Type 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

QLF-O-1 00133448_0


  • Application
  • Description

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

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

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.

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

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.

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Thank you for your message!

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Our department for Service-Requests will contact you asap.
For general question regarding products or services you can also call:
Tel.: +49 (0)2845 / 202-0 | Fax: +49 (0)2845/202-265