INTRODUCTION
Dasco manufacture a variety types of louvers designed for intake, exhaust
and control air movement applications. Their strong, clean lines and careful
workmanship enhance the appearance of the building, whether it is
industrial, commercial or domestic. While most of the louvers are mainly
manufactured in complete lines of extruded aluminium blades, and to
complement or accentuate architectural feature, such as round, arched
and angular structures, Dasco can offer and modify special louvers
incorporating virtually any combination of round, diagonal and rectilinear
frame segments to be suitable for different applications and architectural
requirements.
Introduction
PRODUCT RANGE
It is well understood in HVAC engineering, that a proper air conditioning or ventilating system can not operate
efficiently without an efficient air movement component device. Hence, louver have been always considered
as one of the most important air terminal devices which utilize and control the flow of air in and out of the
buildings. Louver structure “frame and blades” can also be modified and reinforced to withstand excessive
loads and to play a role in effective weather protection.
Plenty of louver blades have been re-developed and many others newly designed to permit and help louvers
to be complied in many of the recent engineering applications.
2
3
Different types of Dasco louver blades
Fresh Air Louver
Sand Louver
Product Range
Sand Louver
(Special heavy duty type)
Sand Trap Louver
Pressure Relief Louver
(Gravity Shutter)
Penthouse Louver
Sightproof Louver
Drainable Louver
Stormproof Louver
Acoustic Louver
Product Range
FRESH AIR LOUVERS
GENERAL
Dasco fresh air louvers (DFL-11H) are considered as
an architectural air inlets and outlets with a remarkable
clean and aesthetically pleasing appearance. They are
widely and successfully used for central airconditioning,
ventilation and industrial ventilation systems. These
louvers have a low resistance to air flow and high free
area, making them a preferred choice for installations
which require high air flow.
Fresh Air Louver (DFL - 11H)
DESCRIPTION
4
5
DFL-11H louvers have a 2 inch deep fixed horizontal vanes (blades) which are carefully designed to get low
pressure drop, maximum free area and to prevent wind and rain-water penetration. They are available in
1.25” flanged (flat or curved) frame which in turn is mechanically joined to give the highest rigidity and
strength. Louvers can be supplied as optional with galvanized bird or aluminium insect screen, volume control
damper and air filter of 1”, 2” or 4” thickness. The filters are accessable from the side or backward of the
louver depending upon type of installation and must be specified by the customers. These louvers are available
in standard given sizes however, they can be supplied in other requested sizes and architectural shapes upon
customers requirements.
MATERIAL AND FINISH
DFL-11H louves are made of heavy gauge extruded
aluminium profiles. They are available in white
polyester powder coated finish or any other RAL
standard colour upon customer’s request. Bird
screens are made of galvanized expanded metal
sheets, however dampers are made of extruded
aluminium profiles.
Fresh Air Louver With Flat Frame
(DFL - 11HFF)
Fresh Air Louvers
PRODUCT CODE
Dasco Fresh Air Louvers
DFL - 11H
-
W
- H
-
C
Width in inch.
Height in inch.
Accessories:
B : Bird screen
D : Volume Control Damper (VCD)
BD : Bird screen & VCD.
I : Insect Screen.
F1 : Aluminium Filter 1’ thick.
F2 : Aluminium Filter 2” thick.
F4 : Aluminium Filter 4” thick.
Use the code of DFL-11HFF to refer to Dasco fresh air louver with flat frame.
Example :
DFL - 11H - 16 - 20 - BD:
Dasco fresh air intake louver size 16” x 20” with bird screen and volume control damper (VCD).
DFL - 11H - 40 - 20 - BDF2:
Dasco fresh air intake louver size 40”x20” with bird screen, volume control damper (VCD) and 2” thick
aluminium filter.
Note: Always specify the horizontal dimension first.
Octagonal
Louver
Triangular Louver
Arched Louver
SPECIAL ARCHITECTURAL LOUVERS
Fresh Air Louvers
DIMENSIONAL DATA
44.0mm
7.5mm
51.5mm
32.0mm
Dasco Fresh Air Louver with curved frame (DFL - 11H)
44.0mm
32.0mm
51.5mm
6
7.5mm
19.0mm
7
Dasco Fresh Air Louver with flat frame (DFL - 11HFF)
DFL - 11H - F2
DFL - 11H - B
Dimensional Data
DEFINITIONS & SELECTION PROCEDURE
DEFINITIONS
Face velocity
:
Is the air stream velocity measured at the face of a louver in FPM.
CFM
:
Is the air flow rate in cubic feet per minute.
Effective free area
:
Is in ft , and is related to the other parameters by the equation :
2
CFM = Free Area x Face velocity
= Ak x Vk
Total pressure drop
:
Is the sum of static pressure and velocity pressure given in inches W.G.
SELECTION PROCEDURE
Example:
Louver size required for an exhaust requirements of 1600 CFM with a total pressure drop of 0.016” W.G.
1.
From the pressure requirement table 1 it shows that a 400 FPM velocity results an exhaust pressure
drop of 0.016 W.G.
2.
Determine the effective free area.
CFM
Effective free area Ak =
Vk
=
3.
1600
400
= 4.0 ft2
2
From table 2 the 4.0 ft effective free area is suitable for the following sizes: 28” x 54”, 48” x 30”
... etc.
Note:
For other louver sizes not shown in table 2. The approximate effective free area in square feet can be
calculated by using the following formula:Effective free area (Ak) = (0.5H - 0.25) x (W-0.125)
where, H is Height in ft and W is Width in ft.
Definitions & Selection
PERFORMANCE DATA
PRESSURE REQUIREMENT
Face Velocity (FPM)
200
300
400
500
600
700
800
900
1000
1200
1400
1600
Intake PD” W. G.
0.005 0.011
0.02
0.031
0.045
0.061
0.08
0.10
0.126
0.18
0.25
0.336
Exhaust PD” W. G.
0.004
0.016 0.024
0.035
0.048
0.062
0.078
0.098
0.14
0.195
0.266
0.009
Table No. 1. Total pressure drop in inches of water as a function of face velocity in FPM for DFL-11H
EFFECTIVE FREE AREA
Height
(Inches)
8
9
Width (Inches)
12
14
16
18
20
24
30
36
42
48
54
60
72
12
0.23
0.30
0.35
0.40
0.45
0.55
0.69
0.78
0.98
1.13
1.28
1.42
1.71
16
0.39
0.46
0.54
0.62
0.69
0.84
1.06
1.29
1.51
1.74
1.96
2.29
2.63
20
0.50
0.62
0.73
0.83
0.93
1.13
1.43
1.74
2.04
2.34
2.64
2.94
3.55
24
0.65
0.79
0.91
1.05
1.17
1.43
1.81
2.19
2.57
2.95
3.33
3.71
4.47
28
0.79
0.96
1.11
1.26
1.41
1.72
2.18
2.63
3.09
3.55
4.01
4.45
5.39
32
0.93
1.12
1.30
1.47
1.65
2.01
2.35
3.08
3.62
4.16
4.69
5.23
6.30
36
1.07
1.28
1.48
1.69
1.89
2.30
2.92
3.53
4.15
4.76
5.38
5.99
7.22
40
1.21
1.44
1.67
1.90
2.14
2.59
3.29
3.98
4.67
5.37
6.06
6.75
8.14
44
1.35
1.60
1.86
2.12
2.38
2.89
3.66
4.43
5.20
5.97
6.74
7.52
9.06
48
1.48
1.77
2.05
2.33
2.62
3.18
4.03
4.88
5.73
6.58
7.43
8.28
9.97
52
1.64
1.93
2.24
2.55
2.86
3.48
4.40
5.33
6.26
7.18
8.11
9.04
10.89
56
1.77
2.11
2.43
2.76
3.09
3.77
4.77
5.78
6.78
7.79
8.80
9.80
11.81
60
1.90
2.27
2.62
2.97
3.34
4.06
5.14
6.23
7.31
8.40
9.48
10.56
12.73
64
2.04
2.43
2.81
3.19
3.58
4.36
5.52
6.68
7.84
9.32
10.16
11.32
13.65
68
2.19
2.59
2.99
3.41
3.82
4.65
5.89
7.13
8.37
9.61
10.58
12.09
14.56
72
2.31
2.76
3.18
3.62
4.06
4.98
6.26
7.58
8.89
10.21
11.53
12.85
15.48
Table No. 2. Effective free area in ft2 (Ak factor) for DFL-11H
Performance Data
SAND LOUVERS
GENERAL
Dasco sand louver DSL-12H are architectural air
inlets. They are widely used for building exteriors
and are suitable for different HVAC and industrial
applications to prevent sand entry. The blades are
carefully designed to provide a low resistance to air
flow and a high free area.
Sand Louver (DSL - 12H)
DESCRIPTION
DSL-12H louvers have 2 inch deep horizontal fixed blades designed carefully for low pressure drop and to
prevent entry of sand. The frame is 1.25” wide (flat or curved) flanged type and is mechanically joined to
give a rugged construction to the louver. These louvers are available as optional with galvanized bird screen,
aluminum type air filter in 1”, 2” and 4” thickness and volume control damper. They are manufactured in
a wide range of standard sizes however, they can be supplied in non-standard sizes, depths or architectural
shapes to suit customers requirements.
MATERIAL AND FINISH
DSL-12H sand louvers are made of heavy extruded
aluminium profiles. They are available in white
polyester powder coated finish or any other RAL
standard colour upon customer’s request. Bird
screens are made of galvanized expanded metal
sheets.
Sand Louver With Flat Frame
(DSL - 12HFF)
Sand Louvers
PRODUCT CODE
Dasco Sand Louver
DSL - 12H
-
W
-
H
-
C
Width in inch.
Height in inch.
Accessories:
B
: Bird screen
D
: Volume Control Damper (VCD)
BD : Bird screen & VCD.
I
: Insect Screen.
F1 : Aluminium Filter 1” thick.
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11
F2 : Aluminium Filter 2” thick.
F4 : Aluminium Filter 4” thick.
Use the code of DSL-12HFF to refer to Dasco sand louver with flat frame.
Example:
• DSL - 12H - 30 - 18 - B:
Dasco Sand Louver - size 30” x 18” with bird screen.
• DSL - 12 H - 24 - 20 BDF1:
Dasco Sand Louver - size 24” x 20” with bird screen, volume control damper and 1” thick aluminium
filter.
A special assembly of sand louver with a bird screen,
volume control damper and a washable aluminium
filter. (All are enclosed in a galvanized box).
Model: DSL-12H - W - H - BDF2
Sand Louvers
DIMENSIONAL DATA
32.0mm
7.5mm
51.5mm
54.0mm
Dasco Sand Louver with curved frame - (DSL - 12H)
32.0mm
7.5mm
51.5mm
54.0mm
Dasco Sand Louver with flat frame - (DSL - 12HFF)
SELECTION PROCEDURE
To select a suitable size of a sand louver (DSL-12H) for a certain application, follow exactly the same procedure
as been explained previously.
Note:
For louver sizes not shown in table 5. The approximate effective free area in square feet can be calculated
by using the following formula:Effective free area (Ak) = (0.45 H-0.08) x (W-0.1)
Where, H is Height in ft and W is Width in ft.
Dimensional Data
PERFORMANCE DATA
AVAILABLE STANDARD SIZES
12x12
12x14
12x16
12x18
12x20
12x24
12x30
12x36
12x42
12x48
16x12
16x14
16x16
16x18
16x20
16x24
16x30
16x36
16x42
16x48
20x12
20x14
20x16
20x18
20x20
20x24
20x30
20x36
20x42
20x48
24x12
24x14
24x16
24x18
24x20
24x24
24x30
24x36
24x42
24x48
28x12
28x14
28x16
28x18
28x20
28x24
28x30
28x36
28x42
28x48
32x12
32x14
32x16
32x18
32x20
32x24
32x30
32x36
32x42
32x48
36x12
36x14
36x16
36x18
36x20
36x24
36x30
36x36
36x42
36x48
40x12
40x14
40x16
40x18
40x20
40x24
40x30
40x36
40x42
40x48
44x12
44x14
44x16
44x18
44x20
44x24
44x30
44x36
44x42
44x48
48x12
48x14
48x16
48x18
48x20
48x24
48x30
48x36
48x42
48x48
Table No. 3 DSL-12H standard sizes available (HxW) in inches.
PRESSURE REQUIREMENT
12
13
Face Velocity (FPM)
200
300
Intake PD” W.G.
0.007 0.016
400
500
600
700
800
900
1000
1200
1400
1600
0.028 0.044
0.063
0.086
0.112
0.141 0.175 0.252
0.338
0.433
Table No. 4 Intake pressure drop in inches of water as a function of face velocity in FPM for DSL-12H.
EFFECTIVE FREE AREA
Height
(Inches)
Width (Inches)
12
14
16
18
20
24
30
36
42
48
12
0.33
0.40
0.46
0.52
0.58
0.70
0.89
1.07
1.26
1.45
16
0.47
0.55
0.64
0.73
0.81
0.99
1.25
1.51
1.77
2.00
20
0.60
0.71
0.83
0.94
1.05
1.27
1.61
1.94
2.28
2.61
24
0.74
0.87
1.01
1.15
1.28
1.56
1.97
2.38
2.79
3.20
28
0.87
1.03
1.20
1.36
1.52
1.84
2.33
2.81
3.30
3.78
32
1.00
1.19
1.38
1.57
1.75
2.12
2.69
3.25
3.81
4.37
36
1.14
1.35
1.57
1.78
1.99
2.41
3.05
3.70
4.32
4.95
40
1.28
1.51
1.75
1.99
2.22
2.70
3.41
4.12
4.83
5.54
44
1.41
1.67
1.94
2.20
2.46
2.98
3.77
4.55
5.34
6.12
48
1.55
1.83
2.12
2.41
2.69
3.30
4.13
5.00
5.85
6.71
Table No. 5. Effective free area in ft2 (Ak factor) for DSL-12H.
Performance Data