What size air conditioner ducts?

[torabora851]

Hi,

I'm looking for advice on ducted air conditioning. I'm planning to install a ducted system and have received a quote for a 12.5 kW system with 7 outlets and 5 zones.

My question is about the size of the ducts and air diffusers. The contractor says he will use 250mm ducts and 250mm round diffusers. From what I’ve seen in other houses, the diffusers were smaller than 250mm, and I feel that 250mm would look huge, especially with a 2.4m ceiling.

Also, one of the ducts will be routed through a built-in wardrobe to reach the ground-floor bedroom, and I’d prefer a smaller duct to save space in the wardrobe.

What do you think? 

[MitchellMc]

Hi @torabora851,

That’s a great question to raise with your installer. The 250mm ducts and diffusers are likely chosen to ensure optimal airflow, but if you’ve seen smaller ones used elsewhere, it’s worth asking whether a more compact option would work for your space. Smaller diffusers could affect airflow efficiency, but your installer should be able to advise if they can size down without compromising performance.

As for the duct running through the wardrobe, you might be able to use a smaller diameter duct or a more space-saving alternative, but again, this could impact airflow. It’s definitely worth discussing with your installer to see if there’s a practical solution that balances aesthetics, space, and performance.

Please let me know if you have any questions.

Mitchell