The extreme climate here in South Australia and the cost of installing an air conditioner have taught us one thing that you can’t afford to waste energy or risk comfort on the wrong air conditioning system.
But between a split system vs a reverse cycle, which should you choose? A lot has been said, but having spent decades installing ACs in different residences and commercial buildings in Adelaide, here’s the short answer:
• If you need both heating and cooling in one system, reverse cycle is king.
• If you only need cooling for one room, a standard split system might be all you need.
There are situations where what you need for efficiency and power saving is both. Keep reading. In this guide, we’ll break down everything.
Table of Contents
- 1 Split System Air Conditioning
- 2 Reverse Cycle Air Conditioning System
- 3 Key Differences Between Split System vs Reverse Cycle Air Conditioning
- 4 How to Choose What’s Right for You
- 5 Not All Split Systems Are Reverse Cycle
- 6 Important Facts That Can Save You Money
- 7 When You Need to Combine Split and Reversed Air Conditioner?
- 8 Start By Measuring Your Rooms
- 9 Frequently Asked Questions
- 10 Make the Right Choice of Aircon for your Space
Split System Air Conditioning
A split system air conditioner has two bits:
• An indoor unit that blows the cold air in.
• An outdoor unit that chucks the hot air out.
It’s designed to cool a single space like bedrooms, small lounges, or your home office. A lot of Adelaide rentals use them because they’re cheaper to install and easy to run.
Example: A 2.5 kW split system in a 3×3 metre bedroom can bring the temp down from 35°C to a comfortable 24°C in under 15 minutes without guzzling too much power.
People go for the split system air conditioners because:
• It’s cheaper upfront: You can get a good brand for about $1,200 plus installation.
• Faster to install: A decent installer can have one up in half a day, no mess, no fuss.
• Lower maintenance: Wipe the filters every couple of months, and get a yearly service. That’s it.
• Energy-friendly for one room: If you’re only cooling a small space, there’s no point paying to heat or cool the whole house.
Reverse Cycle Air Conditioning System
A reverse cycle air conditioning system is a type of air conditioner that can both cool and heat your home.
It consists of five main components: the condenser, compressor, evaporator, expansion valve, and reversing valve.
In summer, it cools. In winter, it flips the refrigerant flow so the indoor unit pumps out warm air.
That means one appliance handles both jobs with no need for plug-in heaters or swapping units around.
Example: A 5 kW reverse cycle air conditioning unit in a 20 m² living room can keep it at 21°C even when it’s 7°C outside, for a fraction of the cost of running a bar heater.
Reverse cycle air conditioners are popular in SA homes as they offer:
• Year-round comfort: You don’t have to think about seasons. One remote, one system, for whatever the climate throws at your home.
• Efficient heating: Reverse cycle systems can deliver up to three times more heat energy than the electricity they use. They can achieve efficiencies ranging from 300% to 600%, meaning they can produce 3 to 6 kilowatts of heat for every 1 kilowatt of electricity used.
• Cleaner air: Many reverse-cycle air conditioners have filters that catch dust and pollen. That’s handy during the brutal hay fever season.
Better value over time: You’ll pay more upfront, but you save every winter compared to electric heaters.
Key Differences Between Split System vs Reverse Cycle Air Conditioning
Choosing between a split system and a reverse cycle air conditioner isn’t just about “cooling or heating.” The right choice can save you hundreds every year on running costs and keep your home comfortable in both Adelaide’s 40°C summer scorchers and its 7°C winter mornings.
Here’s what we’ve learnt from over two decades of installs across South Australia, broken down so you can see exactly where each system’s strength lies.
| Feature | Split System | Reverse Cycle |
| Cooling vs Heating |
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| Running Costs |
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| Upfront Price |
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| Best For |
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| Longevity |
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How to Choose What’s Right for You
When we help Adelaide homeowners decide between a split system and a reverse cycle, we look at four key things:
Your space
If it’s a small bedroom (10–20 m²), a 2.5 kW split system is enough. If it’s an open-plan kitchen-lounge over 40 m², you’ll likely need a 5–7 kW reverse cycle to keep it even.
Your climate use
Adelaide’s winter heating demand is higher than most think. If you’re running heating for 4+ hours a day in winter, a reverse cycle will pay for itself in 2–3 years compared to plug-in heaters.
Your budget
If the budget’s tight, you can start with a cooling-only split system in the main room and add a heater later. But factor in that two separate appliances may cost more long-term than one reverse cycle unit.
Your insulation
In SA homes with R4.0+ ceiling insulation, a reverse cycle’s heating efficiency jumps by up to 25%. Without good insulation, even the most efficient system will struggle and cost more to run.
Not All Split Systems Are Reverse Cycle
This is one of the most common mistakes we see. People see “split system” in a catalogue at Harvey Norman or The Good Guys and assume it will heat in winter, but cheaper models can be cooling only.
Here’s how to check before you waste your money:
• Look for “heating and cooling” or “reverse cycle” in the specs.
• Check the heating capacity in kW. If it’s missing, it’s cooling-only.
•Avoid buying purely on price. A $900 “cool-only” split system might leave you buying a separate $400 heater later.
For example, a customer in Prospect bought a bargain split system online for $950, thinking it would heat. It didn’t.
We ended up installing a reverse cycle downstairs anyway, costing them more overall than if they’d bought the right system upfront.
Important Facts That Can Save You Money
Here’s what a lot of homeowners wish they knew but only got to know until after their first installation:
Reverse cycle works better in insulated homes
If your ceiling insulation is under R4.0 rating (common in older SA homes), a reverse cycle unit can lose up to 25% of its heat output in winter through the roof.
That means higher running costs and longer heating times. Spend $1,000–$1,500 upgrading insulation, and you’ll save far more on bills over the unit’s lifespan.
Bigger isn’t always better
Installing a 7 kW unit in a 20 m² room might seem “future-proof,” but it’ll short-cycle; switching on and off too often.
This wastes electricity, wears out the compressor faster, and can leave the room humid instead of comfortable. Match kW capacity to your room size: as a guide, about 150 watts per m² for Adelaide’s climate.
Fan speed matters
A reverse cycle running on low fan overnight can keep a bedroom at 21°C for under 15¢ an hour. Cranking the fan unnecessarily doubles or triples that cost, especially in heating mode.
Filter cleaning impacts efficiency
A clogged indoor unit filter can reduce airflow by up to 30%, forcing the compressor to run longer. In Adelaide’s dusty summer months, clean filters every 6–8 weeks, not just during your annual service.
Correct outdoor unit placement is critical
Mounting the outdoor unit in full afternoon sun can reduce cooling efficiency by up to 10%. Wherever possible, install it in a shaded, well-ventilated spot with at least 30 cm clearance on all sides for airflow.
When You Need to Combine Split and Reversed Air Conditioner?
So, we had this client in North Adelaide with one of those double-storey townhouses.
Two bedrooms upstairs, both west-facing with big windows. In summer, by 4 pm, those rooms were sitting at 38°C inside, even with blinds down. You’d walk i,n and it was like stepping into an oven.
We ran the numbers and told them: cooling-only split systems upstairs will do the trick. There was no point paying for heating in bedrooms they only use at night. We went with 2.5 kW split system air conditioners in each room. The cost per unit was around $1,350 installed. On a 40°C day, they can lower the room temperature to 24°C in about 12–15 minutes without significantly increasing the power bill.
Downstairs was a different story. It’s their main living space: an open-plan kitchen, lounge, and dining area. They use it all day in winter, so we recommended a 5 kW reverse cycle air conditioner there.
The cost was about $2,500 installed. But here’s the thing: it runs in heating mode at roughly $0.25–$0.30 an hour (based on SA electricity rates and the unit’s COP rating), compared to a plug-in heater that would chew through more than double that.
This combination worked perfectly. They didn’t overspend on heating for rooms that didn’t need it, and they still got year-round comfort where it mattered most.
Start By Measuring Your Rooms
If you’re weighing up the choice between a reverse cycle vs split system, here’s the advice:
Get us to measure your rooms properly. Check to ensure your power board can handle the load. Make sure your ceiling insulation is doing its job.
Otherwise, even the best unit will be flogging itself to keep up.
That’s exactly how we do it at REQ Refrigeration and Air Conditioning. We’re proudly SA-owned with decades in the trade. We’ve installed everything from a single bedroom split system to full ducted reverse cycle systems in multi-storey homes.
Get in touch with REQ. We provide free quotes tailored to your floor plan, ensuring you don’t pay for the wrong unit or waste money on unused capacity.
Frequently Asked Questions
What’s the main difference between a split system and a reverse cycle air conditioner?
A split system air conditioner is built for one job: cooling. You’ve got an indoor unit blowing cold air inside and an outdoor unit dumping the heat outside. A reverse-cycle air conditioner looks the same but has an extra trick. It can reverse the process in winter by pulling heat from the outside air and pumping it inside. Even if it’s 2°C outside, it can still keep your lounge at a cosy 22°C.
Is reverse-cycle air conditioning more energy efficient?
For heating, absolutely. A decent reverse cycle system can give you around 3–5 kW of heat for every 1 kW of electricity it uses. Compare that to an electric bar heater that gives you 1 kW of heat for 1 kW of power. Over a South Aussie winter, that difference can knock hundreds off your bill, especially if you’re heating a big living space most nights.
Which system is better for a small room?
A 2.5 kW split system air conditioner is spot-on for most bedrooms, home offices, or granny flats up to about 16 m². It’ll cool the space in minutes in summer and, if it’s reverse cycle, warm it up on a frosty morning without costing a fortune to run.
Can a reverse-cycle air conditioner heat the whole house?
Yep, but you’ll need the right setup. You can go ducted reverse cycle for even heat in every room, or fit a few reverse cycle split systems in the key living areas and bedrooms. For example, a 14 kW ducted reverse cycle unit will comfortably warm a 4-bedroom Adelaide home all winter, using far less power than a bunch of plug-in heaters scattered around.
Which system costs more to install?
Reverse cycle split systems usually cost a bit more upfront than cooling-only models. A 5 kW cooling-only split might set you back $1,200–$2,500 installed. The reverse cycle version of the same size is more like $1,500–$3,500. But if you’re going to use the heating side for a few months every year, it’ll usually pay for itself in 2–4 winters through lower running costs.
Make the Right Choice of Aircon for your Space
If you just want to keep the bedroom cool through an Adelaide summer, a simple split system air conditioner is all you need. But if you’re sick of freezing in winter and want one system that handles both heating and cooling, reverse cycle air conditioning is the smart buy.
Before you commit, get an expert to size it right for your space and usage.
Call REQ Refrigeration on 1800 202 073 for a free measure and quote anywhere in South Australia. We’ll match you to the right air conditioning system and also help with installation so you stay comfortable and keep your bills sensible all year round.
