AC condenser cleaning in Sydney

A small wall-hung outdoor unit for a single split system sits at the lower end of the range. A larger condenser, such as the outdoor unit of a ducted system, has more coil surface to clean and sits higher. Because the price depends on the unit in front of us, we look at it first instead of guessing over the phone.

The outdoor unit is checked as part of the free in-home inspection on every split system aircon cleaning or ducted aircon cleaning visit. If the coil is clean, we tell you so and you don’t pay for anything you don’t need.

Every split system and every ducted system has two coils. The evaporator coil inside your home absorbs heat from the room air. The refrigerant then carries that heat outside, where the condenser coil rejects it to the outside air, as the Australian Government factsheet on cleaning coils explains. On a reverse cycle system the roles swap in heating mode, but it is the same outdoor coil either way.

The coil sits behind a grille at the back or side of the unit and is made of thin aluminium fins packed closely together. Dust, leaves and grime collect on the air-intake face of those fins. Our clean uses the same professional coil cleaner we use indoors, which is pH neutral and biodegradable, worked through all the coils at the back of the outdoor unit.

The coils factsheet lists dust, dirt, pollen and moisture as the contaminants that build up on coil surfaces and reduce heat transfer. Where the unit sits makes a big difference. Daikin Australia advises keeping outdoor units clear of trees and dusty areas such as driveways, which describes a lot of Sydney side passages, balconies and courtyards.

Salt is the other Sydney problem. Many homes on the eastern and northern beaches and around the harbour have their outdoor unit exposed to sea air. Daikin treats its outdoor coils with an anti-corrosion coating because, in its words, of salt damage and atmospheric corrosion caused by such elements as sea spray. A salt film on the fins traps more dust, and rust is a sign to have the unit looked at by a technician.

• A blanket of dust on the fins: the coil should look like rows of thin metal fins. A grey or dark layer over them means air is being blocked.
• Debris around the unit: leaves, grass clippings or plants growing against the back of the unit. Mitsubishi Heavy Industries Air-Conditioners Australia recommends at least one metre of clear space around the outdoor unit.
• Struggling on hot days: when the coil can’t reject heat, the compressor works longer, so rooms take longer to cool and the system runs more.
• White crust or rust near the coast: a salt film can be cleaned; rust, bent fins or cracks should be checked by a professional service technician.

Indoor symptoms such as a musty smell, dripping or weak airflow from the indoor unit usually point to the indoor side instead. Our guide to the signs your split system needs cleaning covers those.

The same coil cleaning factsheet explains why. A dirty coil raises the condensing temperature, and a rise from 35 to 40°C can cut cooling capacity by 7 per cent while increasing power use by 16 per cent. The drop in capacity is smaller with a dirty condenser than with a dirty evaporator, but efficiency suffers badly because the compressor has to work longer.

The factsheet also notes that poorly performing coils shorten the life of other parts and can lead to compressor problems. Our article on how dirty aircon units affect airflow and power bills covers the indoor side of the same problem.

In Australia, anyone who handles refrigerant must hold a refrigerant handling licence from the Australian Refrigeration Council (ARCtick). Cleaning the coil surface does not touch the refrigerant circuit, which is why it sits with us. If your system shows an error code, our ducted aircon error codes guide explains what the common codes mean and when to call a technician.

The system is switched off before we start, and the coil is cleaned with the same pH neutral, biodegradable coil cleaner we use on indoor coils. You see the price before we start and can say no.

• Power off first: switch the system off at the controller, then turn off the isolator switch mounted next to the outdoor unit so the fan can’t start while your hands are near it.
• Clear by hand: remove leaves, cobwebs and grass from the grille and the ground around the unit, and cut plants back to keep about a metre clear.
• Gentle rinse only: a soft garden hose spray through the rear grille loosens surface dust. High pressure bends the thin aluminium fins and pushes dirt deeper.
• No panels, no tools inside: don’t remove covers, straighten fins with a knife or spray household chemicals into the unit.

The coils factsheet advises that coil cleaning be carried out by experienced service providers so the equipment isn’t damaged. A rinse helps between visits but won’t shift grime bonded to the fins, which is what our coil cleaner is for. For the indoor unit, see what you can safely DIY and what needs a professional.

Mitsubishi Heavy Industries Air-Conditioners Australia recommends a professional maintenance check at least once a year and regular clearing of leaves and branches in areas with a lot of debris. Units near the coast, under trees or beside a dusty driveway collect buildup faster, so they are more likely to need a clean at each yearly check.

A yearly indoor deep clean suits most Sydney homes, with filters washed every 1 to 3 months in heavy use. Our guide on how often to clean your air conditioner goes through usage, pets and allergies.

Extra split systems cost less: $199 + GST for the second unit and $189 + GST each for the third and fourth, with five or more quoted. If you want to keep your ducted filter, the Ducted Deep Scrub & Sanitise is $229 + GST. Every visit includes a free full home inspection, and anything extra, such as the condenser or room ducts, is quoted and approved before work starts.

Our aircon cleaning cost guide for Sydney breaks down every price and what changes it.

Tell us how many indoor units you have, whether they are split or ducted, and where the outdoor unit sits: on the ground, on a balcony, on a roof or on a wall bracket. That helps us plan access. We service all of Sydney, with a focus on the eastern suburbs, the North Shore and the Northern Beaches.