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.
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.
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:
*Chart data courtesy of: Biemayer, P., Lutz, J., & Lekov, A. (2004). Measurement of airflow in residential furnaces*
Just choose Twintech!
I do not usually write reviews and should have done this a few days sooner. But I was and still am enjoying the increased comfort in my home from the new furnace installed by Twintech.
From my initial call and conversation with Bob, I already had a good feeling that I would like this company.
I was provided information, pictures of great quality work previously completed.
When Bob came for the inspection of the furnace he was amazing. He gave so much great advice and told me all the areas that his team would resolve. I was very impressed as some of what he had suggested I had only seen in Youtube videos. The honesty and options for payment made this a no brainer. I decided I would like Twintech to replace my furnace.
The work was scheduled promptly week and took place within half a day. Gregg came to install the new furnace. Again amazing they carried out all the work promised. What was left was the best I have seen and speaks to how they take pride in the work they do and deliver. Gregg was really polite and professional and the furnace in my basement is a work of art.
They were friendly, fast, clean, & answered any questions I had. They are also offering an interest free 12 month payment plan - that really helped me out since this was an unexpected expense.
I had Twintech heating install a new furnace and ac unit. Bob, the sales rep, the installation team of Greg and Mitch were a 10 across the board. They were never pushy, gave me time to think about it. Once we decided , they were there in 24hrs. Great company to deal with. And they were nearly 5k less than a competitors quote for a top of the line furnace/ac unit verse mid level.
I highly recommend Twintech heating to anyone interested in anything HVAC.
Our hot water tank died and with an after hours phone called Bob the sales guy jumped into action. Friendly, courteous and genuinely wanted to do whats best for our house hold we were given options and he awaited an answer with no pressure.
We decided on what we wanted and it was installed asap and Greg and team worked and cleaned up so well, you would never know there was a hot water tank there before!
We love our hot water tank and being able to have back to back to back showers without having to wait for the hot water tank to heat the water!
I had heard of Twin Tech from a good friend of mine.
I needed to get a new Air Conditioner. It was not working properly and was 19 years old. I decided to get a new furnace at the same time.
I gave them a call on Saturday June 28.
I spoke to Bob Graham. I made arrangements for him to attend my house the following day.
I saw him on Sunday June 29 at 1100 AM.
He was on time and looked professional.
He spent 2 hours with me going over what I needed. He also suggested that I purchase a Humidifier. He gave me a quote of just under $11,000.00 for the purchase and installation of a Air Conditioner, Furnace and Humidifier. He was not pushy and gave me time to speak to my wife.
I called Bob on Monday June 30 and made arrangements to have it installed by the end of the week.
On Friday June 3 they arrived at 830 AM.
Again, right on time.
Greg and Mitch worked all day and finished the installation by 430 PM.
They made sure that everything was working properly and the basement was just as clean as it was before they came.
I will now be using Twin Tech to perform any maintenance needed on this equipment.
I was completely satisfied from start to finish with the service provided.
We contacted TwinTech after having another ductless air-conditioning company come in to quote on a solution for our townhouse. We had a unique problem where my office was a hot spot - it's at the front of the unit and gets a lot of sun. If it's 20C outside, It's 29C in my office. The other company could not build a solution that would get a ductless unit to that room because of the location - the AC unit would have to be at the rear, and ductless systems would have to be on that side of the interior. TwinTech suggested a hybrid solution to fit our unique problem, where the ductless unit would move cold air to an air exchanger installed in our bedroom closet, and then they built a ducted vent system between all the upper rooms. This was less intrusive than building a central air system, and less expensive. Each room has a vent that I can close off, so I can push more cold air to my office when needed. We really didn't want ductless units sitting on the walls, and this looks and works better. I really appreciate the extra thought and care that went into the design of a solution, and the attention to detail in the installation. They answered all of our questions, and were able to do a bit extra by installing the ducts around the vents and painting them for us. It cost more than we originally planned for, due to our unique needs, but the fact that they offered financing helped us budget for more.
The job was done fast (I think we got lucky with timing where it wasn't the AC install busy season yet), and the team was very friendly and professional. They arrived and finished each day when they said they would. My office is now running at a comfortable temperature! I'm extremely happy with the experience and would whole heartedly recommend them.
How lucky are we to have this team come save us from our broken down, under sold, poorly installed previous unit (mind you there is a reason SEARS went bankrupt). Bob arrived on time to give us a detailed review of our unit and furnace; very knowledgeable. Greg arrived as planned with the new unit and reiterated what Bob explained how our furnace is equipped to handle the new unit and we didnt need to spend more money on a variable speed air conditioner. Cant say enough on how professional, efficient and personable this team is. Thank you so much guys!
We used Twintech for our replacement AC. Bob did a great job assessing what we needed and organized the install and showed up on install date. Greg and Mitch were on time and were very neat. They covered the traffic areas with a drop cloth and did an excellent install. Great clean up after install complete. Would recommend Twintech for heating and cooling.
They were fantastic, clean, freindly, great service. Would definitely recommend. Answered ally questions and more.
We woke up at about 7 a.m. the Sunday morning before Valentine's Day to a house that was barely 15 degrees Celsius on a really cold day. We tried to call some other suppliers but no answer or call back. We did a quick google search and Twintech came up. Had never dealt with them before. They had a chat line and lo & behold, someone answered; Greg. Helped us diagnose that our 40 year old furnace pilot light was out and walked us through how to relight it. All worked well; he even called me during this process. No charge I was told when asked.
15 minutes later, the pilot went out. It would not stay lit. Greg had Bob call us and we set up a meeting for about 11 a.m. that same Sunday.
Bob walked us through the options and even brought 3 electric space heaters for us to use. By Tuesday afternoon, we had a new Furnace and central air installed.
The team was helpful, responsive and respectful. Very glad we found them by accident and looking forward to a nice cool summer after a warm winter.