Evaporative to Refrigerated Changeover
Changing over is the job people ask us about most, and it is the one nobody locally seems willing to answer plainly: what does it actually take, and what does it actually cost, to stop running evaporative cooling and start running refrigerated. The honest answer has several moving parts, and anyone giving you a firm figure over the phone without seeing your roof space is guessing. Here is how the job works, what drives the price, and — because it is not the right move for every house — when we would tell you to stay with evaporative instead.
Why people change over
Evaporative cooling works by drawing outside air across wet pads and pushing it through the house. In genuinely dry heat it performs well and costs very little to run. The limitation is humidity — as moisture in the air rises, the amount of cooling evaporation can deliver falls away, and on a humid forty-degree day the system ends up circulating warm damp air. That is almost always the moment households in this region start looking at refrigerated.
The second reason is how evaporative has to operate. It needs windows or vents open to exhaust the air it pushes in, which is at odds with security, dust, smoke and keeping a modern sealed house sealed.
When we would tell you not to bother
If your evaporative system copes on the days that matter and the open-window requirement does not trouble you, changing over is a large amount of money for a benefit you will feel on a handful of afternoons a year. Where a unit is simply old, a like-for-like evaporative replacement costs a fraction of a changeover and is often the better decision. We install evaporative systems too, so we have no particular reason to push you off one.
The changeover case is strongest when the system consistently fails you during heatwaves, when the house is modern and sealed, or when a tired gas furnace means you are facing two replacements anyway.
What the job involves
The old unit is disconnected and removed, its water supply capped, and the roof penetration properly closed and made weathertight. Existing ductwork is assessed run by run and retained, modified or replaced on its merits. The indoor fan coil is installed in the roof space, the outdoor condenser on a level pad with proper airflow clearance, and refrigerant lines and condensate drainage run between them. The system is then charged, commissioned and balanced across outlets, with zoning configured where fitted.
Refrigerant work is carried out under ARCtick-licensed trades, and any switchboard or dedicated circuit work is done by a licensed electrician.
What it costs
Fully installed ducted refrigerated systems in Australia typically run $9,000 to $18,000. Most three to four bedroom homes land in the $9,000 to $14,000 band, and complex retrofits can push past $20,000. A changeover sits at the harder end by definition, because it is a retrofit into an occupied house rather than a system installed into an open frame.
Four things move that number more than anything else: how much existing ductwork survives assessment, the capacity your house genuinely needs, how many zones you want, and whether the switchboard needs work. We quote fixed-price after inspecting all four rather than pricing on assumptions and revising later.
Common Questions
Can I keep my existing ducts?
Partially, sometimes. Evaporative ducting is generally larger and lighter than refrigerated systems want, and the outlets sit where evaporative logic put them, so returns and outlets almost always need work. Some runs and the roof-space layout can often be retained. It is the single biggest swing factor in the price, which is why we assess before quoting.
Would I be better off just replacing the evaporative unit?
Quite possibly, and we will tell you if we think so. If the ducting is sound and the system has kept the house comfortable for years, a like-for-like evaporative replacement is a much smaller job at a fraction of the cost. The changeover case is strongest when the system genuinely fails you during heatwaves, when the house is sealed and modern, or when an ageing gas furnace means you are facing two replacements anyway.
What happens to the hole in the roof?
It is closed up properly and made weathertight — tiles replaced and re-bedded, or metal roofing patched and flashed. This is included in our scope, not treated as an extra. It is also the part most commonly rushed, and a poor patch typically shows up as a leak in the first solid autumn rain rather than straight away.
How long am I without cooling during the changeover?
Most straightforward changeovers are completed in one to two days on site. Larger jobs involving substantial new ductwork, extra zoning or switchboard work can run to three. We tell you upfront whether you will be without cooling overnight in between, which matters if we are working through a hot stretch.
Related Services
We also service these areas and offer these specialised services:
Ready to Get Started?
Contact us today for your free, no-obligation quote.