I recently was asked the question, “Can I use a by-pass humidifier on a furnace with an ECM motor?” Now, I had never seen anything to the contrary, so I figured the best source was to go to the ECM Motor manufacturer — Regal Beloit — and ask them the same question.
As we all know, moisture is one of the biggest problems when it comes to any electronics. Since the ECM motor has the motor module on it that contains its electronics, this was a very good question.
Well, according to Regal Beloit, by-pass humidifiers CAN be used with ECM Motors. HOWEVER – when you think about it ( it makes a lot of sense), the return duct with the by-pass humidifier attached to it should come into the furnace on the OPPOSITE side of the furnace from where the motor is mounted into the blower housing. This keeps the “humid air” out of the motor and its electronics.
This was one of those “ah ha!” moments. More over, I learned something new from this question. Then it got me thinking about all the times we hear about furnaces that have repeat ECM Motor failures. How many of these have by-pass humidifiers and have the return on the furnace on the side the motor is mounted?
We always”assume” that most problems with ECM motors are “voltage related” and add “choke coils” to control the voltage better, but how many are simply because the humidifier is actually causing the problem?
So, it was a very good question and I’m glad it was asked. Anytime I can learn something new is a great day. I plan to add this tidbit to my furnace training.
Hopefully, when you install a furnace that has an ECM motor in it and plan to use a by-pass humidifier, try to make sure that the motor is not directly exposed to the moisture or you could have repeat failures of those motors and then ‘bad mouth” the motor or manufacturer when it really is an application issue.