Indoor air quality (IAQ) isn’t a new concept; it’s been around since the start of the hygienic revolution in the 1850s. Until recently, those who seemed most concerned with IAQ were typically people dealing with medical conditions such as allergies or asthma. But in 2020, that all changed with the onset of the COVID-19 pandemic and resulting quarantine. With people spending increased time in their homes, and a renewed concern for respiratory health and well-being, the interest in IAQ equipment and systems has resurged.
A variety of IAQ equipment is available on the market today. Such equipment includes humidifiers, steam humidifiers, media filters, ultra-violet light systems and air cleaners. Some people make the understandable mistake of focusing only on the filter, but it can be more beneficial to consider the air filtration system as a whole. This often comes down to the motor that is at the heart of the IAQ system.
If a homeowner’s fan motor isn’t running continuously, their IAQ equipment isn’t either.
“The best advice I can give someone installing an IAQ system in their home is to pair it with an ECM (electronically commutated motor), because that motor will run continuously,” says Dennis Campbell, Regional Manager Nidec HVACR Aftermarket. “They can then set their thermostat to the ‘On’ position so the fan in their HVAC system continuously circulates the air through the filter, providing for a significant increase in the filtration level.”
There are several benefits to installing ECMs with continuous fan operation in IAQ systems. One of the biggest advantages is an increase in energy savings. Compared to the traditional motors with previous, less efficient motor technology like the PSC (permanent split capacitor), the ECM can be 25% more efficient in heating and cooling modes and up to 75% more efficient in continuous mode.
Energy use compared to a ½ HP PSC motor
Think about leaving five light bulbs on in your house at all times compared to just one.
ECMs can also help improve health with quiet, efficient air filtration. The low continuous fan speed on these motors provides ongoing filtration without the draft or noise of a standard blower motor, all while using less energy than a 100-watt light bulb.
Another big advantage with an ECM is increased comfort with reduced noise and temperature differences. ECMs offer a soft start feature, which reduces fan and duct system noises at startup. In addition, the low air circulation speed produces very little noise in constant fan mode. In most cases the homeowner will not even realize the motor is running. An ECM helps maintain airflow even as the filter becomes full, in turn improving comfort and reducing air stratification.
Air stratification transpires when cool, thick air descends to the floor while warm sparse air upsurges to the ceiling. You can sense a similar effect in building structures when the higher floors become too hot and the lower floors feel too cool.
An ECM can overcome a dirty filter compared to a PSC motor because an ECM will increase speed while maintaining torque, which will result in airflow through a clogged filter. In contrast, a PSC does not maintain constant torque, so the airflow will drop drastically with a clogged filter. Even with an ECM, it’s recommended to change your filter monthly to optimize your IAQ.
Growing Interest in IAQ and ECMs
Morgan Silvey, Director of Marketing – HVACR Aftermarket at Nidec, points out that the growing interest in indoor air quality provides a prime opportunity for manufacturers and distributors to ramp up products and promotional materials for consumers seeking ways to improve their IAQ. According to Silvey, “If the action of running ECMs in IAQ systems ultimately aids in the fight against life-threatening viruses such as COVID-19, we readily join in that fight.”
Dennis Campbell is Regional Manager for Nidec Motor Corporation / U.S. MOTORS and has 22 years’ motor industry experience. Mr. Campbell has a bachelor’s degree from the University of Illinois-Springfield. Morgan Silvey is Nidec’s Director of Marketing – HVACR Aftermarket, and has 17 years' HVACR experience. Mr. Silvey holds a BA from Truman State University, an MAE from Lindenwood University and is working towards an MBA from Washington University in St. Louis. He is also a Black Belt Lean Six Sigma.