Fairair - The right advice means the right choice


Cassette system

A split system that has its indoor unit recessed into the ceiling.


A compressor is the pump that moves refrigerant from the condenser to the evaporator and back again.


A condenser is the part of an air conditioning system that expels unwanted heat. In a split system, the outdoor unit is often referred to as the 'condensing unit', as it is the outdoor unit that transfers the unwanted heat from inside to the atmosphere outside.


Dampers are movable plates that are installed in air conditioning ducts which open and close to control air flow. They are needed to change where air is distributed to in zoned systems.


Abbreviation of 'decibel', the unit for measuring sound power (volume).

dB(A) is a variation on the dB scale which takes into account human hearing response to low pressure level sound (such as that emitted by the outdoor units of air conditioning systems).

Ducted system

A ducted system is one that provides cooling to multiple rooms through a series of ducts, which are usually installed in the roof.

Evaporative system

An evaporative system provides cooling by drawing air across a series of wetted "pads". Water on the pads evaporates as the air flows over it, cooling and humidifying the air.

Sometimes also referred to as a "swamp cooler"


The evaporator is the part of the air conditioning system that absorbs heat from the space being cooled. In a split system, the indoor unit is often referred to as the 'evaporator unit', as it absorbs unwanted heat from the space being cooled and transfers it to the outdoor unit (the condenser) to be expelled.

Heat load calculation

A heat load calculation is the process a licensed contractor goes through to determine the amount of cooling required for a space. It takes into account a number of factors including the area being cooled, the physical properties of the building, its orientation, shading, insulation and local climate.


Acronym for 'heating, ventilation and air conditioning'.


Any material that slows down the transfer of heat.


An "inverter" system is one with a variable speed compressor. This means that the air conditioner can adjust its power output to suit the amount of cooling required at the time, which usually results in an energy saving.

Non-inverter systems only have two modes of operation - full power and off. As a result, they tend to cycle on and off more often to maintain a temperature (ie: it will cool to the set indoor temperature, turn off, then turn back on when the indoor temperature rises again). Air conditioners can draw a large amount of power on startup. Choosing an inverter system can reduce the number of times the air conditioner has to start up during the day.

Kilowatt (kW)

A kilowatt (abbreviation: kW) is 1000 watts and is a measure of cooling capacity. It also a measure of electrical input

Kilowatt hour (kWh)

A kilowatt hour (abbreviation: kWh) is the common unit of measure for electrical energy consumption over time.

Licensed contractor

A licensed contractor is someone who holds a valid license under the Ozone Protection and Synthetic Greenhouse Gas Management Regulations 1995.

All contractors are required by Australian law to hold one of these licenses in order to handle refrigerant. Always ask to see your installer or contractor's license before they install your air conditioner.

Visit www.arctick.org to find a licensed contractor in your area.

Depending on the kind of system being installed, the contractor should also have relevant state electrical and plumbing licenses - be sure to ask your installer to provide these before they install your air conditioner.

Multi-split system

A multi-split system is a split system that has a single outdoor unit connected to multiple indoor units. It is possible to operate these systems independent of each other or at the same time. These systems are best suited to cooling multiple rooms.

Portable air conditioner

Portable air conditioners are usually small in capacity, and may be either refrigerated or evaporative. Normally the only installation they require is to be plugged into an electrical outlet - if this is the case, they can be used without needing a licensed contractor to install them.

Some portable air conditioners may require hoses to be run to an outside space (typically through a window) for water to drain and/or for heat to escape, as a result they may not be suited to all applications.


Refrigerant is used in refrigerated systems to transfer heat from the evaporator to the condenser, where it is rejected to the atmosphere.

Most residential air conditioners use either an HCFC (hydrochlorofluorocarbon) or HFC (hydrofluorocarbon) as refrigerant. HCFCs and HFCs both contribute to global warming if they are released to the atmosphere. HCFCs also contribute to ozone depletion if released to the atmosphere. As a result, it is important that air conditioners using these gases are installed properly to ensure that the gas remains inside the system.

By law, only a licensed contractor is allowed to handle these refrigerants - always use a licensed contractor to install your air conditioner.

Refrigerated system

A refrigerated system uses a refrigerant to take heat from the indoor space and reject it outside.

Reverse cycle

A reverse cycle system is one that can change modes to provide either heating or cooling.

Split system

A split system is one which has two separate units making up the system - an indoor unit (evaporator), which is located inside the space being cooled, and an outdoor unit (condenser) where the heat from inside is rejected. The two units are connected by pipes which carry refrigerant.

Swamp cooler

See evaporative system


The unit of measure for power (cooling or electrical).

Zoned system

A zoned system is usually a ducted system or a multi-split system where different areas of the home have been divided into "zones", and the zones can be controlled independently of one another (ie: can cool one zone independent of the others, or set different temperatures in different zones).