How to zone ducted air conditioning in 5 simple steps

In recent times, inflation in Australia has been surging. As most people know, with inflated prices comes inflated bills - meaning that the costs of energy bills are pushed up significantly. As a result, most Aussies are generally trying to cut back on their power usage.

One way to reduce power usage significantly is by making use of a ducted air conditioner that has zoning capabilities. Zoning is where specific areas of a house (or space) are cooled, rather than the entire thing. 

Ducted air conditioning zoning works through the use of mechanical valves that are called dampers. These dampers allow a zone to be turned on or off, meaning conditioned air is provided or not provided from the supply air grille/s not zone depending on whether the zone is turned on or off. This breaks a house into specific areas and allows just these areas to be cooled (or heated).

An example of zoning is where the living room and kitchen of a house have dampers opened during the day. This means that only these rooms will be cooled and not other areas like the bedrooms because the dampers in these zones are closed. If the residents require cool bedrooms at night but won’t be using the kitchen and living room, they can switch the zoning capabilities to cool just the required areas.

This is a great way to get the most out of your air conditioning unit while using as little energy as possible.

Throughout this article, we explore five simple steps you should keep in mind when picking which areas to zone, as well as guidelines for you to follow to help choose the best ducted air conditioning for your needs.

Most zone controllers will support at least 8 zones, with some capable of doing more - that means some of the steps below will not be relevant if you have less than 8 zones.

Types of Zone Controllers

There are 3 main types / styles of air conditioner zone controllers:

  • standalone
    • these only control the zones and not the air conditioner
    • they are the cheapest type of zone control - but you will have a second control pad on your wall
    • they only support turning zones on or off
  • integrated manufacturer controller
    • these control both the unit and the zones in the same controller
    • some of these are 'smart' controllers with built in wi-fi and independent zone temperature control
  • smart controllers
    • these control both the unit and the zones in the same controller
    • they all have wi-fi and independent zone temperature control
    • most of them integrate with their own or third party home automation systems

What is "zoning" in respect to ducted air conditioning and why is it useful?

Zoning your home air conditioning system is generally a simple-to-set-up process where thermostats are added to each room or specific area in your house. These thermostats will provide a way to cool each specific area and ensure that there is no energy wasted to cool or heat certain rooms that are not being used. These thermostats control the mechanical valves or dampers that will open and close to suit your cooling needs. Older style air conditioners that don’t have zoning capabilities just switch on or off, and cool an entire area, providing much less control and more power usage.

Zoning is a useful feature that improves energy efficiency and is highly effective at reducing power bills and adding longevity to your air conditioner. This is because the air conditioning will only be working to cool specific areas - rather than an entire house - which reduces the amount of work it needs to do, and the related wear and tear.

How to zone ducted air conditioning

1) Consider the layout of your home

Length of ducts

When considering the layout of your home, the length of ducts required is often overlooked and is a very important feature to consider. When the cold air has to move a far distance, it creates pressure resistance. The longer the ducts, the more pressure that is created from the air flow and hence you reduce the volume of air you deliver.

This factor is critical because if rooms are zoned together, but there is extensive ductwork between the rooms, then air flow will be lost because of the resistance that is created. So, it’s important to ensure that zones have minimal ductwork between them, and that the layout is created in the best way possible to reduce pressure. To ensure that this is done correctly, you can consult a professional air conditioning technician who can advise the best lay out.

Additionally, it’s important to note that air conditioners should always be powerful enough to cool a specific sized area. If an air conditioner isn’t powerful enough, it won’t be able to reach the desired temperature and will consistently run in an attempt to achieve so. This will create high power bills and extensive wear and tear on your unit.  To figure out the correct wattage unit your space requires, you can enlist the help of a technician or check out our guide here.

Number of rooms

The number of rooms that you’re planning to cool is an important factor to consider when setting up zoning for your central air conditioning unit. The more rooms a house has, the more zones you will likely need to effectivity save on energy costs. This also works in reverse; a smaller house might only need 2 separate zones in order to effectively cool the house and reduce energy costs.

Size of rooms

The size of rooms should be considered when zoning a house. Unsurprisingly, a higher number of smaller rooms can be grouped together, as compared to larger rooms.

If a room is really large - or you have open plan living - it may be a good idea to give it its own zone. 

Number of Levels

Typically the indoor unit of the air conditioner is located in the roof cavity of the second storey. This means in order to air condition ground levels from a common ducted system you will need to have the means to get ducting to the ground floor - typically by means of 'Droppers' usually in cupboards and concealed ducting in bulkheads.

2) Factor in natural temperatures


While natural light is an aesthetically pleasing feature of a house - it will also allow in a significant amount of heat. These rooms take more energy to cool, so it’s advised to base your zoning set-up on how much natural light an area receives.

If an intended zone has a small amount of natural light, then it may be able to handle more rooms or a bigger area. Whereas, if the intended zone has a lot of natural light, it will be harder for the air conditioner to cool the area, so you may need to make the zone small than originally intended.  


Rooms that are insulated are much more effective at reaching the desired temperature due to the fact that it traps the cool air inside the room better and is effective at keeping outside factors such as sunlight out of the room. 

When insulated rooms are zoned together, it’s possible to reach the desired area easier than when an insulated and uninsulated zone is put together. You should keep this in mind when you are setting up your zones. It’s also a good idea to make a point of telling your zoning technician about these rooms.


Upstairs rooms are notorious for being warmer because heat rises and that they are closer to the roof - where the sun can relentlessly shine on all day. They don’t have the added cooling benefit of a second story to keep sunlight out.

It’s a good idea to zone rooms on the same storey together because they are more likely to cool down at a similar pace.

3) Determine rooms of higher priority

Sleeping areas

Rooms that are used at similar times should be zoned together. A great example of this is bedrooms. Often, residents will only use air conditioning in their bedrooms at night, so a zone can simply be flicked on (or scheduled) to cool all sleeping areas. If a bedroom is zoned with another area, like a kitchen which is used during the day, then a significant amount of extra energy will be used.

Day time areas

It’s a very good idea to have a designated zone that is specifically used during the day when you’re setting up your air conditioner. This will allow for the rooms that are used during the day to be cool and comfortable and then at night time - when these rooms are out of use - the air conditioner will switch off. Examples of these types of rooms are kitchen and living rooms.

Areas that are used at varying times

When zoning rooms, at times it is hard to choose whether a room will be used at a certain time of day, every day.

For this reason, it’s possible to make a set zone for these rooms that can be turned on just when required. This option also is great for rooms that do not get used daily and only need to be air-conditioned at a certain time, like when you’re doing your weekly washing in the laundry room.

Personal preferences

Everyone has their preferences when it comes to the temperatures they enjoy. Some people are also ways hot, and some are always cold. For example, one person might like their bedroom on an icy 16 degrees, while someone else likes to sleep with the temperature sitting in the mid-20s.

It’s important to take this into consideration when zoning rooms together because a zone will need to be set at a certain temperature and every room that’s included in that zone will receive the same level of cooling.

4) Decide which rooms to connect into a single zone

When it comes to deciding which rooms should be connected into a single zone there is no right or wrong answer. But, there are key factors to consider to maximise your air condition potential. Try to remember which rooms are being used at certain times of the day - such as bedrooms at night and living rooms and kitchens during the day. This is a great starting base for deciding which rooms will need to be cooled and which rooms aren’t at particular times of the day.

5) Choose a "constant" Zone

Some zone controllers require you to choose a constant zone. The constant zone is is an area that is always being cooled or heated and essentially provides a relief valve for the system if all zones are inadvertently closed whilst the system is running.

Smart Zone Controller's

In recent years there have been a number of manufacturer's who have come to the market with 'smart' controllers.

These systems have the following advantages:

  • inbuilt wi-fi integration
  • capability to integrate individual room sensors with individual temperature control
  • ability to change the % each zone opens - so as to be able to 'balance' the air flow so it is even between rooms
  • no requirement for a 'constant zone' as the controller can be programmed with an automatic 'relief' zone

These systems allow much better temperature control and more efficient use of the air conditioner as energy is only being used to cool areas that need it.

Additionally these systems can be integrated with / used as home automation systems - controlling among other things - light, sprinklers, garage doors etc.

We work extensively with Air Touch 4, Air Touch 2 and MyAir smart zone control systems. We can provide other brands of system if so desired.

Time to call the experts?

If you are interested in having a ducted air conditioner with zoning installed, but aren't sure where to start - it may be time to call in the experts. Our Brisbane-based air conditioning installation team are on hand to give you the assistance you need.

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