Electric motors account for about 60 percent of power used in industrial buildings in the United States. According to SustainablePlanet.com, 30 percent of U.S. greenhouse gas emissions are due to industrial energy use, making electric motors one of the biggest consumers of electricity. Curiously, there aren’t many debates about electric motors when people talk about the future of energy.
Thanks the advances in brushless DC motors, industries that rely on electric motors can make the switch to a more energy-efficient solution. The HVAC industry, for example, is using BLDC motors in industrial, commercial and residential applications to help make staying comfortable a more earth-friendly endeavor.
About Brushless DC Motors
Unlike its brushed counterpart, brushless motors don’t have commutators and carbon brushes. The windings and magnets are also in different locations of the motor. With a brushless DC design that uses a permanent magnet, efficiency is increased due to decreased losses in the motor’s magnetic and electrical circuits. The current, or electrical commutation, creates a rotating magnetic field that moves the rotors magnets causing the motor’s shaft to rotate. The motor controller board helps modify the motor’s speed without using sparking brushes or a commutator
BLDC Motors and HVAC Efficiency
The use of brushless DC motors in the HVAC industry is a fairly new concept that’s gaining in popularity. In this industry, motors and reliability are the keys to energy efficiency. Some institutions, like universities, have become greener by upgrading the motors in their chilling units with the help of a professional service provider and a maintenance program that keeps the system running optimally, reliably and efficiently.
One of the factors that make brushless motors more efficient than their brushed counterparts is the use of permanent magnets. Because of the magnets, a motor doesn’t need to use electricity to generate a magnetic field across the gap to the rotor.
In addition to saving energy, brushless motors help reduce noise—a feature that consumers like. Consequently, appliance manufacturers are pushing motor suppliers to integrate BLDC motors as a way to remain competitive. Other reasons that the HVAC industry is turning to BLDC motors include:
- Variable speeds.
- The ability to use the motors in smaller packages, such as personal cooling units.
- Lightweight designs.
- Efficient battery use because of high efficiency.
- Control interfaces that allow for simpler product designs and installation.
- The lack of rotating brushes causes less wear and tear on a motor.
- There’s more room for copper windings in the motor, so there’s less friction and less energy wasted.
- Manufacturers also have the ability to use a single BLDC motor design for the different HVAC units produced. This means that they’re simpler to replace as needed because an individual doesn’t need to look for an induction motor that’s optimized for certain type of airflow.
Consumers can find HVAC units that use brushless motors that have a SEER (seasonal energy efficiency ratio) of 13 and above. Unlike units with AC inductor motors, those with brushless motors don’t experience performance and energy losses when the fan operates at lower speeds. The result is a motor that’s up to 33 percent more efficient than conventional ones.
While brushless DC motors cost more than their brushed counterparts, the energy savings experienced makes up for the expense. As the construction of green buildings becomes the standard, more contractors are installing HVAC systems with brushless DC motor designs for their reliability, energy savings and ability to economically keep clients cool.
About the author: Michael Bloom is president of Sinotech in Portland, Oregon. Sinotech offers a wide range of high quality brushless DC motors as well as custom electric motors built to their clients’ design requirements. Sinotech provides custom engineered mechanical products, metal and plastic components, and magnets to a variety of industries and has over 20 years of experience in the industry with engineers personally supervising all tooling and production to ensure quality control.