1
1.0 Introduction
This constant volume damper is designed for installation with
Nuaire’s range of fans.
Units are rectangular in section, manufactured from galvanised
steel.
The CVD damper will control the flowrate passing through it when
the pressure drop across the damper is within the range stated in
the performance envelope.
Two flow settings are available; trickle and boost. The damper will
operate in the trickle setting when it is powered up and will go into
the boost setting when a mains signal is received at the SL terminal
or when the CVD-PIR (optional ancillary) is activated. A run-on timer
(adjustable between 1 to 60 minutes) will hold the damper in the
boost setting for the preset time period.
2.0 Dimensions
Figure 1.
Dimensions in mm.
Code
A
B
C
D
E
F
kg
CVD125
300
180
195
125
75
400
3.5
CVD150
300
200
220
150
90
400
3.7
CVD200
300
230
275
200
115
400
4
3.0 Handling
Handle the units carefully to avoid damage and distortion to
moving parts.
4.0 System Design
A nominal pressure drop must be allowed in order to ensure
adequate airflow through the damper. To ensure the airflow
pattern through the damper produces consistent readings; the
pressure drop across the damper should not exceed the
recommended value. Recommended values are listed in the table
following and show the performance envelope of each damper.
Nominal design pressure is the value needed to produce the
maximum rated airflow for the damper. If the desired flowrate
is less than the maximum, a lower design value may be used
by reading off the lower curve of the appropriate chart. Please
allow 40Pa (min).
Model code
Nominal design
Maximum pressure
pressure drop
across damper*
CVD125
70Pa
140Pa
CVD150
80Pa
160Pa
CVD200
90Pa**
200Pa
*recommended maximum operating pressure to ensure the damper
would work within calibration limits.
Keep the duct velocity as low as possible to ensure the system
produces the lowest energy usage, preferably below 5m/s.
**Allow 90Pa for duties below 100l/s and 150Pa for duties between
100l/s and 125l/s.
CVD125/150/200
Constant Volume Dampers
Installation and Maintenance
10. 05. 17. Leaflet Number 671638
D
B
C
A
F
E
Trickle
Boost
Run-on
10
15
20
5
25
10
15
20
5
25
15
30
45
1
60
Airflow
0
20
40
60
80
100
120
0
10
20
30
40
50
60
Pr
essur
e dr
op P
a
design pressure
140
160
180
Volume flowrate l/s
Figure 2. Performance envelope for CVD125.
Plan view
Side view
0
50
100
150
0
20
40
60
80
100
Pr
essur
e dr
op P
a
design pressure
200
250
Volume flowrate l/s
Figure 3. Performance envelope for CVD150.
0
50
100
150
0
20
40
60
80
160
Pr
essur
e dr
op P
a
Nominal design pressure
200
250
Volume flowrate l/s
300
*
100
120
140
Figure 4. Performance envelope for CVD200.
*Allow 90Pa for duties below 100l/s and 150Pa for duties between
100l/s and 125l/s.
The EMC Directive
2014/30/EU
The Low Voltage
Directive
2014/35/EU
Nuaire: A Trading Division of Polypipe Limited
Western Industrial Estate
Caerphilly United Kingdom CF83 1NA
T: 029 2088 5911 F: 029 2088 7033 E: [email protected] W: www.nuaire.co.uk
