Free Cooling solution for equipment rooms and telecommunication containers

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Air conditioning units for indoor installation

TelAir units are designed for telecommunication containers and equipment rooms. As the precision air conditioning units are installed indoors, noise is kept to a minimum and the units are protected against environmental influences and vandalism.

Optimized for air conditioning containers and modular buildings
Equipment rooms
Equipment rooms
Optimized for air conditioning equipment rooms
Free Cooling
Free Cooling
Maximum potential savings by using cool outside air
Plug & Play
Plug & Play
Units immediately ready for connection and operation

Product Overview

At a glance

Most important benefits

  • Up to 83 % savings on energy costs thanks to Mixed and Free Cooling modes
  • Low refrigerant quantity (less than 10 tons CO2 equivalent)
  • Connectivity: Monitoring and remote access available via a web interface

Most important features

  • Condensation pressure control
  • Outside air conditions: -20/+50 °C winter/summer

Most important technical data

  • Cooling capacity (kW): 4 – 16
  • Air conduction: Downflow, Upflow, Displacement
  • Up to 83 % savings on energy costs thanks to Mixed and Free Cooling modes
  • Low refrigerant quantity (less than 10 tons CO2 equivalent)
  • No annual leak test required in accordance with F-gas regulation*
  • Suitable for residential areas due to low noise emissions
  • Plug and play and therefore immediately ready for connection and use
  • Indoor installation keeps equipment room air conditioning units protected against environmental influences and vandalism
  • Connectivity: Monitoring and remote access available via a web interface
  • Backup operation (Free Cooling and backup cooling) on failure of the main power supply
  • Long maintenance intervals
  • Robust and designed for continuous 24/7 operation, 365 days a year

*due to low refrigerant quantity and hermetically sealed refrigerant circuit (standard for EC compressor)

  • Downflow, upflow and displacement principle
  • Available in 3 sizes
  • Factory tested, filled with refrigerant and ready for operation from the very first day
  • Available with EC compressor
  • Outside air conditions: -20/+50 °C winter/summer
  • Automatic restart after power failure
  • Filter monitor and airflow alarm
  • Equipment room cooling including inside and outside temperature sensors
  • G4 zigzag filter
  • Condensation pressure control
  • Condenser with microchannel technology
Technical Data
Cooling capacity total (kW) 4 – 16
Sizes 2
Air conduction Upflow, Downflow, Displacement
Refrigerant R410A (GWP: 2,088)
R407C (GWP: 1,774)
R134a (GWP: 1,430)

All details about TelAir

Climate. Customized.

From standard units to fully customized solutions

The ability to offer such a wide range to customers is the embodiment of our philosophy, "Climate. Customized.". Size, design, air conduction, system or control: TelAir is a model of adaptability and the shelter units can be precisely adapted to your individual requirements. In addition, a variety of options and equipment versions are available to achieve the optimum result.

Learn more about Climate. Customized.

Climate. Customized.
Optimum operational reliability for your application

Connectivity for maximum availability

Monitoring and remote diagnosis are available for all units via a web interface. This enables rapid intervention and therefore immediate troubleshooting in all situations. What’s more, our units support numerous communication protocols for integration in building services management systems.

  • Data recording
  • Remote configuration
  • Firmware updates
  • Alarm relaying

Backup operation for maximum reliability

In telecommunications, in particular, high reliability is vital to prevent any loss of network availability. Thanks to the additional 48 V DC power source, backup operation with Free Cooling is available. If the main power supply fails, the Shelter Cooling units continue providing backup cooling to keep your system running reliably.

Direct Free Cooling

TelAir equipment room and container cooling units are especially efficient in Free Cooling mode. With their high airflow in Free Cooling and Mixed modes, the units achieve maximum EER values.

Operating modes

Free Cooling mode

At low outside temperatures, outside air is used directly for cooling. The outside air is conveyed into the interior when the air damper is open. Energy-intensive compressor cooling is not needed when outside temperatures are low. This way, Free Cooling brings you huge potential savings.

Mixed mode

If Free Cooling is not sufficiently available due to the outside temperature, the unit can still use the outside air to some extent. The result is a combination of compressor cooling and Free Cooling.

Compressor mode (DX)

If outside temperatures are so high that the outside air would no longer help to cool the inside, all cooling is generated using the compressor. Even in this mode, the perfectly harmonized components we use keep STULZ air conditioning units work reliably and efficiently.

Savings with Free Cooling

Efficient air conduction and intelligent control of operating modes enable savings of up to 83 % to be achieved.

Reliable operation in any weather conditions

Whether your business-critical equipment room cooling system is working in temperatures of up to 55 °C, in ambient air contaminated by particles, in temperatures as low as -40 °C, or in a permanently humid environment – you can always rely on systems from STULZ.

Plug & Play
  • All products in the Shelter Cooling series are factory tested, filled with refrigerant and ready for connection and operation right from the start
  • Reduced installation time and costs
  • Speedier start-up


Flexibility thanks to variable air conduction

The individual models of the TelAir series are available as Upflow, Downflow and Displacement versions. In the Displacement model, the airflow can be directed horizontally or vertically entirely individually as required via adjustable fins, to ensure optimum operation of your servers.




EC compressor

Advantages of the speed-controlled EC compressor

  • Maximum energy efficiency for hvac outside units in partial load mode
  • Constant supply air temperature
  • Refrigerant R410a
  • Integrated compressor soft start
  • Long service life thanks to continuous operation without compressor on/off cycles

Control and monitoring

The consists of a controller and optional operator terminal. The controller manages all functions of the TelAir unit. The operator terminal, consisting of a keypad and LCD, displays the most important operating states and alerts.



The enables up to ten units to be configured in a single air conditioning system. If an individual unit drops out or the heat load rises, the standby unit is switched in for additional support.

Night Mode

  • Time-controlled limitation of the condenser and evaporator fan speed for quiet operation
  • Energy-saving mode

Monitoring and alarm relaying

  • Via BMS systems (Modbus onboard, further protocols via WIB 1000)
  • Nine potential free contacts are available: Alarms can be assigned a high or low priority
  • Via GSM modem (CompTrol SMS)


Simple configuration and software updates

  • Central configuration of units from a laptop
  • Hardware key for uploading and downloading software without a laptop and/or copying the configuration onto other units


Thanks to the numerous options available, you can perfectly adapt STULZ units to your particular requirements.

  • High-temperature operation up to 55 °C with R134a
  • Winter kit up to -40 °C
  • Compressor soft start for low start-up currents
  • Electrical wiring, with connector for plug and play
  • Backup operation with 48 V DC or 230 V/50 Hz/1 Ph
  • External operator terminal
  • Electric heater
  • Humidity sensor
  • Ethernet port

Close to you around the world

As a company with locations across the globe, we offer everything you need in the extremely dynamic world of information technology – plus professional advice in the right place at the right time.

With 21 subsidiaries, 11 production sites, and sales and service partners in over 140 countries, we make sure we are close to our customers wherever they are in the world.

Locations worldwide

Service and maintenance

Our trained and experienced sales and service partners are located in over 140 countries. The resulting proximity to our customers allows fast response times. In addition, regular training courses and an active exchange of information ensure high quality and an extensive knowledge of all our products. This way, you can be sure your products are in the best hands and get the right maintenance – all over the world.


STULZ Service
STULZ Service
STULZ Service
Test Center

At our test center, you can have TelAir units tested under your individual operating and site conditions. This creates transparency and confirms the unit's performance and energy consumption.


Find your individual STULZ contact

Need more information?

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Do you have any questions? We will be happy to help! Please call us or follow our contact form.

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Holsteiner Chaussee 283
22457 Hamburg 

Central Office: +49 40-5585-0
Fax: +49 40-5585-352

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