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Shortening mini split line set?

PoorOwner

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I want to have most of the components available before getting a HVAC company to connect and do the start up, but question on the lineset.

Is it common practice to purchase mini split line set and then let the installer cut one end and flare it to the correct length, since lineset is usually sold between 15, 25, 50' etc, but the job dictates the exact length without looping etc.

I was told the insulation simply get stripped off, since there is no brazing involved, I think that won't be an issue with the foam being shortened?
 
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zmaxmotorsports

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Cut the insulation to where you want it to end up,then just slide it back a little further and use your tubing cutter to hold it while flaring the tubing.
 

JakeKohl

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It is common practice to shorten and flare the ends of that tubing as needed. In fact, a lot of pros don't feel comfortable relying on the factory made flares and will reflare the ends, regardless. There are a couple of things to be aware of: 1) the more modern 410a refrigeration requirements use a different flare angle than the older typical R12 systems and will require specific tools to create it. 2) most split AC systems have a minimum tubing distance between the outdoor and indoor units. I'm not completely sure what that minimum distance does (compressor pulse dampening to the throttling valve, perhaps?) but you should try to keep your lineset lengths within the specification for your unit. 3), make sure you put the nut on before making the new flare in the tubing ;-).
 
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PoorOwner

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Does different line sizes require a different flare tool or die? I am not doing the hook up myself.
 

bzinsky

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Usually you want to use the flare nuts that came with the unit and not the flare nuts that come on the linsets, which means you have to cut both ends off anyway to replace the nuts.
 
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Ohmthis

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I'm assuming you are going to run the wire and lineset and let a HVAC tech do the connection and finish??? If so, leave plenty (5' or so) at each end. Everyone has stated good practice. Use the flare nuts from the equipment, reflare using a quality tool designed for 410a flares, use a little refrigerant oil (I use nylog) on the face of the flare and fitting, torque to the proper amount listed in the install manual. Then it will be ready for a leak test and vacuum. Good luck!
 
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PoorOwner

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I'm assuming you are going to run the wire and lineset and let a HVAC tech do the connection and finish??? If so, leave plenty (5' or so) at each end. Everyone has stated good practice. Use the flare nuts from the equipment, reflare using a quality tool designed for 410a flares, use a little refrigerant oil (I use nylog) on the face of the flare and fitting, torque to the proper amount listed in the install manual. Then it will be ready for a leak test and vacuum. Good luck!

No, I am only running the 240V power supply ready to the outdoor location. I am letting the HVAC tech do everything so there is no doubts about the warranty, installed 100% by licensed pro :) I do have to provide the all the parts and make sure there is enough lineset, looks like I will be ordering 25 foot lineset and just let them trim to length.

Do you guys know of a good wrap for the lineset so I can just get a roll and have that ready too?
 

Ohmthis

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The lineset will have insulation on both lines. The installer will trim the copper as well as the insulation. Are you wanting to double up or something? Armaflex can be bought at most home improvement stores. Check in the plumbing area where pipe insulation is. Don't get the stuff made for water lines. Hope this helps.
 

Ohmthis

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Once verified leak free, the installer should have left ample amounts of insulation to slide back over the copper all the way up to the fitting. If you choose to "double wrap" it, that's not going to do any harm. As a matter of fact, if I pull line sets through an attic I always double up the insulation.
 
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