# Mini split lineset question



## yuri (Nov 29, 2008)

I would call Mitsu and ask them what the heck these guys are doing. Those units have a measured/critical freon charge (to the ounce) and it depends on the proper line size or it won't work properly


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## jerryh3 (Dec 10, 2007)

I believe the unit is precharged for 130' of lineset. But, that is measured with the suggested lineset sizes. I will be around 110'-120' with the four units. I think they are going to have to adjust the charge no matter what, but I'm concerned about the performance of the system and them brazing eight fittings when they didn't need to.


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## yuri (Nov 29, 2008)

Brazing is not real good unless they purged nitrogen thru the lines while doing it. Otherwise you get carbon buildup inside the lines. Minisplits have very little or no filter driers so that can be a big problem.


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## beenthere (Oct 11, 2008)

Geez.

Considering that what your calling the liquid line. Really isn't the liquid line.
CALL mitzu and ask them if it will work ok.

The oversized vapor line, can hiner oil return to the compressor.
The ovesized small line(its actually part or the metering device on min's) may screw up the system from also having too slow of a velocity. And allowing the rerigerant to [ick up too much heat before it reaches the evap coil(even though its insulated).

There was no reason to cut the lines and braze.
If using the larger lines is ok, they make reducing flare fittings. Including 3/8 to 1/4, and 1/2 to 3/8.


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## jerryh3 (Dec 10, 2007)

Just called Mitsu. Their tech guy says they shouldn't have done either of those things. I'm waiting for a call back from the Mitsu area manager now. Not looking good. I'm ready to make a big pile in the front yard and let them pick it up. They have three of the inside units hung and two of the linesets ran.
Been- Is it not consider a "liquid" line since it's beyond the expansion valve and therefore part of the evap?


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## beenthere (Oct 11, 2008)

Yep.

A liquid line feeds liquid refrigerant to a metering device.


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## jerryh3 (Dec 10, 2007)

beenthere said:


> Yep.
> 
> A liquid line feeds liquid refrigerant to a metering device.


Ok. The instuctions label them as "liquid" and "gas." Some pics. I'm just sitting here wondering what to do. I'm ready to call the company's install manager and tell them to come pick up the pile of equipment that will be sitting in the front yard. They already have to bring out a new outside unit tomorrow since the one they tried to install had a big dent in the side.


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## beenthere (Oct 11, 2008)

That small line carries refrigerant in a saturated liquid state.
A true liquid line carries liquid refrigerant in a subcooled liquid state.

So its not a liquid line, in the full meaning of liquid line in regular A/C and refrigeration.

You might want to call the install manager, and tell him what mitzu said.
See what he says in return.


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## yuri (Nov 29, 2008)

I would document everything for the lawyer you may need. Doubt if it will ever work properly as they did not follow the manufacturers procedures and most likely will void the warranty.


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## jerryh3 (Dec 10, 2007)

yuri said:


> I would document everything for the lawyer you may need. Doubt if it will ever work properly as they did not follow the manufacturers procedures and most likely will void the warranty.


I'm trying not to let it get to that point. If I need to put a stop to this now, I will.


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## jerryh3 (Dec 10, 2007)

I spoke to the Mitsu area rep then the company sales rep. The Mitsu rep didn't want to say anything negative until I found out the reason they used oversized lines, but said there was no reason they should have done that. He said they may be brazing the lines because they are more comfortable doing it that way. It sounded like he didn't want to take sides just yet. I then spoke to the sales manager of the company. He said if there was a mistake in the line sizes it was because he spec'ed out the material using the wrong book. Sounded like BS. He said they braze the connections because it is less likey to leak that way, and the flares are prone to cracking. He said any contaminants would be removed during the evacuation.


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## yuri (Nov 29, 2008)

If you have ever seen the inside of a fitting after brazing you will be shocked to see the carbon residue which can only be removed by a flush kit not a vacuum pump which they may use. They are BSing you. Flares if done properly with a high quality flaring tool are not a problem, just requires a skilled installer. I would document everything as I have seen lots of jobs gone wrong and without names, dates and times of who you talked to they will deny everything. Hopefully Mitsu is a reputable company. I work with Lennox and they are very good that way. The eccentric cone flaring tool is the standard for R410 flares for minis:http://www.yellowjacket.com/HVACRProducts.asp?l=9&t=HVACR&c=84
They never crack flares.


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## jerryh3 (Dec 10, 2007)

yuri said:


> If you have ever seen the inside of a fitting after brazing you will be shocked to see the carbon residue which can only be removed by a flush kit not a vacuum pump which they may use. They are BSing you. Flares if done properly with a high quality flaring tool are not a problem, just requires a skilled installer. I would document everything as I have seen lots of jobs gone wrong and without names, dates and times of who you talked to they will deny everything. Hopefully Mitsu is a reputable company. I work with Lennox and they are very good that way. The eccentric cone flaring tool is the standard for R410 flares for minis:http://www.yellowjacket.com/HVACRProducts.asp?l=9&t=HVACR&c=84
> They never crack flares.


I am documenting. I'm still trying to decide what to do. That's the flaring kit I was going to buy if I did the install myself. I thought I was doing the right thing by hiring professionals, but this sucks. I should have saved the four grand and did it myself. If they flow Nitrogen when they braze do you think it would be OK?


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## yuri (Nov 29, 2008)

It is DIFFICULT to do that procedure. I myself have a hard time with it. Too much pressure and it blows the weld apart. Only a skilled tech can do that and it is primarily used for medical gas lines etc. Most AC installs have a good size filter drier. Minisplits are a lot more finicky/precise and flaring is the best way to go. The problem is the weld cools quickly then carbon forms faster and you need to wrap a wet rag around sensitive areas etc etc. Doubt if those guys have that kind of welding skill but anything is possible. If the weld is cold or bubbly then it may leak slowly later. I hate telling you all this negativity but some people think what we do is real simple and easy. There is a lot to it for a proper long lasting install. There is a extra strong type of solder called StayBrite:http://www.harrisproductsgroup.com/consumables/alloys.asp?id=32
which is almost as strong as silfoss and does not require the extreme heat of silfoss (silver solder) which they may use. I don't like it for vibration or high temp jobs but some guys use it.


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## newtech (Mar 21, 2009)

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.


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## jerryh3 (Dec 10, 2007)

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.


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## yuri (Nov 29, 2008)

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.


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## jerryh3 (Dec 10, 2007)

newtech said:


> 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


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## beenthere (Oct 11, 2008)

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.


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## jerryh3 (Dec 10, 2007)

beenthere said:


> 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.


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## newtech (Mar 21, 2009)

yuri said:


> 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.


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## beenthere (Oct 11, 2008)

The Mitzu guy is right.

The sales rep is making up a story.


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## jerryh3 (Dec 10, 2007)

beenthere said:


> 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?


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## beenthere (Oct 11, 2008)

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.


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## jerryh3 (Dec 10, 2007)

beenthere said:


> 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.


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## beenthere (Oct 11, 2008)

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.


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## yuri (Nov 29, 2008)

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.


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## beenthere (Oct 11, 2008)

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


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## jerryh3 (Dec 10, 2007)

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?


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## jerryh3 (Dec 10, 2007)

beenthere said:


> 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.


But doesn't that double the number of connections? More chance of failures?


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## beenthere (Oct 11, 2008)

I didn't say what they would have to do was a good thing.

Yes, it would have added more joints.


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## jerryh3 (Dec 10, 2007)

Update. They're back. They have the correct lineset sizes and are going to flare everything. We'll see how the rest of the job goes...


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## beenthere (Oct 11, 2008)

Cool.

Hope it goes better now.


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## jerryh3 (Dec 10, 2007)

beenthere said:


> Cool.
> 
> Hope it goes better now.


Well, after walking around and looking at a few more things-including the installers only using 1" sheet metal screws into the drywall to hold the mounting plates up, and no kind on sealant on the outside wall penetrations-I called the install manager and went off. I told him to have his guys pack everything up and get out of the house. He was at my house in 30 minutes. We walked the entire job and went through everything of concern. I think he put the installers on notice, and everything has seemed to go a little smoother today. The new outside unit should be delivered on Monday, so hopefully they'll be finished on Tuesday I can put this ordeal behind me. It's beer thirty.


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## beenthere (Oct 11, 2008)

Good luck.


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## jerryh3 (Dec 10, 2007)

beenthere said:


> Good luck.


Thanks. I need it. I'm just going to relax for the weekend.


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## jerryh3 (Dec 10, 2007)

Update. It's done. The system itself is great so far, just the installation left a lot to be desired. I guess I learned if you want something done right, do it yourself.


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## yuri (Nov 29, 2008)

You may want to call another Mitsu dealer and have them check the unit without putting their gauges on. I would be very concerned these "installers" of yours may not know how to charge the unit properly or didn't do so. There is a way to test them if you can find a skilled service tech. Putting gauges on/off blows a few ounces of refrig out and is enough to affect the charge.

Good Luck


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## jerryh3 (Dec 10, 2007)

yuri said:


> You may want to call another Mitsu dealer and have them check the unit without putting their gauges on. I would be very concerned these "installers" of yours may not know how to charge the unit properly or didn't do so. There is a way to test them if you can find a skilled service tech. Putting gauges on/off blows a few ounces of refrig out and is enough to affect the charge.
> 
> Good Luck


They didn't adjust the charge. All they did was vacuum for about an hour, blanked off the compound gauge and checked to see if the needle moved. No pressure test, no micron gauge, no triple evac. The linesets were right around 130' total, which is what the factory charge is calculated for. He did look at the low side pressure gauge after the unit had been running for a while and said it looked good.


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## yuri (Nov 29, 2008)

I hate to be negative but if his pump had moisture laden/dirty oil you may not have gotten a 500 micron vacuum etc. I just want to have you get a system that works properly and I doubt these hacks knew what they were doing. Spending a few bucks more to get a real pro in may be worthwhile. I would not lose sleep over the 500 micron bit as the lines were clean and new but their "skillset" sounds questionable to me.


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## jerryh3 (Dec 10, 2007)

yuri said:


> I hate to be negative but if his pump had moisture laden/dirty oil you may not have gotten a 500 micron vacuum etc. I just want to have you get a system that works properly and I doubt these hacks knew what they were doing. Spending a few bucks more to get a real pro in may be worthwhile. I would not lose sleep over the 500 micron bit as the lines were clean and new but their "skillset" sounds questionable to me.


The oil didn't look too dirty but I really have no reference to compare it to. It's a shame about the whole situation. I though I made a good choice in the company I chose. Local company that's been around for 35 years, A+ BBB rating. I might fire off a heads up letter to the owner to let him know what's going on in their install department.


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## beenthere (Oct 11, 2008)

Fire one off the the BBB.

Then they will get a notice. And perhaps next time, they won't treat a Mini split so carelessly.


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## jerryh3 (Dec 10, 2007)

Update. The saga continues... A few days after the install I notice some water water on the floor near one of the inside units. It seems that they did such a good job insulating the linesets, they are sweating where they run through the wall into the inside units. And since they didn't use wall sleeves like they were supposed too, I have damp drywall and insulation. I had the owner of the company over today and he is sending someone else over to correct all of the deficiencies. Stay tuned for the next chapter...:thumbup:
Enjoy the pics of their handywork.


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## Home Air Direct (Jan 6, 2009)

jerryh3 said:


> Update. It's done. The system itself is great so far, just the installation left a lot to be desired. I guess I learned if you want something done right, do it yourself.


There is no doubt that you have a lot more at stake than a couple of hired wrenches when it comes to your home. There is no reason that you could not have done everything, including setting the outdoor unit, hang the air handler and run the lineset to your specifications (sans hook up and start up).

Sounds like the weak link in your project was the pros in this case. That is a shame. Just make sure and vote with your voice. If you get an opportunity to advise someone about the service and quality that you did not receive, let them know.

In defense of the sweating, that has been one of my biggest issues with the ductless heat pumps. The linesets sweat. But that is no excuse for the pictures you sent. I have a cat that could have done a better job than that.


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## hvaclover (Oct 2, 2008)

Home Air Direct said:


> There is no doubt that you have a lot more at stake than a couple of hired wrenches when it comes to your home. There is no reason that you could not have done everything, including setting the outdoor unit, hang the air handler and run the lineset to your specifications (sans hook up and start up).
> 
> Sounds like the weak link in your project was the pros in this case. That is a shame. Just make sure and vote with your voice. If you get an opportunity to advise someone about the service and quality that you did not receive, let them know.
> 
> In defense of the sweating, that has been one of my biggest issues with the ductless heat pumps. The linesets sweat. But that is no excuse for the pictures you sent. I have a cat that could have done a better job than that.


That sounds like a shameless plug for your business:whistling2:


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## jerryh3 (Dec 10, 2007)

Home Air Direct said:


> There is no doubt that you have a lot more at stake than a couple of hired wrenches when it comes to your home. There is no reason that you could not have done everything, including setting the outdoor unit, hang the air handler and run the lineset to your specifications (sans hook up and start up).
> 
> Sounds like the weak link in your project was the pros in this case. That is a shame. Just make sure and vote with your voice. If you get an opportunity to advise someone about the service and quality that you did not receive, let them know.
> 
> In defense of the sweating, that has been one of my biggest issues with the ductless heat pumps. The linesets sweat. But that is no excuse for the pictures you sent. I have a cat that could have done a better job than that.


Yes. Looking back, I do regret not doing it myself. I could have purchased all of the equipment for around 5K. Another 5-6 hundred for a gauge set, vacuum pump, and flaring tool and I could have saved myself a few thousand. Plus, I know it would have looked a lot neater than this. The lineset that I'm realy having trouble with runs up when it exits the house and goes up through the sofitt into the attic. All of the condensation is dripping down these lines and traveling into the wall. However, if they would have made the insulation connectinos airtight like they should be, the problem could have been mostly avoided.


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## jerryh3 (Dec 10, 2007)

Part three:
Update. The company sent out another crew. They pumped down the system and removed all of the inside units. They installed wall sleeves in the wall penetrations. They wrapped the linesets and drain line in cork tape from the inside unit to the K-Flex insulation. They cut out the tape joints and used contact cement to connect the pieces of insulation together outside. And, they repositioned the wall plates correctly to take the stress of the condensate lines. They seem to drain a lot better now and I haven't seen any problems with the lines sweating. This seems to be the only big mistake this crew performed. That's what happens when you don't properly prepare a plumbing joint.


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## Aikidoka69 (Apr 6, 2010)

Sorry to revive an old thread, but I am looking for a mini-split installer in the Baltimore area. jerryh3, can you PM me the installer you used so I can avoid them? I am also thinking about purchasing the unit myself and mounting everything and just having an installer connect and start it up. Are you happy overall with the unit now?


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