Bar Displacement Diffuser

Smartemp BDF-FD

Floor displacement diffuser with trafficable bar grille.

Displacement discharge
Thermal displacement airflow, with low velocity, low turbulence supply from the diffuser face into the occupancy microclimate. Heat and contaminants rise by natural convection to stratify at a high level. Enhanced levels of indoor air quality are attained in the breathing zone.

Floor location
Air supply from the floor.

VAV dependent throw
Suitable for VAV applications. Horizontal coverage dependent upon airflow rate.

Rectangular face shape
Nominal width: 100 mm, 200 mm or 300 mm. Nominal length: 1000 mm or 2000 mm. Bespoke sizes available on request.

Slotted face pattern
Bar grille with trafficable slats.

Metal Face
Anodised or powder coated aluminium slats.

Airflow rate

  • ≤ 90 L/(s·m) [324 m³/(h·m)]

Temperature differential

  • -1 to -6 K for supply to 1.1 m height.


  • 1000 mm / 2000 mm / bespoke on request


  • 100 / 200 / 300 mm


  • 70 – 80 mm


  • Thermal displacement airflow
  • For installation in raised floors
  • Low velocity discharge for draught-free indoor air flow
  • Large supply air coverage (up to 7 m from diffuser)


The SMARTEMP Bar Displacement Diffuser, type BDF-FD, produces low velocity, low momentum displacement airflow that spreads horizontally across the floor. A perforated fixed damper, located behind the trafficable linear bar grille, produces uniform airflow with low turbulence discharge across the face.

Air oozes from the diffuser with minimal mixing, allowing the high quality supply air to flood the floor with a cool lake of high quality. A low level occupancy microclimate of enhanced indoor air quality is achieved, in which thermals from heat sources such as occupants, equipment and lights rise upwards in convective plumes, drawing in high quality replenishment air from the fresh air lake, to envelop heat sources, such as occupants, in a micro-climate of cool, high quality air. Heat and contaminants stratify at a high level in concentrated form to be removed from the space.

Due to stratification of heat, relatively large supply-to-return temperature differentials are achievable – dependent on ceiling height – despite the relatively high supply air temperature (typically 20°C), thereby minimising fan energy requirements. Energy savings also accrue from the extended free cooling range often achieved by the elevated supply air temperature, as well as from the potential to reduce outdoor airflow rates due to the the improved ventilation effectiveness of the low level displacement supply.

Product Type


Face Material

Face Pattern

Face Shape



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