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Series ECM Blowers

Does anyone know what will happen if you series two air handlers with ECM blowers?

Will they behave or become disoriented?


  • Empire_2
    Empire_2 Member Posts: 2,343

    If I'm not mistaken, there is a setting to twin the 2 units to act as one.  Check your local manufacturers manual.  Others will chime in to check my opinion.  Make sure there is a common plenum so feed back can affect both units.  My .02

    Mike T.
  • Housedoc
    Housedoc Member Posts: 66
    edited October 2012

    Empire, Thanks for your reply.

    I do know there are twinning kits for parallel configurations. But I want to push the air from one blower into the inlet of another. So the blowers are in series. It would seem they would act the same way as circulators. But I am not sure.
  • SWEI
    SWEI Member Posts: 7,356
    blowers in series

    Given that these are EC motors, the question is really about controls.
  • Techman
    Techman Member Posts: 2,144

    I think the motors in series will drive each other crazy
  • Housedoc
    Housedoc Member Posts: 66
    Seems so


    That seems to be the concesus. Apparently theses motors are slow learners. I've been told they will hunt for their programmed operating point and neither one may hit it because the target is constantly moving. But everyone has said they don't know for sure.
  • Techman
    Techman Member Posts: 2,144

    They work off of Back EMF and will not work in series
  • John Mills_5
    John Mills_5 Member Posts: 935

    Series would be one blowing into the next one. That what you mean?

    Twinning would be 2 units side by side sharing the same ducts. Usually you can do this with a fixed speed ECM like an X13. Doing it with variable speed won't work, they will fight each other. Only exception I know of is the Trane/A-S units with a switch to make them fixed speed.
  • Housedoc
    Housedoc Member Posts: 66

    Yes. Supply air from first ahu dumps into return of second.
This discussion has been closed.


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