How does zoning work in a ducted air conditioner?
One indoor unit sits in the roof and pushes air through a network of ducts. Each duct run to a room or group of rooms has a motorised damper. The damper opens to let air in and closes to shut it off.
A zone controller, such as AirTouch 5, opens and closes those dampers. You pick which zones are on, and set a target temperature for each one from a wall panel or an app. The controller reads the room temperature and opens or closes that zone's damper to hold the setting.
Can ducted air con give every room its own temperature?
It can, but only if every room is its own zone. Zones are decided when the system is designed. A common layout puts each bedroom on its own zone and groups the kitchen, living and dining as one open space. A smaller room, like a walk in robe or study, is often joined to a neighbouring zone.
So the honest answer is that you get control per zone, not automatically per room. More zones means more dampers and more ductwork, and that affects the cost. If one room matters to you, say so early so it gets its own zone.
How does the system cope when only one zone is running?
A well designed system handles it fine. The outdoor unit is an inverter type, so the compressor and fan slow down when less cooling is needed. One closed up bedroom asks for much less than a whole house, so the system backs off.
The ducts and the indoor fan still need enough airflow to run properly, even with most dampers closed. If too much air is forced into one small duct, you get noise, whistling or poor performance. Good design deals with this through duct sizing, the zone layout and how the controller manages the dampers. Some systems keep a minimum airflow by holding another zone partly open or by using a bypass. How that works depends on the brand and the controller.
Is running one bedroom at night worth doing?
For most homes, yes. You only condition the room you are sleeping in, so you are not cooling or heating empty space. A bedroom zone running alone usually draws far less than the whole house running together.
Shut doors help. A zone does best when the room is closed off from the rest of the house. If the door is open to a hallway, the air leaks out and the system works harder than it should. Insulation, window glass and the afternoon sun on that side of the house also change how well it holds temperature.
How does Delta Temp plan zones for a ducted system?
We start with a free site inspection before any ducted quote. We look at insulation, glass, ceiling height and orientation, then work out which rooms should be their own zone. The quote is fixed after the inspection.
For sizing, we add up the heat load of every zoned room at about 150 W per square metre, then size the system at about 70% of that total. The zones are never all running flat out at once. In practice a 12.5 kW system suits 5 zones, being 4 bedrooms plus an open kitchen, living and dining, about 120 m2 of zoned rooms. A 14 kW suits 6 zones, the same plus a media room or similar, about 130 m2.
