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LineSet size

I'm having a new 4-ton r-22 Trane system installed and the product manuals specify 1 1/8 inch and 3/8 inch lineset. My installer says the large size is unnecessary since the lineset is only 20 feet long (15 feet height diff). So he plans on using reducers and 7/8 linset.

I don't want to bust his nuts and he seems experienced and recommended. But, Will this pose warranty or operation issues? Thanks


  • Empire_2
    Empire_2 Member Posts: 2,343

    7/8" lineset should be fine. I could see if it was 50' or more and your height of 15' is nothing. 5 ton is usually 7/8-3/8". I'll bet you that if you were looking at the connection (suction) at the compressor you will find that it is 7/8" line.
  • soot_seeker_4
    soot_seeker_4 Member Posts: 22
    dear author \"soot_seeker \" of this thread......

    dear author "soot_seeker " of this thread.

    kindly, use your own name or at least a different handle other than "soot_seeker" as i have used that handle for my postings across many boards over the last two years. i do not wish to see any confusion of authors arising from same if possible.


    ss soot_seeker
  • Rodney Summers
    Rodney Summers Member Posts: 748
    lineset size

    Mike T , did you mean at the actual compressor? I'll cehck when it gets here. The specs clearly identify 1 1/8 on both air handler and the condensor. Does anyone think this affects the warrantee or operation/performance? Anyone have opinions or cautions using Trane 4ton units (2TTR2 and 2TEP)?

    soot_seeker, sorry, there must be software glitch. a cookie was dropped on my pc. i cleared it.
  • Marty
    Marty Member Posts: 109

    Will it work ? probably. Is it right ? no. small reduction in capacity and effiency with a short run,as far as warrenty trane would be well within their rights to refuse any warrenty claims. I am sure if they could have used smaller (less expensive) connections they would have.
  • soot_seeker_2
    soot_seeker_2 Member Posts: 228
    should be fine..

    the answer is 7/8 s/b fine for 20ft. 1 1/8" would be good for about 100ft.

    read more here:
  • Empire_2
    Empire_2 Member Posts: 2,343
    Read it

    Nice article,.Very informative. Thanx.........
    Mike T.
  • Empire_2
    Empire_2 Member Posts: 2,343

    I thought I would check the connection at the compressor if I was that person. I'll bet it's 7/8".....?
  • soot_seeker_4
    soot_seeker_4 Member Posts: 22
    50ft charts & other stuff ...

    those charts are graphed per 100ft of pipe. i guess 50ft charts would have been easier to see but the loadline is linear so once you get there you can basically slide up & down the pipesize to check the temp loss below.

    technically all the bends & valves add some effective length to the p/t loss but there's still plenty of room in there if you use 2f max loss at ari stand 40f evap and 105f condenser.

    btw, check out all the other articles that the guy wrote at that website - equally fantastic resources for heating/cooling.

  • Marty
    Marty Member Posts: 109
    probably is

    Might even be 3/4.... Trane was one of the first to go to larger than "standard" line sizes. In the quest for higher seer ratings manufactures will do alot for a measly tenth of a point.
  • michael terry
    michael terry Member Posts: 30

    will be fine, no longer than the line set is.If there is vertical lift .the increase in refrigerant velocity will be benefiecial in the movement of oil should it leave the compressor.with a 20 ft line set 7/8 would not bother me in the least.

    mike terry
  • CDM2
    CDM2 Member Posts: 18
    Lineset sizing

    Does the spec sheet call out for 1-1/8" x 3/8" lineset, or is that the suction and liquid connection sizes? Some manufacturers will have 1-1/8" on the suction connection on their 4 and 5 ton units to accommodate the need for
    1-1/8" in a long line application. You need to check out the refrigerant piping section of either the Trane engineering handbook data, or the installation instructions.
    If you have the complete model numbers of both indoor and outdoor units, I can get that info for you.

    Dean Meece
    Territory Manager
    Habegger Corporation
  • greg_28
    greg_28 Member Posts: 22
    lineset size

    Thanks for all the info. I'll speak with the installer when he starts (should be this week). The guy has my sympathy with the heat index near 100 in Long Island and having to crawl around my attic. I offered to help his crew and suggested they get an early a start as possible. How's a 5 Am start sound?
  • soot_seeker_4
    soot_seeker_4 Member Posts: 22
    early start - good idea..

    early start - good idea..

    here's another good idea - make real sure with an attic installation that they route both the primary & secondary condensate piping out of harms way of other people doing work in the attic in future years (including future a/c guys). the pvc must be strong & setup such that nobody kicks it or cracks it or you can have some really spectacular water damage starting in the attic - thru the m/b ceiling - and along the walls & ceilings down to the wood floor in the den. $15K damage later & that was 10 yrs ago. happened to me - they paid for it - but i don't let anybody up there any more - including alarm wiring guys. be careful.

    fellow long islander - huntington.


  • soot_seeker_4
    soot_seeker_4 Member Posts: 22
    ? you lost me...


    3/4 (6/8) is *smaller* than 7/8".......
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