Where can an outdoor air conditioner unit be installed?

Two separate constraints apply and installers sometimes only consider the first. The unit needs airflow and service access to work properly. It also has to not create a nuisance next door, and that is where the disputes come from.

Performance considerations

• Manufacturer clearances at the front, sides and above, which are needed for airflow and are commonly ignored in tight side passages.
• Not discharging into an enclosed space or against a fence a short distance away, since the unit then recirculates its own hot air.
• Out of direct afternoon sun where possible, which improves efficiency.
• Access for servicing, since a unit boxed in behind a fixed screen becomes expensive to maintain.
• Condensate drainage that goes somewhere sensible rather than onto a path or a neighbour's land.

Noise

States regulate noise from residential air conditioners, generally with limits measured at the neighbouring property and stricter limits at night. Local councils and environment agencies handle complaints, and tribunals can order changes. Prevention is far cheaper: siting the unit away from a neighbour's bedroom window, on mounts that isolate vibration, and choosing a quieter unit.