PSC vs. ECM Motors: Know Their Differences

24 / 7 Emergency Service Available. Call Us Now: 1.844.894.6832


[BACK]
PSC vs. ECM Motors: Know Their Differences

Posted On: October 19, 2016

PSC vs. ECM Motors: Know Their Differences

The heating, ventilation and air conditioning (HVAC) industry uses a variety of motor technologies in its equipment. Historically, the two predominant motor types have been permanent split capacitor (PSC) single speed motors and electronically commutated motors (ECM) with variable-speed capability. HVAC professionals understand the key differences between these motor types. This article aims to share those differences to you today. 

PSC Motors 

For many years, PSC single-speed motor technology has been the standard in the HVAC industry. It represents the highest installed base. 

PSC motors are considered single-speed (speed refers to rate of rotational motion) because they have no internal controls that can be programmed automatically to vary the rotation of the motor over an operating range. In order to make PSC motors more flexible for various applications, speed taps are included to allow the mechanical contractor to manipulate the motor’s speed to ensure that the correct amount of airflow is delivered. There is, of course, a limit to the amount of static pressure the motor can handle, so it is important to keep in mind the optimal performance and safety. As static pressure increases, a PSC motor’s performance tends to drop off because it cannot adjust torque or speed. 

Because of its design, there are some disadvantages intrinsic in PSC motors. They are less efficient than other motors because they consume more watts. They are not ideal for continuous fan operation because since they run close to full speed, they use more energy than what the function requires. This also makes them less attractive for other continuous filtration applications. They are also the least quiet among the motor technologies. They do not offer customized airflow patterns that are often critical when it comes to managing humidity. 
 


twintechchart-image

ECM Motors 

ECM variable speed motor technology is highly variable and is ideal for various advanced applications. 

ECM technology is based on a direct current (DC) design that is more efficient and it runs cooler than AC PSC motors. They are, in fact, approximately 80% efficient compared to the 60% efficiency rating of PSC designs. ECM motors are programmable. In the case of a failure, the control or the motor can be replaced without having to replace the entire unit. They are also designed to run over a wide range of speeds, making them ideal for delivering airflow in a multitude of system designs. They also draw the least amount of watts, making them the most efficient motor technology. They are also the quietest among the motor technologies since they have the ability to ramp up and down slowly, making them ideal for certain applications with noise concerns. 

When it comes to disadvantages, ECM variable-speed motors come at a premium cost. 

To see the difference in performance between the two types of motors, check out this chart:


 


dfd

*Chart data courtesy of: Biemayer, P., Lutz, J., & Lekov, A. (2004). Measurement of airflow in residential furnaces*




[BACK]

See What Our Customers Are Saying:

by Elizabeth and John L from Scarborough on Twintech Heating and Cooling

In October 2018, I contacted Greg at Twintech to do a furnace cleaning. Greg discovered that my furnace, installed in 2006 by another company, had been installed incorrectly, leading to restricted air flow. The heat exchanger was also defective. As well, my furnace was too large for the size of my house.

In my opinion, the biggest concern most of us have as consumers is that we have no idea of the quality or knowledge and experience of the technicians any heating and cooling company will send into our homes. I could have avoided having my 2006 furnace installed improperly (leading to early replacement), had I known about Twintech then.

With Twintech you get it all. Because Twintech is a smaller company you can rest assured that the only technicians who will work in your home are Greg and his twin brother Grant who are co-owners and fully licensed and certified with over 30 years of experience in installing and servicing heating and cooling equipment. They are both friendly and personable and answer all your questions. Their workmanship is outstanding. We had a 2 stage, variable speed Goodman furnace installed. My wife and I noticed a difference in the heating and even temperature of our 2 storey home almost immediately. Our old furnace always heated too much on the main floor and too little upstairs. We are also impressed with how quiet the furnace is.

Twintech's office manager, David Gergley, is equally friendly and not only gave us a competitive quote to replace our furnace (we sought other quotes), but also went above and beyond my expectations when he made arrangements with an energy audit company so that we would be considered for a grant from Enbridge and IESO.

Needless to say, I give Twintech a 10 out of 10 and highly recommend them!

by James, Ajax on Twintech Heating and Cooling

Clean, Fast and Efficient Work. Between all the quotes I received Twintech was a few dollars less and offered the best warranty.

by garysumnec360, Whitby on Twintech Heating and Cooling

They did an excellent job. Everything was very well explained. At the end of the job everything was very well cleaned up.

by Glade, Pickering on Twintech Heating and Cooling

Twintech offered me a competitive price but more importantly great sales and installation service. They did everything with attention to detail and quality workmanship that is hard to find in this day and age. Dave who first game to visit me answered most of my questions and probed about my needs. For the technical/install questions he was unable to answer he quickly had Greg and Grant the owners answer for me. They did not cut corners on the installation or do anything to simply save time. They stayed into the early evening to complete the job and removed all my old components and even fixed up mistakes other workers ahd made in the past. I would highly recommend them and use them again if the need arises in the future. If you are looking for service or new equipment I would highly recommend Twintech be on your list of Heating companies to get a quote from and ask your questions to.

by Anne of Major Oaks in Pickering on Twintech Heating and Cooling

The company epitomizes high quality service: from the initial client interaction with Dave to the installation and follow up with the technical team. One of the key features I look for is the ability of a technical person to talk to and not talk down to the customer when responding to questions and I had quite a few, all of which were very professionally addressed. I was also quite impressed with the follow up service, promptness, the obvious competence of the team who left no stone un-turned to ensure I was a satisfied customer. Thank you guys.

by Aileen Johnson in Toronto on Twintech Heating and Cooling

All staff concerned were total professionals. Sales rep Dave was like having an old friend at your house. No up selling or pressure, just good honest facts and figures. The owners and assistant who installed our unit worked quietly, efficiently and left our home clean. We could not have been happier with the service and attention we were given. We are so happy a family member recommended Twintech. She said "don't call anyone else, just call them...they are amazing". And they were!!! Thank you guys for the great work!!! A. Johnson

by Lynsey from Toronto on Twintech Heating and Cooling

We are completing a large project adding an addition on to our house and couldn’t be more pleased with our decision to trust Twintech with our hvac work. They removed and replaced the furnace, installed a new A/C unit, swapped our tank water heater for a tankless unit, and completed ducting and new A/C lines through the addition. Without hesitation we would recommend Twintech to anyone.

by Oldtown in Pickering on Twintech Heating and Cooling

Honest, very personable , men of their word ,workmanship xcellent ,showed up when promised ,They do not try to up sell ,rather give good advice instead . Price was very fair in my opinion .We have a family member with a medical condition and I think they made us a priority .Very happy with these guys . (Nice guys ) Stu Leffler Ajax.

by Mike B. Toronto on Twintech Heating and Cooling

Very professional, courteous, knowledgeable staff. Sales staff (David Gergley) excellent in knowledge and getting the job setup and installation was very prompt. Greg and Peter (technicians) knew their stuff and stuck around after completion to make sure it all worked properly and that I understood how it all was installed and how the unit worked. Would highly recommend them! Thanks for a great job-house is now cool and comfortable.

by Steve S in Toronto on Twintech Heating and Cooling

I had Twintech install a brand new air condition back in June of this year and I'm very happy with their service. I have a very busy schedule so I sent out an email to 7 or 8 HVAC companies just to get an idea of what it would cost. Dave at Twintech and only one other company were able to give me an approximate quote through email. Many of the companies I reached out to didn't even respond. I decided to meet with Dave and he was very friendly and professional. He gave me a good quote for a name brand/energy efficient AC with installation from their certified technicians. It was an easy decision to go with them.

Within a week I had the unit installed and working perfectly. Their technicians were very helpful and answered all of my questions. I'll definitely be calling them back for all of my HVAC needs in the future.