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New heat pump with 5/16" liquid line?

Does anyone know of manufacturer that has ratings for their heat pump to be used with a 5/16" liquid line? We have a replacement job, that has an existing 25' silv flos'ed liquid line that we would like to re use. I know most manufacturers now are calling for 3/8", But if possible we would like to re use this line and save the customer the extra charge in having it replaced. Thanks to all. '

Comments

  • Steve MinnichSteve Minnich Member Posts: 2,517
    About 25 years ago, I had a compressor fail within the warranty time frame. I was denied the warranty because I used a 7/8" suction line on 4 ton system that should have had a an 1 1/8" suction line because of its extended length. That was a hard lesson to learn. I never give them an opportunity to deny, anymore.
    PHC News Columnist
    Minnich Hydronic Consulting & Design, LLC
    https://heatinghelp.com/find-a-contractor/detail/minnich-hydronic-consulting-and-design
    SuperTech
  • JUGHNEJUGHNE Member Posts: 6,628
    Was this 5/16 on an old R-22 system?
    Ruud/Rheem did the 5/16 years ago.

    A new 410A HP?
  • zepfanzepfan Member Posts: 287
    Thanks for the response. It is a Trane 1987 2 ton, r22 air handler, and we would be installing an 410a hp and air handler
  • unclejohnunclejohn Member Posts: 1,494
    Should be ok up to 3 tons. Add as much 3/8th as you can at the unit. I have never had a warranty job denied.
  • JUGHNEJUGHNE Member Posts: 6,628
    Is the remaining oil from the R-22 system a concern?
    Or how do you deal with it?
    Or is it as much of the issue that was thought when 410A became popular?
  • John Mills_5John Mills_5 Member Posts: 935
    Rheem is fine with it in long lengths up to 3 on, above better be pretty short.

    Otherwise I'd check with tech support on the brand you want to use. I called 1 brand once and was told absolutely nothing less than 3/8". Dead comps usually don't go back so yes, warranty won't be denied but it will cost someone!

    Old lines blow out with nitro and unless you had a burnout, should be OK. Of course if easy to change I'd much rather see shiny new copper. POE oil is a GOOD cleaner removing any crud built up on the inside of the old lines.
  • JUGHNEJUGHNE Member Posts: 6,628
    On a walk in cooler I had both TXV plugged screens twice after 134A and new oil.
    So for a heat pump with possibly TXV inside and out, also reversing valve, where is the best place for the bi-flow filter drier.....would one for each end be a consideration?
  • EBEBRATT-EdEBEBRATT-Ed Member Posts: 6,741
    5/16 will be fine for 2 tons. Blast it with nitrogen first
  • G Averill_2G Averill_2 Member Posts: 44
    Our refrigeration and air conditioning staffs recommend a product by Nu Calgon, item number Rx-11-flush when changing refrigerants. Take a look on their website.
    SuperTech
  • pecmsgpecmsg Member Posts: 1,258
    Flushes cause more damage and are not advised. just blow out the line set. No issues with a mixture of POE & MO.
    Remember the POE oil is a cleaning agent, We recommend a suction filter in use for several days to trap any and all crap that will come back to the compressor. Remove it after a few days.
    unclejohnChrisJicy78
  • CaymanCayman Member Posts: 1
    edited March 24
    Hey guys, I have a similar situation as the original poster here. Replacing a 2.5 ton R22 Trane HeatPump that has an existing 5/16" liquid line. Replacing the unit with a Goodman GSZ140301 (2.5 ton HeatPump) and a Goodman ARUF37C14 a/h. The existing lineset runs through interior finished space of the house and the HO doesn't want a new lineset running up the exterior wall. In this case, the a/h is in the attic with a total 50' lineset run with approx 18' of that being a vertical lift. Goodman's technical publication 107 makes a 5/16" for a/c only applications, but, makes no mention of heatpump applications. Thought I'd reach out to you for your thoughts. Do you think I can get away with using the existing lineset? Thanks in advance.
  • pecmsgpecmsg Member Posts: 1,258
    Cayman said:

    Hey guys, I have a similar situation as the original poster here. Replacing a 2.5 ton R22 Trane HeatPump that has an existing 5/16" liquid line. Replacing the unit with a Goodman GSZ140301 (2.5 ton HeatPump) and a Goodman ARUF37C14 a/h. The existing lineset runs through interior finished space of the house and the HO doesn't want a new lineset running up the exterior wall. In this case, the a/h is in the attic with a total 50' lineset run with approx 18' of that being a vertical lift. Goodman's technical publication 107 makes a 5/16" for a/c only applications, but, makes no mention of heatpump applications. Thought I'd reach out to you for your thoughts. Do you think I can get away with using the existing lineset? Thanks in advance.

    and there's your answer.

    Contact Goodman tech support before taking on the job.
  • EBEBRATT-EdEBEBRATT-Ed Member Posts: 6,741
    3/8 is good for 3 1/2 tons at 25' so I don't see 5/16 being an issue on 2 1/2 at 25'

    Heat pump or ac makes no difference it's the same amount of liquid flowing only the direction changes. The weight of R-22 and R-410 in a liquid phase is virtually the same
  • ratioratio Member Posts: 2,280
    In the lineset sizing paperworks I've read, the liquid line size was dictated by refrigerant velocity as well as pressure drop & often gave a range of sizes. That said, I can't recall seeing any R-410A A/C system that permitted anything smaller than 3/8". It's possible that it'd work, but I'm quite sure that Goodman, or any other mfgr, will not honor a warranty that doesn't meet their minimum spec.

    If it were me, I'd walk away. I don't know how reasonable the homeowner is, but I know how those kind of things fall out for me.

    Ironman
  • GWGW Member Posts: 3,646
    we did that on a condo 3 years ago, no issues yet. 2 ton
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    www.wilsonph.com
    [email protected]
  • IronmanIronman Member Posts: 5,514
    edited March 25
    Get the manufacturer to okay it in writing. If they won't, then tell the customer it has to be changed.

    Gentlemen, we cannot let the customer dictate what's proper design or procedure. That's our job.
    Bob Boan


    You can choose to do what you want, but you cannot choose the consequences.
    pecmsgicy78ratio
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