Free Cooling

Potential savings thanks to Free Cooling

In temperate climes north and south of the equatorial zone, the energy-saving advantages of the STULZ CyberAir 3PRO DX ASR with Indirect Dynamic Free Cooling or Direct Free Cooling can be exploited to the full.

Regions suitable for Free Cooling

Indirect Dynamic Free Cooling

Up to 60 % savings on running costs with Indirect Dynamic Free Cooling

  • The electronically controlled GE refrigeration system combines compressor cooling and Free Cooling in four stages:
    • FC – Free Cooling energy-saving mode
    • EFC – Extended Free Cooling mode
    • Mixed – Compressor and Free Cooling
    • DX – Compressor cooling
  • Electronic load distribution for partial load mode
  • Increased compressor efficiency in Mixed mode thanks to the electronic expansion valve
  • The world’s first system with automated efficiency optimization
  • Control based on outside temperature and heat load in the Data Center, without fixed Free Cooling starting temperature with networking of all active components: air conditioning units including standby units, control valves, compressors, EC fans, pumps and dry coolers

Direct Free Cooling for small to medium-sized Data Centers

To enable Direct Free Cooling to be used in small and medium-sized Data Centers as well, the CyberAir 3PRO DX units can be equipped with the FreeCool Plenum Free Cooling box. 

CyberAir 3PRO DX with FreeCool Plenum

The CyberAir 3PRO DX with FreeCool Plenum combines Free Cooling and compressor cooling in 4 stages:

1. Free Cooling

  • The outside air damper opens
  • Outside air is conveyed through the filter of the FreeCool Plenum directly into the unit, then into the data center
  • The compressor of the unit remains off, completely saving the cooling energy normally required

2. Mixed mode

  • As 1, plus:
  • The compressor of the unit is additionally switched on for support
  • When the outside air damper is open, the compressor of the unit runs in partial load mode
  • The return air damper of the FreeCool Plenum opens to the appropriate degree

3. DX mode

  • The CyberAir 3PRO DX cools exclusively using the compressor
  • The outside air damper remains closed, and no outside air is used for cooling
  • Return air damper open 100 %



Contact us

Please choose your contact

  • Contact Sales
  • Contact Service
More contact options
Login on E-Stulz

for detailed technical specs

Contact us

Holsteiner Chaussee 283
22457 Hamburg 

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

Contact us
To top