Buying a furnace can be an overwhelming experience. There are many different types and models to consider, and it’s easiest to just take the word of your HVAC expert without researching the different technologies for yourself. One major difference that every buyer should understand is the difference between a PSC and an ECM blower motor. Each type of motor is widely used today, but they operate very differently from one another. PSC motors or Permanent Split Capacitor motors are used more heavily in older systems, while ECM or Electronically Commutated Motors are often considered to be the new standard. Learning to understand how these two options are different will help you understand which technology is right for you when it’s time to start furnace shopping.
How PSC Motors Work
A PSC (Permanent Split Capacitor motor) is a simple product designed to turn on and off effectively. It runs at one speed all the time and can’t be adjusted to a higher or lower speed during operation. This is an issue when it comes to efficiency. The motor runs at full power even when all that power isn’t needed. For that reason, a PSC motor wastes power and is less efficient during operation than an ECM-style motor is.
How ECM Motors Work
ECM motors (Electronically Commutated Motors) can be adjusted to different power levels automatically. These blower motors usually start off slowly as heat is being generated in your furnace, and they build up power over time as heat levels increase to get to an efficient operating level. ECM motors are known for operating more smoothly and they make use of ball bearings that don’t require any sort of lubrication, making them easier to keep in good shape over time. They are much more complex machines than PSC motors are, which makes them more expensive to purchase. That added cost is a justified one though, because these motors are good at reducing your power consumption over time.
ECMs can reduce energy consumption by as much as 75% when put into a properly installed system that represents major savings over time. Not only are these variable motors more efficient, but they’re also more durable. ECM motors use a soft start and stop system, which is more gradual and significantly easier on all the equipment. Many ECM motors offer a usage life of around 90,000 hours, which is approximately double the usage life of a PSC motor. Investing in a system with a quality ECM motor installed in it will give you more precise control over the temperature of your home, it will help reduce hot and cold spots throughout your space, and will boost operational efficiency so you’re spending less to heat your home. All those reasons are good ones to make the switch to an ECM motor when you’re ready to upgrade your system.
ECMs Aren’t All Good Though
High quality ECM motors offer efficiency improvements over standard induction motors in good quality heating and cooling systems. We don’t live in a perfect world though, and many heating setups are far from ideal. In heating systems with higher-than-recommended levels of restriction on air flow, known as TESP or static pressure, ECM motors aren’t able to function as they were meant to. In systems with too much static pressure the motors are far less efficient than they are under ideal operating conditions. They might even be less efficient than a PSC motor would be in the same situation. Not only that, but often an ECM needs to work really hard to maintain the right air volume in highly restricted systems. This means the motor is prone to overheating, and that you could experience noisy vents. All of these issues are only issues in poorly installed and designed HVAC setups though. Before considering an upgrade to an ECM motor, it’s a good idea to have your vents tested for static resistance just to make sure your system is optimal. If it isn’t it would be worth upgrading to fix your setup whether you switch motors or not, but without upgrading your system’s high resistance levels would be very obvious if you choose to switch to an ECM.
ECM Motors Will be Legally Required after July 2019
Through years of testing ECM motors have proven themselves to be superior to basic PSC motors in terms of efficiency and comfort levels. They have such an impressive track record that the DEO or U.S. Department of Energy is requiring by law that all new furnace installations after July 3, 2019 include one of these adjustable blowers. An ECM motor will effectively reduce energy consumption when a furnace is being used, when circulation mode is activated and when a home is utilizing a central air system. It’s estimated that making this switch throughout the country will reduce overall carbon pollution by 34 million metric tons, or the output generated annually from about 4.7 million homes. The new standard is expected to save Americans about $9 billion in energy costs by 2030 as well. The standard is a major change for the industry, and will force some HVAC professionals to change the way they do business, but the top quality companies are already installing equipment that complies with the new requirements.
PSC motors continue to be used in homes around the country today because they’re affordable and homeowners opt for the lowest cost furnaces that they can get in many situations. This is a trend that will change starting in July of 2019, but it’s a trend that you can start shifting right now if you’re due for a new furnace. Consider investing in the slightly costlier, but more capable variable-speed two phase furnace. These furnaces are more efficient, they’re more comfortable and they’re worth the investment. Sure, you’ll spend more, but you’ll be glad you did when you notice that you’re saving on utilities. Just make sure the new unit is installed by a trained professional, because a top-quality furnace is only as good as its installer. ECM motors are actually less efficient when added to poorly designed systems, so make sure your system is checked and optimized properly before you try and make the upgrade. When installed properly a quality furnace is worth the investment, and new models should all come equipped with an ECM motor for the best in efficiency and comfort.