81
NON RETURN DAMPERS
DESCRIPTION DIMENSIONS (mm) - PRESSURE DROP
W x
H
Wall
Fresh Air
Non return dampers(wall mounted)
50
0505
W +
50
x H
+ 5
0
W x
H
Non return dampers(duct mounted)
mounted)
• •Non ret
(duct
•••urn damper
••• • •Non return damper(wall mounted)
Non return/pressure relief dampers are designed for use in intake and discharge opening in commercial and residential airconditioning systems.
Option :â•¢ Gasket is Provided on blade for low leakage.
CONSTRUCTION :
• • •
When the ventilation system is on, the blades of the non-return damper are held in the open position by the airflow.
If the system is switched off,the damper blades close automatically, thus preventing reverse airflow and giving protection against the ingress of untem-pered air, rain and birds into theair conditioning system.
VOLUME CONTROL DAMPER
STANDERD CONSTRUCTION
FRAME 24 gauge sizes up to 12 in galvanized steel roll formed and clinched double beaded for rigidity and spiral Duct connetion .
BLADES Single blade galvanized BLADE
BUSH Nolon / PVC
Finish Mill galvanized Standerd extended shaft 8mm & 12mm square zinc plated steel Shaft extending 25mm beyond the air control Damper frame Sizes Minimum : 4 di Maximum : 24 di
OPTION:IRIS Round danper with double skin bladed & silicon seal.
Face
Size
82
BYPASS TERMINAL UNITSNON RETURN DAMPERS
Static Pressure Drop (Pa) Static Pressure Drop (in WC) NRD Leakage (CFM) Leakage Per Sq Ft (CFM/Sqft)
101 0.4 0 0184 0.7 0 0220 0.9 0 0285 1.1 0 0335 1.3 0 0415 1.7 0 0470 1.9 0 0570 2.3 0 0630 2.5 13.11 1.22740 3.0 13.11 1.22810 3.3 13.11 1.22930 3.8 24.16 2.241020 4.1 24.16 2.241150 4.6 42.70 3.97
LEAKAGE PERFORMANCE FOR LOW LEAKAGE CONSTRUCTION
TESTING DONE ON A 1000 X 1000 MM NON-RETURN DAMPER
TECHNICAL PRESSURE DROP
50
40
30
20
10
01 2 3 4 5 6
Vf (m/s)
P (P
a)Ł
∆
Recommended air velocity
Total pressure loss in Pa
Air velocity in the duct (m/s)
PŁ
Vf
83
BYPASS TERMINAL UNITSNON RETURN DAMPERS
Static Pressure Drop (Pa) Static Pressure Drop (in WC) NRD Leakage (CFM) Leakage Per Sq Ft (CFM/Sqft)
101 0.4 0 0184 0.7 0 0220 0.9 0 0285 1.1 0 0335 1.3 0 0415 1.7 0 0470 1.9 0 0570 2.3 0 0630 2.5 13.11 1.22740 3.0 13.11 1.22810 3.3 13.11 1.22930 3.8 24.16 2.241020 4.1 24.16 2.241150 4.6 42.70 3.97
LEAKAGE PERFORMANCE FOR LOW LEAKAGE CONSTRUCTION
TESTING DONE ON A 1000 X 1000 MM NON-RETURN DAMPER
TECHNICAL PRESSURE DROP
50
40
30
20
10
01 2 3 4 5 6
Vf (m/s)
P (P
a)Ł
∆
Recommended air velocity
Total pressure loss in Pa
Air velocity in the duct (m/s)
PŁ
Vf
84
BYPASS TERMINAL UNITSBYPASS TERMINAL UNITS
85
BYPASS TERMINAL UNITSBYPASS TERMINAL UNITS
86
BYPASS TERMINAL UNITSBYPASS TERMINAL UNITS
87
BYPASS TERMINAL UNITSBYPASS TERMINAL UNITS
88
BYPASS TERMINAL UNITSBYPASS TERMINAL UNITS
89
BYPASS TERMINAL UNITSBYPASS TERMINAL UNITS