Flare or Solder

[aone]

I am planning to install a 5 zone mini split Mitsubishi. I told the hvac guy that I will do the install and I want him to pressure and ck for leak, vacuum and charge (release and check the r410a). He said he would do it.

But he wants the cut the flares and solder all the joints. (kinda do not like him cutting the flare on the compressor,) Anyone knows if solder is better than flare?

Oh he does not want to pressure test. He said he will know of leaks from his gauges . Should I run from him or what?

Thanks.

 

[2xs]

Yes solder is much better conection then a flare. I would get a second opionion on it. But personally get the hell away from him and pressure check it with nitrogen is cheaper then 410a and he is full of **** saying he will know if there is a leak with his gauges. The only way to identify a leak with a tester and or the appearance of oil at the leak site. The flare being on the compressor is for ease of install it is a premade line set so could just hook the flare up tighten it and evac the system and go. He would know if there was a leak if he evacs with a micron gauge but doesn't sound like what he is going to do.

 

[joel63]

Yes solder is much better conection then a flare. I would get a second opionion on it. But personally get the hell away from him and pressure check it with nitrogen is cheaper then 410a and he is full of **** saying he will know if there is a leak with his gauges. The only way to identify a leak with a tester and or the appearance of oil at the leak site. The flare being on the compressor is for ease of install it is a premade line set so could just hook the flare up tighten it and evac the system and go. He would know if there was a leak if he evacs with a micron gauge but doesn't sound like what he is going to do.

^^ Sound advice^^^^

Using gauges is not the way to check for leaks.

IRMC

 

[monkeyspanners]

Yes it needs pressure testing.

Personally i like to cut the flares off indoor units and braze, (note that this can invalidate the warranty with some manufacturers) also you will need to purge the pipe with nitrogen as you braze to stop copper oxide from forming. Copper oxide will shorten the life of the system, or kill it in severe cases.
There is nothing wrong with a properly made and tightened flare. ( i just don't like them)

I don't like the sound of your ac guy.

 

[rlitman]

R410a flares are the same size and angle as R22 flares, but the higher pressures have less room for error.

Note that the flare nuts that come with linesets are often not the same as the flare nuts that come with the mini-split. The lineset tubing may be fine for R410a pressure, but the included nuts are often pretty thin brass behind the flare, while the nuts supplied with the unit will have very thick shoulders. This can make a big different in long-term leak-free performance. So, cut the flares off linesets, put on the flare nut that comes with the mini-split, and re-flare the ends.

Oh, and the mini-split instructions will have torque to use on the nuts. I bought crows-foot flare-nut sockets to use with my torque wrench. If you trust your calibrated arm, go right ahead and take the risk. (same thing goes for any time you diverge from the manufacturer's instructions)

Lastly, the caps on the valves are the primary seal (not the valve stem packing). Loose caps are the biggest source of leaks.

Personally, I don't think flares are any worse than a brazed joint, IF done right. Both have plenty of room for error.

 

[Disney]

AMEN!!! I used to come across missing caps all the time and people would never trust me that I could fill the system and get new caps to fix them up. Most of the time, that was the leak.

 

[aone]

I will stick with the flares and insist on him to do the hydrogen pressure test. If he does not want to do the hydrogen pressure test, I am going to call someone else. Maybe he does not have the equipment. Everyone, thank you.

 

[91 zeee]

the flare fittings on the mini split are fine; of course a brazed connection is always better though. The way your ac guy really needs to do this would be to make his connections, apply a nitrogen test,check for leaks, then evacuate the system USING A MICRON GAUGE and verify it pulls down below 500 microns. Then he will know he has a clean dry system that is ready for charging.

 

[KRB52]

I will stick with the flares and insist on him to do the hydrogen pressure test. If he does not want to do the hydrogen pressure test, I am going to call someone else. Maybe he does not have the equipment. Everyone, thank you.

Hydrogen? I think you mean nitrogen. Hydrogen is flammable/explosive.

 

[Jackfre]

When I represented Fujitsu I had a customer who insisted on brazing his line sets. I did a lot of business with him on other lines as well and consider him and his crew to be "hands". But... I just kept getting unit failures on his installs. I was asking him to please just flare the line sets. He wouldn't go for it and the problems continued until we mutually decided that he needed to go to another line. Keep in mind that I covered six states and had a very broad sampling of flare/braze

The manufacturers require flaring the line sets and the "void warranty" is real. I'm a fitter/welder by trade. I know that brazing is one and done...BUT, a lot of the smaller mshp Evaps have 1/4" lines. It doesn't take a heck of a lot to get a *********** inside that line and there goes your performance/unit. The best guys can do it every time, correctly every time. The other issue is the contamination inside the line set if a proper purge is not done inside the line set. You get contaminants in the line set and you are screwed.

Flare the lines. Cut off the factory supplied flare on the line set and re-flare. Use either the Ritchie or Ridged flaring tool. Do the Nitrogen test.

These things are the balls when they are done right. They are a nightmare of the first order when the installation is not "just so"

 

[theoldwizard1]

I was "supervising" the re-installation of an A/C unit a couple of years ago. The guy laughed when I asked about soldering. "We only braze !"

 

[Random Guy]

It's been mentioned, but not outright stated, so I'm gonna go ahead and say it myself. If you don't use the flares, you want to braze the lineset, not solder it. They are different processes, and soldering won't hold up to the pressures R410a runs.

 

[PelicanPines]

I was "supervising" the re-installation of an A/C unit a couple of years ago. The guy laughed when I asked about soldering. "We only braze !"

^^^ My guy says the same thing.

 

[Jackfre]

Again, it depends upon the guy doing the brazing and how thorough his purge and process is. The best make the joint every time.

Statistically, in my 12 years representing a major line in 6 states and 10's of thousands of units sold, flaring had fewer problems. As well, when problems occurred they were easier to identify and correct.

 

[Smoky14]

I work 3000PSI oxygen systems, flares work just fine. It's the quality of the flare...welding Ox fittings ain't a job I'd care for.
Smoky

 

[James-W]

Personally, I would be more than a little concerned about voiding the warranty. If the installer does anything to void the warranty and you have problems with the system later on, is the installer going to repair the system under warranty?

 

[aone]

Hydrogen? I think you mean nitrogen. Hydrogen is flammable/explosive.

My mistake. Nitrogen it is.

 

[Mike007]

I'm just going to throw my $.02 in, if you feel a need to tell the installer how to do his job, you need to find another installer you are comfortable with. At the end of the day he is supposed to be the "Professional".

 

[aone]

Thank you everyone for replying.

I called another guy, and he is happy to pressure test the mini split. Actually, he told me that he will have to pressure test with nitrogen for leaks (if any exist he will fix), vacuum and release the refrigerant then top it off if it needs to. And start up the system. He said usually he would have to add about 2lbs. He quote me as $800 to $1,000.

The one thing I did not like that I asked is if the system has too much refrigerant will he take the excess out. He said not at all. I find that strange - any thoughts?

Thanks.

 

[monkeyspanners]

If he is going to add 2lbs to your system, make sure he shows you the calculation in the instal manual that shows it actually needs 2lbs. I doubt it would need more than a few ounces, unless it is a very big system and a long pipe run. (I have installed a big multi system in a college doing 36 class rooms over two floors and the whole system only holds about 25lbs.

 

[2xs]

Yeah monkey is very much right shouldn't need extra gas maybe a few ounces should like you have a pro in this new guy I wouldn't worry about it. Let the pro take care of you and sleep easy at night. Notice you said usually I think he has his **** together and won't just cut and run.

 

[aone]

If he is going to add 2lbs to your system, make sure he shows you the calculation in the instal manual that shows it actually needs 2lbs. I doubt it would need more than a few ounces, unless it is a very big system and a long pipe run. (I have installed a big multi system in a college doing 36 class rooms over two floors and the whole system only holds about 25lbs.

Good point. I will ask him how he measures the amount he is putting in. Usually a digital scale is used.

The system will have 5 zones with linesets of 2 35ft, 1 7ft, and 2 12ft. The compressor will be wall mounted. I do not know if this is a large one.

Yeah monkey is very much right shouldn't need extra gas maybe a few ounces should like you have a pro in this new guy I wouldn't worry about it. Let the pro take care of you and sleep easy at night. Notice you said usually I think he has his **** together and won't just cut and run.

Yeah, I have a good feeling with this guy. And if the job is well done I will have him do the services (seasonal if needed).

 

[jonathan75]

Flare the lines. Cut off the factory supplied flare on the line set and re-flare. Use either the Ritchie or Ridged flaring tool. Do the Nitrogen test.

On my Pioneer install I cut off the factory flares and did my own using a Yellow Jacket tool. My very first flare in my whole life was better then the factory flare. The factory flare had a ridge near the top and was not as deep as it should be. I did more and more flares to practice to make sure I got it the best I could. Good thing I had plenty of extra line!

Factory flare is the cut off one on the left in the first picture.

 

[monkeyspanners]

The system will have 5 zones with linesets of 2 35ft, 1 7ft, and 2 12ft. The compressor will be wall mounted. I do not know if this is a large one.

Ah thats a bit different as its a multi split so it could take more, the few ounces extra would be a single split. There will be a formula in the instal manual on how to calculate if extra charge is needed.

There are so many different makes of ac, and so many new models, it is impossible to keep up with them all, plus we get different models here.

The 2bls extra may be like the way garages always charge you for screen wash when they service your car, even if its full. It may not be right but it is a way to make a living when dealing with the general public who don't always appreciate what it costs to run a business. Or not. So long as he is doing it right and you are happy with the price.

 

[Jackfre]

I would be surprised if you need any additional refrigerant. I think the 4 zone units I am familiar with have pre-charge for about 168'. Check your specs and carefully calc the line set lengths again. I am always surprised how laterals and offsets seem to eat up pipe length

You do not have to "remove" excess 410A. If you are within the "pre-charge length" the charge is correct. The units have an accumulator that will handle the pre-charge without problem.

As noted there is a oz/ft of charge once you go above the "pre-charge length". It must be weighed in with a digital scale.

 

[zmaxmotorsports]

AMEN!!! I used to come across missing caps all the time and people would never trust me that I could fill the system and get new caps to fix them up. Most of the time, that was the leak.

If I had a dollar for every leak Ive fixed over the years by tightening a shrader valve Id be rich.
Putting a new cap on is not the same as fixixing a leaking shrader valve.

 

[Lewisthepilgrim]

On my Pioneer install I cut off the factory flares and did my own using a Yellow Jacket tool. My very first flare in my whole life was better then the factory flare. The factory flare had a ridge near the top and was not as deep as it should be. I did more and more flares to practice to make sure I got it the best I could. Good thing I had plenty of extra line!

Factory flare is the cut off one on the left in the first picture.

those are some nice flares ! I need one of those yellowjacket tools !

 

[jonathan75]

those are some nice flares ! I need one of those yellowjacket tools !

Thank you, I found using some Nylog was important also to make a good flare.

 

[aone]

I would be surprised if you need any additional refrigerant. I think the 4 zone units I am familiar with have pre-charge for about 168'. Check your specs and carefully calc the line set lengths again. I am always surprised how laterals and offsets seem to eat up pipe length

You do not have to "remove" excess 410A. If you are within the "pre-charge length" the charge is correct. The units have an accumulator that will handle the pre-charge without problem.

As noted there is a oz/ft of charge once you go above the "pre-charge length". It must be weighed in with a digital scale.

You are right I would not need additional refrigerant, at least according the specs. I upload an image of it. Max length per indoor unit is 82ft. And I overstate the total I will run which is 101ft.

Here is the kicker - I asked the new guy to show me how he measure the amount of refrigerant he is putting in when he is on site. He replied that he cannot do the job because he will be busy for the summer. Oh well I will look for another. Thank you.

Ah thats a bit different as its a multi split so it could take more, the few ounces extra would be a single split. There will be a formula in the instal manual on how to calculate if extra charge is needed.

There are so many different makes of ac, and so many new models, it is impossible to keep up with them all, plus we get different models here.

The 2bls extra may be like the way garages always charge you for screen wash when they service your car, even if its full. It may not be right but it is a way to make a living when dealing with the general public who don't always appreciate what it costs to run a business. Or not. So long as he is doing it right and you are happy with the price.

I look at the specs of the compressor (attached) and it turns out I would not need additional. When I asked him to show me how he measure the refrigerant amount he will put in when he is on site so I know, he told me he would not be able to do the job anymore. (see the attached image)

Thank you.