Results 1 to 12 of 12

Thread: Condenser Line Set Sizing Question

  1. #1
    Join Date
    Oct 2018
    Location
    New York
    Posts
    14
    Post Likes

    Condenser Line Set Sizing Question

    Hello. So I have an install coming up soon for a new 3 ton Goodman or Bryant AC. Evaporator is in the attic and they want to relocate the condenser.

    Problem is theres a 3/4 suction line and 3/8 Liquid line. The air handler is already about 25-30 feet away from the condenser and they want to move it another 25 feet away, roughly 50 feet total from the indoor coil to the condenser. Goodman calls for anything 50 feet to be 7/8 suction and 3/8 liquid not sure about Bryant but if memory serves it's the same thing. Changing the line is close to impossible due to circumstances.

    My question is can I run 7/8 suction on the outside 25 feet connected to the 3/4 going to the attic.

    Should I just run the whole thing 3/4.

    Or I dont think this is practical and dont really want to do this but should I up the system to a 4 ton. I know I Will loses efficiency but more worried about losing capacity. The house is 1,300 Square feet.

    Thanks.

  2. #2
    Join Date
    Jun 2017
    Location
    Portland, OR(Previous: Arizona, Texas, Oklahoma)
    Posts
    71
    Post Likes
    Quote Originally Posted by HVAC Guy7 View Post
    Hello. So I have an install coming up soon for a new 3 ton Goodman or Bryant AC. Evaporator is in the attic and they want to relocate the condenser.

    Problem is theres a 3/4 suction line and 3/8 Liquid line. The air handler is already about 25-30 feet away from the condenser and they want to move it another 25 feet away, roughly 50 feet total from the indoor coil to the condenser. Goodman calls for anything 50 feet to be 7/8 suction and 3/8 liquid not sure about Bryant but if memory serves it's the same thing. Changing the line is close to impossible due to circumstances.

    My question is can I run 7/8 suction on the outside 25 feet connected to the 3/4 going to the attic.

    Should I just run the whole thing 3/4.

    Or I dont think this is practical and dont really want to do this but should I up the system to a 4 ton. I know I Will loses efficiency but more worried about losing capacity. The house is 1,300 Square feet.

    Thanks.
    I would check in the manual with the product you are about to install to see which linesets are approved for what length. If you can't find it call tech support and get an answer

    Or

    You can install it, wait a few months and install another one.





    Sent from my LM-G710VM using Tapatalk

  3. #3
    Join Date
    Jan 2014
    Location
    New England
    Posts
    9,240
    Post Likes
    Why don’t you do a load calculation 1st to see what you really need, chances are you probably can get by with a tad smaller unit, negating your linesize worries.

    Here’s a free one: https://www.loadcalc.net/

    Upsize to a 4 ton? Your ductwork can handle 4 tons let alone 3 tons?

  4. Likes FreeThrowGuy liked this post.
  5. #4
    Join Date
    Sep 2002
    Posts
    30,352
    Post Likes
    The suction line flow direction is all horizontal and down, right?

    So how much of the line run can be installed as / be changed to: 1 1/8" ? Certainly all of the line set is not inaccessible, right? Then the only part which will be undersized is the 3/4" portion and the 1 1/8" portions will contribute pretty much nothing in terms of pressure drop.

    Why are you installing a 3 or 3 1/2 ton system in a 1300 square foot residence in New York?

    PHM
    --------


    Quote Originally Posted by HVAC Guy7 View Post
    Hello. So I have an install coming up soon for a new 3 ton Goodman or Bryant AC. Evaporator is in the attic and they want to relocate the condenser.

    Problem is theres a 3/4 suction line and 3/8 Liquid line. The air handler is already about 25-30 feet away from the condenser and they want to move it another 25 feet away, roughly 50 feet total from the indoor coil to the condenser. Goodman calls for anything 50 feet to be 7/8 suction and 3/8 liquid not sure about Bryant but if memory serves it's the same thing. Changing the line is close to impossible due to circumstances.

    My question is can I run 7/8 suction on the outside 25 feet connected to the 3/4 going to the attic.

    Should I just run the whole thing 3/4.

    Or I dont think this is practical and dont really want to do this but should I up the system to a 4 ton. I know I Will loses efficiency but more worried about losing capacity. The house is 1,300 Square feet.

    Thanks.
    PHM
    --------
    The conventional view serves to protect us from the painful job of Thinking

  6. #5
    Join Date
    May 2019
    Location
    Central, IL
    Posts
    34
    Post Likes
    I second the load calc, i cool my 1200 sq ft house with 2tons , and it has short cycles on all but the hottest days ( 95+)

  7. #6
    Join Date
    Jan 2010
    Posts
    23,539
    Post Likes
    Well the size really depends on the integrity of the envelope. So this leads us back to a proper load calculation.

  8. #7
    Join Date
    Aug 2002
    Location
    Southold, NY
    Posts
    33,641
    Post Likes
    Quote Originally Posted by HVAC Guy7 View Post

    The house is 1,300 Square feet.
    X-5 You need a load calc before changing anything!

  9. #8
    Join Date
    Jul 2000
    Location
    Guayaquil, EC
    Posts
    14,651
    Post Likes
    According to the Goodman long lineset capacity loss chart for a 3-ton R410A unit, if the entire 50 ft run is 3/4" the capacity multiplier would be .93 and if it's 7/8" the multiplier would be .98 . If 1/2 the total run is 3/4" and 1/2 is 7/8" the multiplier would then be .955, so the resulting capacity would be 34,380 Btuh.

    https://docs.google.com/viewer?url=h...d%2BTP-107.pdf

  10. #9
    Join Date
    Jun 2017
    Location
    Portland, OR(Previous: Arizona, Texas, Oklahoma)
    Posts
    71
    Post Likes
    Quote Originally Posted by icemeister View Post
    According to the Goodman long lineset capacity loss chart for a 3-ton R410A unit, if the entire 50 ft run is 3/4" the capacity multiplier would be .93 and if it's 7/8" the multiplier would be .98 . If 1/2 the total run is 3/4" and 1/2 is 7/8" the multiplier would then be .955, so the resulting capacity would be 34,380 Btuh.

    https://docs.google.com/viewer?url=h...d%2BTP-107.pdf
    ^ there's your educated answer

    Sent from my LM-G710VM using Tapatalk

  11. #10
    Join Date
    Jan 2015
    Location
    San Diego, CA
    Posts
    801
    Post Likes
    Another vote for a load calc. A lot of homes have oversized systems and if the calc shows a smaller system you may be fine with the existing suction line diameter. Sq ft alone does not mean much - things like the climate/state you live in, the number of south facing windows, glass type etc all factor into the final sizing of the unit and airflow.

    I've been using Coolcalc lately and while there are still some issues that need to be ironed out you can generate a proper ACCA approved Man J which you can give to your customer. I also find it affordable compared to other ACCA approved software.

    www.coolcalc.com

  12. #11
    Join Date
    Jan 2014
    Location
    New England
    Posts
    9,240
    Post Likes
    https://www.alpinehomeair.com/related/IO-258T.pdf

    Page 3 dated 2018

    Says anything over 79 feet is considered long lineset. If your going with a Goodman OD unit, install guide says to install a inverted loop by Air Handler.

    Make sure to register your the equipment as manufacturers warranty decreases significantly if never register.

    So what’s your plan, a load calculation or not going to rock the boat and replace with what’s in there already?

  13. #12
    Join Date
    Sep 2005
    Location
    Atlanta GA area
    Posts
    47,626
    Post Likes
    Tell your contractor to run the lineset up the outside of the house, then enclose it in either a lineset hiding product...
    Or a gutter downspout.

    It is done regularly... solves the problem of needing a larger lineset.
    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)
    *The value of comfort, over the long term; leave economic choices behind!
    Choose your contractor wisely!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •