What Is a Split System Air Conditioner and How Does It Work?

Split system air conditioners are the most common type installed in Australian homes. If you have ever seen a rectangular unit mounted high on a wall inside a room, with a boxy unit sitting outside on the ground or mounted on a wall bracket — that is a split system. Here is how they work and what makes them the preferred choice for most Sydney households.

What Are the Two Parts?

A split system air conditioner is called a "split" because it has two separate components:

• Indoor unit: Mounted on the wall inside your room. Contains the evaporator coil and a fan that blows conditioned air into the room.
• Outdoor unit: Installed outside — on the ground, on a wall bracket or on a roof. Contains the compressor and condenser coil.

The two units are connected by copper refrigerant pipes and electrical cables that pass through a small hole in the wall. Installation typically takes two to four hours for a qualified technician.

How Does a Split System Cool a Room?

The cooling cycle uses refrigerant — a chemical that alternately evaporates and condenses to absorb and release heat:

1. Warm air from the room is drawn over the evaporator coil inside the indoor unit.
2. The refrigerant inside the coil absorbs heat from the air, cooling it.
3. The cooled air is blown back into the room.
4. The refrigerant, now carrying the heat, travels through the pipes to the outdoor unit.
5. The outdoor compressor and condenser coil release the heat to the outside air.
6. The refrigerant returns to the indoor unit to repeat the cycle.

How Does a Reverse Cycle Split System Heat?

A reverse cycle split system can reverse this process to heat your room in winter. Instead of moving heat from inside to outside, it extracts heat from the outside air (even cold air contains heat energy) and moves it inside. This is why reverse cycle heating is three to five times more energy-efficient than electric panel heaters, which simply convert electricity to heat directly.

Key Advantages of Split Systems

• Both heat and cool (reverse cycle models).
• Very quiet indoor operation.
• Energy-efficient compared to portable units.
• Precise temperature control.
• Can be controlled via remote or smartphone app.
• Can cool or heat a specific room rather than the whole house.

What Size Split System Do You Need?

Capacity is measured in kilowatts (kW). As a rough guide for Sydney homes:

• Small bedroom (up to 15 m²): 2 to 2.5 kW
• Medium bedroom (15 to 25 m²): 2.5 to 3.5 kW
• Living room (25 to 40 m²): 3.5 to 5 kW
• Open plan area (40 to 60 m²): 5 to 7 kW

Shop Split Systems at Oceania Appliances

We stock reverse cycle split system air conditioners from leading brands including Daikin, Mitsubishi, Panasonic, Samsung and LG, with free delivery across Sydney. Our team can advise on the right capacity and model for your room. Visit our Wetherill Park showroom or shop online.