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Furnace blows too much air into small zone.

ako88 Member Posts: 1
I recently had a Carrier 80% Variable speed 4 ton furnace installed in my 2100 sq. ft. home.  I also had 3 zones set up.  Unfortunately when the system uses one zone, the air flow is so high that it's EXTREMELY loud.  (Something to do with the CFMs and pressure)  The installer returned and decided to install a "barametric damper" in my attic.  Basically, it's diverting the extra air into my attic.  Now, shouldn't the system recognize it's only heating one zone and use it's lower air setting since this is a "variable speed" unit?  My other option is to swap out the unit for a 3 ton unit.  Does his solution sound right?  Is the system runnning as expected?


  • Empire_2
    Empire_2 Member Posts: 2,343
    edited December 2011

    While zoning you system allows direct control to selected areas, it is concerning that the by-Pass was not installed in the first place.  The furnace is Mod, but still has minimum settings that have to be, First:selected/via dip switch settings and 2nd meeting the required settings for a given application.  Since there is a multitude of factors that come into play,  no quick answer can be provided at this time.  Can you call the contractor with the complaint and have them continue addressing the problem? 

    My .02

    Mike T.
  • Techman
    Techman Member Posts: 2,144
    Size of zones

    What is the zone by zone sizing and use? With your 4ton unit ,do you mean, besides the "furnace" you also have a 4t AC system ? The AC needs more CFM then the heating does. With ECM motors the CFM is usually  controlled by "dip switches"  or terminal boards . The "damper " and "damper ducting " should be bypass air directly from the supply duct trunk to the return duct trunk when needed.
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