Reverse cycle air conditioning has become the go-to choice for homeowners who want year-round comfort without running separate heating and cooling systems. One unit that heats in winter and cools in summer sounds straightforward enough, but getting the best result from a reverse cycle setup depends on asking the right questions before installation day.
Whether you’re building new, renovating, or replacing an aging system, these are the questions worth raising with your installer.
How Does Reverse Cycle Heating and Cooling Work?
A reverse cycle system uses a refrigeration cycle to transfer heat rather than generate it. In cooling mode, it extracts heat from inside your home and moves it outdoors. In heating mode, the process reverses – the system draws warmth from the outdoor air (even in cold conditions) and transfers it inside.
This heat-transfer process is what makes reverse cycle so energy efficient. For every kilowatt of electricity used, a well-rated system can produce three or more kilowatts of heating or cooling output. That efficiency edge is why reverse cycle has largely replaced gas ducted heating and standalone cooling in many homes.
Understanding how the system works gives you a stronger foundation for the conversation with your installer — and helps you evaluate whether the answers you’re getting make sense.
Questions About System Sizing and Selection
“How do you calculate the right system size for my home?”
This is the most important question you can ask. A quality installer will carry out a heat load calculation rather than estimating based on room size alone. The calculation accounts for ceiling height, insulation levels, window size and orientation, shading, building materials, and local climate data.
An undersized system runs continuously without reaching the set temperature, driving up energy costs. An oversized system short-cycles (switching on and off too frequently) which creates uneven temperatures, increases wear on the compressor, and wastes energy. Both outcomes are avoidable with proper sizing.
Follow-up worth asking:“Can I see the heat load calculation, and what assumptions have you made about insulation and window performance?”
“Should I go with a split system or ducted for heating and cooling?”
Both deliver reverse cycle heating and cooling, but they suit different situations.
A split system is ideal when you want to condition one or two key rooms without major installation work. A multi-split setup connects several indoor units to a single outdoor unit, covering more of the home while still allowing independent temperature control in each room.
A ducted system distributes conditioned air through ceiling or underfloor ducts across the whole home. With zone control, you can choose which areas are active at any given time, which keeps energy use in check. Ducted systems involve more installation work and higher upfront cost, but they offer a seamless, discreet finish with no wall-mounted units visible inside.
Follow-up worth asking:“Based on my home’s layout, which option gives me the best balance of comfort and running costs?”
“Which brands do you recommend, and why?”
A trustworthy installer will explain why they recommend certain brands rather than defaulting to whatever they have in stock. Look for answers that reference performance data, warranty support, parts availability, and suitability for your local climate — not just price.
Questions About Energy Efficiency
“What energy rating should I be looking for?”
Zoned Energy Rating Labels (ZERL) provides efficiency data tailored to your climate zone. Rather than a single star rating, ZERL shows how the system performs in heating and cooling across different regions.
Ask your installer to explain how the models they’re quoting perform in your climate zone — and in both modes. A system that rates well for cooling but poorly for heating (or vice versa) won’t deliver balanced year-round efficiency.
Follow-up worth asking:“What are the estimated annual running costs for this model in both heating and cooling mode?”
“How does the system perform in very cold or very hot conditions?”
Reverse cycle systems work harder as the gap between indoor and outdoor temperatures increases. In heating mode, performance can drop when outdoor temperatures fall below 5°C, though modern systems with advanced defrost cycles and enhanced low-temperature operation handle this far better than older models.
In cooling mode, extreme heat days above 40°C can also reduce output. Ask whether the system you’re considering has been tested at temperature extremes relevant to your area, and how it performs under those conditions.
“Is a smart thermostat or Wi-Fi controller worth adding?”
Smart controllers allow you to schedule heating and cooling around your routine, adjust settings remotely, and monitor energy usage in real time. Some systems come with built-in Wi-Fi, while others offer it as an add-on.
For households with predictable routines, scheduling alone can reduce running costs noticeably. If you’re already using home automation platforms like Google Home or Apple HomeKit, ask whether the system integrates smoothly.
Questions About Installation
“Where will you position the indoor and outdoor units?”
Unit placement directly affects performance, noise levels, and aesthetics. Indoor units should be positioned for even airflow distribution across the room, away from direct sunlight and heat sources. For ducted systems, duct layout and the location of supply and return air vents influence both comfort and efficiency.
Outdoor units need adequate clearance for airflow — at least 300mm on all sides — and should be protected from direct afternoon sun where possible without restricting ventilation. In tightly spaced homes, outdoor unit noise can be a concern for neighbours, so placement matters.
Follow-up worth asking:“Will the outdoor unit meet local noise regulations at the proposed location?”
“What’s involved in the installation, and how long will it take?”
A split system installation typically takes half a day to a full day. A ducted system is a larger job — often two to three days depending on the home’s layout, roof access, and whether existing ductwork is being reused or replaced.
Understanding the scope of work upfront avoids surprises. Ask whether any electrical upgrades are needed, whether building or strata approval is required, and what the process looks like from start to commissioning.
“Do you provide a certificate of compliance?”
Licensed refrigeration and air conditioning technicians are required to supply a certificate of compliance after installation. This confirms the work meets code and that refrigerant handling has been carried out by a qualified person holding a licence. If an installer can’t provide this, that’s a clear sign to look elsewhere.
Questions About Ongoing Costs and Maintenance
“What does regular maintenance look like?”
At a minimum, homeowners should clean or replace filters every four to six weeks during peak season. Blocked filters restrict airflow, reduce efficiency, and put unnecessary strain on the system.
A professional service every 12 to 24 months covers refrigerant levels, electrical connections, coil condition, and drainage. Regular servicing extends the system’s life and helps maintain warranty coverage.
Follow-up worth asking:“Do you offer a maintenance plan, and what does it include?”
“What will this system cost to run?”
Running costs depend on the system’s capacity, energy rating, your local electricity tariff, and how you use it. A good installer should be able to give you a realistic estimate based on your usage patterns and tariff.
As a general guide, a well-rated reverse cycle split system costs roughly one-third as much to run in heating mode as an equivalent gas heater, and significantly less than portable electric heaters. That running cost advantage is one of the strongest reasons to invest in a quality system upfront.
Questions About Warranties and Support
“What warranties come with the system and the installation?”
Manufacturer warranties typically cover the system for five years, with some brands extending compressor coverage to seven years. Ask whether the warranty covers parts and labour, or parts only — a parts-only warranty can leave you paying for a technician’s time if something goes wrong.
Separately, your installer should offer a workmanship warranty covering the installation itself. This protects you against issues like refrigerant leaks, drainage problems, or electrical faults caused by installation errors.
Follow-up worth asking:“If I need a warranty claim, do I contact you or the manufacturer?”
“What happens if I need support after installation?”
Knowing who to call (and how responsive they are) matters more than most homeowners realise until something goes wrong mid-heatwave. Ask whether the installer provides ongoing support, how quickly they respond to callouts, and whether they carry common spare parts for the brands they install.
Making the Most of Your Consultation
A good installer welcomes questions, it’s a sign you’re engaged and serious about getting the right outcome. If an installer rushes the conversation, avoids detail, or can’t explain their recommendations clearly, treat that as useful information too.
Get at least two to three quotes, and compare them not just on price but on the quality of the answers you receive. The installer who takes the time to assess your home properly, explain the options, and size the system accurately is the one most likely to deliver a result you’ll be happy with for years to come.