaints from neighbours.
Under the Act, residential noise is considered unreasonable if it happens during prohibited times and can be heard in a habitable room of a neighbouring residence, meaning bedrooms, living rooms, and dining rooms, but not kitchens, bathrooms, laundries, or storage areas. Even outside those prohibited hours, a council officer can still assess noise as unreasonable if it has qualities that make it excessive, such as unnecessarily loud volume, so ticking the “right hours” box doesn’t automatically mean you’re in the clear.
The Actual Permitted Hours for Air Conditioners
This is where it gets specific, and where a lot of homeowners get caught out, because cooling and heating are treated differently under the regulations.
Air conditioners, evaporative coolers, or split systems used for cooling fall under a separate category to heating, with prohibited times of weekdays before 7am and after 11pm, and weekends and public holidays before 9am and after 11pm.
Air conditioners and split systems used for heating are grouped together with home heaters and hot water systems, with tighter prohibited times of weekdays before 7am and after 10pm, and weekends and public holidays before 9am and after 10pm.
There’s also a useful exception worth knowing about: the prohibited times don’t apply if you’re running your air conditioner during a Department of Health heat health warning, though a council officer can still deem the noise unreasonable in that period if it’s excessively loud.
What Counts as "Excessive" Noise
Victoria doesn’t rely purely on a fixed decibel number written into legislation for residential noise, it’s more about whether the noise is audible and unreasonable in a neighbour’s habitable room during prohibited hours. That said, industry guidance commonly references a practical benchmark: air conditioner noise generally shouldn’t exceed the background noise level by more than 5 dB when measured from inside a neighbouring home. In practice, this means a unit that might sound perfectly normal in your own backyard could still be a genuine problem if it’s audible well above the ambient noise level next door once night falls.
What Happens If a Complaint Is Made
If a neighbour raises a noise complaint about your outdoor unit, the process generally follows a fairly predictable path. It typically starts with an informal conversation, moves to a formal complaint lodged with your local council if the issue continues, and can escalate to EPA involvement for serious or ongoing breaches. Councils have the power to issue formal notices requiring the issue to be fixed, and in more serious cases, can direct a unit to be relocated or even switched off altogether. None of these outcomes are cheap or convenient, which is exactly why getting placement and unit selection right from the outset matters so much more than dealing with a complaint after the fact.
Practical Ways to Reduce Compressor Noise
The good news is that outdoor unit noise is usually very manageable with the right approach, whether you’re installing a new system or trying to quieten an existing one.
Choose a quieter unit from the start. Not all compressors are created equal. Inverter-driven systems, which modulate output rather than cycling on and off at full power, tend to run noticeably quieter than older fixed-speed units. If you’re comparing options, our breakdown of leading brands like Daikin, Mitsubishi, and Fujitsu covers how different manufacturers stack up on noise levels alongside efficiency and reliability.
Get the placement right. Positioning the outdoor unit away from bedroom windows, both your own and your neighbour’s, makes a bigger difference than most people expect. Angling the unit so its fan faces away from adjoining properties, and avoiding tight corners or alcoves that can amplify sound through reflection, both help reduce how much noise actually travels next door.
Maintain adequate clearance. Keeping clear space around the unit isn’t just good for airflow and efficiency, it also reduces vibration-related noise caused by restricted airflow forcing the compressor to work harder than necessary.
Use vibration isolation. Anti-vibration mounts or pads under the outdoor unit reduce the amount of mechanical vibration transmitted through the ground or wall structure, which is often a bigger contributor to perceived noise than the fan or compressor sound itself.
Consider acoustic barriers. A well-placed acoustic fence panel or barrier between the unit and a neighbouring property can meaningfully reduce noise transmission without needing to relocate the unit entirely.
Keep up with regular servicing. A poorly maintained compressor, particularly one running low on refrigerant or with worn components, often runs louder than it should. Regular air conditioner maintenance catches these issues before they turn into a full-blown noise complaint.
If You're Already Dealing With a Noisy Unit
If your existing outdoor unit has become noticeably louder over time, that’s often a sign something’s changed mechanically, worn bearings, a failing fan motor, or refrigerant issues can all increase noise output well beyond what the unit produced when new. Rather than waiting for a complaint to force the issue, it’s worth booking a professional inspection to identify the cause and assess whether a repair, sound-dampening upgrade, or unit replacement makes the most sense.
Getting It Right From Installation
The easiest way to avoid noise issues altogether is to get expert advice on unit selection and placement before installation, rather than working backwards from a complaint. Our team factors in noise considerations as a standard part of every air conditioning installation we complete, assessing your property layout, proximity to neighbouring homes, and the best unit for genuinely quiet operation.
With over 13 years’ experience installing and servicing air conditioning systems across Melbourne, the team at Kelvinaire can help you choose and position a system that keeps both you and your neighbours happy, well within Victoria’s noise regulations.
Get in touch with Kelvinaire today for advice on quiet, compliant air conditioning installation for your home.
