What the convention actually is
An appliance described this way draws its combustion air from outside the room rather than from it, through a dedicated duct. The reason it exists is buildings: a well-sealed modern house with mechanical ventilation does not reliably supply an open appliance with air, and an appliance and an extractor competing for the same air is a situation with an unpleasant failure mode.
On the German market the term is attached to an approval regime operated nationally, and a listing that uses it is usually referring to that. The survey behind this site found it in appliance titles as a headline feature.
An appliance built to take ducted air and an appliance approved for room-sealed operation in a particular country are not automatically the same thing, and that gap is the whole subject of this page.
What it does not promise
It does not carry across borders on its own. An approval issued under one national regime is that regime’s statement, and whether it satisfies the requirements where you live is a question for your own authority.
It does not mean an installation is safe. Whether an appliance may be installed alongside mechanical ventilation, and under what conditions, is settled by the rules where you live and by whoever inspects the installation — not by a word in a title.
And it does not remove the need for the air duct itself, which is a separate purchase with its own diameter and its own route through a wall. The wall sleeve family on this site exists partly for that reason.
The documents that sit beside it
The appliance standards test an appliance including how it takes its air, and a maker that publishes a duct diameter publishes it there.
The flue sizing calculation is affected too: an appliance taking ducted air and one taking room air are not presenting the same conditions to the chimney.
And carbon monoxide detection sits alongside all of this. This site treats an alarm as a family of its own and never as a substitute for an installation being right — which is why the alarm pages cite a detection standard rather than making a claim about the installation.
Where it appears on this site
On the appliance families where a listing uses the term, and on the wall sleeve family, which is where the duct actually gets bought.
The page exists because this is the clearest case on the site of a genuine technical property, a genuine approval regime, and a word in a listing that is read as covering both in every country. The page reports what the maker states and names the regime, and stops at the border the claim stops at.
Questions that keep arriving by post
Do I need this if my house is modern?
Air supply in a well-sealed building is exactly the case where it matters, and it is also exactly the case this site cannot rule on: what a particular building needs depends on its ventilation and on the rules where you live. The page reports what the appliance is built and approved for.
Is the air duct included?
Rarely. It is a separate article with its own diameter and its own route through a wall, and the wall sleeve family on this site is where that purchase lives. Where a maker states a duct diameter, the page prints it.
Does an alarm make up for an air problem?
No, and nothing on this site is described as making an installation safe. A detector is a detector: it reports a condition. The pages for that family cite a detection standard and say what it defines, which is a different subject from whether an appliance is getting its air.
Last reviewed 22 September 2026