The easiest way to get a suitable air conditioner is to ask an air conditioning technician. There are many factors that influence the type of air conditioner you need including the size of the space, height of the ceiling, ‘heat load’ from people and items in a room, aspect and desired features. 

Size: Your first consideration is how much power do you need to cool your home or business. Air conditioner capacity is rated by BTU (British Thermal Unit) and power output in kilowatts. As smaller units are cheaper than bigger units, without suitable advice customers invariable pick a system that is too small. When undersized they don’t cool effectively and the compressor runs flat out, costing a fortune in electricity. A rough guide for air conditioning sizing is below:

• 2.4kW to 3.5kW suits most bedrooms 10m2 to 20m2
• 3.5kW to 5.6kW suits loungerooms 20m2 to 30m2
• 5.6kW to 7kW suits open-plan layouts 30m2 to 45m2
• 7kW to 9.4kw suits large open plan layouts 45m2 to 65m2

Hybrid gas ducted systems and gas fireplaces are a good way to supplement heating power.

Features: Features fall in two to main categories being air cleanliness and interconnectivity. If you smoke inside or have asthma consider models with HEPA filters, multi-stage purification and humidification control to improve internal air quality. Many customers are requesting wifi, mobile and smart home connectivity to Alexia or Google assistant. You can control their system from anywhere, set alerts, monitor your electricity and gas usage.

Efficiency: Air conditioners and heaters have a star rating on them, the more stars the better the efficiency. For units with cooling and heating functions, they will two separate star ratings. Generally, cheaper models will cost less initially but use more energy. If you plan to use your system regularly it may be worth considering a higher model or a hybrid system that is customised to your home and preferences.

Maintenance: The last major consideration is on-going maintenance, having a split system for each bedroom and the lounge room will be more maintenance than a ducted system. 4 Indoor air handlers, 4 filters and 4 compressors require more cost and maintenance than 1 ducted system. The upside of multiple units is if one system stops working, you can still cool the rest of the building with the 3 other units. Multiple or redundant systems should be considered if your business relies on good customer experience.

Portable conditioners are handy options for small rooms and temporary usage. However, they are no match for a professionally installed fixed position air conditioner.

Power: The maximum power on a portable unit is around 4.1 Kw, which is serviceable for an enclosed lounge room or master bedroom.  Given the all in one design, they need more power to get the same results. Higher rated portable units aren’t able to reach their maximum power unless you upgrading your electrical supply. All but the smallest installed air conditioners have a dedicated power circuit.  Being on on the same circuit as other appliances mean portable air conditioners easily tripped and overload breakers. Due to this electricity drawn, most people will only be able to run one unit at the time, making them impractical for larger spaces.

Running costs: In an installed system, the air handler is inside and the condenser coils are outside.  In summer heat is dumped outside whilst the inside air is cooled. The all in one design of a portable unit means the condenser coils are inside, which releases heat inside. Portable units use a fan to directs hot air outside, this lowers internal air pressure causing warm outside air to be drawn in through doors, cracks and openings. These two inherent inefficiencies mean that they are expensive to run.

Footprint & access: Portable systems need to be positioned where needed, require a powerpoint and a way to exhaust hot air outside.  Inevitably the requirements rarely coincide and you see people boarding holes in sliding doors with cardboard, running power cables everywhere or practically sit on them to get some relief. An installed air conditioning system is far more practical requiring no internal floor space or jerry-rigging.  Ducted air conditioning systems are the most discrete with the only visual impact inside being vents.

Noise: Since the compressor (motor) is in the room with you, portable systems are noisy.  This is really annoying if it is a hot night and you are trying to sleep. Split or ducted air conditioning systems locate the compressor outside, most quality systems having a whisper mode perfect for light sleepers.

Condensate: Most portable systems have a drip tray to catch condensate, which is water drawn from humid internal air.  If you forget to regularly empty the tray, your portable system will stop working. All installed air conditioning systems have a condensate drain, which directs moisture outside which is far more convenient.