Air Conditioning systems Terminology and Explanations
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- Types of Air Conditioning systems
- The Outdoor unit
- The Indoor unit (also called Fan Coil unit)
- Control systems
- Cooling or Heating capacities Conversion table
- Air Conditioning services Quote Request
Related pages
Air conditioning Explanations and Terminology provided by The Building Centre, to help you understand and select wisely
Types of Air Conditioning systems
An air conditioning system, comprises of an Outdoor Unit, and one or multiple Indoor Units. The following are different solutions:
- A Split System
An Outdoor Unit, to which is connected one wall mounted Indoor Unit. - A Multi-Split System
Different models, to which can be connected usually two or four Indoor Units to the Outdoor Unit. Each Indoor unit requires a two refrigerant lines connection. - A VRV (variable refrigerant volume) System
The most expensive system. Almost unlimited Indoor Units that are connected to the one Outdoor Unit (or a series of then in turn connected together) where the two refrigerant lines connection is shared in a continuous path. - A Ducted System
An Outdoor Unit, to which is connected one Indoor Unit located in the ceiling space. Ducts and risers (a special duct to carry air from the ceiling to lower floors usually positioned in cupboards). The Ducts are insulated and can be either flexible or made of sheet metal or other lightweight materials. Sometimes fire resistant rating ducts need to be used.- Smart Zones - controlling
temperature in each room filled with a Smart Zone.
Optional: This clever additional system enables a different temperature in each outlet to be set and maintained, by the installation of variable motor driven dampers to each room and an overall Controller Unit. The Controller Unit varies the volume of air being sent to each room. If a room is not used, the damper can be set to LOW or OFF. It means that as different people have different temperature needs, such needs can be accommodated, as the volume of air needed is increased or decreased according to the need. Additionally if a one room faces North and another South, the Northern facing room in Summer, will be hotter and will need more air to keep it at the set temperature.
Only a Smart Zone system can achieve this with a ducted system. In Summer, rooms can only be warmer than the temperature you set at the Controller. Conversely in Winter, rooms can only be cooler than the temperature you set at the Controller. One busy zone will need to be nominated as the constant zone.
- Smart Zones - controlling
temperature in each room filled with a Smart Zone.
The Outdoor Unit
This part of the system contains the compressor which carries out the heat exchange process. Two refrigerant lines run from the Outdoor Unit to the Indoor Unit(s). The power circuit runs from the Power Boards to this Outdoor Unit. In turn, power runs from here to the Indoor Unit(s). Condensation is produced, which need to be directed to a drain or garden.
Constant Velocity Outdoor Units
In this long standing design, the compressor starts and stops as the demand for temperature conditioning is and runs at a constant speed.
Inverter Technology Outdoor Units
This new technology, instead of using alternating current (AC) motors, uses direct current (DC) motors, which have superior performance, greater energy efficiency, low running costs (usually their running costs are 33% to 40 % less) and are they are quieter inside and outside. Please Note: They also slowly turn themselves OFF when they have delivered the desired temperature, i.e. go to sleep mode, and then ON again as needed. They therefore DO NOT run all the time, hence saving more running costs, giving you lower electricity bills and minimizing the generation of Green House gases associated with the generation of electrical power. They operate, as needed, using variable speed which increases their efficiency.
The Indoor Unit (also called Fan Coil Unit)
The refrigerant lines are connected to this indoor unit, to facilitate heat transfer. A fan blows the air out. A Return Air intake, enables air to return form the room or area, where (temperature wise) it is re-conditioned. Condensate can be produced, hence it is vital to have condensate trays properly install and to which is connected a drainage line. There are different types, to enable physical and aesthetic factors to resolved.
Wall Mounted (Split, Multi-Split and VRV)
The most common solution for most split systems. A fan blows through a single outlet the conditioned air, through a louvre that can be angles and many models oscillate up and down to aid air circulation. Air returns to this unit via a Return Air section that also contains a filter that needs to be regularly cleaned. The condensate drains away, via the connection of a drainage pipe, by gravity.
Under Ceiling or Floor Mounted (Split, Multi-Split and VRV)
The fan blows the conditioned air through a single outlet the conditioned air, through a louvre that can be angles and many models oscillate up and down to aid air circulation. Air returns to this unit via a Return Air section that also contains a filter that needs to be regularly cleaned. The condensate drains away, via the connection of a drainage pipe, by gravity.
Cassette (Split, Multi-Split and VRV)
There can be different models where the fan blows the conditioned air through either two or four outlets to maximize air distribution. These units are ideally mounted in the centre of the room or area, for maximum air distribution. Air returns to this unit via a central Return Air section that also contains a filter that needs to be regularly cleaned. A pump removed the condensate.
Mounted in the Ceiling Space (Mini Ducted and Full-Size Ducted)
This unit needs to be mounted in the ceiling space and there needs to be good access to get it in the roof space .The fan blows the conditioned air to a plenum box from which insulated ducts in the ceiling, transports the conditioned air to air outlets mounted in the ceiling. Rooms are usually grouped into zones which typically can be DAY or NIGHT usage.
Air returns to this unit via a Return Air grill mounted in the ceiling, usually close to Fan Coil unit. It contains a filter that needs to be regularly cleaned. The condensate drains away, via the connection of a drainage pipe, by gravity. A condensation safety tray is usually also connected.
Other aspects of a Mini or Full-Size Ducted systems:
- Air Outlets - There are different types, styles, sizes, shapes and finished.
- Return Air Grill - Usually rectangular in shape, with a hinged 'filter' door, for easy cleaning.
- Zones - Ducts can be grouped into practical multiple Zones, to provide flexibility.
- Dampers - Zones selected are turned ON and OFF via switches to which are connected damper motors.
- Smart Zones - Optional. This uniquely enables variable room temperature settings in a ducted system. The different temperatures in each room are controlled by varying the volume of air using the dampers via a Controllers Unit & room sensors.
Control systems
These days, a user-friendly programmable digital Control Unit allows push button control (cooling or heating, ON/OFF, temperature and sometimes timer) of your environment. For Ducted systems, this will be a combined wall mounted control and thermostat. For Split, Multi-Split, VRV systems, they are infrared hand-held units, like a TV remote Control Unit.
Cooling or Heating capacities Conversion table
Where HP = Horse Power and kW = kilowatt.- 1 HP = 2.55kW
- 1.5 HP = 3.5 kW
- 2 HP = 5.1 kW
- 2.5 HP = 6 kW
- 3 HP = 7 kW
- 4 HP = 8 kW
- 5 HP = 12 kW
- 6 HP = 14 kW
- 8 HP = 16 kW
- 9 HP = 21 kW
To obtain a quote for a new or replacement Air Conditioning system simply complete Air Conditioning system Quote Request on-line, or call us on (02) 8303 0508 Monday to Friday 9am to 5pm (AEST).
