Linear Swirl Diffuser

Smartemp LSW-FD

Single slot side-blow diffuser with high induction multi-swirl discharge, for installation in walls or bulkheads.

Mixed flow discharge
High induction counter-rotating swirl discharge intensely mixes supply air with room air. Strong supply air diltuion with rapid discharge velocity decay produces draught-free, high momentum supply air motion for uniform temperature distribution over short or long throws. Ideal for enhanced thermal comfort (ADPI ≥ 90%).

Wall location
Air supply from walls or bulkheads.

Fixed direction
Slightly inclined discharge for extended horizontal air pattern projection above head height.

Linear face shape
Discharge chambers recessed within a horizontal slot. Diffusers may abut to form continuous linear aesthetic.

Slot face pattern
Single horizontal slot. Metal Face: Powder coated sheet metal finish.

Airflow rate

  • 28 – 300 L/s; (100 – 1100 m³/h)

Nominal sizes (discharge chamber height)

  • 45 mm
  • 65 mm

Standard lengths

  • 1 – 1.1 m

Discharge height

  • 2.6 – 6 m


  • High induction discharge, comprising 5 swirling air streams
  • 2 sizes, with linear diffuser face
  • High linear metre airflow rate of up to 300 L/(s · m)
  • Quiet operation
  • Suitable for constant airflow HVAC systems cooling to ΔT = -8 K
  • ADPI > 90% for enhanced thermal comfort
  • Galvanised metal, optionally powder coated
  • Connection to flexible or spiral duct via top entry opening (open to plenum or duct) or side entry connection box
  • Optional bottom entry version (technical drawings available on request only)
  • Optional low height version for low ceiling plenums


The SMARTEMP Linear Swirl Diffuser, type LSW-FD, is a high induction fixed discharge direction wall diffuser with a single visible slot containing a row of recessed rectangular openings that each discharge a pair of counter-rotating swirling air streams. The diffuser face is made of galvanised sheet metal, which may optionally be powder coated.

Air entry is from above (standard), or optionally from below (on request only). Each rectangular chamber discharges a pair of highly inductive, counter-rotating supply air vortices. High aspiration and intense mixing at the diffuser discharge face strongly dilute the swirling supply air streams with large quantities of room air.

High induction provides rapid temperature equalisation of each swirling supply air stream with room air, preventing cold air dumping, thereby ensuring uniform temperature distribution (no cold and draughty or hot and stagnant spots) and high comfort levels in the space. High induction also improves heating performance. High induction produces a strong increase in supply air stream mass flow rate, as well as rapid discharge velocity decay. As a result, at any given airflow rate, the WL diffuser is suitable both for long throws (due to the high momentum of each supply air stream) as well as short throws (due to the supply air streams’ low velocity).

The stable discharge characteristics of the WL diffuser operating at constant airflow over a wide range of supply air temperatures of ΔTsupply-room ≥ -8 K ensure enhanced levels of comfort over horizontal throws of ≤ 16 m with air diffusion performance (ADPI) exceeding 90%.


Product Type

Face Material

Face Pattern

Face Shape


Back to products
Category: Tag: