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  1. #1
    Join Date
    Aug 2009
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    HVAC company uses spray foam INSIDE the trunk?

    Im Building a home, getting bids from local hvac companies. One guy says he insulates the trunk from the inside with spray foam. Ive never heard of this but he says he does it all the time with good results. Thoughts?

    Thank you.

  2. #2
    Join Date
    Aug 2002
    Location
    Southold, NY
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    Quote Originally Posted by rykertest View Post
    Im Building a home, getting bids from local hvac companies. One guy says he insulates the trunk from the inside with spray foam. Ive never heard of this but he says he does it all the time with good results. Thoughts?

    Thank you.
    I dont know why? The ducts need to be oversized for the loss of size.
    Questionable on the fire codes.

    Really dont see any advantage.

  3. #3
    Join Date
    Nov 2006
    Location
    Athens, Ohio
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    7,207
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    Quote Originally Posted by rykertest View Post
    Im Building a home, getting bids from local hvac companies. One guy says he insulates the trunk from the inside with spray foam. Ive never heard of this but he says he does it all the time with good results. Thoughts?

    Thank you.
    I've never heard of that use. I suspect he's using customer's systems as experiments.

    I would ask for approval from the spray foam provider for that application.

    I can't imagine the surface would be very smooth, giving rise to turbulence and static pressure issues.
    AOP Rules: Rules For Equipment Owners.

    Free online load calculator: http://www.loadcalc.net/


    There = not here. Their = possessive pronoun. They're = they are
    It's = contraction of it is. Its = the possessive form of it
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    Questions should end with a question mark "?" Statements end with a period "."

  4. #4
    Join Date
    Nov 2004
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    SW FL
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    YOU DON.T need to be someone's Guinea PIG.

    Start over.

    ___ ZIP _ _ _ _ _ ?

    ACCA Manuals J, S & D
    J - LOAD CALCS
    __ S - EQUIPMENT SELECTION
    ____ D - Duct Layout

    2018 IECC
    https://www.energycodes.gov/sites/de...esidential.pdf

    A COMPLETE DESIGN with Equipment Specs needs to be provided in THE RFP process.

    https://www.smacna.org/docs/default-...l.pdf?sfvrsn=0

    Otherwise, Proposal Evaluations will be VERY Confusing.

    https://www.acca.org/communities/com...e-0ae579bfe24a

    MY Gmail address: racingdan11
    Designer Dan
    It's Not Rocket Science, But It is SCIENCE with "Some Art". ___ ___ K EEP I T S IMPLE & S INCERE

    Define the Building Envelope and Perform a Detailed Load Calc: It's ALL About Windows and Make-up Air Requirements. Know Your Equipment Capabilities

  5. #5
    Join Date
    Sep 2008
    Location
    VA
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    I could be mistaken, but I’m not aware of any spray foam that is “approved” for use inside ducting. Flame spread index would likely be an issue. I’ve heard of spray foam on the outside of sheet metal.

    Like the others have said, internal cross-sectional area is reduced, likely to cause airflow issues.
    "The only true wisdom is in knowing you know nothing" Socrates

  6. #6
    Join Date
    Sep 2005
    Location
    Atlanta GA area
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    Better place, IMO, for the foam... is the underside of the roof!
    Imagine a house where the attic is not super HOT or super cold... imagine the lower energy costs and increased comfort.

    Having said this... choose your foam contractor carefully!
    GA-HVAC-Tech

    Your comfort, Your way, Everyday!

    GA's basic rules of home heating and AC upgrades:
    *Installation is more important than the brand of equipment
    *The duct system keeps the house comfortable; the equipment only heats and cools (and dehumidifies)
    *Cheap is not good, good is not cheap; however expensive is not a guarantee of quality!
    Choose your contractor wisely!

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