How Refrigerated Air Conditioning Works in Melbourne Homes

When Melbourne homeowners start shopping for air conditioning, they’ll quickly encounter the term “refrigerated air conditioning.” But what exactly does it mean, and how does it differ from other cooling options? More importantly, how does refrigerated air conditioning work to keep your Carlton terrace cool in February or your Brunswick bungalow warm in July?

Let’s break down how refrigerated air conditioning systems work, and explore why they’re one of the most popular climate control choices for Melbourne’s inner suburbs.

Table of Contents

What Is Refrigerated Air Conditioning?

Refrigerated air conditioning is the technical term for what most people simply call “air conditioning.” It’s called “refrigerated” because it uses the same refrigeration technology found in your fridge or freezer. This is a closed-loop system that moves heat from one place to another using refrigerant gas. Our guide to refrigerant gases covers this further.

In Melbourne, we use the term “refrigerated” to distinguish this technology from evaporative cooling, which works on an entirely different principle (water evaporation). This distinction matters because both types of cooling system are available in Melbourne, and each has different applications and benefits.

The beauty of refrigerated systems is their versatility. They can cool your home in summer, and they can heat your home efficiently in winter. This dual functionality makes them ideal for Melbourne’s variable climate where you need both heating and cooling throughout the year.

How Refrigerated Air Conditioning Works

At its heart, refrigerated air conditioning works on two simple scientific principles:

  1. When a liquid evaporates, it absorbs heat from its surroundings.
  2. When a gas condenses back into liquid, it releases heat. 

By controlling where these phase changes happen, refrigerated systems can move heat from inside your home to outside (cooling) or vice versa (heating).

Here’s how the refrigeration cycle works in your air conditioning system:

Step 1: Compression

The cycle starts with the compressor in the outdoor unit. The compressor pressurises refrigerant gas, which causes its temperature to rise dramatically. Consider the last time you used a hand pump for an air mattress or pool toy. You’ll notice the pump cylinder gets warm as you repeatedly compress the air inside. The refrigerant might reach temperatures of 70-80°C in this stage.

Step 2: Condensation

This hot, high-pressure gas flows through the condenser coil (also in the outdoor unit). As Melbourne’s outdoor air passes over these coils via a fan, the refrigerant releases its heat to the outside environment and condenses into a high-pressure liquid. This is why you feel warm air coming from the outdoor unit when it’s running in cooling mode.

Step 3: Expansion

The liquid refrigerant passes through an expansion valve, where the pressure suddenly drops. This is similar to what happens when you release pressure from an aerosol can, the contents become very cold. The refrigerant temperature can drop to as low as -20°C or colder.

Step 4: Evaporation

This cold, low-pressure refrigerant enters the evaporator coil in the indoor unit. As warm air from your room passes over these cold coils, the refrigerant absorbs the heat and evaporates back into a gas. The now-cooled air is blown back into your room, and the refrigerant (now carrying the heat from your room) returns to the compressor to begin the cycle again.

This continuous cycle moves heat from inside your home to outside, effectively cooling your indoor space. Modern systems can complete this cycle many times per minute, maintaining precise temperature control.

So, How Does Refrigerated Air Conditioning Also Heat?

Here’s where refrigerated air conditioning gets clever. A reverse cycle air conditioner (which describes most modern refrigerated ac systems in Melbourne) can literally reverse the refrigeration cycle. 

A four-way valve switches the direction of refrigerant flow, so the indoor coil becomes the condenser (releasing heat) and the outdoor coil becomes the evaporator (absorbing heat).

Even when it’s cold outside, like on a 5°C Melbourne winter morning, there’s still heat energy in the air. The system extracts this heat from the outdoor air, amplifies it through compression, and delivers it inside your home. This is why reverse cycle systems are actually heat pumps: they don’t generate heat like an electric heater or gas furnace, they move existing heat from one place to another.

This heat pump principle is remarkably efficient. For every unit of electricity consumed, a reverse cycle system can deliver 3-4 units of heating or cooling. This efficiency is measured by the Coefficient of Performance (COP). 

By comparison, a traditional electric heater has a COP of 1 (one unit of electricity produces one unit of heat), making reverse cycle systems up to four times more efficient for heating.

Types of Refrigerated Air Conditioning Systems

Refrigerated air conditioning technology can be delivered through different configurations, each suited to different homes and needs:

Ducted Refrigerated Air Conditioners

These use a central indoor unit (usually in the roof space) connected to an outdoor unit, with a network of ducts distributing air throughout your home via ceiling vents. Ducted systems offer whole-home climate control with discreet aesthetics, usually subtle ceiling grilles visible in each room. Zoning capabilities allow you to control different areas independently, making them energy-efficient for larger homes. Read our post on how ducted air conditioning works for more information. 

Split System Air Conditioners

These consist of one outdoor unit connected to one indoor wall-mounted unit. Split systems are ideal for cooling or heating individual rooms or open-plan areas. They’re the most common type in Melbourne homes, offering excellent efficiency and simple installation. 

Installing split system air conditioners allow you to heat or cool individual areas at your discretion. As the lowest cost way of installing refrigerated air conditioning, a split system fits with most budgets, and installing one at a time as your budget allows, doesn’t require a huge outlay. 

Multi-Split Systems

A multi split system is a fairly new concept, where one outdoor unit is connected to multiple indoor units (usually  up to 5 wall mounted heads). Each indoor unit can be controlled independently, allowing different temperatures in different rooms. Multi-split systems offer some of the benefits of ducted systems (whole-home coverage, single outdoor unit) with the flexibility of split systems (individual room control, no ductwork required). 

To learn more, read our guide to multi split air conditioners, or our comparison of multi-split systems vs ducted air conditioning.

All three types of air conditioners use the same refrigeration technology. What differs is how they distribute the conditioned air through your home.

Why Refrigerated Air Conditioning Suits Melbourne Homes

Melbourne’s climate presents challenges that make refrigerated air conditioning particularly well-suited to our needs:

Year Round Use for Our Temperature Extremes

If you live in Melbourne, you know how unpredictable the weather can be. Refrigerated systems handle both hot summer weather and cold 5°C winter mornings effectively. You get powerful cooling when needed and efficient heating during cold snaps all from the same system.

Humidity Control

Refrigerated air conditioning naturally dehumidifies as it cools. When warm, humid air passes over the cold evaporator coil, moisture condenses out of the air (this is the water you see dripping from the outdoor unit). This dehumidification makes Melbourne’s occasional humid summer days more comfortable. Evaporative cooling, by contrast, adds moisture to the air. On humid days, your evaporative cooling system isn’t likely to feel very cold at all. For a deeper comparison, read our post on evaporative cooling vs air conditioning. 

Heritage Home Compatibility

Many inner Melbourne suburbs feature heritage homes with high ceilings, large windows, and period details. Split system refrigerated units can be installed with minimal impact on these architectural features, while ducted systems can be completely concealed in roof spaces, preserving the home’s character.

Energy Efficiency and Star Ratings

Modern refrigerated air conditioners are remarkably energy-efficient. You’ll notice each system has star ratings based on the Australian climate zones. Here’s how they work:

Energy Star Ratings

All refrigerated air conditioners sold in Australia must display an Energy Rating Label showing stars (more stars = more efficient) and estimated annual energy consumption. For cooling, look for units with 5 stars or higher. For heating, check the heating star rating separately on reverse cycle units. In Melbourne, they are all pretty much the same – 1-2 stars for heating, given our cold climate zone.

SEER and SCOP

These acronyms measure Seasonal Energy Efficiency Ratio (for cooling) and Seasonal Coefficient of Performance (for heating). Modern quality systems achieve SEER ratings above 7.0 and SCOP ratings above 4.0, meaning they’re highly efficient across varying conditions.

Inverter Technology

Most modern refrigerated systems use inverter compressors that vary their speed to match the required heating or cooling load. Rather than switching on and off repeatedly (like older systems and cheap window air conditioners), inverter units run continuously at variable speeds.

This provides more consistent temperatures, quieter operation, and significantly better energy efficiency. They tend to consume 30-40% less energy than non-inverter systems.

For Melbourne homeowners, choosing a high-efficiency system matters not just for environmental reasons but for running costs, which we’ll explore next.

How Much Does Refrigerated Air Conditioning Cost to Run?

Running costs of refrigerated air conditioners depend on: 

  • Your system’s size and efficiency
  • How you use it (single room or whole home, a few hours a day or all day and night)
  • Your home’s insulation
  • Current electricity rates (currently 25-35 cents per kilowatt-hour in Melbourne).

Here are some approximate running costs of refrigerated air conditioning systems:

Split System Running Costs:

A typical 2.5kW split system draws about 0.7-0.8kW of power when running. At 30 cents per kWh, that’s roughly 21-24 cents per hour. Running it 4 hours per day through summer (90 days) would cost around $75 to $85 for the season.

Ducted System Running Costs

A mid-sized ducted refrigerated system with a power input of 5-7kW costs approximately $1.50 to $2.50 per hour to run. Using it strategically with zoning for 6 hours daily through summer, could cost $800 to $1,350 for the season.

Heating Costs

Thanks to the heat pump principle and higher COP for heating, running costs for winter heating are often similar to or slightly less than summer cooling costs, making reverse cycle systems more economical than electric oil, bar or fan heaters, and gas heating. This is why many Melbourne homeowners are choosing to take advantage of VEU rebates and replace gas heating with electric heating and cooling.

Cost-Saving Strategies

Set thermostats to moderate temperatures (24-25°C for cooling, 18-20°C for heating), use zoning on ducted systems, ensure your home has good insulation (R4.0-R6.0 ceiling batts recommended for Melbourne), and run systems during off-peak periods if you have time-of-use electricity tariffs.

What Ongoing Maintenance is Needed for Refrigerated Air Conditioners?

Refrigerated air conditioning systems are relatively low-maintenance but do require some regular care:

  • Filter Cleaning: Indoor unit filters should be cleaned monthly during heavy-use periods. Dirty filters restrict airflow, reduce efficiency, and increase running costs. You can do this yourself.
  • Professional Servicing: Annual servicing by a licensed technician ensures refrigerant levels are correct, components are functioning properly, and efficiency is maintained. This typically costs $250 to $350 depending on the unit size and accessibility. Click here to book a service.  
  • Expected Lifespan: Quality refrigerated air conditioners typically last at least 15 years with maintenance. Split systems often outlast ducted systems slightly due to fewer components, but both represent long-term investments.
  • Common Issues: Refrigerant leaks, blocked condensate drains, or compressor failures are the main problems. Regular servicing can help catch these issues early and hopefully prevent needing air conditioning repairs. 

Is Refrigerated Air Conditioning Right for Your Melbourne Home?

Now you understand how refrigerated air conditioning works, let’s sum up whether it’s right for your home in Melbourne. This technology provides:

  • Year-round climate control from a single system
  • Consistent performance regardless of humidity or weather
  • Energy efficiency through modern inverter technology and heat pump principles
  • Flexibility through various configurations (ducted, split, or multi-split)
  • Dehumidification for improved comfort during humid periods

Whether you choose a single split system for targeted cooling, multiple splits for room-by-room control, or a ducted system for whole-home comfort, you’re getting proven refrigeration technology suited to Melbourne’s variable climate.

Don’t hesitate to reach out to our Melbourne HVAC specialists who understand local climate patterns, council requirements, and the challenges of inner-city installation. We’re here to help you make the best choice for your home so you can enjoy your refrigerated heating and cooling for years to come. 

Complete our form below to book a no obligation quote, or give our office a call on 1800 407 882.