tony Moving Heat Quiz April 14, 2022, 9:47 am

By April 14, 2022

tony Moving Heat Quiz April 14, 2022, 9:47 am

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HVAC School – For Techs, By Techs

Real training for HVAC ( Heating, Ventilation, Air Conditioning and Refrigeration) Technicians. Including recorded tech training, interviews, diagnostics and general conversations about the trade.

ECM expert Chris Mohalley joins the podcast to talk about the balance between selecting air filtration and motor performance, also known as “MERV vs. Motors.”

As the industry realizes that filtration is more important, we’re starting to see an interest in filters with MERV ratings of 13 or higher. However, there are some design challenges associated with static pressure drops across filters, motor responses to static pressure, and airflow. If the airflow isn’t set properly, that could affect the refrigerant charge and temperature rise.

PSC motors’ performance directly follows the load; as static pressure increases, the airflow rate produced by the motor decreases. They may also make loud noises when the static pressure is high but satisfactory airflow. However, they are robust and don’t typically fail quickly due to high static pressure.

Electrically commutated motors (ECMs) are operated by electronic controls and come in constant torque or constant airflow varieties. The former has a performance curve (like a PSC motor) but doesn’t appear to suffer from longevity issues when the static pressure is high; the latter can adjust airflow based on static pressure, but it is likely to have issues maintaining airflow during high static pressure conditions. Regardless, there is still an operational envelope; going outside of that envelope will likely result in a capacity and/or efficiency hit if there is high static pressure.

Chris and Bryan also discuss:

COVID-19 pandemic and the evolution of filtration
Face velocity across filters
Amps in constant torque vs constant airflow motors
Swings in airflow/performance
Educating the customer about “upgrading” filters
Using performance manuals

Learn more about Regal Rexnord’s training at https://regal.mmu.com.

Learn more about the 4th Annual HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium.

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Search Episodes

MERV vs. Motors

02/07/2023

Bryan Orr

Effective Filtration & More w/ John Ellis

02/02/2023

Bryan Orr

Do Houses Need to Breathe? w/ Allison Bailes

01/26/2023

Bryan Orr

What the Heck is High Performance HVAC w/ David Holt

01/19/2023

Bryan Orr

Setting Realistic Customer Expectations w/ Ed Janowiak

01/12/2023

Bryan Orr

Mini Split Install and Service Tips

01/03/2023

Bryan Orr

CO Doesn't Leak w/ David Richardson

12/29/2022

Bryan Orr

One HSI Furnace Control to Rule Them All w/ Jim Fultz

12/27/2022

Bryan Orr

Using Ice to Balance Energy Consumption

12/22/2022

Bryan Orr

We need to Pay Better! – An Audio Manifesto

12/20/2022

Bryan Orr

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