Why this ducting earns its place
This converter sits inside your extraction ducting and transitions airflow from 400 mm down to 250 mm — a substantial step often needed when a main hood feeds into a narrower secondary duct or when combining multiple hood outputs into a single run. The key to a good converter is the taper — too abrupt and you get turbulence, noise, and reduced efficiency; too gradual and it becomes unwieldy to install. Combisteel's 400–250 mm converter is engineered to accelerate the airflow smoothly, so your extraction fan maintains its rated performance and the kitchen stays quiet. At 3 kg, it's heavy enough to resist vibration under continuous operation, and the aluminium construction won't degrade in the humid, greasy kitchen environment.
When you spec a ducting system, a quality converter is what separates an installation that hums quietly from one that whistles and drones. It's also where airflow efficiency is made or lost — a poor step-down kills system performance.
