The electronically commutated motor (ECM) is worth learning a little about if you’re concerned about your HVAC system’s efficiency. This type of motor is one of the most important features in modern energy-efficient furnaces, heat pumps and A/Cs. Especially in the Denver Metro area’s continental climate, an ECM could save you big on your energy bills.
The air handler in most older, mid-efficiency heating and cooling equipment contains a permanent split capacitor (PSC) motor. These motors average around 50 percent efficiency and can’t vary their speeds in response to your home’s heating and cooling demands.
In most of today’s high-efficiency furnaces (90 to 98.5 percent AFUE), you’ll find an electronically commutated motor, also known as a brushless DC motor. The design of these motors allows them to reach efficiencies that are simply unattainable for PSC motors. An ECM is between 65 to 75 percent efficient.
You’ll find ECMs powering variable-speed blowers. They’re equipped with a pre-programmed microprocessor that allows them to choose the optimal speed for air delivery based on your home’s heating and cooling needs.
Greater efficiency and more precise control over air delivery provides a number of benefits.
- Energy savings – An electronically commutated motor can reduce your home’s total electricity use by an average of 15 percent if you use air conditioning and around 23 percent if you don’t. Because they produce minimal heat and don’t contain erosion-prone brushes, ECMs last longer than PSC motors, saving you on replacement costs.
- Greater comfort – PSC motors run your system at only one high speed, which causes drafts and temperature fluctuations. ECMs use “soft start” technology to start up at a low speed. They ramp up to a higher speed only if the selected thermostat setting isn’t reached within a certain amount of time. The result is more consistent temperatures without drafts. Because they usually run at a lower, more continuous speed, they provide superior humidity control and air filtration.
- Quieter operation – The ECM’s design makes it naturally quieter than the PSC motor.
If you’d like professional guidance on choosing an efficient HVAC system or upgrading your current system, contact us at Coffman and Companies or give us a call at 303-366-1112. We provide satisfaction-guaranteed HVAC services throughout the Denver Metro area.
Our goal is to help educate our customers in the greater Denver, Colorado area about energy and home comfort issues (specific to HVAC systems). For more information about electronically commutated motors and other HVAC topics, download our free Home Comfort Resource guide.
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