A linear slot diffuser is an air-distribution device built around one or more long, narrow slots. The format is used where a linear architectural appearance is preferred, but its primary job is still HVAC air distribution.
What makes a slot diffuser “linear”?
The visible opening has a high length-to-width ratio, creating a long line rather than the wider face associated with many conventional grilles and ceiling diffusers. Linear slot products can be made in different lengths, slot widths, slot counts, frame styles and mounting configurations.
How does a linear slot diffuser move air?
In a supply application, conditioned air reaches the outlet through ductwork or a plenum and enters the room through the slot openings. Some diffuser designs include pattern controllers or other internal components that change discharge direction; others use different geometries. Those features are product-specific and should be confirmed from the product data rather than assumed from the appearance.
What does slot count mean?
Slot count is simply the number of parallel slot openings in the diffuser. It is one of the dimensions used to describe a linear slot product, but slot count by itself does not determine airflow capacity.
For the Airvian standard-size matrix, slot count is also used as a simple catalog-width convention: each slot corresponds to 2 inches of nominal catalog width. That is an Airvian catalog convention, not a universal rule for every linear slot diffuser on the market.
Supply and return are different applications
Linear-looking air devices can be built for supply, return or both, depending on the model. A supply outlet introduces air into the space; a return inlet removes room air back toward the HVAC system. Do not assume that a product can serve both functions unless its specifications say so.
What should you compare before choosing one?
- Nominal catalog size and actual product dimensions
- Slot count and slot geometry
- Supply or return application
- Mounting location and available clearance
- Plenum or duct connection requirements
- Material and finish
- Validated airflow, pressure, throw and sound data where those values matter to the HVAC design
Why tested performance data matters
Airflow and sound are not reliable conclusions to draw from appearance or nominal size alone. ANSI/ASHRAE Standard 70-2023 defines laboratory methods for determining aerodynamic performance and sound generation of air outlets and air inlets. Airvian will publish performance figures only where validated product data is available.
For selection help, read how to measure for a linear slot diffuser or browse the Airvian catalog.