Page 1 of 2 12 LastLast
Results 1 to 13 of 15
  1. #1

    Effects of bends in duct

    So here's the story...bought a house built in the 1950s in southeast Wisconsin. Furnace is an 80%er. I saw the paperwork for the installment of said furnace that the previous owner left and I believe it was 67,000 BTUs. The supply registers are all on the inside of the house and I plan on changing that by running new round duct to the outside of all rooms. The house is 2 bedrooms and approximately 868 sq. ft. All the ducts right now are rectangular and measure 5" x 7". Here's the breakdown of the house right now...

    CURRENT PLANNED
    East Bed (108 sq ft) 1 supply East Bed 7" round
    West Bed (132 sq ft) 1 supply West Bed 7" round
    Bath (50 sq ft) 1 supply Bath 5" round
    Living Room (232 sq ft) 2 supplies Living Room 7" round (2)
    Kitchen (154 sq ft) 1 supply Kitchen 8" round
    (all supplies 5" x 7" duct)

    I plan on insulating this round duct. Here's where my worries come into play...a few of these runs will have quite a few elbows on them. The living room in particular. A run for the living room will come off the plenum running parallel (between) the floor joists, then it will have to make a 90 down, then a 90 to run perpendicular to the floor joists, then a 90 up to get between the floor joists...then run to the register boot. I'm wondering if all these turns are going to slow down the air flow enough that I should increase the size of the living room ducts to 8" round? Anyone have any advice for me?

    Also I should tell you that I'm trying to keep as much headroom as possible and thus i don't want to use a 45 to complete the run...so the 90s are necessary.

  2. #2
    Join Date
    Nov 2010
    Location
    Andover Kansas
    Posts
    2,115
    Welcome ,

    Glad to have you aboard...I think you will enjoy this site, I know I have.

    Of course this is not DIY (do it yourself) site and we cannot tell you how to work on your equipment or ductwork. We can answer questions to a point. Can't tell you how to install the ductwork, but I can tell you that yes any bend/turn in the ductowrk will decrease the amount of airflow. Some fittings decrease it more than others.

    It would be worth your time and money, in my opinion, to have a company come out and do a load calc on your house to see what size equipment the house requires for best comfort as well as how much airflow (CFM) each individual room needs.


    Good luck and enjoy yourself.
    .


    The statement below is my signature and just my overall feeling towards our industry and does not necessarily pertain to you nor this thread.


    There really isn't a legitimate excuse for not doing the job correctly!

  3. #3
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,913
    Please don't make duplicate threads in the forums. I removed your other one.

    Someone will see this one and reply if they think they can be of assistance within ours rules.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  4. #4
    108 6 inch, 132 6 or 7 inch, 50 if it inside bath meaning no outside walls dont bother with it. living room 8 inch, kitchen 7 inch. all boots can b 10x4 , 8 inch even 10x6 ...
    If you have a lil xtra doe hers a nice way to insulate. 7 inch pipe buy 8 inch flex and measure distance of piperun total with elbows. Cut the flex to that lenth plus a couple feel slide all of it on to one pipe squish it up do ur piperun and release the flex i hold in place with tape. now u have a double wall insulator well beyond the r value u need to pass code...

  5. #5
    Join Date
    Nov 2010
    Location
    Andover Kansas
    Posts
    2,115
    Quote Originally Posted by allamericanclow View Post
    108 6 inch, 132 6 or 7 inch, 50 if it inside bath meaning no outside walls dont bother with it. living room 8 inch, kitchen 7 inch. all boots can b 10x4 , 8 inch even 10x6 ...
    If you have a lil xtra doe hers a nice way to insulate. 7 inch pipe buy 8 inch flex and measure distance of piperun total with elbows. Cut the flex to that lenth plus a couple feel slide all of it on to one pipe squish it up do ur piperun and release the flex i hold in place with tape. now u have a double wall insulator well beyond the r value u need to pass code...
    Welcome allamericanclow,

    I know you are new around here, but the rules state that we are not allowed to give DIY (do it yourself) help here in the open forums.

    Take care,
    .


    The statement below is my signature and just my overall feeling towards our industry and does not necessarily pertain to you nor this thread.


    There really isn't a legitimate excuse for not doing the job correctly!

  6. #6

    sorry bout that

    Quote Originally Posted by Tech23 View Post
    Welcome allamericanclow,

    I know you are new around here, but the rules state that we are not allowed to give DIY (do it yourself) help here in the open forums.

    Take care,
    i am new and it won`t happen again. Just like to help peeps

  7. #7
    Join Date
    Nov 2010
    Location
    Andover Kansas
    Posts
    2,115
    Quote Originally Posted by allamericanclow View Post
    i am new and it won`t happen again. Just like to help peeps
    Me too, me too...but we have to balance between the help the rules allow us to give and what breaks the rules....for the home owners safety.

    Take care, see ya around.
    .


    The statement below is my signature and just my overall feeling towards our industry and does not necessarily pertain to you nor this thread.


    There really isn't a legitimate excuse for not doing the job correctly!

  8. #8
    Join Date
    Aug 2009
    Location
    NW FL
    Posts
    176
    What is the name of that junction-like box that takes the bend out of the flex duct when you have a low ceiling and not much room to gently curve and connect to the register w/o kinking the flex duct?

  9. #9
    Join Date
    Jun 2007
    Location
    Round Rock
    Posts
    3,549
    Quote Originally Posted by Tech23 View Post
    Welcome allamericanclow,

    I know you are new around here, but the rules state that we are not allowed to give DIY (do it yourself) help here in the open forums.

    Take care,
    I couldn't make a bit of sense out of what he typed. If anybody else can, interpret it, believe it without him seeing the job and do it. What the hell. They get what they deserve.
    I like DIY'ers. They pay better to fix.

  10. #10
    Join Date
    Aug 2009
    Location
    NW FL
    Posts
    176
    It's a device that enables you to transition from a 90 degree bend in to a register, where there is not a lot of space to gently sweep the flexible duct into the register.

  11. #11
    Join Date
    Aug 2009
    Location
    NW FL
    Posts
    176
    Maybe it's an elbow, but I thought there was a more specific product for connecting to a register at 90 degrees?

  12. #12
    Join Date
    Nov 2010
    Location
    Andover Kansas
    Posts
    2,115
    Quote Originally Posted by RoseRx View Post
    Maybe it's an elbow, but I thought there was a more specific product for connecting to a register at 90 degrees?
    Do you mean an "Angle Boot"?
    .


    The statement below is my signature and just my overall feeling towards our industry and does not necessarily pertain to you nor this thread.


    There really isn't a legitimate excuse for not doing the job correctly!

  13. #13
    Join Date
    Aug 2009
    Location
    NW FL
    Posts
    176
    That's it!

    I do aplogize for not knowing the term and feebly attempting to describe it.

Page 1 of 2 12 LastLast

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