Thermal motors – brushed or brushless?

The DC motors used for thermal ancillary applications are witnessing a gradual shift from Brushed DC (BDC) motors to Brushless DC motor (BLDC) due to the clear technical advantage of this design – the falling costs of BLDC motor is acting as a catalyst for this change.

The quest for improved efficiency either through better component control parameters or reducing ancillary power load on the engine has been the blueprint that automakers have been following for improving vehicle performance and efficiency. Electric motor driven components have been gaining traction in automotive applications for one of two primary reasons – either to replace a mechanically driven solution for greater reliability, reduced size/weight, and improved efficiency. From the thermal management ancillary viewpoint, the efficiency of these motors, which are used to drive the HVAC and engine cooling sub-systems, contribute to the overall efficiency of the vehicle. Given the increasingly stringent emission and fuel efficiency regulations, even minute efficiency gains add up in reaching the targets. The cooling fan motor which powers the powertrain cooling fan, the HVAC blower, and in the case of electric vehicles the battery cooling fan, is powered with electric motors. The electric cooling fan and HVAC blower are usually powered by a direct current (DC) motor. The motor used may be of a brushed or a brushless design.