Type VSD 35-Varyset

Type VSD35 Varyset

For large, variable volume flow rate ranges, stable discharge patterns even with small volume flow rates

Slot diffusers with 35 mm nominal width, with adjustable air control elements and self-powered Varyset flap for the adjustment of the active slot diffuser length

Nominal length from 900 to 1500 mm, 1 or 4 slots
Volume flow rate range 8 – 90 (l/s)/m or 29 – 324 (m³/h)/m
Diffuser face made of extruded aluminium sections
For variable volume flows
Excellent room ventilation even with small volume flow rates due to self-powered Varyset flap
Suitable for continuous linear arrangement
High induction results in a rapid reduction of the temperature difference and airflow velocity
Individually adjustable air control elements to meet individual local requirements

Optional equipment and accessories

Exposed diffuser face available in RAL CLASSIC colours
Diffuser face with extended border
End plates, end angles

VSD35-1-VA/1200 00131172_0

Installation in continuous ceilings

Application

Type VSD35 Varyset slot diffusers are used as supply air diffusers in comfort zones
They blend in inconspicuously with continuous grid ceilings and plasterboard ceilings
Excellent room ventilation even with minimum volume flow rates (V_min)
Air discharge is one-way or alternating horizontal, or alternating angled; turbulent flow (mixed flow ventilation)
High induction results in a rapid reduction of the temperature difference and airflow velocity
For variable volume flows
For supply air to room air temperature differences from –10 to +10 K
For room heights up to 4 m (lower edge of suspended ceiling)
For suspended ceilings; suitable for restricted ceiling voids due to the low overall height of the plenum box
Suitable for continuous linear arrangement

Special characteristics

Individually adjustable air control elements to meet individual local requirements
Excellent room ventilation even with minimum volume flow rates (V_min)
High induction results in a rapid reduction of the temperature difference and airflow velocity
Diffuser face has been optimised for maximum volume flow rate at low sound power levels
Suitable for continuous linear arrangement

Nominal sizes

L_N: 900, 1050, 1200, 1350, 1500 mm
Diffuser face available in intermediate sizes from 901 to 2550 mm, in increments of 1 mm

Variants

VSD35-VA-*: 1, 2, 3 or 4 slots
VSD35-VA-...: Diffuser face without extended border
VSD35-VA-.../B00: Diffuser face with extended border
VSD35-VA-...: Black air control elements
VSD35-VA-.../WW: White air control elements,

Parts and characteristics

Diffuser face with individually adjustable air control elements
Plenum box for horizontal duct connection
Self-powered Varyset flap with external balance weight
Protective cap for the balance weight
Clamp fixing
Connecting pins and alignment plates to connect and align slot diffusers for a continuous linear arrangement

Attachments

C1, C2: Two end plates
C5, C6: Two end angles

Accessories

Lip seal

Useful additions

EP: Two end plates
EW: Two end angles
To be ordered separately for continuous linear runs
Corner section, see Type VSD35

Construction features

Spigot suitable for circular ducts to EN 1506 or EN 13180

Materials and surfaces

Diffuser face made from extruded aluminium sections
Air control elements made of plastic, UL 94, V-0, flame retardant
Plenum box made of galvanised sheet steel
Varyset flap, end plate and end angle made of aluminium
Lip seal made of rubber
Diffuser face with anodised finish, E6-C-0, natural colour
P1: Powder-coated, RAL CLASSIC colour
Air control elements similar to RAL 9005, black
WW: Air control elements similar to RAL 9010, white

Standards and guidelines

Sound power level of the air-regenerated noise measured according to EN ISO 5135

Maintenance

Maintenance-free as construction and materials are not subject to wear
Inspection and cleaning to VDI 6022

Teknisk information

Schematic illustration of VSD35 Varyset 00129740_0

① Diffuser face
② Adjustable air control element
③ Neck
④ Plenum box
⑤ Suspension lug
⑥ Varyset casing with damper blade and balance weight
⑦ Spigot
⑧ Clamp fixing

Functional description

Slot diffusers direct the air from air conditioning systems into the room, either horizontally or at an angle. The resulting airflow induces high levels of room air, thereby rapidly reducing the airflow velocity and the temperature difference between supply air and room air. The result is a mixed flow ventilation in comfort zones, with good overall room ventilation, creating only very little turbulence in the occupied zone.

Type VSD35 Varyset slot diffusers have adjustable air control elements. The air pattern can be adjusted to meet different local requirements. Air discharge is one-way or alternating horizontal. Heating mode with angled air discharge is also possible. The supply air to room air temperature difference may range from –10 to +10 K.

Principle of operation – Varyset

Each diffuser requires for a stable horizontal air pattern in cooling mode a certain minimum volume flow rate; this minimum flow rate depends on the supply air to room air difference. If the actual volume flow rate is lower than the required minimum, the supply air does not adhere to the ceiling long enough, or not at all, but 'falls' immediately vertically into the occupied zone. This may result in draughts.

The Varyset diffuser allows for smaller minimum volume flow rates and hence for larger variable volume flow rate ranges.

The discharge velocity is reduced more slowly with decreasing volume flow rates when a Varyset diffuser is used. This ensures the self-powered Varyset flap within the plenum box. At the minimum volume flow rate the Varyset flap remains closed, and the supply air is discharged through only 25 % of the total slot length. As the volume flow rate increases, the Varyset damper opens due to the dynamic pressure. More and more air flows through the remaining slot length.

Advantages of Varyset

Stable horizontal air discharge in cooling mode with a large variable volume flow rate range
Elimination of draughts with the minimum volume flow rate
Excellent room ventilation even with the minimum volume flow rate
Smaller vertical temperature differences in the occupied zone, particularly in heating mode with angled air discharge

Nominal length	900, 1050, 1200, 1350, 1500 mm
Number of slots	1, 2, 3, 4
Minimum volume flow rate	8 – 22 (l/s)/m or 29 – 80 (m³/h)/m
Maximum volume flow rate	33 – 90 (l/s)/m or 120 – 324 (m³/h)/m
Supply air to room air temperature difference	–10 to +10 K

Quick sizing – sound power level and total differential pressure

Nominal length	V		Δp_t	L_WA
Nominal length	l/s	m³/h	Pa	dB(A)
900	7.5	27	10	<15
900	15	54	15	20
900	30	108	33	35
900	35	126	41	40
1200	10	36	12	15
1200	20	72	18	22
1200	40	144	39	39
1200	45	162	46	43
1500	12.5	45	19	24
1500	20	72	23	26
1500	40	144	32	36
1500	50	180	40	42

Quick sizing – sound power level and total differential pressure

Nominal length	V		Δp_t	L_WA
Nominal length	l/s	m³/h	Pa	dB(A)
900	10	36	6	16
900	20	72	12	22
900	40	144	27	33
900	50	180	37	38
1200	15	54	9	16
1200	30	108	15	23
1200	60	216	32	36
1200	70	252	41	40
1500	20	72	13	18
1500	40	144	20	26
1500	60	216	31	35
1500	80	288	44	42

Quick sizing – sound power level and total differential pressure

Nominal length	V		Δp_t	L_WA
Nominal length	l/s	m³/h	Pa	dB(A)
900	15	54	10	15
900	30	108	13	26
900	60	216	23	37
900	70	252	28	40
1200	20	72	12	21
1200	40	144	16	28
1200	80	288	23	39
1200	90	324	30	42
1500	25	90	15	23
1500	50	180	20	32
1500	80	288	25	39
1500	100	360	32	42

Quick sizing – sound power level and total differential pressure

Nominal length	V		Δp_t	L_WA
Nominal length	l/s	m³/h	Pa	dB(A)
900	20	72	11	25
900	40	144	17	32
900	60	216	21	36
900	80	288	26	40
1200	25	90	10	21
1200	40	144	14	27
1200	60	216	19	32
1200	100	360	28	40
1500	30	108	16	25
1500	50	180	19	31
1500	80	288	23	37
1500	100	360	27	39

Slot diffusers with individually manually adjustable air control elements and an aesthetically shaped face section with one to four slots, for one-way horizontal, alternating horizontal or alternating angled air discharge. For supply air, for large variable volume flow rate ranges. For installation into suspended ceilings.

Ready-to-install component which consists of the diffuser face with individually adjustable black or white air control elements, and of a plenum box with side entry spigot, self-powered Varyset flap and suspension lugs.

Spigot suitable for circular ducts to EN 1506 or EN 13180.

Sound power level of the air-regenerated noise measured according to EN ISO 5135.

Special characteristics

Individually adjustable air control elements to meet individual local requirements
Excellent room ventilation even with minimum volume flow rates (V_min)
High induction results in a rapid reduction of the temperature difference and airflow velocity
Diffuser face has been optimised for maximum volume flow rate at low sound power levels
Suitable for continuous linear arrangement

Materials and surfaces

Diffuser face made from extruded aluminium sections
Air control elements made of plastic, UL 94, V-0, flame retardant
Plenum box made of galvanised sheet steel
Varyset flap, end plate and end angle made of aluminium
Lip seal made of rubber
Diffuser face with anodised finish, E6-C-0, natural colour
P1: Powder-coated, RAL CLASSIC colour
Air control elements similar to RAL 9005, black
WW: Air control elements similar to RAL 9010, white

Technical data

Nominal length: 900, 1050, 1200, 1350, 1500 mm
Number of slots: 1, 2, 3, 4
Minimum volume flow rate: 8 – 22 (l/s)/m or 29 – 80 (m³/h)/m
Maximum volume flow rate with L_WA ≅ 50 dB(A): 33 – 90 (l/s)/m or 120 – 324 (m³/h)/m
Supply air to room air temperature difference: –10 to +10 K

Type
VSD35-VA Slot diffuser with Varyset

Number of slots
1
2
3
4

Nominal size [mm]
Nominal length L_N
900
1050
1200
1350
1500

End pieces
       No entry: without
       Both ends with end angles factory fitted
C1       to profile 000
C2       to profile B00
       Both ends with end plates factory fitted
C5       to profile 000
C6       to profile B00
       To be ordered separately for slot diffusers for linear arrangement

Extended border
No entry: none
B00 With extended border

Exposed surface
No entry: anodised, E6-C-0, natural colour
P1 Powder-coated, specify RAL CLASSIC colour

       Gloss level
       RAL 9010 50 %
       RAL 9006 30 %
       All other RAL colours 70 %

Air pattern
       No entry: alternating horizontal (WH)
WS       Alternating angled
HL       Horizontal left (opposite direction from spigot)
HR       Horizontal right (same direction as spigot)