small_tab1_Serie RN
RN_1
hygiene
small_tab1_Serie RN
RN_1
hygiene

RN

CIRCULAR SELF-POWERED VOLUME FLOW CONTROLLERS FOR THE CONTROL OF SUPPLY AIR OR EXTRACT AIR IN CONSTANT AIR VOLUME SYSTEMS.


Key information

Volume flow rate can be set using an external scale, no tools required
High control accuracy
No on-site test measurements required for commissioning
Suitable for airflow velocities of up to 12 m/s
Any installation orientation; maintenance-free
Casing air leakage to EN 1751, class C

Optional equipment and accessories
  • Acoustic cladding for the reduction of case-radiated noise
  • Secondary silencer Type CA, CS or CF for the reduction of air-regenerated noise
  • Hot water heat exchanger Type WL and electric air heater Type EL for reheating the airflow
  • Actuator for switching between setpoint values

APPLICATION

Application

  • Circular CONSTANTFLOW CAV controllers of Type RN for the precise supply air or extract air flow control in constant air volume systems
  • Mechanical self-powered volume flow control without external power supply
  • Simplified project handling with orders based on nominal size
  • Volume flow rate setpoint can be set on external scale
  • Switching between Vmin and Vmax using optional actuator

Special features

  • Volume flow rate can be set using an external scale; no tools required
  • High volume flow rate control accuracy
  • Any installation orientation

Nominal sizes

  • RN-S: 80, 100, 125
  • RN: 80, 100, 125, 160, 200, 250, 315, 400
  • RN-FL: 100, 125, 160, 200, 250, 315, 400

DESCRIPTION

Variants
  • RN-S: Compact-height volume flow controller
  • RN: Volume flow controller
  • RN-D: Volume flow controller with acoustic cladding
  • RN-FL: Volume flow controller with flanges on both ends
  • RN-D-FL: Volume flow controller with acoustic cladding and flanges on both ends
  • Units with acoustic cladding and/or a secondary silencer Type CA, CS or CF for demanding acoustic requirements
  • Acoustic cladding cannot be retrofitted

Construction
  • Galvanised sheet steel
  • P1: Powder-coated, silver grey (RAL 7001)
  • A2: Stainless steel

Parts and characteristics
  • Ready-to-commission controller
  • Damper blade with low-friction bearings
  • Bellows that acts as an oscillation damper
  • Cam plate with leaf spring
  • Scale with pointer to set the volume flow rate setpoint
  • Aerodynamic function testing of each unit on a special test rig prior to shipping
  • Correct operation even under unfavourable upstream conditions (1.5 D straight section required upstream)

Attachments
  • Min/Max actuators: Actuators for switching between minimum and maximum volume flow rate setpoint values
  • Modulating actuators: Actuators for the stepless adjustment of volume flow rates or to switch between minimum and maximum volume flow rate setpoint values
  • Retrofit kits: Actuators and installation accessories
  • Variant RN-S cannot be combined with an actuator

Accessories
  • Lip seals on both ends (factory fitted)
  • Matching flanges for both ends

Useful additions
  • Secondary silencer Type CA, CS or CF
  • Heat exchanger Type WL
  • Electric air heater Type EL

Construction features

  • Circular casing
  • Spigot suitable for circular ducts to EN 1506 or EN 13180
  • Spigot with groove for lip seal (RN-P1/80 and RN-A2/80 without groove)
  • RN-FL: Circular flanges to EN 12220

Materials and surfaces

  • Casing made of galvanised sheet steel
  • Interior parts, nominal sizes 80 – 125: stainless steel 1.4301, nominal sizes 160 – 400: galvanised sheet steel
  • Polyurethane bellows
  • Plain bearings with PTFE coating
  • Leaf spring made of stainless steel

Powder-coated construction (P1)

  • Casing made of galvanised sheet steel, powder-coated
  • Interior parts, nominal sizes 80 – 125: stainless steel 1.4301, nominal sizes 160 – 400: galvanised sheet steel, powder-coated

Stainless steel construction (A2)

  • Casing made of stainless steel 1.4301
  • Interior parts made of stainless steel

Variant with acoustic cladding (-D)
  • Acoustic cladding made of galvanised sheet steel
  • Rubber profile for the insulation of structure-borne noise
  • Lining is mineral wool

Mineral wool
  • To EN 13501, fire rating class A1, non-combustible
  • RAL quality mark RAL-GZ 388
  • Biosoluble and hence hygienically safe according to the German TRGS 905 (Technical Rules for Hazardous Substances) and EU directive 97/69/EC

Standards and guidelines
  • Hygiene conforms to VDI 6022
  • Casing air leakage to EN 1751, class C

Maintenance
  • Maintenance-free as construction and materials are not subject to wear

TECHNICAL INFORMATION

  • FUNCTION
  • TECHNICAL DATA
  • QUICK SIZING
  • SPECIFICATION TEXT
  • ORDER CODE

Functional description
The volume flow controller is a mechanical self-powered unit and works without external power supply. A damper blade with low-friction bearings is adjusted by aerodynamic forces such that the set volume flow rate is maintained within the differential pressure range.

The aerodynamic forces of the airflow create a closing torque on the damper blade. The bellows extends and increases this force while at the same time acting as an oscillation damper. The closing force is countered by a leaf spring that unrolls over a cam plate. The shape of the cam plate is such that a change in the differential pressure leads to an adjustment of the damper blade in a way that the volume flow rate is maintained almost exactly.

Efficient commissioning
The volume flow rate setpoint value can be set quickly and easily using the pointer on the external scale; no measurements are required.

The advantage over flow adjustment dampers is that there is no need for repeat measurements or adjustments by an air conditioning engineer. Should the system pressure change, e.g. by opening or closing of duct sections, the flow rates in the entire system will also change if flow adjustment dampers are used; however, this is not the case with mechanical self-powered volume flow controllers A mechanical self-powered controller reacts immediately and adjusts the damper blade such that the set constant volume flow rate is maintained.

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Volume flow rate ranges

The minimum differential pressure of CAV controllers is an important factor in designing the ductwork and in rating the fan including speed control.

Sufficient duct pressure must be ensured for all operating conditions and for all control units. The measurement points for fan speed control must be selected accordingly.

Quick sizing tables provide a good overview of the room sound pressure levels that can be expected. Approximate intermediate values can be interpolated. Precise intermediate values and spectral data can be calculated with our Easy Product Finder design programme.

The first selection criteria for the nominal size are the actual volume flow rates Vmin and Vmax. The quick sizing tables are based on generally accepted attenuation levels. If the sound pressure level exceeds the required level, a larger air terminal unit and/or a silencer is required.

Sizing example

Given data

Vmax = 280 l/s (1010 m3/h)

Δpst = 150 Pa

Required sound pressure level in the room 35 dB(A)

Quick sizing
RN/200 with circular silencer CS 050/200×1000
Air-regenerated noise LPA = 26 dB(A)

Case-radiated noise LPA = 31 dB(A)

Circular volume flow controllers for constant air volume systems, mechanical self-powered, without external power supply, suitable for supply or extract air, available in 8 nominal sizes.

Ready-to-commission unit consists of the casing containing a damper blade with low-friction bearings, bellows, external cam plate and leaf spring.

Volume flow controllers without actuators are factory set to a reference volume flow rate (customers can set the required volume flow rate on site).

Spigot with groove for lip seal, suitable for connecting ducts according to EN 1506 or EN 13180.

Casing air leakage to EN 1751, class C.

Special features

  • Volume flow rate can be set using an external scale; no tools required
  • High volume flow rate control accuracy
  • Any installation orientation


Materials and surfaces

Galvanised sheet steel construction

  • Casing made of galvanised sheet steel
  • Interior parts, nominal sizes 80 – 125: stainless steel 1.4301, nominal sizes 160 – 400: galvanised sheet steel
  • Polyurethane bellows
  • Plain bearings with PTFE coating
  • Leaf spring made of stainless steel


Powder-coated construction (P1)

  • Casing made of galvanised sheet steel, powder-coated
  • Interior parts, nominal sizes 80 – 125: stainless steel 1.4301, nominal sizes 160 – 400: galvanised sheet steel, powder-coated


Stainless steel construction (A2)

  • Casing made of stainless steel 1.4301
  • Interior parts made of stainless steel


Variant with acoustic cladding (-D)

  • Acoustic cladding made of galvanised sheet steel
  • Rubber profile for the insulation of structure-borne noise
  • Lining is mineral wool


Mineral wool

  • To EN 13501, fire rating class A1, non-combustible
  • RAL quality mark RAL-GZ 388
  • Biosoluble and hence hygienically safe according to the German TRGS 905 (Technical Rules for Hazardous Substances) and EU directive 97/69/EC

Construction

  • Galvanised sheet steel
  • P1: Powder-coated, silver grey (RAL 7001)
  • A2: Stainless steel

Technical data

  • Nominal sizes: 80 to 400 mm
  • Volume flow rate range: 11 to 1400 l/s or 40 to 5040 m³/h
  • Volume flow rate control range: approx. 25 – 100 % of the nominal volume flow rate
  • Minimum differential pressure: 50 Pa (nominal size 80: 100 Pa)
  • Maximum differential pressure: 1000 Pa

Sizing data

  • V _______________________ [m³/h]
  • Δpst _______________________ [Pa]

Air-regenerated noise

  • LPA _______________________ [dB(A)]

Case-radiated noise

  • LPA _______________________ [dB(A)]

This specification text describes the general properties of the product. Texts for variants can be generated with our Easy Product Finder design programme.

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Thank you for your message!

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Our department for Service-Requests will contact you asap.
For general question regarding products or services you can also call:
Tel.: +49 (0)2845 / 202-0 | Fax: +49 (0)2845/202-265