AC Replacement in Melbourne

The cooling season in Melbourne is short, and that is what makes the age of an air conditioner misleading. A system that cools for ten or twelve weeks a year puts on a fraction of the running hours the same model accumulates in the south, so it can still be cooling years after the date on the equipment suggested it would stop.

In a climate like this the refrigerant question usually arrives before wear does. A system installed before about 2010 may be charged with R-22: manufacture of new R-22 equipment stopped in 2010, and production and import of the refrigerant itself ended in 2020. A system charged with R-410A sits differently, because it stays lawful to run, service, repair and recharge, and no end date is attached to that. What did change is what a new system arrives charged with: since 1 January 2025 new residential equipment is no longer manufactured or imported factory-charged with R-410A, and what ships now is charged with R-454B or R-32 instead.

The other half of the decision is usually in the same cabinet. Where a furnace and the indoor coil share one, they almost always went in on the same day, and a changeout that replaces one and leaves the other means a contractor opens that cabinet twice. A changeout usually takes about one day, and a heating climate leaves eight months in which that day is not an emergency.

A replacement here has to suit two different summers, because Melbourne gets both of them. There are weeks when the air is heavy and the coil spends real time taking water out of it, and there are longer stretches when it is not and the job is temperature alone. A contractor sizes the equipment for the heavy weeks, which is right, and the system then spends most of its hours well below the load it was chosen for. June and September are where that shows: the temperature is mild, so the system barely runs, and the moisture has not gone anywhere — a house can sit damp in a month nobody would call hot. That is the thing to raise early, because what a system does on a mild wet day follows from what was ordered rather than from how anyone sets it afterwards.

The outdoor unit is the same box either way, so the choice between an air conditioner and a heat pump arrives with the replacement rather than later. The nights that decide it are the ones below 20°F, and there are enough of them here to plan for: a heat pump hands the work to electric resistance strips once the outdoor temperature drops far enough, and the electric bill in a cold snap follows whichever of the two is doing the work. The temperature at which the strips take over is a property of the installed system rather than of heat pumps, and a contractor can say what it will be beforehand. Ask what will be carrying the house on the coldest nights — strips, an existing furnace, or a second stage — and put the question before the contractor picks the model.

The sealed can with a gauge on the top is the usual first move, and it deserves an honest answer. A system low on refrigerant does cool badly, and putting refrigerant into it does make it cool better for a while — that part is real. What the can cannot do is find the hole: refrigerant is not used up, so a system that is low is leaking, and the gap between cans gets shorter every time. The cans on the shelf beside the motor oil are charged for car systems, which use a different refrigerant from a home air conditioner, and the ones with a sealant in them add a second problem to the first — sealant can set in the metering device, and it fouls the recovery machine a technician has to connect.

The hard-start kit also does what it says, which is exactly what makes it misleading. It adds starting torque to a compressor that is struggling to start, and it can carry a system through a hot weekend. What it does not do is change why the compressor was struggling: worn bearings, tired windings, a failed run capacitor, or a voltage problem at the unit. A kit that has sat on a compressor for two seasons is propping up a machine that has been reporting something for two seasons.

The filter is the exception on that shelf: it is not a repair pretending to be one, and it is worth being exact about what it reaches. A blocked filter starves the coil of air, the coil ices, and a coil that ices repeatedly sends liquid refrigerant back to the compressor — a real failure with an avoidable cause, and a clean filter removes that cause. What it does not reach is what has already happened: a compressor that has taken liquid, a coil that is iced now, or a charge that is low because the system is leaking. Ice that returns on a clean filter is not a filter problem at all, and at that point the filter has told you what it can.