View Full Version : 5/16 line going to work for both Trane and Lennox compressors?
05-12-2009, 06:05 PM
Still trying to decide between the two below proposals for either Trane or Lennox. I'm replacing a 22 year old Rheem that has a 5/16 line running between the compressor and air handler. Of my two quotes for Lennox equipment only one sales guy says I need to replace the lines with different sized lines. Other ones says it is OK. None of the Trane guys say I need to repalce so I'm assuming 5/16 is OK for Trane.
Trane: 2.5 ton XL15i heat pump w/ 4TEE3F31 variable speed blower;
Lennox: 2.5 ton XP14 heat pump w/ CBX27UH030 ECM air handler;
05-12-2009, 06:09 PM
Always have your lineset changed when you are installing a new system. Its like changing your oil and using the old filter. It does not make sense to do so and it is just cutting corners.:cool:
05-12-2009, 06:17 PM
The guy who came out today said he always changes lines when he installs a new system, said it needed to be done anyway given the size of the lines. He is the only one who said they would do this. The other 4 quotes were from the 4 biggest HVAC firms in town. I'm surprised they are cutting corners, figured I'd get the 'big sell' from them to pay for every little thing they wanted to sell me. They said they'd purge, clean, pressure test and reuse with the new refrigerant.
05-12-2009, 06:20 PM
well not 100 percent positive but i just replaced a system with a xr13 2,5 ton and it said to pout 3/4 suction and yes 5/16 LL but i dont buy 5/16 so i put 3/8 ..yes u should change the lines if they were that old but with a proper flush you could use the old lines if neccessary...
05-12-2009, 06:22 PM
why after getting 22 years out of a Rheem product you are not looking at another?
05-12-2009, 06:41 PM
tinner, I called the top 5 companies in town and it isn't a line any of them carry. Unfortunately I do not know who is making good equipment nowadays and am having to do my homework online and talking with friends. So far I'm hearing both Trane and Lennox are good brands and it is something I am finding local companies carry.
05-12-2009, 07:22 PM
Both units call for a 3/8" liquid line to be used, from the manufacturer. Many times linesets aren't replaced and are reused, and usually it's fine if done properly, but since you're replacing a 22-year-old system with a slightly small liquid line, I'd replace.
05-12-2009, 07:45 PM
agreed if they call for 3/8 then change them for sure..
05-12-2009, 09:08 PM
How hard is it to change them? The price of copper is WAY down. Seems to me they ought to go if wrong size. And yes, it doesn't surprise me that nobody cared but the one guy. I'm beating the heads of our salesmen to make sure sizing is appropriate, it can be a never ending battle. Of course they find that if they want to do it right and change lines but the competition doesn't, they'll lose the job so the HO can save a buck!
While we use a flush if we don't change lines but change refrigerant, I wonder just how good of a job it does. Just my little old opinion.
BTW, if it is hard to change lines, Rheem is just fine with a 5/16" liquid line on their pumps. The RPQL has some impressive numbers!
If the refrigerant lines are accessible it’s my preference to go ahead and replace them even if they are the right size.
In any case.
What size is the suction line?
What is the total length of piping and how many bends does it make?
Does the piping run vertically at any point and if so for what length?
The refrigerant pipe sizing is very important. For example a 2 ½ ton unit could easily lose 30% of its efficiency due to a 5/8” suction line and 5/16” liquid line.
05-12-2009, 09:53 PM
The lineset size requirements depend on the size of the furnace and the length/vertical height of the lineset run. Technically, you can use a smaller lineset than recommended but you loose efficiency. But I would always replace the lineset unless it is not practical (eg running under/in a cement slab or sealed wall cavity).
05-12-2009, 11:56 PM
The linesets nowadays are much thinner than the old stuff.. I prefer to keep the old 'heavy duty' lines if size is ok. Copper lasts forever, no need to throw it away
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