Kaeser refrigerated air dryer from 162 to 1130 scfm

SECOTEC energy-saving refrigerated dryers with impressive latent heat storage

Kaeser's renowned SECOTEC industrial quality refrigerated dryers (TD-TF (*) series) have long been valued for their stable pressure dew point performance, their exceptional reliability and their low total life-cycle costs. The SECOTEC TF offers a choice of air- or water-cooled models.

Together with the innovative SECOPACK LS latent heat storage heat exchanger system and the SIGMA CONTROL SMART controller, the next generation of these advanced dryers sets new standards when it comes to energy efficiency, compact design and user-friendliness.

  • Exceptional durability due to corrosion-resistant air piping and aluminum heat exchanger (condenser and SECOPACK LS)
  • With Modbus TCP communication module for integration in the SIGMA NETWORK

Your advantages

  • Energy savings:
    TD, TE, and TF refrigeration dryers require less than 6 W for every cfm of air to be dried (ISO 7183 A2) Thanks to energy-saving control, in partial-load operation, excess cooling power can be temporarily stored in the thermal mass for later cooling without the need for power consumption. The rapid-response SECOPACK LS heat exchanger system ensures stable pressure dew points at all times.
  • Intuitive operation:
    The SIGMA CONTROL SMART electronic controller offers straightforward and intuitive operation. Message memory, component-specific operating hours counters and maintenance timers enable efficient monitoring and analysis of operating data. Floating contacts and the Modbus TCP communication module provide easy networking with master controllers such as the SIGMA AIR MANAGER 4.0.
  • Optimized compact design:
    The thermal mass chamber of the innovative SECOPACK LS heat exchanger system is filled with a phase change material. Its significantly higher thermal storage density means that 98% less storage material is required to achieve the same capacity as conventional storage media. Storage capacity for pressure dew point stability therefore goes hand in hand with hugely reduced space requirements. Optimized flow paths minimize pressure losses and consequently help enhance SECOTEC dryer efficiency.

* Dryers from this series contain the fluorinated greenhouse gas R-513A.


Product details

Reduce life-cycle costs!
KAESER life-cycle cost management

Thanks to cycling control mode and high storage density, the new generation of SECOTEC refrigerated dryers requires very little electrical power, almost regardless of load.

In contrast to other typical systems on the market, excess cooling power is not wasted, but rather used to cool down a thermal mass. Once cooled, it supplies cooling for compressed air drying, eliminating the need for additional electric power.

Furthermore, the new design ensures minimal maintenance requirement and service work is made quick and easy.

Want to find out more about how KAESER is reducing life-cycle costs?

SECOTEC – always saving energy

The load on a refrigerated dryer doesn't just depend on the volume of compressed air to be dried (grey area), but more importantly depends on how much water the incoming compressed air contains. The volume of water (moisture) increases as the temperature rises, so the load on refrigerated dryers increases dramatically when ambient temperatures are high, such as during summer (yellow curve).

Conversely, when the temperature drops during the winter (turquoise curve), there is less load on refrigerated dryers. To maintain a stable pressure dew point throughout these fluctuations, refrigerated dryers should be designed to provide sufficient performance during peak load times, and have additional reserve capacity.

Like the flow rate and temperature range, refrigerated dryers are always operating within the load range of 0 to 100%. Because SECOTEC storage control ensures energy is only used as needed across this entire load range, users benefit from exceptional savings.

The energy-saving effect
R-513A: A future-proof refrigerant

The use of small volumes of the future-proof R-513A refrigerant provides security of supply for maintenance work throughout the entire life of the refrigerated dryer.


  • The use of greenhouse gases is becoming ever more strictly regulated throughout the world. Installation of highly compact heat exchangers - such as SECOPACK LS and micro-channel condensers - considerably reduces refrigerant demand.
  • The greenhouse gas potential of R-513A is significantly lower compared to the refrigerants that have commonly been used in refrigerated dryers up until now.
  • R-513A is equivalent to R-134a. It is neither toxic nor flammable.
Maximum energy savings thanks to storage control
Maximum energy savings thanks to storage control with SECOTEC refrigeration dryers

The duty-cycle of refrigerated dryers is always fluctuating between 0 and 100%. Unlike conventional partial-load control systems, SECOTEC storage control precisely adjusts electrical power consumption during all load phases.

This allows SECOTEC refrigerated dryers to save almost 60% of energy costs compared to refrigerated dryers with hot gas bypass control running at an average of 40% of capacity.

In contrast to conventional systems, the thermal mass in SECOTEC dryers always remains cool. This means compressed air can be dried effectively even during start-up phases. The high-quality insulation around the thermal mass also helps to keep energy use to a minimum. With SECOTEC refrigerated dryers, compressed air drying takes place with outstanding energy efficiency and it's especially gentle on the equipment thanks to the high thermal mass capacity.

Optimal drying with low-wear operation
Optimum drying performance and environmentally-sound operation with SECOTEC refrigeration dryers

SECOTEC refrigeration dryers efficiently maintain pressure dew points of up to +38°F during full load operation. Thanks to their narrow fluctuation range, pressure dew points are also more stable during partial load operation than is the case with conventional refrigeration dryers. 

Conventional refrigeration dryers with switching operating modes, but without an additional thermal mass, use the heat exchanger material itself as a thermal mass. In these dryers it is therefore necessary to switch the refrigerant compressors and fan motors on and off much more frequently, in order to maintain the required cooling performance. 

To reduce switching frequency and wear, the refrigerant circuit therefore only switches on at much higher pressure dew points. The resulting fluctuations in the pressure dew point negatively affect drying performance. This can be risky, since corrosion can take hold even with relative compressed air humidity of 40% – corrosion can therefore occur even without condensate formation. 

SECOTEC refrigerated dryers, on the other hand, ensure long-life operation thanks to their high thermal mass storage capacity. Once the thermal mass has been charged, the refrigerant compressor and fan motor can remain switched off for much longer without impacting pressure dew point stability.


Refrigerant circuit

Refrigerant circuit includes:

  • Scroll compressor
  • Aluminum micro-channel condenser with fan
  • Safety pressure switch
  • Thermal mass
  • Filter dryer
  • Thermostatic expansion valve
  • SECOPACK LS aluminum heat exchanger system
  • Temperature and pressure transducer


  • Air/air and air/refrigerant heat exchanger in aluminum block design
  • Integrated thermal mass chamber with phase change material
  • Condensate separator
  • Heat insulation


SIGMA CONTROL SMART: electronic control with color display
  • Electronic control with color display
  • Language-neutral menu navigation
  • Dew point trend display
  • P&I diagram displaying current operating data and messages
  • Event memory
  • Operating hours counter
  • Maintenance timer

Floating relay contacts

  • "Fault" and "Refrigerant compressor running" service messages 
  • "Maintenance/warning" and "High pressure dew point" warning messages
  • Operating hours counter
  • Maintenance timer

Condensate drainage

  • Eco-Drain 31 Vario electronic condensate drain with tap on condensate inlet, incl. insulation of cold surfaces


  • Powder-coated housing
  • Removable panel for straightforward electric connection
  • Efficient condenser cleaning
  • Removable side panel serves as main access point to the interior
  • Machine mounts


  • Corrosion-resistant compressed air piping
  • Bulkhead pipe fitting for external condensate line connection
  • Cables for mains connection on rear panel (cut-outs in the unit's top metal panel for alternative connection from above)

Electrical equipment

  • Electrical equipment and testing to EN 60204-1 "Safety of machines"
  • Control cabinet to protection rating IP 54

Options and accessories

  • Refrigerated dryers for use in ambient temperatures up to 122°F (standard for TD models)
  • Water-cooled refrigerated dryer (TF series)
  • Compressed air connections left (TF series)
  • Replacement pipework kit TF 173, 203, 251 (pre-assembled) (TF series)
  • Adjustable machine mounts
  • Integrated transformer with primary voltage of 200 V – 440 V (external for TD models)
  • Integrated transformer with primary voltage of 500 V / 3 Ph / 50 Hz and 575 V / 3 Ph / 60 Hz (external for TD models)
  • Silicon-free design (VW Plant Standard 3.10.7)
SECOTEC – Industrie 4.0 ready
Warning message on the SIGMA AIR MANAGER 4.0 flow diagram

With the Modbus TCP module, SECOTEC refrigerated dryers can be easily integrated into the SIGMA NETWORK. All essential operational parameters and messages are available in real-time. This enables comprehensive system monitoring of the entire compressed air station and creates the basis for needs-based preventive maintenance.
The result: Maximum availability with minimal costs.

In addition, SIGMA AIR MANAGER 4.0 provides a complete overview of all essential operating parameters of the refrigeration dryers. Color-coded warnings and alarms are displayed in the compressed air station's P&I diagram. By clicking the dryer icon, all key operational parameters and message texts are displayed in plain text.

SECOPACK LS – The efficiency module
SECOPACK heat exchanger - sectional view
  1. Compressed air inlet
  2. Condensate outlet
  3. Refrigerant inlet (cold)
  4. Refrigerant outlet (warm)
  5. Heat transfer
  6. Compressed air outlet

TD, TE and TF series refrigerated dryers are equipped with the innovative SECOPACK LS heat exchanger system. Its latent heat thermal mass is composed of a phase change material. Compressed air warms the material until its melting point (thermal mass discharge), absorbing latent melting heat in the process. This is significantly greater than the amount of heat that it can absorb based on its normal specific heat capacity (without phase change). The latent thermal mass in these dryers therefore has a significantly higher thermal storage density and requires 98% less storage material to achieve the same capacity as conventional storage media.

The key advantages: high thermal capacity for stable pressure dew points and material-friendly operation combined with dramatically reduced unit footprint.

Innovative control with “Storage Plus” and phase change material
SECOTEC: Innovative control with “Storage Plus” and phase change material
  1. The compressor provides cold refrigerant for compressed air drying purposes and to cool down the thermal mass.
  2. The thermal mass solidifies at a constant temperature, thereby conducting a significant amount of heat away, via the refrigerant.
  3. The refrigerant then cools the thermal mass further until the cut-out point is reached.
  4. The refrigerant compressor switches off.
  1. The thermal mass provides cold for drying the compressed air, whilst itself warming up.
  2. The thermal mass melts at a constant temperature, thereby absorbing a significant amount of heat from the moist compressed air.
  3. The thermal mass heats up until the cut-in point of the compressor is reached.
Design and Function
Component layout of SECOTEC TF energy-saving refrigeration dryers
  1. Compressed air inlet
  2. SECOPACK LS heat exchanger system
  3. Compressed air outlet
  4. Condensate outlet
  5. Eco-Drain condensate drain
  6. Refrigerant compressor
  1. Micro-channel condenser
  2. Fan
  3. Filter/dryer
  4. Thermal mass
  5. Expansion valve
Technical specifications

The technical specifications can be found in this brochure: