TERMO – trench heaters

Date: 20.1.2017
TERMO New Practic trench heaters combine many years of experience acquired in the course of designing, manufacturing and supplying the original production series installed for you by ISAN and partners for more than 10 years. They are provided in two basic versions: with forced convection (TERMO FRT) and natural convection (TERMO FRK), and newly also in special design variants complying with specific market requirements. The fans used are equipped with EC motors with very low electricity consumption and continuous speed control and mainly work at a safe voltage of 24 V DC. The trench heaters excel at quiet operation; the materials used were chosen with respect to their resistance; the internal coat matches the exposed components. Choose one of the new TERMO models.

TERMO FRZ trench heaters with a voltage source of 24 V

A switching source of voltage is installed in the trench heater; the connection allows easy control of large projects.

TERMO FRZ with integrated voltage source is used for larger projects requiring concurrent control of several trench heaters. The network does not need to be dimensioned according to the power demand as the trench heaters are supplied from their own installed voltage source. The internal voltage source also facilitates the solution in projects where it is not clear how many trench heaters are to be placed in each room until the last moment (e.g. depending on the lease of retail space in shopping centres). Wiring can be flexibly modified, and individual units can be easily detached and complemented with a room thermostat.

TERMO FRZ trench heater with integrated voltage source


  • Shopping centres, office buildings
  • Relax and sports centres, gyms, wellness
  • Conference halls and rooms
  • Restaurants, cafés, hotels

 Benefits and range of the models

  • Easy to connect a large number of trench heaters
  • Connection over long distances
  • Connection with IP67 electric protection
  • Negligible voltage drops on lines
  • Easy integration into intelligent buildings
  • Model range the same as for TERMO FRT trench heaters
  • Length 900 – 4 800 mm in 100mm steps
Thermostat RTM201
Manual thermostat with three speed levels, simple control, for 24 V DC trench heaters.
The room thermostat is a decision and control element of trench heaters with a fan. It is modified to control up-to-date TERMO FRT trench heaters in which fans and electrothermic actuators operating at a safe 24 V DC voltage are installed. The electronics installed in the thermostats enables connection of a sensor of heat exchanger temperature which complements the protective and decision functions.

Manual room thermostat RTM201


In shops, storehouses, entrance halls, operating areas and children's bedrooms where no above-average, sophisticated control is required and where a stable temperature is kept.


Technical parameters

– Operating voltage 24 V DC
– Setting of the required temperature from 8 to 30 °C
– Three-level switch of fan speeds
– Control of electrothermic actuator
– Optional connection of the heat exchanger temperature sensor TE30
– Two-pipe system with forced circulation
– White colour

TERMO FDT and FDK trench heaters with wire Cu-Cu heat exchanger

Selected TERMO FRT models are equipped with a popular wire heat exchanger

The TERMO FRT range was completed by models with a Cu-Cu heat exchanger. They have a special woven cover of fine copper wires firmly connected to the bearing pipe through which the heat carrier is flowing. It proved useful in the Active model series and is favoured for its easy cleaning, rigid structure and long service life. Models with fans and natural convection are available in sizes of height x width: 90 × 200 mm and 90 × 250 mm.

Trench heater TERMO FDT with wire Cu-Cu heat exchanger


Grill with increased bearing capacity and resistance

Thick-walled stainless grill with rectangular slots

Suitable for well-frequented places with busy pedestrian traffic (entrance door, shopping centres) where the grill is subjected to excessive abrasion and load, e.g. by chairs and tables (restaurants, bars, dining halls), but also in places where stilettos could get stuck (theatres, conference halls, showrooms).

Thick-walled stainless grill

Technical parameters

– For trench heaters with a width of 175, 200, 250 and 300 mm except for trench heaters with a low grill
– Grill segments of max. length 1 m; longer grills are divided into several parts
– Material: thick sheets of brushed stainless steel
– Robust structure resistant to mechanical stress and abrasion

For detailed information please visit www.isan.cz or write at marketing@isan.cz

Trench heaters are buried directly in the floor structure. They suck cold ambient air (naturally or by means of fans). The heat exchanger then heats the air up. It creates a thermal barrier in front of the cold glass wall or window, separates it from the interior and prevents air humidity condensation on its surface.