00133448_0
QLF-O-1


00141311_0
QLF-1


00141322_0
QLF-3


00133448_0
00141311_0
00141322_0

QLF

Rectangular casing, one-way or three-way air discharge, for industrial and comfort zones

Slender, space saving displacement flow diffusers in an unusual design with chamfered front edges

  • Nominal widths 300 – 1250 mm, nominal heights 450 – 2000 mm
  • Volume flow rate range 15 – 865 l/s or 54 – 3114 m³/h
  • Perforated plate, square pitch
  • Rectangular duct connection
  • Duct connection at the top or bottom
  • Equalising element (perforated sheet metal basket)


Optional equipment and accessories

  • Exposed surface in RAL CLASSIC colours
  • Fixing material

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    Application

    Application

    • Type QLF displacement flow diffusers are used as supply air units for industrial and comfort zones
    • Attractive design element for building owners and architects with demanding aesthetic requirements
    • Floor-standing installation on walls, either individually or several units arranged in a row
    • Low-velocity airflow, causing only low levels of induction and resulting in low-turbulence displacement ventilation.
    • Excellent air quality in the occupied zone
    • Draught-free and economical ventilation and air conditioning also of larger internal spaces such as shop floors or auditoriums, with several displacement flow diffusers in a regular arrangement
    • For variable and constant volume flows
    • For supply air to room air temperature differences from –6 to –1 K

    Special characteristics

    • One-way or three-way air discharge
    • Duct connection at the top or bottom

    Nominal sizes

    • B: 300, 450, 600, 750, 1000, 1250 mm
    • H: 450, 600, 750, 1000, 1250, 1500, 1750, 2000 mm

    Description

    Variants

    • QLE-F: Spigot at the top
    • QLF-U: Spigot at the bottom
    • QLF-*-1: One-way air discharge
    • QLF-*-3: Three-way air discharge

    Parts and characteristics

    • Casing
    • Front frame with inserted perforated plate
    • Perforated sheet metal basket
    • Side parts with optional perforated sheet metal inserts for three-way air discharge

    Useful additions

    • Fixing brackets and screws

    Construction features

    • Spigot suitable for rectangular ducts

    Materials and surfaces

    • Casing, diffuser face and perforated sheet metal basket made of galvanised sheet steel
    • Casing and diffuser face powder-coated RAL 9010, pure white
    • Casing rear and perforated sheet metal basket dip coated RAL 9005, jet black
    • P1: Powder-coated, RAL CLASSIC colour

    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

    Technical information

    Function, Technical data, Quick sizing, Specification text, Order code

    • Function
    • Technical data
    • Quick sizing
    • Specification text
    • Order code
    Schematic illustration of QLF with rectangular spigot at the top
    00189965_0
    ① Diffuser face
    ② Casing
    ③ Perforated sheet metal basket
    ④ Spigot
    Optional
    ⑤ Perforated sheet metal side part


    00189965_0
    00128503_0
    00128508_0

    Functional description

    Displacement flow diffusers discharge the air from air conditioning systems with a low velocity and near the floor. The low-turbulence airflow creates a pool of fresh air that covers the entire floor area. The convection from people and other heat sources causes the fresh air from the pool to rise and create comfortable conditions in the occupied zone.

    This draught-free and economical type of ventilation is also suitable for large internal spaces, such as auditoriums or shop floors, with several regularly arranged units.

    Displacement ventilation is characterised by low airflow velocities and low turbulence. The air quality in the occupied zone is very high.

    Displacement ventilation with air discharge near the floor is suitable only for cooling. The maximum supply air to room air temperature difference is –6 K.

    Type QLF displacement flow diffusers are fitted with a perforated sheet metal basket as an equalising element; it distributes the supply air flow equally across the entire diffuser area. The perforated sheet metal diffuser face helps to equalise the airflow further. One-way or three-way air discharge.

    With displacement ventilation, i.e. air discharge near the floor, extract air units should be installed in the upper part of a room, above the occupied zone.

    Nominal sizes (B × H)

    300 × 450 to 1250 × 2000 mm

    Minimum volume flow rate, at 0.1 m/s

    15 – 355 l/s or 54 – 1278 m³/h

    Maximum volume flow rate, at 0.3 m/s

    40 – 865 l/s or 144 – 3114 m³/h

    Supply air to room air temperature difference

    –6 to –1 K

    Sound power level, at 0.3 m/s

    42 dB(A) max.


    Quick sizing tables provide a good overview of the volume flow rates and corresponding sound power levels and differential pressures.

    QLE-*-1, sound power level, total differential pressure and near zone

    Nominal size V v0 Δpt LWA Lnz
    Nominal size l/s m³/h m/s Pa dB(A) m

    300 × 450

    15

    54

    0.11

    <3

    <15

    <

    300 × 450

    25

    90

    0.19

    4

    <15

    <

    300 × 450

    35

    126

    0.26

    9

    <15

    <

    300 × 450

    40

    144

    0.30

    11

    <15

    <

    450 × 450

    20

    72

    0.10

    <3

    <15

    <

    450 × 450

    35

    126

    0.17

    3

    <15

    <

    450 × 450

    40

    144

    0.20

    3

    <15

    <

    450 × 450

    60

    216

    0.30

    8

    <15

    <

    300 × 600

    20

    72

    0.11

    3

    <15

    <

    300 × 600

    30

    108

    0.17

    6

    <15

    <

    300 × 600

    40

    144

    0.22

    11

    <15

    <

    300 × 600

    55

    198

    0.31

    20

    15

    <

    450 × 600

    30

    108

    0.11

    <3

    <15

    <

    450 × 600

    45

    162

    0.17

    4

    <15

    <

    450 × 600

    65

    234

    0.24

    8

    <15

    <

    450 × 600

    80

    288

    0.30

    12

    <15

    <

    600 × 600

    35

    126

    0.10

    <3

    <15

    <

    600 × 600

    60

    216

    0.17

    <3

    <15

    <

    600 × 600

    90

    324

    0.25

    3

    <15

    <

    600 × 600

    110

    396

    0.31

    5

    <15

    <

    450 × 750

    35

    126

    0.10

    <3

    <15

    <

    450 × 750

    60

    216

    0.18

    6

    <15

    <

    450 × 750

    80

    288

    0.24

    12

    <15

    <

    450 × 750

    100

    360

    0.30

    18

    19

    3.33

    600 × 750

    45

    162

    0.10

    <3

    <15

    <

    600 × 750

    75

    270

    0.17

    <3

    <15

    <

    600 × 750

    105

    378

    0.23

    4

    <15

    2.23

    600 × 750

    135

    486

    0.30

    7

    <15

    3.14

    750 × 750

    55

    198

    0.10

    <3

    <15

    <

    750 × 750

    90

    324

    0.16

    <3

    <15

    1.28

    750 × 750

    135

    486

    ,024

    <3

    <15

    2.17

    750 × 750

    170

    612

    0.30

    4

    <15

    2.93

    600 × 1000

    60

    216

    0.10

    <3

    <15

    0.91

    600 × 1000

    100

    360

    0.17

    3

    <15

    1.76

    600 × 1000

    140

    504

    0.23

    7

    <15

    2.71

    600 × 1000

    180

    648

    0.30

    11

    <15

    3.76

    750 × 1000

    75

    270

    0.10

    <3

    <15

    0.89

    750 × 1000

    125

    450

    0.17

    <3

    <15

    1.67

    750 × 1000

    175

    630

    0.23

    4

    <15

    2.53

    750 × 1000

    225

    810

    0.30

    6

    <15

    3.45

    600 × 1250

    75

    270

    0.10

    <3

    <15

    1.12

    600 × 1250

    125

    450

    0.17

    5

    <15

    2.10

    600 × 1250

    175

    630

    0.23

    10

    <15

    3.18

    600 × 1250

    225

    810

    0.30

    16

    21

    4.33

    750 × 1250

    95

    342

    0.10

    <3

    <15

    1.13

    750 × 1250

    140

    504

    0.15

    <3

    <15

    1.77

    750 × 1250

    220

    792

    0.23

    5

    <15

    2.98

    750 × 1250

    285

    1026

    0.30

    9

    <15

    4.01

    750 × 1500

    110

    396

    0.10

    <3

    <15

    1.34

    750 × 1500

    185

    666

    0.16

    3

    <15

    2.33

    750 × 1500

    260

    936

    0.23

    7

    <15

    3.36

    750 × 1500

    340

    1224

    0.30

    12

    17

    4.48

    1000 × 1500

    145

    522

    0.10

    <3

    <15

    1.36

    1000 × 1500

    250

    900

    0.17

    3

    <15

    2.24

    1000 × 1500

    360

    1296

    0.24

    6

    <15

    3.14

    1000 × 1500

    455

    1638

    0.30

    10

    18

    3.90

    750 × 1750

    125

    450

    0.10

    <3

    <15

    1.58

    750 × 1750

    215

    774

    0.16

    5

    <15

    2.72

    750 × 1750

    305

    1098

    0.23

    9

    <15

    3.85

    750 × 1750

    400

    1440

    0.30

    16

    22

    5.04

    1000 × 1750

    170

    612

    0.10

    <3

    <15

    1.72

    1000 × 1750

    295

    1062

    0.17

    4

    <15

    2.70

    1000 × 1750

    415

    1494

    0.24

    7

    <15

    3.58

    1000 × 1750

    530

    1908

    0.30

    12

    23

    4.38

    1250 × 1750

    210

    756

    0.10

    <3

    <15

    1.85

    1250 × 1750

    360

    1296

    0.16

    4

    <15

    2.64

    1250 × 1750

    510

    1836

    0.23

    7

    17

    3.33

    1250 × 1750

    665

    2394

    0.30

    13

    26

    3.97

    1000 × 2000

    190

    684

    0.10

    <3

    <15

    2.13

    1000 × 2000

    330

    1188

    0.17

    5

    <15

    3.19

    1000 × 2000

    470

    1692

    0.24

    9

    18

    4.13

    1000 × 2000

    605

    2178

    0.30

    15

    27

    4.96

    1250 × 2000

    240

    864

    0.10

    <3

    <15

    2.45

    1250 × 2000

    415

    1494

    0.17

    5

    <15

    3.32

    1250 × 2000

    590

    2124

    0.24

    10

    21

    4.04

    1250 × 2000

    760

    2736

    0.30

    16

    31

    4.65

    <: 0.2 m/s are not achieved

    The near zone values are based on a supply air to room air temperature difference of –3 K


    QLF-*-3, sound power level, total differential pressure and near zone

    Nominal size V v0 Δpt LWA Lnz
    Nominal size l/s m³/h m/s Pa dB(A) m

    300 × 450

    25

    90

    0.10

    4

    <15

    <

    300 × 450

    35

    126

    0.14

    9

    <15

    <

    300 × 450

    50

    180

    0.20

    18

    26

    <

    300 × 450

    65

    234

    0.26

    30

    36

    <

    450 × 450

    35

    126

    0.11

    3

    <15

    <

    450 × 450

    50

    180

    0.16

    5

    <15

    <

    450 × 450

    65

    234

    0.21

    9

    <15

    <

    450 × 450

    80

    288

    0.25

    14

    22

    <

    300 × 600

    35

    126

    0.11

    8

    <15

    <

    300 × 600

    50

    180

    0.15

    17

    26

    <

    300 × 600

    65

    234

    0.20

    28

    35

    <

    300 × 600

    85

    306

    0.26

    48

    45

    <

    450 × 600

    40

    144

    0.10

    3

    <15

    <

    450 × 600

    65

    234

    0.15

    8

    <15

    <

    450 × 600

    85

    306

    0.20

    14

    23

    <

    450 × 600

    105

    378

    0.25

    21

    31

    <

    600 × 600

    55

    198

    0.10

    <3

    <15

    <

    600 × 600

    80

    288

    0.15

    3

    <15

    <

    600 × 600

    110

    396

    0.20

    5

    <15

    <

    600 × 600

    135

    486

    0.25

    7

    <15

    <

    450 × 750

    50

    180

    0.10

    4

    <15

    <

    450 × 750

    80

    288

    0.15

    12

    20

    <

    450 × 750

    105

    378

    0.20

    20

    30

    1.75

    450 × 750

    130

    468

    0.25

    30

    38

    2.33

    600 × 750

    70

    252

    0.10

    <3

    <15

    <

    600 × 750

    100

    360

    0.15

    4

    <15

    1.09

    600 × 750

    135

    486

    0.20

    7

    <15

    1.59

    600 × 750

    170

    612

    0.25

    11

    22

    2.13

    750 × 750

    80

    288

    0.10

    <3

    <15

    <

    750 × 750

    120

    432

    0.15

    <3

    <15

    1.09

    750 × 750

    160

    576

    0.20

    3

    <15

    1.54

    750 × 750

    200

    720

    0.25

    5

    <15

    2.02

    600 × 1000

    90

    324

    0.10

    3

    <15

    0.86

    600 × 1000

    135

    486

    0.15

    6

    <15

    1.37

    600 × 1000

    185

    666

    0.20

    11

    24

    1.97

    600 × 1000

    230

    828

    0.25

    18

    32

    2.54

    750 × 1000

    105

    378

    0.10

    <3

    <15

    0.85

    750 × 1000

    160

    576

    0.15

    3

    <15

    1.35

    750 × 1000

    215

    774

    0.20

    5

    <15

    1.86

    750 × 1000

    265

    954

    0.25

    8

    18

    2.34

    600 × 1250

    115

    414

    0.10

    4

    <15

    1.12

    600 × 1250

    175

    630

    0.15

    10

    21

    1.74

    600 × 1250

    230

    828

    0.20

    16

    31

    2.33

    600 × 1250

    290

    1044

    0.25

    26

    40

    2.98

    750 × 1250

    140

    504

    0.10

    <3

    <15

    1.17

    750 × 1250

    200

    720

    0.15

    4

    <15

    1.66

    750 × 1250

    265

    954

    0.20

    8

    16

    2.19

    750 × 1250

    340

    1224

    0.25

    13

    25

    2.80

    750 × 1500

    160

    576

    0.10

    3

    <15

    1.41

    750 × 1500

    240

    864

    0.15

    6

    <15

    2.02

    750 × 1500

    320

    1152

    0.20

    10

    22

    2.61

    750 × 1500

    400

    1440

    0.25

    16

    31

    3.17

    1000 × 1500

    215

    774

    0.10

    <3

    <15

    1.50

    1000 × 1500

    335

    1206

    0.15

    5

    15

    2.02

    1000 × 1500

    440

    1584

    0.20

    9

    25

    2.43

    1000 × 1500

    550

    1980

    0.25

    14

    33

    2.82

    750 × 1750

    185

    666

    0.10

    3

    <15

    1.78

    750 × 1750

    280

    1008

    0.15

    8

    17

    2.46

    750 × 1750

    375

    1350

    0.20

    14

    28

    3.09

    750 × 1750

    475

    1710

    0.25

    22

    36

    3.72

    1000 × 1750

    250

    900

    0.10

    3

    <15

    2.04

    1000 × 1750

    390

    1404

    0.15

    7

    20

    2.60

    1000 × 1750

    515

    1854

    0.20

    12

    30

    3.03

    1000 × 1750

    640

    2304

    0.25

    18

    38

    3.41

    1250 × 1750

    310

    1116

    0.10

    3

    <15

    2.37

    1250 × 1750

    455

    1638

    0.15

    6

    20

    2.77

    1250 × 1750

    605

    2178

    0.20

    10

    30

    3.11

    1250 × 1750

    750

    2700

    0.25

    16

    38

    3.40

    1000 × 2000

    280

    1008

    0.10

    3

    <15

    2.81

    1000 × 2000

    445

    1602

    0.15

    8

    24

    3.43

    1000 × 2000

    590

    2124

    0.20

    15

    34

    3.87

    1000 × 2000

    735

    2646

    0.25

    23

    42

    4.25

    1250 × 2000

    355

    1278

    0.10

    3

    <15

    3.56

    1250 × 2000

    525

    1890

    0.15

    8

    24

    3.98

    1250 × 2000

    695

    2502

    0.20

    13

    34

    4.32

    1250 × 2000

    865

    3114

    0.25

    21

    42

    4.60

    <: 0.2 m/s are not achieved

    The near zone values are based on a supply air to room air temperature difference of –3 K


    Displacement flow diffusers for air discharge near the floor, suitable for comfort and industrial zones with special demands on architecture and design.

    With one-way or three-way air discharge for low-turbulence displacement ventilation. Rectangular casing for installation on a wall.

    Ready-to-install component which consists of a casing with spigot at the top or bottom, a perforated sheet metal basket as an equalising element, and a perforated sheet metal diffuser face.

    Spigot suitable for rectangular ducts.

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

    Special characteristics

    • One-way or three-way air discharge
    • Duct connection at the top or bottom

    Materials and surfaces

    • Casing, diffuser face and perforated sheet metal basket made of galvanised sheet steel
    • Casing and diffuser face powder-coated RAL 9010, pure white
    • Casing rear and perforated sheet metal basket dip coated RAL 9005, jet black
    • P1: Powder-coated, RAL CLASSIC colour

    Technical data

    • Nominal sizes (B × H): 300 × 450 – 1250 × 2000 mm
    • Minimum volume flow rate, at 0.1 m/s: 15 – 355 l/s or 54 – 1278 m³/h
    • Maximum volume flow rate, at 0.3 m/s: 40 – 865 l/s or 144 – 3114 m³/h
    • Supply air to room air temperature difference: –6 to –1 K
    • Sound power level, at 0.3 m/s: 42 dB(A) max.

    Sizing data

    • V _______________________ [m³/h]
    • Δpt _______________________ [Pa]

    Air-regenerated noise

    • LWA _______________________ [dB(A)]

    This specification text describes the general properties of the product. Texts for variants can be generated with our Easy Product Finder design programme.

    00135933_0

     Type
    QLF       Displacement flow diffuser

     Connection
           Rectangular spigot
    O       Top
    U       Bottom

     Air discharge
    1       One-way
    3       Three-way

    		 

     Nominal size [mm]
           B × H

     Exposed surface
           No entry: powder-coated
           RAL 9010, pure white
    P1       Powder-coated, specify RAL CLASSIC colour

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

    00135933_0
    00173852_0

    Order example: QLF–O–3/450×750/P1–RAL 9016

    Connection

    Rectangular spigot at the top

    Air discharge

    Three-way

    Nominal size

    450 × 750 mm

    Exposed surface

    RAL 9016, traffic white, gloss level 70 %


     

    Variants, Dimensions and weight

    • Variants
    • Dimensions and weight
    QLF-U-1
    00140850_0


    00140850_0
    00133448_0
    00140855_0
    00140832_0
    QLF-U-1
    00141758_0


    00141758_0
    00117246_0...
    00141681_0
    00141675_0

    The nominal size (nominal width × nominal height) is equal to the discharge opening.

    QLF

    Nominal size
    		 B1
    mm
    		 H1
    mm
    		 T1
    mm
    		 B4
    mm
    		 T4
    mm
    		 m
    kg
    300×450 370 520 185 160 80 9
    450×450 520 520 185 300 80 11
    300×600 370 670 185 160 80 10
    450×600 520 670 185 300 80 14
    600×600 670 670 235 360 150 17
    450×750 520 820 185 300 80 16
    600×750 670 820 235 360 150 18
    750×750 820 820 235 625 150 25
    600×1000 670 1070 235 360 150 20
    750×1000 820 1070 235 625 150 31
    600×1250 670 1320 235 360 150 25
    750×1250 820 1320 235 625 150 37
    750×1500 820 1570 235 625 150 43
    1000×1500 1070 1570 287 715 200 54
    750×1750 820 1820 235 625 150 49
    1000×1750 1070 1820 287 715 200 62
    1250×1750 1320 1820 287 890 200 72
    1000×2000 1070 2070 287 715 200 69
    1250×2000 1320 2070 287 890 200 81


    Installation details, Basic information and nomenclature

    • Installation details
    • Basic information and nomenclature

    Installation and commissioning

    • With displacement ventilation and air discharge near the floor, extract air devices should be installed in the upper part of a room, above the occupied zone.

    Principal dimensions

    B₁ [mm]

    Width of diffuser face

    B₄ [mm]

    Width of a rectangular spigot

    ØD [mm]

    Outer diameter of the spigot

    ØD₁ [mm]

    Casing diameter

    H₁ [mm]

    Height of diffuser face

    T₁ [mm]

    Casing depth

    T₄ [mm]

    Depth of a rectangular spigot

    m [kg]

    Weight

    Nomenclature

    LWA [dB(A)]

    A-weighted sound power level of air-regenerated noise

    V [m³/h] and [l/s]

    Volume flow rate

    v0 [m/s]

    Theoretical airflow velocity across the diffuser area, at a distance of 0 m from the diffuser face

    Lnz [m]

    Near zone of the displacement flow diffuser, where the comfort criteria may not be achieved

    The near zone is at least 0.5 m, independent of the airflow velocity

    At distance Lnz the airflow velocity is 0.2 m/s max., measured 0.1 m above the floor

    Δtz [K]

    Supply air to room air temperature difference, i.e. supply air temperature minus room temperature

    Δpt [Pa]

    Total differential pressure

    Aeff [m²]

    Effective air discharge area


    All sound power levels are based on 1 pW.

    Downloads

    product information

    • Product data sheet Type QLF

      Product data sheet 2,7 MB pdf

    certificates

    • Declaration of hygiene conformity Type QLF

      QLF_HC_2024_05_DE_en Hygiene certificate 1,6 MB pdf

    • Non-CE Manufacturer's statement QLF

      QLF_NotCE_2022_02_08_14_36_30_DE_en Certificate 1,6 MB pdf
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