Thermokey Deutschland GmbH

ThermoKey condenser with AFS (Air Fresh System)

AFS (Air Fresh System) stands for the adiabatic on THERMOKEY outdoor units - the air-cooled condenser as well as dry or glycol cooler.

Refrigerant condenser with AFS (Air Fresh System)

AFS (Air Fresh System) stands for the adiabatic on THERMOKEY outdoor units - the air-cooled condenser as well as dry or glycol cooler. With the Air Fresh System, the physical effect is used in that the water extracts heat from the air as it evaporates and, ideally, the air cools down to the wet-bulb temperature. The higher and drier the outside air is, the greater the cooling effect or cooling of the outside air, i.e. at outside temperatures above +30°C.

  • If, for example, the condensation or cooling water flow temperature is reduced by approx. 10K compared to a conventional air-cooled system, the coefficient of performance of this refrigeration system increases from the conventional 3.7 to approx. 5.0.
    • The refrigeration system uses less energy.
  • The difference between the condensation / cooling water flow temperature and the inlet temperature is decisive for the cooling capacity. If the outside air is reduced by 10K, the cooling capacity of the device increases 2.5 times.
    • Power reserves are available without installing spare devices.
    • In cramped installation situations, more cooling capacity can be installed per m2 of installation space.
  • Adiabatic uses only spray water in the upper temperature range, i.e. only a few hours a year.
    • After switching off the adiabatic, the slats are dry - no risk of legionella.

The most important design features compared to standard devices are:

  • Axial fans from Ziehl-Abegg, EBM or Südelektrik with two speeds, suitable for stepless speed control through phase control or frequency converters are available, alternatively EC fans for energy-optimized applications and noise-relevant applications.  
  • Fans with a diameter of 900 mm in four different volume levels are used. The number of fans per device can vary between 2 and 18 depending on the design data.
  • Great stability and torsional rigidity (particularly with large unit lengths) of the V-shaped heat exchangers thanks to the galvanized steel frame, completely powder-coated in RAL 7035. Alternatively also available completely made of stainless steel.

A complete range of accessories and special equipment rounds off the "TURBO-J" series:

  • Complete factory switching and control unit with main switch, speed controller using phase control or frequency converter and 3 to 6-stage adiabatic control. Also possible in versions according to customer or end customer requirements.  
  • Fins made of aluminum with a hydrophilic coating (blue fin) for operation with partially softened water or fins made of stainless steel are possible.  
  • Tubes made of copper or stainless steel (V4A).



  • Small control cabinet.
  • Speed ​​control (phase control, frequency converter or step controller).
  • Alternatively, complete main switch cabinet including the fan control instead of points 1 + 2.
  • Air-water heat exchanger with hydrophilic fins (blue fins) and temperature sensor.
  • Small control cabinet AFS (adiabatic).
  • Electronic control to regulate the adiabatic.
  • High pressure pump (10/20 bar), power supply 230V/1Ph/50Hz, complete with manual adjustment of the working pressure.
  • Pressure gauge to check the system pressure.
  • 4 ramps with spray nozzles on units with one fan row and 6 ramps on units with two fan rows.
  • Copper connecting pipe for complete emptying of the ramps when the AFS system is not in use.
  • Solenoid valve for filling the adiabatic system with softened water.
  • Solenoid valve for draining the adiabatic system.
  • Manual shut-off valve.


Know-How Article