Results 1 to 6 of 6
  1. #1
    Join Date
    Jun 2009
    Location
    Spicewood, Tx
    Posts
    35

    Main air duct size

    We lost our house in a wildfire Sept. 4th. The site is cleaned up and I'm planning the rebuild. Metal building, house 30x44, garage 30x24 and RV garage 18x46. Not sure if we have the funds to finish the inside of the house, so we may be in the RV for awhile.

    But before I lock-in the metal building height, I need to make sure there is room in the attic for the main A/C duct. The main duct will be a straight run of about 32 ft, six rooms, half cathedral, half flat 8 ft ceilings. With a 3/12 roof pitch, I will have a max. height of about 36 inches, dropping 3 inches for each foot of width. Can anyone tell me what cross-sectional duct size is needed? Too early for a full A/C plan, it will be another week before the RV slab is poured. Thanks if you can help.

  2. #2
    Join Date
    Jun 2010
    Location
    Philadelphia PA
    Posts
    2,159
    !4" plus the height of insulation at the center and you're golden
    You have got to learn from other people's mistakes! Because God knows you don't live long enough to make them all yourself !!!!!!!!

  3. #3
    Join Date
    Jun 2009
    Location
    Spicewood, Tx
    Posts
    35
    Thanks so much, one less thing to have to worry about right now. Once I can get the sub contractor started on the building, I still have to re-run water, sewer and electric lines and get someone to recover the well pump since it dropped to the bottom of the well bore.

  4. #4
    Quote Originally Posted by genduct View Post
    !4" plus the height of insulation at the center and you're golden
    If I read this right,,the cross section or is it diameter of the duct should be 14 inches??? how can that size be arrived at?? or did I not understand the question.

  5. #5
    Join Date
    Jun 2010
    Location
    Philadelphia PA
    Posts
    2,159

    I was thinking

    of the height as being important
    You have got to learn from other people's mistakes! Because God knows you don't live long enough to make them all yourself !!!!!!!!

  6. #6
    Join Date
    Aug 2011
    Posts
    10

    Since you are starting from scratch...

    If you live in a hot climate zone have you given any thought to running your ductwork somewhere besides in the attic for better energy efficiency? What do other folks think about this? Starting from scratch leaves room for some other options I think. Where do you live?

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event