Lengthen a mini-split line set

[theoldwizard1]

Asking for a "friend of a friend", who is working on a budget.

Installing 2 full mini-splits. First one the line set is too long by a good 4'-6'. The second on the line set is short by about 2'.

Cut the ends off with leaving and extra 2'+ on the long one and then splice it on to the opposite set of lines ? Braze is what professional would do, but how about solder ?

 

[Movover]

Asking for a "friend of a friend", who is working on a budget.

Installing 2 full mini-splits. First one the line set is too long by a good 4'-6'. The second on the line set is short by about 2'.

Cut the ends off with leaving and extra 2'+ on the long one and then splice it on to the opposite set of lines ? Braze is what professional would do, but how about solder ?

How about m-m flare connection? I did this exact thing on my last 2 unit install and hid the flare in the line cover

 

[nadogail]

How about m-m flare connection? I did this exact thing on my last 2 unit install and hid the flare in the line cover

Or you could silver solder the connections.

 

[Jackfre]

If the lines are braised as they should, not soldered, be make sure there is nitrogen in the lines. They can be flared as well. Check the pre-charge specs and weigh in the appropriate amount of juice.

 

[klassenl]

Asking for a "friend of a friend", who is working on a budget.

Installing 2 full mini-splits. First one the line set is too long by a good 4'-6'. The second on the line set is short by about 2'.

Cut the ends off with leaving and extra 2'+ on the long one and then splice it on to the opposite set of lines ? Braze is what professional would do, but how about solder ?

Is this a YouTube friend by any chance.

 

[metlmunchr]

The lines can be soft soldered using Stay Brite or Stay Brite #8. Both are recommended by the manufacturer (Harris) for use on HVAC lines.

#8 is a bit easier to use due to its wide temperature range from solid to liquid, but the standard Stay Brite works fine when used by someone with soft soldering experience. The standard product is available in a half ounce kit from Home Depot with solder and the proper flux for less than $10 and contains plenty of material for splicing a pair of lines. For a DIY guy this is a significant saving over $70 or so for a pound roll and flux, or $90 for a pound pack of 15% silfos.

Soft soldering negates the need for nitrogen purging as the temperature remains well below the point where oxides begin to form on the interior of the tubing.

Personally, I've always considered flare unions as a last resort for joining refrigerant lines. This would be particularly risky for DIY types with limited experience both in judging what is a proper flare and in knowing to use the proper short flare nuts rather than nuts designed for water use that are readily available at home centers but well known in the trade for causing cracks at the base of the flare over time if used on refrigerant lines.

 

[chinboys]

use Mapp gas torch, buy silver solder rod with flux and swage the female end with nitrogen flowing.

 

[mrobins297aaa]

The lines can be soft soldered using Stay Brite or Stay Brite #8. Both are recommended by the manufacturer (Harris) for use on HVAC lines.

#8 is a bit easier to use due to its wide temperature range from solid to liquid, but the standard Stay Brite works fine when used by someone with soft soldering experience. The standard product is available in a half ounce kit from Home Depot with solder and the proper flux for less than $10 and contains plenty of material for splicing a pair of lines. For a DIY guy this is a significant saving over $70 or so for a pound roll and flux, or $90 for a pound pack of 15% silfos.

Soft soldering negates the need for nitrogen purging as the temperature remains well below the point where oxides begin to form on the interior of the tubing.

Personally, I've always considered flare unions as a last resort for joining refrigerant lines. This would be particularly risky for DIY types with limited experience both in judging what is a proper flare and in knowing to use the proper short flare nuts rather than nuts designed for water use that are readily available at home centers but well known in the trade for causing cracks at the base of the flare over time if used on refrigerant lines.

this^^^, stay brite #8, just as strong as a brazed joint and no mess on the inside.

 

[mrobins297aaa]

also all you need is a propane torch, you don'y need any mapp gas or anything hotter than a propane torch

 

[LS6 Tommy]

If the lines are braised as they should, not soldered, be make sure there is nitrogen in the lines.

I find they always taste better brasied than soldered.

Sorry. I couldn't help it.

Most manufacturers require flare unions to extend mini split line sets, if they allow it at all.

Tommy

 

[theoldwizard1]

IMost manufacturers require flare unions to extend mini split line sets, if they allow it at all.

I have always heard unions were no-no's and could void warranties.

 

[dcg9381]

No no or not, I'd rather braze that have triple flares.

 

[LS6 Tommy]

The lines can be soft soldered using Stay Brite or Stay Brite #8. Both are recommended by the manufacturer (Harris) for use on HVAC lines.

410A systems MUST be brazed, not silver soldered. Definitely never soft soldered. No HVAC manufacturer recommends or approves #8 for R410a. Harris is the manufacturer of #8. Although they recommend it for HVAC lines, they do not state which refrigerants or system types. That being said, I've seen silver soldered R22 compressor discharge lines blow completely off a compressor. I won't even consider it on 410A.

Tommy

 

[jjrbus]

What people seem to miss is the difference in operating pressure. What would be sufficient on R12, R22 or 134a may fail with R410. The spec'ed nitrogen test pressure for R410a Daikin minis is 625 psi. This is getting into NASA territory.

What I see on forums and what is reported by the industry is most mini failures are due to improper installation. So I will be following the manufactures directions.