Air Conditioner Buyers Guide
This guide covers the main decisions when choosing an air conditioning system: the type of system, the capacity, and what to check before you order. It is general information only. A licensed installer should confirm the right system and size for your property before you buy.
1. Choose the system type
Split system (high wall)
One indoor unit on the wall, connected by refrigerant pipes to one outdoor unit. Suits a single room or an open-plan area. Most models are reverse cycle, so they heat as well as cool.
Multi-head split system
One outdoor unit running two or more indoor units. Useful when you want to condition several rooms but have limited space outside for outdoor units. Each indoor unit is controlled separately.
Ducted system
A concealed indoor unit, usually in the roof space or under the floor, delivers air through ducts to ceiling or floor outlets. Suits whole-home or multi-room comfort, and zoning lets you choose which rooms are conditioned.
Cassette, under ceiling, floor console and bulkhead units
Cassettes sit flush in the ceiling and spread air in several directions. Under ceiling units mount on the ceiling surface. Floor consoles sit low on the wall and suit rooms without space for a high wall unit. Bulkhead units are concealed in a bulkhead with short ducts to nearby grilles.
Gas ducted heating and evaporative cooling
Gas ducted heaters heat the whole home through ducts, and must be installed by a licensed gasfitter. Evaporative coolers cool by passing outside air through wet pads. They work best in dry climates and need windows or doors left partly open.
2. Work out the capacity
Air conditioner capacity is measured in kilowatts (kW), with separate figures for cooling and heating. The right capacity depends on more than floor area. Ceiling height, insulation, window size and direction, shading, the number of people and the local climate all change the load.
As a rough starting point for a well-insulated room with a standard 2.4 m ceiling:
| Room area | Typical starting capacity |
|---|---|
| Up to about 20 m² | 2.0 to 2.5 kW |
| About 20 to 30 m² | 2.5 to 3.5 kW |
| About 30 to 45 m² | 3.5 to 5.0 kW |
| About 45 to 65 m² | 5.0 to 7.1 kW |
| Over 65 m² or several rooms | Larger split, multi-head or ducted system |
These figures are a guide only. Rooms with high ceilings, large west-facing windows, poor insulation or hot climates usually need more capacity. A system that is too small runs flat out without reaching the set temperature, while one that is too large cycles on and off and controls humidity poorly. Ask a licensed installer to do a heat load calculation for your site.
3. Compare the details that matter
- Energy efficiency: compare the Energy Rating Label and the rated input power in the manufacturer's specifications. More efficient models usually cost more to buy and less to run.
- Heating performance: if you need heating in cold weather, check the heating capacity and the lowest outdoor temperature the model is designed to operate in.
- Noise: check the indoor and outdoor sound levels, especially for bedrooms and units close to neighbours.
- Controls: some models include Wi-Fi control or it is available as an optional adaptor. Check the product page.
- Warranty: manufacturer warranty terms vary by brand and product. See Warranty Information.
4. Plan the installation
- Refrigerant systems must be installed by an ARC-licensed technician, gas heaters by a licensed gasfitter, and electrical work by a licensed electrician.
- Confirm the indoor and outdoor unit locations, pipe run length, drainage and electrical supply with your installer.
- Check what installation materials you need, such as pair coil, brackets, ducting or condensate pumps. We list these in our components range.
5. Before you order
- Check delivery for your postcode and the delivery charge at checkout. See our Shipping and Delivery Policy.
- Read our Returns and Refunds Policy. Change-of-mind returns attract a 15% restocking fee, so confirm the size and model first.
- If you are unsure, contact us with the room size and your installer's advice and we will help you compare models.
Questions? Phone +61 473 575 383 or email sales@achub.com.au.