Furnace motor efficiency greatly contributes to the overall efficiency levels that a furnace can reach. Electronically Commutated Motors (ECMs) are the result of a new generation of technology that has given furnace motor efficiency a big boost over other types of motors.

Alternating Current (AC) motors are comprised of two major components – a strator, and a rotor. Alternating current powers coils on the strator, which develops rotating magnetic fields. The force of these magnetic fields causes the rotor to revolve, creating torque. These motors got the job done, cost less, but they aren't energy efficient.

Direct Current (DC) motors offer a more promising performance. A brushed DC motor has three major parts– a commutator, brushes, and a set of permanent magnets. The magnets replace the strator, and the commutator, brushes, and coils are located on a rotor. Brushes connect DC to the commutator, which switches the direct current between the coils and creates a repelling force against the permanent magnets, thus turning the rotor and creating torque. 

A brushless DC motor, or an ECM, is an improvement upon the brushed DC motor because the permanent magnets rotate around a fixed armature (what would be the rotor in a brushed DC motor), so there is no need for brushes. An electronic controller replaces the commutator/brush system that a brushed DC motor uses. 

As a result of ECMs high-tech advancements, they're able to offer homeowners an upgraded experience all around:

• An AC motor produces considerably more noise than a DC motor at full speed. However, if an AC motor's speed is lessened, its efficiency drops to 12 to 45 percent. An ECM can operate at various speeds and maintain 65 to 75 percent efficiency.
• ECM's, unlike AC motors, are not prone to overheating, and do not call for added precautions to offset the production of heat.
• A brushed DC motor's commutator and brushes wear down over time and need to be replaced – an ECM does not have this issue.

The possibilities for energy savings make ECMs are smart choice to advance furnace motor efficiency. Tri-County Heating and Cooling is happy to address any questions you may have, and offer expert advise! Please contact us today!

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