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  1. #1
    Join Date
    Aug 2002
    Posts
    123

    Cool

    I got a small ranch..AC job..
    will be installing the AHU in the attic..
    I will be adding a 3 -ton unit..

    Was wondering how do I figure the Trunk-line...coming out of the discharge on the AHU
    the Ranch is 46' Wide

    the house is a little under 1400 sq. ft.

    thoughts

    talk soon
    dismas

  2. #2
    Join Date
    Nov 2004
    Location
    SW FL
    Posts
    6,243

    Exclamation Drawing + ACCA Manual D

    Duct layout guidance can only realistically be developed after a floor plan is provided.

    ... 3-Ton is ~ 1,200 CFM,
    ... FOR A STARTer :
    ... AHU outlet duct should be ~1.5 Sq. Feet
    ... 12" x 18" hard duct at least 6 feet long

    Any branches sizing is guessing.
    ... 800 CFM = 1.0 Sq. Foot ( 12"*12" or 14" diameter )
    ... 600 CFM = 0.8 Sq. Foot ( 10"*12" or 12" diameter )

    Add up all the dP's for straight runs, fittings, outlets on each flow path to assure you have met ACCA Manual D criteria and AHU fan capability.
    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

  3. #3
    Join Date
    Aug 2002
    Posts
    123

    Confused Sizing up duct work

    Thanks Dan,

    If I can get you the ..floor plan...could you help me out
    until ..I can afford the HVAC Software...

    I do have the Manual D...but, can't claim to be a pro..at it

    I will be having the duct work..made up at the sheet metal shop...so I am trying to be close ..

    talk soon
    Dismas

  4. #4
    Join Date
    Nov 2004
    Location
    SW FL
    Posts
    6,243

    Exclamation Re: Sizing up duct work

    Originally posted by dismas66
    If I can get you the floor plan could you help me out until I can afford the HVAC Software

    I will be having the duct work made up at the sheet metal shop so I am trying to be close ..

    O.K., minimal charge for 1,400 Sq. Feet depending on extent of details needed and permitting documentation required.

    Send .PDF file to
    racingdan11 at comcast dot net
    ___________ @ ________ . _____
    ( /\ address per Forum rules)

    OR can you snail mail if you have the time.
    OR FedEx if your schedule dictates.

    I can complete in < 1 day after all info is provided.

    You need to be Nearly EXACT on a REALISTIC DUCT and AHU layout depending on space allocation as required by buidling structure.

    or write for other arrangements
    + necessary buidling design details.

    1. City, State
    2. House Orientation
    3. AHU Location: Qty. 1
    4. Insulation
    R-__ wall .. ceilings
    __ Batt
    or __ Spray Foam

    5. Window schedule
    __ Mfg: Anderson or other

    6. Wall Height:
    _ 8 9 feet
    _ 10 feet
    7. One story

    8. Special internal gains, if any,
    i.e. A-V or computer room
    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
    Aug 2002
    Posts
    123

    Confused Sizing

    Thanks Dan,

    you can e-mail me
    @ joemonahan@comcast.net

    pdf file should work

    accobat too

    talk soon
    DISMAS

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