For more than 60 years products from our house ensure the right temperatures. Through path- breaking developments in the field of refrigeration and air- conditioning engineering we have gained worldwide recognition.

Our product range covers unit air coolers, fan coils and finned heat exchangers. We only produce at our company located in Gerlingen near Stuttgart.

Fan Coil Units
Air Coolers
Heat Exchangers

Options V

Heat exchangers

Our air coolers are designed for refrigeration applications. Our cooler work efficient in the Standard Condtions according to EN 328, with refrigerants like R404A, R507A or R134a.

If a cooler should be operated outside the limits specified in the catalogues or the selection software, it is possible to adjust the circuiting of the air unit coolers to ensure the operation of the unit.

For different refrigerants e.g. R410A, R407C etc. special heat exchangers are available on request.

Water/ brine heat exchangers

Water connectionUnit air coolers can be equipped with heat exchangers for water or brine operation. Compared to refrigerant heat exchangers the ones for water operation are equipped with threaded fittings, and have an optimised circuiting for water / brine operation. On request the heat exchangers can be prepared for bleeding/ draining.

The maximum allowable pressure for "water" heat exchangers is PS 16 bar.

Regulary used brines are e.g.

  • Ethylene glycol
  • Propylene glycol
  • Temper
  • Tyfoxit

The heat exchanger consists of wide tubes for a minimum of pressure loss, and optimised ciruiting to suit your application.


Due to frost formation on the fins, coolers have to be defrosted regualary to keep their performance. Frost can be removed in many ways.

MS heater rods

MS heater rods are one of the greatest benefits of Roller air unit coolers. These heaters are designed for different purposes around the air unit cooler.

Defrost of air unit coolers

MS heater rodsThese MS heater rods can be retro fitted into most of the Roller air unit coolers. They can be simply inserted into the coil. The rods are made of stainless steel and have a special vulcanisation for the appliance in cold rooms.

These type of defrost is designed to work at cooling chamber temperatures near the freezing point, to boost the natural defrost of the ambient and to achieve a complete deicing of the cooler.

We don't recommend the usage of MS heater rods for defrost in low temperature applications.

Defrost safety thermostat

Defrost safety thermostatThe defrost safety thermostat terminates the defrost in case of an failure of the defrost control. A wide range of Roller air unit coolers is already prepared for the installation of the defrost safety thermostat.

Technical data:

Fixed break point,
disconnects +25 °C,
connects +3,5 °C
Contact load at 230 V, 50 Hz:
ohmic Imax 25 A,
inductive Imax 5 A,
Protection class IP 44.
Connection cable 2 cores, 75 cm long.

SI flexible heater

SI flexible heaterThe SI flexible heater is designed to heat the plumbing of the condensate drain. It's available in different lengths to satisfy your application. The SI flexible heater is not designed for contious operation.


Different accessories bring the portfolio of cubic air coolers up to a round figure.

Stainless steel casing

Stainless steel casingCasings of the air unit coolers can be made of stainless steel (V2A, 1.4301, AISI 304). The stainless steel casing is superior robust compared to the Aluminium casing.

If you like pure metalic designs the stainless steel casing may also be an option.

Drain pan for wall mounted ceiling air coolers.

Drain pan wall mountingCeiling type air unit coolers are in most cases wall- mount able with an additional drain pan. Evaporators can be equipped with the drain pan as an accessory. In case of a water/ brine heat exchanger the intention of a wall mounting should be known in advance to ensure a correct bleeding of the heat exchanger.