ECOFIT single-inlet forward-curved centrifugal fans

ECOFIT single-inlet forward-curved centrifugal fans are designed to provide efficient airflow in a wide range of ventilation, heating, air-conditioning and equipment-cooling applications.
What do the designations TRE, GRE and GRF used in this range mean? These three acronyms refer to different configurations built around the same centrifugal ventilation principle.
 

How does a single-inlet forward-curved centrifugal fan work?
In a single-inlet centrifugal fan, air is drawn into one side of the impeller, parallel to the axis of rotation. As the impeller rotates, the air is driven outwards and discharged at a right angle through the blades.
A forward-curved impeller is characterised by blades that curve in the direction of rotation.
Based on this common principle, ECOFIT offers three configurations: TRE, GRE and GRF.
 

TRE: the motorised impeller
TRE stands for “Turbine à Rotor Extérieur” (external-rotor impeller).
The TRE is the simplest configuration, combining a forward-curved centrifugal impeller with an external-rotor motor. This assembly is also known as a motorised impeller.
It therefore forms the functional core of the fan and can be integrated directly into equipment whose design provides the required airflow guidance.
TRE = motor + forward-curved impeller.
 

GRE: the motorised impeller fitted with a scroll housing
GRE stands for “Groupe Rotor Extérieur” (external-rotor fan assembly).
The GRE is based on the TRE principle, with the addition of a scroll housing around the impeller. This housing features a side opening, or air inlet, through which air enters, as well as an outlet.
The scroll housing directs the air moved by the impeller.
Several configurations are available to meet different integration requirements. The scroll housing can be supplied on its own, fitted with two mounting brackets, or integrated into a frame.
The brackets and frame make it easier to install the fan within the equipment, providing a stable, reliable mounting solution suited to integration into the ventilation system.
In simple terms:
GRE = TRE + scroll housing, with several mounting and integration options.
 

GRF: a design tailored to railway applications
GRF stands for “Groupe Rotor Ferroviaire” (railway fan assembly).
The GRF is based on the principle of a framed centrifugal fan assembly but features a more robust design specifically developed for integration into railway systems.
The GRF configuration is available with our motors featuring stack heights of 45, 55 and 65 mm.
It incorporates a reinforced structure and a finger guard to meet the specific requirements of railway equipment.
 

This variety enables ECOFIT to offer not only different aerodynamic performance levels but also different levels of mechanical integration. The choice between TRE, GRE and GRF therefore depends on the required performance as well as how the fan is to be installed and integrated into the final equipment.