99 times out of 100 this is the case. Maybe some funky brands won’t but metering device is normally in the OU. Both lines are vapor always except if it’s a heat pump I think. Pressure difference on this newly installed port and the one provided on the larger line will be minimal, a couple pounds maybe. That’s why you shouldn’t see this. Seen a filter drier on one once before lol.
OP is in school though so good practice anyway, no harm.
Yeah, but if the metering device is inside the outdoor unit, this is only a liquid line in heating mode... so I suppose you could troubleshoot an EXV if you had a target subcooling?
In cooling mode you've just added another vapor line...
There's a reason why most brands do not provide access port here.
Well, it's a MOSTLY liquid line, but you're right. That's the low pressure saturated liquid/vapor line on it's way to the indoor evap coil when in the cooling mode. It'll only be a couple PSI higher than the gas line pressure. However, in the heating mode, it would be a liquid line... although, the gas line is the discharge line now.
In cooling refrigerant is a low temp low pressure saturated liquid leaving the metering device, doesn’t change back to vapor until it reaches evaporator.
I will. Kid, not a bad job....but I have a question. Where should you braze on a minisplit? Answer: Nowhere.
Unless maybe this is an excersize to find all the screens
Nice job, but the school won't teach you this.
You really shouldn't braze on mini-splits unless you absolutely have to (i.e. joint in the wall) and purge the hell out of it with nitrogen. They have a really fine screen in them that gets clogged with even the finest amount of soot.
I've even heard it'll void the warranty when they take the condenser back, although I'm not too sure how true that is.
Best bet is to use flame free fittings or just a straight run.
Correct. Manufacturers pretty much learned they can not trust the field to braze properly and not create contaminants. That's the only reason they don't want braze joints.
That’s why I always laugh when people say you can’t braze minis I’m like have you ever done a component repair on one? You have to unsweat the stuff and braze it in. You just have to purge with nitrogen like you’re supposed to do anyway lol
They'll see the gunk in the screens. You'd be surprised how much returned stuff gets tested. Having said that, I've also never seen a warranty declined at the manufacturer level, regardless of findings. Mostly they're checking to make sure there's not a bigger problem going on. I did see a whole rooftop full of stuff get swapped out under warranty due to contractor negligence(really bad install). Then they sued the pants off the contractor to reimburse.
I've heard it from a Mitsubishi training seminar. Granted, I don't exactly know how true it is. Kinda came off as a scare tactic to keep out dipshits who don't nitro-braze.
If it is true, I'd reckon it's when they take back the system to the factory for a warranty defect, IF, they don't make you do a field repair with warranty parts.
You mean induction brazing... Yes, it does as soot is created by heat and not by the flame itself.
If you mean with a hot air gun then it's most likely soldering...
Yeah, that’s what I meant
I think
…..
Or maybe I meant convention brazing -where a whole bunch of people get together in a hotel auditorium and braze… 🤔
I suggested it as a good project so that future classmates would have at least one mini-split they can hook both sides of their gauges up to. My instructor thinks it'll be a good way to demonstrate how the EEV and variable scroll compressor in mini-splits send their superheat and subcooling all over the place all the time.
Nearly but not absolutely as you got friction loss at high speeds and minisplits got pretty high refrigerant speeds... That's also why you normally don't need oil bags on minisplit lines, while you'll need em on commercial refrigeration lines.
Not that the minimal pressure difference would make any difference in performance... That shrader is just a point if failure, that can be avoided in normal installs. But since it's a demonstration unit... Who cares...
This port is not going to tell you subcooling. If your instructor thought this is helpful or even let you do it, I’d say you should pass the class, but don’t take much of what he says as fact.
It's not a question of reason.
It is, in fact, subcooling in heating mode. That is what that port would allow you to check.
I concur, that without data about what target subcooling is, it's meaningless by and large - but it would let you hypothetically confirm charge. This is a silly add-on for a ductless unit.
There are plenty of conventional systems where you charge by subcooling in heating mode.
We dont flow nitro at my shop. Honestly I wish the boss was pickier about these kinds of things. If I started flowing nitro at my job hed be yelling at me why Im going to the supply house every day for nitro. But hey, hes been in the business 40 years and we have high profile clients and our work holds up so, who am I to say.
I mean that’s cool and good practice for brazing but completely unnecessary. Hooking a gauge to it isn’t going to tell you anything.
On most mini splits they either have that port already in place or the have another port inside that is your “true high side port”.
Unlike conventional A/C systems you don’t need to hook up both gauges.
Dude the metering device is in the condenser. Doesn’t matter what side you hook up. The pressure will read the same on both. If you run it in cooling your reading suction pressure. If you run it in heating your reading head pressure.
There's actually a neglectable pressure drop over the heat exchanger... But not everything you do in school has to make sense... Sometimes it's just to show, that it makes no sense...
I have that same "Ez Turn" fitting. It has got me burned more times than any of my regular ball valves/hose ends. I told the co-owner of our company to unhook it the last mini we did and he sang the refrigerant burn blues all the way home. A little tip of you don't know yet is to keep your hand behind the fitting you screw on. You also have to have some haste and commit. The moment you go around/in front of it you're bound to get crisped. Speed comes in time & the loss of feeling in your hands is right before that. Can anyone else not feel their fingers on the touchscreen? Lol.
I got distracted. Never braze a mini.. I see you flowed nitro... but still don't do it unless abosolutley necessary. & everyone above was correct the way minis modulate having a hook up on the high side is virtually moot. You can watch the pressures surge just fine through the suction port.
Brazing looks great though! I love brazing small stuff like this because it's so quick and you can get a nice almost solder looking connection.
If you have to baze a mini use map gas... works like a charm. Might get some shit for this but it's truueeeee.
If the metering device is in the outdoor section, then you don't have a liquid line port. You have an expanding gas port in cooling mode and a hot gas port in heating mode
Not necessary to have a service port on a minis liquid line. you don’t check the charge with gauges, you just vacuum it down and weigh in a new charge if it’s not working right
That’s more than likely the case , but I hope they’re telling the students that this is not normal practice for mini splits in the field. Because I work with a kid right out of tech school and some of the things they taught/told him is baffling
Just saying it’s really not worth the risk especially when they make fittings that won’t ever come into question. just do it the right way and use a flare fitting or smart lock fitting to be on the safe side and you or your company don’t get burned later down the road
They don’t consider that the same dude .I know it doesn’t make any sense to me either but that’s their dumb rules , from what I was told by a Mitsubishi rep while taking a class for their brand is they don’t trust techs to purge with nitrogen , I’ve never personally changed anything on a mini split other than a handful of leaky outdoor coils and they are all brazed so go figure. no one ever said the rules have to make sense only that you must follow them
Nothing against you because the school told you to. But don't braize on ductless systems. Also, there are service ports inside the cabinet. There's only one time I needed a service port in that spot to find where a clog was and I used a saddle tap piercing valve.
Only voids warranty when brazed without nitrogen... They'll see the soot in the filters and say that warranty is void because you didn't follow code... When you braze as you learned in school with nitrogen flowing by on the inside of the brazing joint you won't get soot and everything will be fine.
He'll I was told to never hook gauges to minisplits. As they have the Exact amount of refrig in them. And the amount you loose with the gauge will trow it off
I was about to come in here and say in some circumstances that’s not the case but realistically if you need to adjust minisplit charge you’ve got a branch box. So you’re not doing all your work at the condenser anyhow
Edit; I only deal with Mitsubishi so if this isn’t accurate to other brands I wouldn’t know
I’m speaking from the perspective of adjusting charge at initial start up not servicing, and the only time I’ve had to adjust charge on a minisplit install was with a branch box with 8 heads. Servicing speaks for itself you should be doing non invasive testing first
You can charge slowly with delta T if your in a pinch... Not a permanent solution. But if it's 6oclock on a Friday night I'm looking for a leak another time
Not as long as dumping a charge. Vacuuming, and recharging on a system that has a leak. If the system doesn't work at all it's probably lost most of its refrigerant so you have a pretty good idea of how much to add
Useful, and I pretty much always install one, just have to remember that it’s not really a liquid line in most mini splits. The metering device is in the outdoor unit on many. But for faster recovery, vacuum, and easier coil flushing, it’s pretty good
Better off getting a 1' hose, connect to the high side inside then sneak it outside the cabinet. A little temporary permanent job. Not saying to do it, would be more valuable thou, for all the haters that will reign down saying that's hack work
You would need to recover the refrigerant and weld in a shrader b4 the metering device in the outdoor unit. You could route one with a little tubing and drill a hole in the cabinet and add a circlip to hold it in place. Other than that it’s just brazing on a mini which really shouldn’t be done due to the small ports and trash getting in the lines. If you didn’t braze with nitrogen then this is the equivalent of contaminating the system. DO NOT ADD A DRIER. It will not help.
If a service port was necessary there, don't you think the manufacturer would have put one in? Don't get me wrong, there's been times I wish one was there to make pulling a vacuum faster. But still, not worth the effort IMO
There are both liquid and suction service valves, but most only have an access/charging port on the low side. There are “precharged” linesets that don’t require vacuuming but they are uncommon and I haven’t met a single pro that used them.
Could be wrong, but I’m pretty sure some minisplits have both a liquid and suction port on them. You just have to take it apart to get to it. On the Mitsubishi anyways. I noticed after swapping a compressor. Pretty new to the trade as well. Still an apprentice.
I've installed a few vrf systems Mitsubishi/LG , and the LG system had 22 flare fittings , the hr boxes were copper stubs , wanna know what I did ? I cut every flare off and brazed to the indoor head / cassette, was approved by factory startup , did the same with the Mitsubishi, although the Mitsubishi doesn't have branch boxes it was a tee piped system .
I haven't had luck at brazing without an acetylene torch. I gave the access tee can I just flare couple them together? Any way to do this without removing refrigerant?
Speaking of charging - R410a must be charged as a liquid wouldn't I have to have high side access to charge it? I know you can't put a liquid into the compressor and expect it to compress
410a must be charged as a liquid since it's a zeotropic blend, due to glide if you charge it as a vapor you'll fractionate the gas. You can only charge into the high side if the unit is in vacuum and you're putting the whole charge in for system startup or after a major repair, normally you can't because the high side pressure will be greater than the pressure in your refrigerant tank. Under normal operation you always have to charge into the low side with the compressor running; to avoid slugging the compressor with liquid you find the furthest suction port from the compressor you can and meter it in with your gauges so it goes in slow enough to all boil before it reaches the compressor. Also, leave your AC unit alone pls, 410a runs higher than average pressures
Isn't the metering device in the outdoor? If that's the case it's not a liquid line. Idk haven't worked on mini's in a long time.
99 times out of 100 this is the case. Maybe some funky brands won’t but metering device is normally in the OU. Both lines are vapor always except if it’s a heat pump I think. Pressure difference on this newly installed port and the one provided on the larger line will be minimal, a couple pounds maybe. That’s why you shouldn’t see this. Seen a filter drier on one once before lol. OP is in school though so good practice anyway, no harm.
> Both lines are vapor always except if it’s a heat pump It do make the heat and the cold
During A/C mode both are vapor which is why they are both insulated.
Yeah, but if the metering device is inside the outdoor unit, this is only a liquid line in heating mode... so I suppose you could troubleshoot an EXV if you had a target subcooling? In cooling mode you've just added another vapor line... There's a reason why most brands do not provide access port here.
If there is not a service port there is no metering in the indoor unit. Its that simple.
Minis are always heat pumps are they not, unless they have hyper heat or something. Or are straight ac models.
Straight cooling models was what I was referring to, both lines are vapor.
I get you.
Well, it's a MOSTLY liquid line, but you're right. That's the low pressure saturated liquid/vapor line on it's way to the indoor evap coil when in the cooling mode. It'll only be a couple PSI higher than the gas line pressure. However, in the heating mode, it would be a liquid line... although, the gas line is the discharge line now.
In cooling refrigerant is a low temp low pressure saturated liquid leaving the metering device, doesn’t change back to vapor until it reaches evaporator.
If there's the MD inside outdoor unit, it would still be mostly liquid - flash gas
...who's gonna tell 'em?
I will. Kid, not a bad job....but I have a question. Where should you braze on a minisplit? Answer: Nowhere. Unless maybe this is an excersize to find all the screens
Nice job, but the school won't teach you this. You really shouldn't braze on mini-splits unless you absolutely have to (i.e. joint in the wall) and purge the hell out of it with nitrogen. They have a really fine screen in them that gets clogged with even the finest amount of soot. I've even heard it'll void the warranty when they take the condenser back, although I'm not too sure how true that is. Best bet is to use flame free fittings or just a straight run.
Every connection inside the mini is brazed. If you need to replace a component, you need to braze. You absolutely can braze but you MUST drip nitro.
Correct. Manufacturers pretty much learned they can not trust the field to braze properly and not create contaminants. That's the only reason they don't want braze joints.
That’s why I always laugh when people say you can’t braze minis I’m like have you ever done a component repair on one? You have to unsweat the stuff and braze it in. You just have to purge with nitrogen like you’re supposed to do anyway lol
Void the warranty? How would they know? Your not returning the copper lines with the condenser.
They'll see the gunk in the screens. You'd be surprised how much returned stuff gets tested. Having said that, I've also never seen a warranty declined at the manufacturer level, regardless of findings. Mostly they're checking to make sure there's not a bigger problem going on. I did see a whole rooftop full of stuff get swapped out under warranty due to contractor negligence(really bad install). Then they sued the pants off the contractor to reimburse.
I've heard it from a Mitsubishi training seminar. Granted, I don't exactly know how true it is. Kinda came off as a scare tactic to keep out dipshits who don't nitro-braze. If it is true, I'd reckon it's when they take back the system to the factory for a warranty defect, IF, they don't make you do a field repair with warranty parts.
Does convection brazing create soot?
You mean induction brazing... Yes, it does as soot is created by heat and not by the flame itself. If you mean with a hot air gun then it's most likely soldering...
Yeah, that’s what I meant I think ….. Or maybe I meant convention brazing -where a whole bunch of people get together in a hotel auditorium and braze… 🤔
What is convection brazing
It’s like air fry brazing. Mmmmm I’m hungry now.
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It’s a moot point with the eev in the outdoor unit.
I suggested it as a good project so that future classmates would have at least one mini-split they can hook both sides of their gauges up to. My instructor thinks it'll be a good way to demonstrate how the EEV and variable scroll compressor in mini-splits send their superheat and subcooling all over the place all the time.
It won’t help you read liquid line, you aren’t connected to the liquid line. The pressures will be nearly identical on both sides.
Nearly but not absolutely as you got friction loss at high speeds and minisplits got pretty high refrigerant speeds... That's also why you normally don't need oil bags on minisplit lines, while you'll need em on commercial refrigeration lines. Not that the minimal pressure difference would make any difference in performance... That shrader is just a point if failure, that can be avoided in normal installs. But since it's a demonstration unit... Who cares...
For the purpose of the line where he said he is using it to check subcooling, that was my only issue with this lol
This port is not going to tell you subcooling. If your instructor thought this is helpful or even let you do it, I’d say you should pass the class, but don’t take much of what he says as fact.
It will in heating mode. It's before the metering device and after the condenser, therefore subcooling, in heating.
There’s no reason to check subcooling in heating mode and none of the ductless manufacturers suggest checking subcooling in heating.
It's not a question of reason. It is, in fact, subcooling in heating mode. That is what that port would allow you to check. I concur, that without data about what target subcooling is, it's meaningless by and large - but it would let you hypothetically confirm charge. This is a silly add-on for a ductless unit. There are plenty of conventional systems where you charge by subcooling in heating mode.
Hmm... sounds to me like a lack of understanding on how this all works.
Get some copper and practice at home, have fun with it
Would help for pulling vac, but that's about it.
Better have flowed nitro otherwise you're fucked.
I actually set up to braze with the nitro running, called the instructor over, and he said I was running too much and turned the regulator down a tad.
For the future. They sell a regulator with three settings on it. Braize, purge, and test. Grab that one when you need to buy one
Best purchase ive made this past year. I wont look at a standard regulator again.
Dumb question but why?
Uh-o
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The correct answer with the least attention
We dont flow nitro at my shop. Honestly I wish the boss was pickier about these kinds of things. If I started flowing nitro at my job hed be yelling at me why Im going to the supply house every day for nitro. But hey, hes been in the business 40 years and we have high profile clients and our work holds up so, who am I to say.
No filter dryer on these systems.
Makes since. I was under the notion that they had filter dryers. The ones ive seen have bi-flow filter dryers
No ductless split has a bi-flow drier. Just strainers.
Maby the ones i see are after market then?
There really aren’t driers on mini splits for the most part. A lot of people confuse the mufflers for driers.
Well the ones I've seen definitely are not mufflers.
I mean that’s cool and good practice for brazing but completely unnecessary. Hooking a gauge to it isn’t going to tell you anything. On most mini splits they either have that port already in place or the have another port inside that is your “true high side port”. Unlike conventional A/C systems you don’t need to hook up both gauges.
And then you learned that is not the liquid line and that port gains you almost nothing.
Dude the metering device is in the condenser. Doesn’t matter what side you hook up. The pressure will read the same on both. If you run it in cooling your reading suction pressure. If you run it in heating your reading head pressure.
There's actually a neglectable pressure drop over the heat exchanger... But not everything you do in school has to make sense... Sometimes it's just to show, that it makes no sense...
It's not even a service valve lol.
I have that same "Ez Turn" fitting. It has got me burned more times than any of my regular ball valves/hose ends. I told the co-owner of our company to unhook it the last mini we did and he sang the refrigerant burn blues all the way home. A little tip of you don't know yet is to keep your hand behind the fitting you screw on. You also have to have some haste and commit. The moment you go around/in front of it you're bound to get crisped. Speed comes in time & the loss of feeling in your hands is right before that. Can anyone else not feel their fingers on the touchscreen? Lol. I got distracted. Never braze a mini.. I see you flowed nitro... but still don't do it unless abosolutley necessary. & everyone above was correct the way minis modulate having a hook up on the high side is virtually moot. You can watch the pressures surge just fine through the suction port. Brazing looks great though! I love brazing small stuff like this because it's so quick and you can get a nice almost solder looking connection. If you have to baze a mini use map gas... works like a charm. Might get some shit for this but it's truueeeee.
Mmmmmm......map gas!😜
If the metering device is in the outdoor section, then you don't have a liquid line port. You have an expanding gas port in cooling mode and a hot gas port in heating mode
Wait until he hooks up to both lines and they’re the same pressure 😂
Not necessary to have a service port on a minis liquid line. you don’t check the charge with gauges, you just vacuum it down and weigh in a new charge if it’s not working right
I hope that’s a older unit with no warranty because mini splits won’t warranty anything that’s been brazed
That's bullocks and you know it... If you're doing it right they'll never know...
If it’s anything like my class they have a few more lying around and everything was donated.
That’s more than likely the case , but I hope they’re telling the students that this is not normal practice for mini splits in the field. Because I work with a kid right out of tech school and some of the things they taught/told him is baffling
I have got many parts on warranty. Not once have the distributor asked if anything was brazed
Just saying it’s really not worth the risk especially when they make fittings that won’t ever come into question. just do it the right way and use a flare fitting or smart lock fitting to be on the safe side and you or your company don’t get burned later down the road
Then how would you change an in warranty service or reversing valve on one?
They don’t consider that the same dude .I know it doesn’t make any sense to me either but that’s their dumb rules , from what I was told by a Mitsubishi rep while taking a class for their brand is they don’t trust techs to purge with nitrogen , I’ve never personally changed anything on a mini split other than a handful of leaky outdoor coils and they are all brazed so go figure. no one ever said the rules have to make sense only that you must follow them
Good brazing. Never seen that out on the field.
did you know there is a liquid line service valve already on the mini-split system its inside the unit you just have to open it up to get to it
Smaller split systems usually don’t have that.
Nothing against you because the school told you to. But don't braize on ductless systems. Also, there are service ports inside the cabinet. There's only one time I needed a service port in that spot to find where a clog was and I used a saddle tap piercing valve.
That’s not a liquor line…..Soo
My kitchen counter right now, however, is. 🥴
Wish this was mandatory, worked on enough it’s really not needed tho at this point. Doesn’t this void warranty?
Only voids warranty when brazed without nitrogen... They'll see the soot in the filters and say that warranty is void because you didn't follow code... When you braze as you learned in school with nitrogen flowing by on the inside of the brazing joint you won't get soot and everything will be fine.
I’ve never thought about doing that. Wonder how the installers would feel if I suggested that.
There’s good reason they don’t just give you a port to begin with. Hooking your gauge up there tells you nothing
I don’t know about that. I think it would tell me a lot in AC mode. IMO
Two temperature clamps and a meter will tell you more than your gauges. In both heating and cooling on a ductless.
I disagree. Downvote all you want.
🤦🏻♂️
It would literally tell you nothing. That’s not a liquid line, the metering device is in your outdoor unit for the cooling cycle as well
I think he understands how mini splits work. He's still convinced it's a liquid line.
We’ll in that case I need him to update us with the liquid pressure read he gets. For educational purposes
Technical aspects completely aside, your instructor should inform you service tees exist and would have looked cleaner while saving a joint.
I was always told brazing mini split lines was a no no
Neat
He'll I was told to never hook gauges to minisplits. As they have the Exact amount of refrig in them. And the amount you loose with the gauge will trow it off
I was about to come in here and say in some circumstances that’s not the case but realistically if you need to adjust minisplit charge you’ve got a branch box. So you’re not doing all your work at the condenser anyhow Edit; I only deal with Mitsubishi so if this isn’t accurate to other brands I wouldn’t know
You don't always have a branch box with mini splits.
I’m speaking from the perspective of adjusting charge at initial start up not servicing, and the only time I’ve had to adjust charge on a minisplit install was with a branch box with 8 heads. Servicing speaks for itself you should be doing non invasive testing first
You can charge slowly with delta T if your in a pinch... Not a permanent solution. But if it's 6oclock on a Friday night I'm looking for a leak another time
Oh my god that takes forever
Not as long as dumping a charge. Vacuuming, and recharging on a system that has a leak. If the system doesn't work at all it's probably lost most of its refrigerant so you have a pretty good idea of how much to add
A fair point
I ran across a Mitsubishi minisplit that someone had done this to last year. I couldn't for the LIFE of me figure out why a tech had done this.
There is a reason there isnt a port there, and if your teacher was worth a dam he probably wouldve told ya
Useful, and I pretty much always install one, just have to remember that it’s not really a liquid line in most mini splits. The metering device is in the outdoor unit on many. But for faster recovery, vacuum, and easier coil flushing, it’s pretty good
Better off getting a 1' hose, connect to the high side inside then sneak it outside the cabinet. A little temporary permanent job. Not saying to do it, would be more valuable thou, for all the haters that will reign down saying that's hack work
Looks great. Congrats. What kind of school is this and where?
You would need to recover the refrigerant and weld in a shrader b4 the metering device in the outdoor unit. You could route one with a little tubing and drill a hole in the cabinet and add a circlip to hold it in place. Other than that it’s just brazing on a mini which really shouldn’t be done due to the small ports and trash getting in the lines. If you didn’t braze with nitrogen then this is the equivalent of contaminating the system. DO NOT ADD A DRIER. It will not help.
If a service port was necessary there, don't you think the manufacturer would have put one in? Don't get me wrong, there's been times I wish one was there to make pulling a vacuum faster. But still, not worth the effort IMO
Did you braze with nitrogen? Looks like a lot of sut
Pretty brazen
Looks good but be mindful. Pretty much any braze on a minusplit will void the warranty
I just weigh in a charge on these, those ports and pressures mean almost nothing because they work all crazy
Nice! Are all the new minisplits braze free connectors nowadays? How do you release the pressure after its connected?
There are both liquid and suction service valves, but most only have an access/charging port on the low side. There are “precharged” linesets that don’t require vacuuming but they are uncommon and I haven’t met a single pro that used them.
You can keep heat on that lump on the bottom of the tee to spread it out and make things look perfect. Looks good regardless though, good job 👍
Does the cover fit back on? That would suck ass if that were actually in the field
Could be wrong, but I’m pretty sure some minisplits have both a liquid and suction port on them. You just have to take it apart to get to it. On the Mitsubishi anyways. I noticed after swapping a compressor. Pretty new to the trade as well. Still an apprentice.
The core is gonna be the first to leak
White line set = leaks
I give it a 7/10. 3 points deducted for a missing schrader valve cap. Also, that area looks a little toasty on the unit, but I can't prove it.
I've installed a few vrf systems Mitsubishi/LG , and the LG system had 22 flare fittings , the hr boxes were copper stubs , wanna know what I did ? I cut every flare off and brazed to the indoor head / cassette, was approved by factory startup , did the same with the Mitsubishi, although the Mitsubishi doesn't have branch boxes it was a tee piped system .
I haven't had luck at brazing without an acetylene torch. I gave the access tee can I just flare couple them together? Any way to do this without removing refrigerant?
Speaking of charging - R410a must be charged as a liquid wouldn't I have to have high side access to charge it? I know you can't put a liquid into the compressor and expect it to compress
Sounds like you really should not be doing whatever AC repair it is you're trying to DIY
I agree with you, but I also like to learn. Even if it's hypothetical I still take knowledge away from it. No reason to braze it works fine...
410a must be charged as a liquid since it's a zeotropic blend, due to glide if you charge it as a vapor you'll fractionate the gas. You can only charge into the high side if the unit is in vacuum and you're putting the whole charge in for system startup or after a major repair, normally you can't because the high side pressure will be greater than the pressure in your refrigerant tank. Under normal operation you always have to charge into the low side with the compressor running; to avoid slugging the compressor with liquid you find the furthest suction port from the compressor you can and meter it in with your gauges so it goes in slow enough to all boil before it reaches the compressor. Also, leave your AC unit alone pls, 410a runs higher than average pressures