for

Pleasant &HealthyAir-Distribution

ISO 9001:2000

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Product Bulletin 133-D Linear Slot Diffusers

Pleasant . . Serene. .YOU & DASCO.. .

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Partners for good health

Since 1964

Introduction

Linear slot diffusers are always considered as the most

attractive air distribution devices. They are specially

designed for ceiling mounting in a wide range of

applications in heating, ventilation and air conditionin

systems. At a perfect setting, linear slot diffusers provide a

stable pattern of diffusion to produce an optimum

performance for both supply and return air in addition to

their pleasant appearance.

To satisfy both architectural and engineering needs, curved

slot diffusers have been also developed and designed.

Whether it requires a continuous linear run, ellipse,

complete circle orserpentine curve,…. LINEAR/CURVED

SLOT DIFFUSERS CAN ALWAYS BE INCORPORATED

INTO ANY DESIGN.

INTRODUCTION

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Linear Slot Diffusers

Dasco linear slot diffusers for both supply and return applications DLD-C(S/R) are designed to give unobstrusive continuous air diffusion with a pleasing aesthetic appearance .Hairline joints ensure clean continuous runs of linear slot diffusers for both active and dummy sections. They are normally connected to the main ducting system by means of connection boxes (Plenums), and are adjustable in height for accurate lining-up with the ceiling.

LINEAR SLOT DIFFUSERS

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GENERAL

Linear Slot Diffuser ( 3 Slots)

Linear Slot Diffuser ( 2 Slots)

Mitered Corner ( 90º )

In general , DLD-C(S/R) linear slot diffuser is considered as a unique type of an air distribution device, dispenses proper air quantities, controls air pattern for ultimate human comfort and adapts to any design concept perceived by architect / design engineer.

Linear Slot Diffusers

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Dasco linear slot diffusers DLD-C(S/R) are designed to give a comprehensive and full range of air flow patterns and volumes. Their deflector blades and volume control dampers give a full flexibility in air patternand volume control. These are fully adjustable from the face of the diffuser. Single or multiple slot arrangements can provide any combinations of horizontal, vertical or any intermediate setting of air flow pattern over a full range of 180º adjustment, as each slot is individually adjustable. Volume control dampers consist of two strips of extruded aluminium profiles, one fixed and one movable. They can be also usedas equalizing grids.

DESCRIPTION

SINGLE SLOT ADJUSTMENTS

MULTIPLE SLOT ADJUSTMENTS (TWO TO EIGHT SLOTS )

Horizontal right Horizontal left Fully Vertical Dampered Horizontal Fully Closed

Horizontal one-way

Horizontal two-way

Fully Vertical Horizontal two-wayDampered(unequal flow)

Vertical Horizontal

Mitered Corners (Different angles)

Linear Slot Diffusers

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Two types of linear slot diffusers are available:

MATERIAL & FINISH

Linear slot diffusers with 3/4” slot width.Linear slot diffusers with 1” slot width.

••Both are manufactured in one up to eight slots with a maximum one–piece length of 6 meters as a standard, permitting complete control of flow rate without disturbing the selected air pattern. Linear slot diffusers with other lengths and /or number of slots can also be provided on request.

End caps on both sides are supplied on one piece linear slot diffusers, and on one side of end sections of continuous units. Sections are connected by using alignment strips.

High quality and heavy gauge extruded aluminium profiles. They are available in white polyester powder coated finish. However, any other RAL standard colours are also available upon customer’s request.Deflector blades and dampers are also made from extruded aluminium profiles normally in black colour. Plenum boxes are made from galvanized steel.

LINEAR DIFFUSER (3-SLOTS) WITH DAMPERS

Linear Slot Diffusers

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Linear Slot Diffuser(Hexagonal Shape)

Linear Slot Diffuser(T-Shape)

Linear Slot Diffusers (2Slots)Special Geometric Shapes

Vertical outside Mitered corner section

Vertical inside Mitered corner section

Vertical inside Mitered corner sectionChamfered type

2 Slots DiffuserCircular Shape

Accessories

ACCESSORIES

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A complete variety of accessories and options are always available for DLD-C(S/R)

1. MOUNTING BRACKETSAre used normally for ceiling installations. They are made from Z-27(gauge 20 ) galvanized steel and are arranged with holes for easy installations .

2. ALIGNMENT STRIPSAre used for continuous sections and are made from aluminium sheets.

3. END CAPSL-Shape flanges, manufactured from aluminium extruded profiles and are available in different lengths to match different number of slots and widths.They are usually fixed at the end of linear slot diffusers and are very easy to install and remove .

Mounting Brackets

Alignment strips

Alignment strips

End caps

Without end caps End caps (both sides)End cap (left or right)

Accessories

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With exactly the same construction of supply air linear slot diffusers but with blank off damper sheets. Are used along with continuation sections of supply and /or return linear slot diffusers for decoration purposes.

4. DUMMY SECTIONS

Linear Diffuser (3 Slots) - Dummy Type

Are usually used when slot diffusers are designed to form closed loops. They are available in one to eight slots and can have any combination of L1, L2 and angle ø.

5. MITERED CORNERS

Mitered Corners

Plenum Boxes

PLENUM BOXES

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Plenum Box without insulation

It is designed to ensure even air distribution along the associated linear slot diffusers, and therefore maintaining correct performance characteristics. Plenum boxes, are available with or without internal lining of thermal and acoustic insulation and are available for single or continuous installations. All joints are sealed for a perfect tightness and in most cases are “Lock formed”, which adds to maintain rigidity.

DESCRIPTION

Fiberglass 25 mm thick (16kg/m3) with black tissue face for acoustic and thermal insulation (Available as optional)

INSULATION

Galvanized sheet steel Z-27 (Gauge 24 )

MATERIAL

Plenum Box with insulation

Plenum Boxes

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Insulated Plenum

Available in various neck openings (5”to12”) suitable for fixing linear slot diffusers (1 to 8 slots). Maximum plenum length is 240 cm per piece. Longer lengths are provided with special joints to fit continuous shape.

SIZES

Plenum without Insulation

Single Installation DLD-C withPlenum box DPB-C

Table 1. Dimensions of plenum boxes ( with /without ) insulation

Ordering Code

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ORDERING CODE

DLD-C a - b - c - d - eDasco Linear Slot Diffuser

S :SupplyR :ReturnRD :Return with volume control damperD :Dummy

1,2,3,4,5,6,7,8

1 :3/4” slot width2 :1” slot width

(Maximum 600)

0 : Without1 : One end cap2 : Two end caps

a =Version

b =Number of slots

c =Slot width

d =Length ,cm

e =Number of end caps

DPB-C a - b - c - d - eDasco Plenum Box

S :Single UnitI :In - Line

1,2,3,4,5,6,7,8

1 :3/4” slot width2 :1” slot width

(Maximum 240)

0 : Without thermal insulation1 : With thermal insulation

a =Installation

b =Number of slots

c = Slot width

d =Length, cm

e =Thermal insulation

Dimensional Data

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DIMENSIONAL DATA

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Linear slot diffuser with 3/4 “ slot width

Linear slot diffuser with 1” slot width

Dimensional Data

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DIMENSIONS OF LISTED SIZES:

Table 2. Dimensions of linear slot diffusers with 3/4” slot width

a) Linear slot diffusers with 3/4” slot width

Table 3. Dimensions of linear slot diffusers with 1 “ slot width

a) Linear slot diffusers with 1” slot width

Curved DiffusersArched Shape

Woodall Colour

Engineering Data

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DEFINITIONS

ENGINEERING DATA

Table 4. CFM range for supply linear slot diffusers (1 to 8 slots).

Throw of an outlet, in m (feet), is the distance from the center of the

outlet to a point in the mixed air stream where the highest sustained

velocity of the mixed air stream has been reduced to a specified level,

i. e, 100 and 50 FPM.

• Throw (T) :

Is the air flow rate in cubic feet per minute.• CFM :Discharge or intake velocity of an outlet or inlet , in m/s (FPM) measured

with an approved calibrated velometer at specified locations relative to

the face of the outlet or inlet. Sometimes referred to as jet velocity.

• Velocity (Vk) :

Terminal velocity from an outlet, in m/s (FPM), is the highest sustained

velocity in the mixed air stream arbitrarily specified and used to

determine throw.

• Terminal velocity (Vt) :

Is the area factor of an outlet or inlet which is also a flow factor

determined from the discharge or intake velocity ( Vk ), and the volume

flow rate (CFM).

• Area factor (Ak) :

Ak =CFM

VkThe outward force within a duct measured in mm (inch) W.G.• Static Pressure (Ps) :

The forward moving force of an air stream within a duct measured in

mm ( inch) W.G.

• Velocity pressure (Pd) (Dynamic pressure)

:

The sum of the velocity pressure and static pressure measured in mm

(inch) W.G.• Total pressure (Pt) :

The following table could be helpful before starting the selection of a linear slot diffuser.

Noise Criteria

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NOISE CRITERIA

The sound pressure level of 8 octave bands acceptable to human ears

and are estimated from table 5.

• Noise criteria :

The sound caused by an air outlet is directly proportional to the velocity

of the air passing through it.

ENVIRONMENTAL SOUND – Existing within the space with air

conditioning Equipment off

Ambient sounds a)

EXTERNAL SOUND – Entering a space from outdoors.b)

INTRUDING SOUND – Entering from adjacent spaces.c)

Prior to selection of NC level from table 5, the three ambient sounds above must be considered.

Is the difference between the sound power level of a terminal and the

sound pressure level sensed by human ears in the room, and is affected

by room size, sound absorption characteristic of the room surfaces,

ceiling height, space volume, distance of listener to terminal, terminal

location and number of terminals.

• The room effect :

Curved Slot Diffuser Concave Shape

Curved Slot DiffusersConvex Shape

Noise Criteria

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RECOMMENDED NOISE CRITERIA FOR ROOMS

Table 5. Recommended range of noise criteria from ASHRAE GUIDE.

Performance Data

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BASIC PERFORMANCE DATA FOR DLD-CS

Note

A. Supply linear slot diffusers with 3/4” slot width

1 2 3 4 5 6 7 8

CFM/Ft 8012-23

<20

Number of slots

NC

2010 30 40 50 60 704-8 7-147-12 8-16 9-18 11-20 11-22

<20 <20 <20 <20 <20 02<02<

18-3127

120

NC

CFM/Ft 3015 45 60 75 9092-7172-5151-9

<20 <20 20 22 23 5202<

10542-4101-6 12-2111-19

24-3830

160

NC

CFM/Ft 4020 60 80

20-33 22-3620 22 26 27 28 9242

140

03-8121-8 16-2714-24

100 120

10-19

30-4234

200

NC

CFM/Ft 5025 7525-36 28-39

25 26 30 31 32 3382

17522-3220-3017-26125 150

13-22100

10-14

33-4538

2406030 9029-40 31-42

30 32 34 35 36 7333

21025-3424-3320-29150 180

15-24120

12-17

NC

CFM/Ft

34-4942

280703531-44 33-47

33 35 38 39 40 1473

24527-3825-3622-33175 210

17-26140

13-18105

NC

CFM/Ft

36-54

46

320804033-47 35-51

36 38 42 43 44 5404

28029-4126-3824-35200 240

19-28160

14-20120

NC

CFM/Ft

38-5850

3609045

35-50 37-5439 42 46 47 48 9444

315

32-4527-4026-38225 270

21-30180

15-22135

NC

CFM/Ft

40-6242 44 48 50 5246 54 56

400

NC

5037-54 39-58

35035-5028-4429-40250 300

24-33200

17-24150100CFM/Ft

Throw (Ft)

Throw (Ft)

Throw (Ft)

Throw (Ft)

Throw (Ft)

Throw (Ft)

Throw (Ft)

Throw (Ft)

Throw (Ft)

Table 6. Performance data for supply linear slot diffusers with 3/4” Slot width

• Throw data (Ft) is based on terminal velocities of 100 & 50 FPM for horizontal discharge.• NC values are for horizontal discharge. For vertical discharge subtract(5) from NC values.• NC values are for 4 Ft long unit and assume room attenuation 10 db.

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Performance Data

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EFFECTIVE FREE AREA (Ak)

Table 7. Effective free area Ak (Ft2 /Ft run) for DLC-CS (3/4” Slot width)

Note • Static pressure drop in inch W.G. for horizontal discharge. For vertical discharge multiply by 0.6

Number of Slots

Curve 1. Static pressure drop Vs. Air flow for DLD-CS (3/4” Slot width)

1 2 3 4 5 6 7 8

10 20 30 50 70 100 200 300

SupplyP.D.” W.G.

0.3

0.2

0.1

0.05

0.03

0.02

Performance Data

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BASIC PERFORMANCE DATA FOR DLD-CS

Note

B. Supply linear slot diffusers with 1 ” slot width

17-3026

120

NC

CFM/FtThrow (Ft)

3015 45 60 75 9072-6162-4141-8

221202<02< 4202<

10532-319-5 11-2010-18

<20

23-3630

160

NC

CFM/FtThrow (Ft)

4020 60 80

19-32 21-3421 25 26 27 8232

140

92-7121-8 15-2613-23

100 120

9-19<20

29-4033

200

NC

CFM/FtThrow (Ft)

5025 7524-36 27-38

24 25 28 30 31 2362

17521-3120-3016-25125 150

12-21100

9-14

32-4437

2406030 9027-39 30-40

27 29 32 34 35 6303

21024-3423-3218-28150 180

14-23120

11-17

NC

CFM/FtThrow (Ft)

33-4841

280703530-43 32-46

30 32 36 38 39 0443

24526-3824-3621-32175 210

16-25140

12-18105

NC

CFM/FtThrow (Ft)

36-52

45

320804031-46 34-50

33 35 39 40 41 3473

28028-4225-3823-34200 240

18-28160

14-20120

NC

CFM/FtThrow (Ft)

37-5649

3609045

34-49 36-5235 38 43 45 46 7404

315

30-4426-4025-38225 270

20-30180

15-22135

NC

CFM/FtThrow (Ft)

39-6039 41 46 48 5044 52 54

400

NC

5036-53 38-56

35034-4929-4327-39250 300

24-32200

16-24150100CFM/Ft

Throw (Ft)

CFM/Ft1 2 3 4 5 6 7 8

8012-22

<20

Number of slots

NCThrow (Ft)

2010 30 40 50 60 704-7 7-137-11 8-15 9-17 11-19 11-21

<20 <20 <20 <20 <20 02<02<

Table 8. Performance data for supply linear slot diffusers with 1˝ slot width

• Throw data (Ft) is based on terminal velocities of 100 & 50 FPM for horizontal discharge.• NC values are for horizontal discharge. For vertical discharge subtract(5) from NC values.• NC values are for 4 Ft long unit and assume room attenuation 10 db.

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Performance Data

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EFFECTIVE FREE AREA (Ak)

Table 9. Effective free area Ak (Ft2 /Ft run) for DLC-CS (1” Slot width)

Note • Static pressure drop in inch W.G. for horizontal discharge. For vertical discharge multiply by 0.6

Number of Slots

Curve 2. Static pressure drop Vs. Air flow for DLD-CS ( 1˝ slot width)

1 2 3 4 5 6 7 8

10 20 30 50 70 100 200 300

SupplyP.D.” W.G.

0.15

0.1

0.05

0.025

0.015

0.01

Performance Data

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BASIC PERFORMANCE DATA FOR DLD-CR

Note

A. Return linear slot diffusers with 3/4 ” slot width

1 2 3 4 5 6 7

CFM/Ft

Static PressureDrop W.G

Number of slots

CFM/Ft

CFM/Ft 1203015 45 60 75 90 105

16040 041080602 100 120CFM/Ft

20050 5715752 125 150100CFM/Ft

24060 0120903 150 180120CFM/Ft

28070 54253 175 210140105CFM/Ft

32080 08204 200 240160120

36090 51354 225 270180135CFM/Ft

40005305 250 300200150100CFM/Ft

21 23 24 726202<20<20

21 22 26 28 29 130342

25 27 31 32 33 534392

31 33 35 36 37 938343

34 36 39 40 41 342483

37 39 43 44 45 746414

40 43 47 48 49 150554

43 45 49 51 53 755574

NC

NC

NC

NC

NC

NC

NC

NC

NC

<2002<02<02< 02<02< <20<202010 30 40 50 60 70 80

0.4520.0620.030 0.117 0.173 0.236 0.3350.007

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Table 10. Performance data for return linear slot diffusers with 3/4˝ slot width

•Performance data are for return linear slot diffusers with deflection blades.•NC values are for 4 Ft long unit and assume room attenuation 10 db.•Static pressure values are in inches W.G.

EFFECTIVE FREE AREA (Ak)

Table 11. Effective free area Ak (Ft2 /Ft run) for DLC-CR (3/4˝ Slot width)

Note

B. Return linear slot diffusers with 1 ” slot width

CFM/Ft

Static PressureDrop W.G

Number of slots

CFM/Ft

CFM/Ft

CFM/Ft

CFM/Ft

CFM/Ft

CFM/Ft

CFM/Ft

CFM/Ft

NC

NC

NC

NC

NC

NC

NC

NC

NC

81 2 3 4 5 6 7

16040 041080602 100 120

20050 5715752 125 150100

24060 0120903 150 180120

28070 54253 175 210140105

32080 08204 200 240160120

36090 51354 225 270180135

40005305 250 300200150100

40 42 47 49 51 552554

36 39 44 46 47 059414

34 36 40 41 42 644483

31 33 37 39 40 241453

28 29 33 35 36 837313

24 26 29 31 32 433372

22 26 27 28 039242<20

20 22 23 25 26<20<20 <20

1203015 45 60 75 90 105

02<02<02< 02<02< <20 0202<802010 30 40 50 60 70

0.3100.0440.020 0.078 0.115 0.164 0.2310.005

Table 12. Performance data for return linear slot diffusers with 1 ˝ slot width

•Performance data are for return linear slot diffusers with deflection blades.•NC values are for 4 Ft long unit and assume room attenuation 10 db.•Static pressure values are in inches W.G.

EFFECTIVE FREE AREA (Ak)

Table 13. Effective free area Ak (Ft2 /Ft run) for DLC-CR (1 ˝ slot width)

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Performance Data

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BASIC PERFORMANCE DATA FOR DLD-CR

Correction Factors

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CORRECTION FACTORS

A) Supply Linear slot diffusers

Table 14. Correction factors for throw and NC values at different active lengths of supply linear slot diffusers

• Throw and NC values in performance tables are based on supply linear slot diffusers with active length of 4 Ft. To determine throw and NC values for other lengths, use the correction factors in the following table :

Table 16. Correction factors for NC values at different active lengths of return linear slot diffusers.

Table 15. Correction factors for static pressure drop and NC values at different damper adjustments

• Static pressure drop and NC values in performance table/curves are based on 100% damper opening . Use the following correction factors for different damper adjustments.

B) Return linear slot diffusers• NC values in performance tables are based on return linear slot diffusers with active length of 4 Ft. To determine NC values for other lengths, use the correction factors in the following table:

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AIR BALANCING ADJUSTMENT

Air Balancing

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Right Flow

Use measuring tools for air velocity like ALNOR 2220 A or 2220 probe, or anemotherm air

meter model 60.

Take number of measuring points ( should be not less than 4)based on 4 Ft long linear dif--

fuser, and probe should be located and adjusted as to measure the maximum air velocity by

facing the probe to the air flow direction on the face of the linear slot diffuser as shown.

Take the arithmetic average of velocity readings to obtain the Vk (average) as follows:

Determine the area factor (Ak) from previous tables considering the linear diffuser length

and number of slots.

Calculate the air volume ( CFM ) with the following formula :

1)

2)

3)

4)

5)

To determine the CFM, follow up the following procedure:

DEFLECTOR SETTINGThe deflector blades of the supply linear slot diffusers can be fully adjusted to give either a hori--

zontal / vertical air pattern, or any combination of them.

The horizontal air flow adjustment may be set for either left or right hand throw.

Left Flow Vertical Flow Return

Vk ( average) =( V1+V2+.....+Vk)

K

CFM = Vk (average) x Ak

Note If the air volume calculated from above procedure is not satisfactory, repeat the same proce--dure after adjusting the deflector angle.

Fixing Method

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Linear Diffuser (2 slots)without end caps

Linear Diffuser (2 slots)with end cap from one side

STANDARD FIXING METHOD

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CONVERSION TABLE

Conversion Table

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Table 17. Metric guide conversion factors.

Quantity Imperial Unit Metric Unit From Imperial To From Metric To

Metric Multiply By Imperial Multiply By

Area Square foot Square meter (m2) 0.0929 10.764

Square inch Square millimeter (mm2) 645.16 0.00155

Density Pounds per cubic foot Kilograms per cubic 16.018 0.624

meter (kg/m3)

Length 4930.04.52)mm(retemillimhcni

82300.08.403)mm(retemillimtoof

8082.38403.0)m(retemtoof

8390.14419.0)m(retemdray

Pressure 9120.46842.0)aPk(lacsapoliKnmulocretawfohcni

2523.07389.2)aPk(lacsapoliKnmulocretawfotoof

4692.01473.3)aPk(lacsapoliKnmulocyrucremfohcni

6023.29034.0)aPk(lacsapoliKhcnierauqsrepsecnuo

541.08498.6)aPk(lacsapoliKhcnierauqsrepsdnuop

Temperature 23+)Cº5/9()23-Fº(9/5)Cº(suiclectiehnerhaf

Velocity feet per second meters per second (m/s) 0.3048 3.2808

feet per minute ( fpm) meters per second (m/s) 0.00508 196.85

miles per hour meters per second (m/s) 0.44704 2.2369

Volume Flow Cubic feet per minute (cfm) Liters per second (L/s) 0.4719 2.119

Cubic feet per minute (cfm) Cubic meters per second (m3/s) 0.0004719 2119.0

Cubic feet per hour ( cfh) Milliliters per second( ml/s) 7.8658 0.127133

Gallons per minute(U.S.) Liters per second( L/s) 0.6309 15.850

Gallons per minute(imperial) Liters per second( L/s) 0.7577 13.198

Different samples from DASCO air terminal devices (Linear Slot Diffusers) were tested at ITS (Intertek Testing Services) labs in accordance with:

TESTING AND APPROVAL

Testing & Approval

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Air diffusion council test code for grilles, registers and diffusers No. ADC 1062: GRD-84.ISO 5219 “Air distribution and air diffusion laboratory aerodynamic testing and rating of air terminal devices”.ANSI/ASHRAE 70-1991, “Method of testing for rating the performance of air outlets and inlets”.

•

•

•

TESTING AND APPROVAL

LINEAR SLOT DIFFUSERS WERE TESTED FOR:

Sound (NC Noise Criteria).Static pressure in inches W.G.Throw, feet.Ak (Area factor).

a.b.c.d.

DASCO offers a first class service by introducing a wide range of perfect polyester powder coating on all of its aluminium products of air terminal devices.The best quality of polyester powder Corro-Coat are used in according to the inter--national standards (BS,ISO,DIN,ASTM). PE-F architectural grade polyester powders are used perfectly with pre-treatment, electrostatic spray and curing in accordance with the above standards recommendations. A complete range of RAL-Standard colours are always available in addition to a vast range of special compound colours as per our customers request.

COATING WITH POWDERCOATING WITH POWDER

NOW YOU CAN ACHIEVE OPTIMAL COATING PERFORMANCEON ALL PRODUCTS YOU PAINT!

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RAL Standard Colour Chart Swatch

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Since 1962

P.O. Box: 6192 Hawalli 32036 Kuwait.Tel: +965 4839911 Fax: +965 4815498

www.dasco.com.kw Prod

uct B

ulle

tin 1

33-D