High induction circular step swirl diffuser for location in the vertical staircase or step face, especially beneath seats, in tiered auditoria and lecture theatres. 

	Location – side: Air supply from vertical step face.
	Displacement airflow: Thermal displacement airflow, with low level swirl supply from steps beneath seats. Heat and contaminants rise from occupants in convective plumes to stratify at a high level. Enhanced levels of thermal comfort and indoor air quality are attained in the occupancy micro-climate.
	VAV dependent throw: Suitable for VAV applications. Horizontal coverage dependent upon airflow rate.
	Fixed direction: Highly inductive swirl pattern parallel to vertical step face.
	Circular face shape: Round face flange.
	Radial face pattern: Visible swirl vanes.
	Plastic Face: Visible parts made of V0 fire retardent ABS, dyed grey or black. Bespoke colours available depending on quantity.

SMARTEMP Auditorium Step Swirl Diffuser CSS-FD

Airflow rate

• ≤ 16 L/s (58 m³/h)

Nominal neck sizes

• DN100
• DN125

Sound power level

• ≤ 18 dB(A)

Features

• For tiered auditoria and lecture theatres
• Location independent of seating
• Built into step front at apptroimately 100 mm height
• High induction swirl discharge breaks down discharge velocity and equalises temperature.
• Installation in wooden or concrete steps
• Connection to pressurised plenum 

Function

The SMARTEMP Auditorium Step Swirl Diffuser, type CSS-FD, is a circular swirl diffuser that produces high induction swirl discharge from the vertical step face beneath tiered auditorium seating or from a staircase. Intense mixing of room air into the supply air stream directly at the diffuser face breaks down the discharge velocity and raises the supply air stream temperature by dilution. Velocities in the ankle regions of seated occupants are low, preventing the sensation of draughts. A low level occupancy microclimate of enhanced indoor air quality is created, in which thermal plumes from occupants and other heat sources rise upwards by convection. This draws in high quality air from the occupancy microclimate, enveloping occupants in cooler, high quality replenishment air. Heat and contaminants stratify at a high level in concentrated form, to be removed from the space. The discharge pattern is parallel to the vertical step face. This air patterns stabalises the pools of cool ankle level air from cascading down the tiered steps. This is especially beneficial in steeply raked applications, such as lecture theatres and sports arenas.

The SMARTEMP Auditorium Floor Swirl Diffuser, type ASF-AD, is a high induction, low air velocity, round floor swirl diffuser for draught-free air supply with rapid air temperature equalisation from beneath auditorium or lecture theatre seating. 

Occupant thermal comfort and indoor air quality are enhanced by the provision of displacement airflow to the low level occupancy microclimate. Heat and contaminants, which rise from occupants as plumes of natural convection, accumulate in a high level stratified layer where they are removed from the space in concentrated form. Occupants are enveloped in a cocoon of high indoor air quality and enhanced thermal comfort. 

Velocities in the ankle regions of seated occupants are low, preventing the sensation of draughts. A low level occupancy microclimate of enhanced indoor air quality is created, in which thermal plumes from occupants and other heat sources rise upwards by convection. This draws in high quality air from the occupancy microclimate, enveloping occupants in cooler, high quality replenishment 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 18°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 improved ventilation effectiveness of the low level displacement supply.