Commercial HVAC Motors: ECM vs PSC
Most mechanical contractors will suggest an ECM for your commercial HVAC system. But why should you choose an ECM? What is the difference between ECM and a traditional PSC HVAC motor?
Your HVAC system has a motor that essentially pushes air through your system. Some call it a blower motor. There are two types motors – Electronically Commutated Motor (ECM), and a Permanent Split Capacitor (PSC) Motor. ECMs are more efficient, programmable and versatile. ECMs are more efficient because they automatically adjust the blowing speed. PSCs do not adjust.
HVAC motors work to maintain air flow through your HVAC duct work. They push against a pressure. The ECMs will work more or less depending on the resistance and pressure in the HVAC system. The PCSs will keep spinning, since it is fixed. The motor will turn on or off depending on the demand. ECM actually changes the speed of the motor to maintain airflow. One example to illustrate the difference is that PCS motors are like a driver who is either accelerating or hitting the breaks. ECMs are on cruise control.
Much like cruise control, energy savings can be upwards of 75% with an ECM. Energy savings with an ECM pump are reported to “pay back” within 2 years.
One thing to consider is up front costs. PSC motors do cost less to install. However, PSC motors have brush components that wear out over time. They need replacement and maintenance. An ECM lasts longer since they do not have brushes. ECM motors will cost less to maintain in the long run. ECMs have microprocessors that ensure efficient heating and cooling while decreasing mechanical stress on your motor.
Between the cost savings, programmability and longevity, it’s easy to see the benefits of choosing ECMs over PSCs.
Considering upgrading from a PSC motor to an ECM pump? Or have more questions? Our amazing team of professional HVAC engineers, designers and technicians are eager to help out.