Mini split lineset question

newtech · 07-01-2009, 06:52 PM

Most, if not all companies have a maximum length of a line set that can be used for a certain unit or for a multiple evap with one condensing unit. If you exceed it all warranties are void. They DO not recommend up sizing the line size. They are sized for proper oil return, cooling, and heating (if you have a heat pump). Post the model and serial number and I will see what I can dig up.

jerryh3 · 07-01-2009, 06:52 PM

I don't mind the negativity. I like to hear honest answers. I know HVAC takes a lot of knowledge and skills and that's why this is the one project in my house I contracted out. The line sizes should be corrected tomorrow, now it's just the brazing part we'll have to address. I think I'm going to insist they extend the labor and parts warranty out to six years since they're not adhering to the suggested install procedures. If they say this is the better way to install it, let them stand behind it.

yuri · 07-01-2009, 06:54 PM

Read my updated previous post about the StayBrite solder. That may be okay for you. Want to hear from Beenthere and the other guys about their opinion of it first.

jerryh3 · 07-01-2009, 06:55 PM

Quote:

Originally Posted by newtech

Most, if not all companies have a maximum length of a line set that can be used for a certain unit or for a multiple evap with one condensing unit. If you exceed it all warranties are void. They DO not recommend up sizing the line size. They are sized for proper oil return, cooling, and heating (if you have a heat pump). Post the model and serial number and I will see what I can dig up.

I have the install manuals for the outside and inside units and I'm within the max line lengths. It's only the sizing they messed up on.
Outside: MXZ-4A36NA
Inside: Three MSZ-A09NA and one MSZ-A15NA

**beenthere** · 07-01-2009, 07:00 PM

Sounds like the sales rep your talking to, is for the installing company, not Mitzu.

Flare nuts made for refrigeration DO NOT crack.
And it isn't hard to learn proper flaring procedures.

jerryh3 · 07-01-2009, 07:16 PM

Quote:

Originally Posted by beenthere

Sounds like the sales rep your talking to, is for the installing company, not Mitzu.

Flare nuts made for refrigeration DO NOT crack.
And it isn't hard to learn proper flaring procedures.

Yeah. The installing company rep brought up the flare cracking thing. The Mitsu rep said there's no reason to use brazing over the flares. He said correctly installed flares(correct cone length, torqued properly, etc..) should never have a problem.

newtech · 07-01-2009, 07:18 PM

Quote:

Originally Posted by yuri

Read my updated previous post about the StayBrite solder. That may be okay for you. Want to hear from Beenthere and the other guys about their opinion of it first.

StayBrite is the best out there. Getting hard to find around here. Just don't know if I would trust it with 410-a. Used it many times on R-22 on TXV's.

**beenthere** · 07-01-2009, 07:24 PM

The Mitzu guy is right.

The sales rep is making up a story.

jerryh3 · 07-01-2009, 07:36 PM

Quote:

Originally Posted by beenthere

The Mitzu guy is right.

The sales rep is making up a story.

Ok. Damage control. The sales rep said they will reflare the inside unit's lines if that's what I want. I guess at that point they'll put a union to join the lineset to the inside unit. I saw the guy's flaring tools and their definately not anything high end or R410A specific. Should I go this route?

**beenthere** · 07-01-2009, 07:51 PM

I'd prefer flares for it.

It it ever needs service down the road. You don't want to be paying for someone to always be rebrazing those lines.

I's also want the right size lines.

jerryh3 · 07-01-2009, 08:00 PM

Quote:

Originally Posted by beenthere

I'd prefer flares for it.

It it ever needs service down the road. You don't want to be paying for someone to always be rebrazing those lines.

I's also want the right size lines.

They're bringing the correct size lines in the morning. We'll discuss the brazing verses flares then too. No matter what, they should not braze at the condenser, right? I don't even see how they could with this setup.
P.S. Like my dent? It hit so hard it bent the cabinet and that fitting rack. I think they dropped it getting it out the truck, but I got blank stares when I brought it up.

**beenthere** · 07-01-2009, 08:07 PM

Dropped, or slammed it with something else.

They would have to use flare stubs to attach to the condenser. And then braze to the stubs.

yuri · 07-01-2009, 08:12 PM

Beenthere is right. If you ever have to replace one of the indoor units it should have flare fittings. I would be concerned about them starting the wall on fire also. You are the customer and should insist on flared fittings. Not sure if they will have a good attitude after that but watch them carefully. The correct way to torque them is to put a bit of refrig oil on the flare and nut and tighten it, loosen it, retighten and repeat 3 times in total. This works the copper to the brass properly. Get the name of the district manager and quote it if necessary to get them to do what you want.

**beenthere** · 07-01-2009, 08:15 PM

Should also use oil on the copper while you flare it. POE oil in this case.

jerryh3 · 07-01-2009, 08:55 PM

I hate this. I shouldn't have to tell an installer how to do his job correctly. It puts me in a bad spot no matter what. How hard is it to read an installation manual??? They couldn't even level the condenser pad correctly. If I knew if it was going to be this much trouble, I would have installed the unit myself. I can flip the switch on a vacuum pump. That's all there is to it, right?