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Tandem 300

Heated and ambient air streams for more effective cold air screening.

Tandem 300
Your benefits:
  • 38% energy-savings, thanks to patented Tandem technology

  • Minimal heating requirement with the same penetration depth

  • Valves (optional) can be concealed behind the casing

Key features

  • Short delivery times for our standard door air curtains
  • For controlled screening of cold air with open doors
  • Energy savings of up to 38% compared to conventional systems
  • One fan group with patented separation of the air stream for ambient and warm air stream (Tandem technology)
  • Improved use of space Workplaces can be arranged more closely to the entrance
  • Faster return on investment compared to conventional systems
  • Officially verified property right: European Patent EP 1462730 A1



  • Coanda effect to improve the depth of penetration of the door air curtain:
    - Ambient air stream pulls the warm air stream
    - Improved screening and higher installation heights compared to conventional systems
  • Ambient air stream acts as a back-up stream
  • Adverse energy-intensive turbulence occurs primarily between the outside air and the unheated ambient air stream
  • Adverse weather stays outside, thanks to the enhanced penetration depth between two parallel air streams of different temperature
  • High-performance copper/aluminium heat exchanger
  • Easily removable air filter (grade G 2 in line with DIN EN 779); easy to clean by vacuuming or washing
  • Anti-torsion mechanism for heating connections prevents damage to the heat exchanger when screwing in the valves; valves optionally available as accessories


  • Versatile use in showrooms and sales floors of all kinds, malls and public buildings
  • Wall or ceiling-mounted
  • Modular design enables multiple devices to appear as a single visual unit
  • Can also be installed within a suspended ceiling
  • Lengths 1.25, 2.0, 2.5 and 3.0 m
  • Suitable for mounting heights of 2.7 to 3.2 m

... also good to know

  • KaControl system or electromechanical control possible
  • Integration in KaControl networks or building automation systems, such as BACnet, Modbus or LON possible
  • Non-standard designs, i.e. other RAL colours, on request
Technical catalogues
Tandem 300 door air curtainsdownload as.pdf, 8,27 MB
Spezial Tandem 300 door air curtains, screen-optimizeddownload as.pdf, 2,67 MB
Cross-product information
Product overview, products available in UKdownload as.pdf, 4,79 MB
Overview product innovations 2017download as.pdf, 2,41 MB
Spezial Hoteldownload as.pdf, 2,41 MB
Spezial retail chainsdownload as.pdf, 3,45 MB
Spezial Commercial buildingsdownload as.pdf, 2,17 MB
Spezial KaControl building automationdownload as.pdf, 794,90 KB
Spezial Logistics buildingsdownload as.pdf, 830,76 KB
Spezial sports halldownload as.pdf, 2,26 MB
Overview Heating and Cooling with Refrigerantsdownload as.pdf, 4,39 MB
Installation manuals
Tandem 300, Tandem 300 ceiling cassette unit Door air curtains, (new version 2017)download as.pdf, 3,47 MB
Building product declaration door air curtainsdownload as.pdf, 209,67 KB
TÜV Certificate ISO 9001:2008download as.pdf, 140,21 KB
EU Declaration of Conformity UniLine, Vario, Tandem door air curtainsdownload as.pdf, 1,70 MB
CAD drawings
Tandem 300 EC door air curtain, model size 12download as.dwg, 217,97 KB.dxf, 1,57 MB.pdf, 83,11 KB
Tandem 300 EC door air curtain, model size 20download as.dwg, 247,88 KB.dxf, 1,84 MB.pdf, 88,45 KB
Tandem 300 EC door air curtain, model size 25download as.dwg, 250,09 KB.dxf, 1,84 MB.pdf, 88,64 KB
Tandem 300 EC door air curtain, model size 30download as.dwg, 242,63 KB.dxf, 1,82 MB.pdf, 86,10 KB
Technical details

This table only gives you a brief overview of the technical data. If you are looking for a more detailed product description and further technical data, please use the technical catalogue. The product configurator and the calculation program will help you to find the right article for your selection.

KaControl recirculating air control accessories


wall-mounted room control unit, with integral room temperature sensor, only for use with C1 controller
Installation instructions: i385_kurz_kacontroller_int.pdf

Download specifications (.rtf)
Article no.:

Room temperature sensor

wall-mounted, surface-mounted, IP30, colour white RAL 9010

Is the KaController installation site suitable for a temperature measurement? - If it is not suitable, e.g. behind a curtain, then a KaControl room temperature sensor should be chosen for each group!
Download specifications (.rtf)
Article no.:

Cable sensor

length 600 mm
Download specifications (.rtf)
Article no.:

Serial CANbus card

For increasing the number of units in a single-circuit system to a maximum of 30 units, one required per unit
For increasing the cable length from the first to the last unit from 30 to 500 m
Download specifications (.rtf)
Article no.:

Serial Modbus card

One needed per unit for connecting to KaControl panels or on-site Modbus networks
Download specifications (.rtf)
Article no.:

Control accessories electromechanical EC

Speed controller

for continuously variable fan speed control, flush-mounted
Download specifications (.rtf)
Article no.:

Compact controller

for fan speed control, room temperature control, door contact control and night heating operation, surface-mounted, max. two units can be connected in parallel
Download specifications (.rtf)
Article no.:

Surface-mounted frame

for surface-mounted installation of the speed controller, art. no. 194000146936
Download specifications (.rtf)
Article no.:


Thermoelectric shut-off valve

230 VAC, 3/4", for KaControl and stage switch!
Download specifications (.rtf)
Article no.:

Leaving air temperature limiting valve

3/4", temperature setting range 20 - 50 °C
Download specifications (.rtf)
Article no.:


Wall brackets

made of sendzimir galvanised steel for wall mounting, powdercoated traffic white RAL 9016
Download specifications (.rtf)
Article no.:

Ceiling brackets

made of sendzimir galvanised steel for adjustable suspension from the ceiling, powdercoated traffic white RAL 9016
Download specifications (.rtf)
Article no.:



with frame for basic unit, 1 set = 1 piece
Download specifications (.rtf)
Article no.:


Connecting kit for unit extension

to connect several Tandem 300 EC, powder-coated, RAL 9016 traffic white
Download specifications (.rtf)
Article no.:

How does Tandem technology work?

In addition to the warm air stream, the fan group produces an unheated ambient air stream that has a greater penetration depth and acts as a "back-up" air stream for the warm air stream. At the same time it acts as a separation layer towards the cold outside air: cold outside air cannot penetrate and warm air cannot escape.

What is the "Coanda" effect?

The penetration depth and screening effect are both increased by the contraction of the primary air stream and the warm air stream without this needing additional energy. This also means that the units can even be fitted at a greater height.

How are energy-savings achieved with Tandem door air curtains?

An energy-saving of approx. 38 % is possible by the combination of:


  • Increased penetration depth caused by the Coanda effect
  • Unheated primary air stream
  • A resulting smaller volume of warm air curtain