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Electric round duct heaters

 Electric circular heaters

When designing a heating system, the crucial thing is to choose an appropriate method to perform this task. There are a lot of heating methods and devices available on the market, e.g. water heaters, electric heaters, air curtains, heat pumps, etc. Very often both the simplest and a very effective solution is the choice of an electric heater. Every building is equipped with an electrical system, therefore we avoid problems with connecting the electric heater. What's more, this choice has additional advantages, which include easy control and adjustment, and quick heating of premises available all year round. 

What is the use of a duct electric heater? 

Duct electric heaters are intended for installation in ventilation systems where it is necessary to raise the temperature of supply air or to maintain it at a constant level. They are designed to work with the duct fans. HDE and HDE-CO circular duct electric heaters can be used to heat air in shops, offices, homes, workshops, garages, warehouses, production halls, etc.


Construction of electric heaters

The HDE and HDE-CO circular duct electric heaters are made up of the following basic elements:

  • Housing
  • Connection box 
  • Heating elements 
  • Thermal protections 
  • Electric wires 
  • Electric terminals 

The housing of the HDE heater and the connection box are made of galvanized steel sheet. On both sides of the housing there are connector pipes  for the ventilation system, equipped with an EPDM gasket.

Electric duct heater

The range consists of 6 sizes for diameters of connector pipes ranging from 100mm to 250mm. Heating elements  are made of stainless steel. The special, spiral-like shape of the heating elements allows for uniform heating of passing air. Depending on the power of the HDE heater, the number of heating elements ranges from 1 to 4. In the connection box there are electric wires, electric terminals and thermal protections. All HDE heaters have two thermal protections. The first is an automatic thermostat; the other is a manual thermostat. All HDE heaters are designed for single-phase 230V power supply. The HDE and HDE-CO circular duct electric heaters are additionally fitted with one or two contactors through which it is possible to easily control the heaters via another device such as a recuperator. The number of contactors depends on heating power of a heater. Two contactors allow for gradual switching on of heating elements, that is the first contactor switches on two heating elements and in the case of not enough heating power, the other contactor switches on other two heating elements.


After feeding the HDE circular duct electric heater, and in the case of the HDE-CO circular duct electric heaters after receiving a control signal, e.g. from an external temperature controller of a thermostat-type, or from an external device, e.g. a heat recovery unit, contactors switch to the conduction state, and heating elements heat up to set temperature. The value of this temperature is dependent on the speed and efficiency of air flow in the ventilation duct in which HDE or HDE-CO circular duct electric heaters are mounted. A correctly selected HDE or HDE-CO circular duct electric heaters guarantee to increase the supply air temperature or maintaining it at a constant level, up to a maximum permissible value of +40°C. In the case of exceedance of the permissible air temperature level, the first protection is an automatic thermostat - it switches on when the temperature reaches the level of +60°C. After lowering the temperature to an appropriate level, the heater switches on automatically. The second, manual thermostat operates when the temperature rises to 90°C. Upon activation of the second thermostat, manual device reset is required to restart it.


 See the article "HDE and HDE-CO Circular Duct Heaters for more information
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