Welcome to the first in a series of articles on how we, as HVACR technicians, can do our bit to help improve the energy efficiency of our customers’ HVACR systems. If we incorporate this knowledge into our service and installation work, we’ll be saving our customers money and making their lives better and more comfortable, as well as contributing to the larger goal of wise use of limited and costly energy resources.
By Dan Linthicum
So, what do you know about ECM’s?
This was the first question I was asked when I got into this industry about ten years ago. I shook my head a little and said, “I don’t know. What’s an ECM?”
My interviewer shot back with “Electronically Commutated Motor. What do you know about them?”
“Whoops, I’m in the deep end of the pool now…,” I thought … lol ….
An Electronically Commutated Motor is essentially a direct current motor coupled with an electronic motor control that is mounted on the end of the motor casing. These are the hot items to use in HVACR applications such as air handlers, furnaces, heat pumps and AC/refrigeration condenser and evaporator fan motors.
Why? Compared to the older style Shaded Pole and PSC motors, ECM’s are:
- vastly more efficient
- require less energy to operate
- provide improved environmental comfort
- and improve the overall service life of the whole HVACR system.
How much more efficient? Depending on the speed at which it is running, typically you will see a 30% electrical savings at high speed and up to 70% savings at a lower constant speed. That can add up to a ton of money over a year, especially for commercial customers who may have dozens of motors running in their HVACR systems at any given time.
ECM’s provide a constant airflow under varying static pressure conditions, which results in improved comfort for the end user due to better humidity control, quieter fan operation and reduced temperature swings.
In addition, constant and consistent airflow, particularly in indoor blowers, provides stable pressures and temperatures in A/C and heat pumps, and helps provide for proper temperature rise in a gas heating application. As an example in an A/C application, if we didn’t have adequate airflow it could lead to problems such as iced up coils and liquid slugging at the compressor, which of course is detrimental to the operational lifespan of the equipment. Efficient motors contribute to efficient systems, helping everything to work better, longer.
Want to learn more about ECM’s and how they work?
Check out our course: 114 HVACR Electrical Motors in our HVACRedu.net Master Catalog, then e-mail our Student Services department at firstname.lastname@example.org. Tell them “I want to learn more about motors!” and they’ll fix you right up.