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HRV discharge temp

Im assuming the supply discharge temp is 30% warmer or cooler than the ambient air in the house. If I put in a stand alone HRV in the attic where do you think I should place the supply diffusers so as not to make the home uncomfortable.


  • NRT_Rob
    NRT_Rob Member Posts: 1,013

    I believe most ERV/HRV equipment requires that they operate in ambient temperatures of 50 degrees or higher.

    it's always best practice to mix your discharge air at the ceiling though. High-wall and angled up or on the ceiling and throwing flat is best IMHO.
    Rob Brown
    Designer for Rockport Mechanical
    in beautiful Rockport Maine.
  • BillW
    BillW Member Posts: 198
    edited December 2010
    HRV in attic

    Heat recovery ventilators have to have a drain and some way of melting any ice that may form in them on cold days.  Some use an electric element, others recirculate room air.  They will freeze up in an attic, and are best installed in a basement where the temperature stays above freezing.  ER/HR ventilators are about 80% efficient, so the discharge may be cold on an extremely cold day.  A small hydronic or electric reheat will solve that issue.
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