AIRTECHNIC RDA Rectangular Volume Dampers Instruction Manual

AIRTECHNIC RDA Rectangular Volume Dampers

Product Information:

Rectangular volume dampers (RDA) are designed for air duct installation in air-conditioning and ventilation systems. They are used to regulate volume flow and pressure control. The dampers can be adjusted manually or automatically using actuators and can be combined with thermostats and automation systems. The casing is typically made from galvanized steel sheet with flanges on both sides. The blades, rotating in opposite directions, are manufactured from hollow-body aluminum profile.

Product Usage Instructions

Damper Selection:

Refer to technical specifications and diagrams for selecting the appropriate rectangular damper based on width, height, blade angle, surface factor, pressure drop, maximum velocity, and noise level.

Dividing Large Rectangular Dampers:

If the damper is very large, follow the guidelines for dividing the damper either vertically or horizontally as per requirements.

Installation:

Rectangular dampers can be installed between air ducts, on the air duct’s inlet, on the air duct’s outlet, or on a wall. Follow the specific installation instructions for each type of installation.

FAQ

• Q: Can the damper be manufactured in custom dimensions?
  • A: Yes, it is possible to manufacture rectangular dampers in any dimension under order.
• Q: What materials are used for manufacturing the casing?
  • A: The casing is typically made from galvanized steel sheet but can also be made from aluminum, copper, stainless steel sheet, or plastic PVC.

Product Information

Rectangular dampers are used in air-conditioning and ventilation systems when it is required to regulate the volume flow or for pressure control. The air volume and the blade angle can be adjusted either manually or automatically using On – Off actuators 230V (or 24V) or analog actuators 24V and it can be combined with suitable thermostats and automation systems. The casing is manufactured from galvanised steel sheet (or from aluminum, copper and stainless steel sheet) with perimetric flanges on both sides. It’s possible to manufacture the damper from plastic PVC. The blades are manufactured from hollow-body aluminum profile and they are rotating in opposite directions, via external plastic gear wheels.

The standard dimensions for rectangular dampers are presented in a following table . However, it is possible to manufacture rectangular dampers in any dimension, under order. The following diagrams provide data suitable for selecting dampers in open full (00) position as well as for selecting dampers with blade angle 150, 350, 450 & 600. In case the damper is very large (with height over 1.500 mm and width over 1.600 mm) it can be divided horizontally or vertically according to the requirements

RECTANGULAR DAMPER SELECTION

The technical specifications for rectangular dampers are the following :

The selection of rectangular dampers will be made using the following diagrams and in accordance with the normative document CR 1752:1998 (Ventilation for buildings – Design criteria for the indoor environment).

DAMPER WITH WEATHER RESISTANT LOUVRE WALL INSTALLATION EXAMPLE

DIVIDING LARGE RECTANGULAR DAMPERS

INSTALLATION

Rectangular dampers are suitable for installation:

• (Α) Between air-ducts
• (Β) On the air-ducts inlet
• (C) On the air-ducts outlet
• (D) On a wall

The following diagrams provide data suitabe for selecting fully open dampers (00), for all installation types and for selecting blade angle 150, 300, 450 & 600 for installation between air ducts (type Α). In order to calculate the pressure drop, for blade angle 150, 300, 450 & 600, for installation type B, C & D, we calculate the pressure drop according to diagrams and we multiply the result using the correction factors that are provided in the following table (*). The noise produced, is not depend from the volume flow type.

*() See the calculation example.**

SPECIAL VOLUME DAMPER CONSTRUCTION

Weather-resistant louver with intergraded volume damper, weather-resistant louvre with intergraded volume damper and prefilter G2, G3 or G4, weather- resistant louvre with intergraded sand filter. This special construction ensures better protection from rain, while, at the same time the intergration of prefilters G2, G3 or G4 increase the quality of the supplied air. The addition of a sand filter gives a boost at the performance of the entire air- conditioning/ventilation system as well as an increase of the life span of the other filters in the installation

In order to calculate the pressure drop in special volume damper constructions, please contact the AIRTECHNIC technical department

BLADE ANGLE

BLADE ANGLE – 0

BLADE ANGLE – 15

BLADE ANGLE – 30

BLADE ANGLE – 45

BLADE ANGLE – 60

Selection example 1 :

What are the dimensions of a rectangular damper for air duct installation type A when the air flow is 4.500 m3/h?

From diagram 1.2 we notice that for 4.500 m3/h the range of the pressure drop is from 1 to 100 Pa using surface factors  Af from 11 to 150. Assuming that, for fully open damper, a pressure drop of 10 Pa, in the air duct system is satisfying, we establish from diagram 1.2, that the surface factor Af is 42. The dimensions of the damper are usually selected according to the dimensions of the connecting air duct, in order to have at least one dimension, preferably the height, identical and avoid installing additional adaptors. Therefore, if the desired height is 600 mm then, from the surface factor selection table, we conclude that for a damper height equal to 600 mm the damper width must be 700 mm. From diagram 1.1 we calculate that the maximum air velocity inside the damper 700 x 600 is equal to 3,5 m/s, while from diagram 1.3 we calculate that the produced noise is equal to 40 dB(A).

Selection example 2 :

How much will the pressure drop increase if the blades of the volume damper, of example 1, change from fully open position to angle 300?

In example 1, we calculated that the volume damper 700 x 600, has a pressure drop of 10 Pa when its blades are in fully open position (00), and the air flow is 4.500 m3/h. If the blade angle changes to 300 then, according to diagram 3.2 (page 7) the new pressure drop will be 38,5 Pa.

Selection example 3 :

How much would the pressure drop be, if the volume damper, of example 1, was installed on the air duct’s outlet (type C) and the blade angle was 450?

In example 1, we calculated that the volume damper 700 x 600, has a pressure drop of 10 Pa when its blades are in fully open position (00), and the airflow is 4.500 m3/h. If the blade angle changes to 450 then, according to diagram 4.2 (page 8) the new pressure drop will be 76 Pa. We then multiply the result using the proper correction factor, for type C installation and blade angle 450 (1,5) and we calculate that the pressure drop is equal to 114 Pa.

The diagrams above, are an approximate selection method for volume dampers. For more precise calculations, please use the volume damper calculation software KlimaCalc from AIRTECHNIC or contact us.

SURFACE FACTOR SELECTION TABLE

DAMPER ACTUATOR SELECTION

The basic actuator types are distinguished to those with return springs and to those with no return springs.

Regardless of type, they offer the following, typical, control options:

1. Οn / Off control using actuators 230V or 24V
2. 3 Position control using actuators 230V or 24V
3. Modulating control using actuators 24V (signal 0…10V)

Under order, AIRTECHNIC can also provide actuators with special specifications:

1. Fast-acting actuators 2 sec.
2. Actuators with integrated controller and differencial pressure sensor for zoning systems which require constant air supply. They do not require additional automation installation. For technical data and special actuator selection, please contact with AIRTECHNIC technical department.

DAMPER ACTUATORS – NON-SPRING RETURN (SIEMENS)

DAMPER ACTUATORS – SPRING RETURN (SIEMENS)

DAMPER ACTUATORS – NON-SPRING RETURN (BELIMO)

DAMPER ACTUATORS – SPRING RETURN (BELIMO)

DAMPER ACTUATOR SELECTION

The selection for the damper actuator is based on the torque required for the rotation of the damper’s blades. The following table gives the necessary torque, according to the damper’s surface

DAMPER ACTUATORS INDICATIVE DIMENSIONS

ACTUATORS FOR TORQUE 5 Nm & 10 Nm

ACTUATORS FOR TORQUE 20 Nm

DAMPER ACTUATORS INSTALLATION

RECTANGULAR DAMPERS ORDER

For the proper order of rectangular dampers please use the following code :

Examples

• RDA 600 x 600 +G + MA | PN20 =
  • Rectangular, multi-leaf air duct damper, 600 mm in width and in height, with protection grid, air duct profile Νο20, frame from galvanized steel and blades from aluminum. The damper will be controlled with an analog actuator 24V.
• RDA 500 x 400 | PN30Ι | FR.I | BL.I =
  • Rectangular, multi-leaf air duct damper 500 mm in width & 400 mm in height, with air duct profile Νο30 ΙΝΟΧ, frame and blades from stainless steel. The damper will be controlled manually.
• RDA 700 x 500 +MO | FR.7015 | GL.GL =
  • Rectangular, multi-leaf air duct damper 700 mm in width & 500 mm in height, without air duct profile, frame powder painted in RAL 7015 and blades from galvanized steel. The damper will be controlled with On / Off actuator 230V.

SPECIFICATION

Rectangular, multi-leaf air duct damper, RDA

Rectangular, multi-leaf air duct damper, indicative type RDA by AIRTECHNIC, manufactured of galvanized steel / painted in RAL… color/aluminum/copper / stainless steel/plastic PVC, with opposite moving blades manufactured of hollow-body aluminum profile / galvanized steel/copper / stainless steel. The blade movement will be achieved via plastic gears. The blade angle adjustment will be achieved manually (RDA) / automatically via actuator On/Off 230V (RDA+ΜΟ) / automatically via analog actuator 24V (RDA+MΑ). It will be possible to install a 3-position actuator [M…/3] / actuator with auxiliary contacts [Μ…/Α]. The manufacturer will have performed measurements of the technical characteristics of the grille, in an independent laboratory according to the standard

ELOT EN 1751:1998. It will not have air duct profile / It will have air duct profile Νο 20, 30, 40, 30 INOX [PN20, PN30, PN40, PN30I]. It will have grid [G]. It will be suitable for placement within an air duct system, for indoor air exhaust or fresh air intake. The factory will be certified according to ISO 9001:2015 (Quality Management
Systems) and according to ISO 14001:2015 (Environmental Management Systems).

• It will be manufactured by AIRTECHNIC type RDA / RDA +G / RDA | PN20, PN30, PN40, PN30I

• It will be manufactured by AIRTECHNIC type RDA+ΜΟ

• It will be manufactured by AIRTECHNIC type RDA+ΜΑ

• Management System

• ISO 14001:2015

• Valid until:

• 2024-09-24

• www.tuv.com

• ID 9108650718

Contact

Main Office ATHENS

• Paparrigopoulou 10 & Lagada,
• 12132, Peristeri, Athens211 – 705.55.00
• sales@airtechnic.gr

Factory – THIV

• A4th km Thiva – Chalkida Hwy,32200, Thiva22620 – 89.006
• factory@airtechnic.gr

Factory – THESSALONIKI

• End of Meandrou Str.,57013, Oraiokastro, Thessaloniki2311 – 82.40.00
• thessaloniki@airtechnic.gr

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