31 year old replacement

Dave0176

Replaced a 31 year old Acroair AC system. It was done the AHU was rotted from all the years of the condensate leaking. Home owner built a wall around the AHU so it was a pain in the azz working around it however I got it done... Went in with a York 14SEER 3ton system.

EdTheHeaterMan

Looks good. What is the map gas touch for? Soft solder for the line set?

Dave0176

EdTheHeaterMan said:

Looks good. What is the map gas touch for? Soft solder for the line set?

No that system is in the laundry room so I moved a few pipes at the same time for him. Refrigeration systems get brazed.

unclejohn

How much pipe did you bury

Dave0176

unclejohn said:

How much pipe did you bury

The old pipe was buried about 12” the new piping is about 4” down.

HVACNUT

Condensate line doesn't need to be trapped?

ChrisJ

Since it was kind of mentioned, but kind of not.

What's the downside to Staybrite 8 vs Silphos? My guess is the flux but I really don't know.

Dave0176

ChrisJ said:

Since it was kind of mentioned, but kind of not.

What's the downside to Staybrite 8 vs Silphos? My guess is the flux but I really don't know.

If you call Harris and ask them if you can use staybrite 8 they won’t tell it’s recommended however they will tell you stay brite produces a stronger joint then brazing because your not annealing the copper so much. From what I understand soft soldering is not recommended by certain towns due to the lower melting point. I’m guessing their thoughts are in a fire situation where it could get over 1000 degrees their worries is the lines could melt and separate causing a blowoff.

mattmia2

It seems to me that copper is pretty thoroughly annealed at soft soldering temps but I'm not a metallurgist.

ChrisJ

mattmia2 said:

It seems to me that copper is pretty thoroughly annealed at soft soldering temps but I'm not a metallurgist.

I think it depends on how long it's at the temperature etc.

That said..........why is annealing a bad thing for copper tubing? Most linesets are soft copper already.

EBEBRATT-Ed

What @Dave0176 explained is correct. Soft solder is a stronger joint but melts at low temp. Some places and codes insist on brazing

I have never been able to get a straight answer on this. I have worked with some of the Trane technicians and they tell me Stay Brite is not a problem

I had a new Trane unit with a 1 3/8 suction line. We brazed everything except the last joint at the unit, jammed against a panel with wiring on the other side there was no way to braze this successfully even soft solder was difficult. They told me soft solder was ok. It was either that or dump the factory charge and cut the suction line inside the unit make the field connection and then add a coupling where we cut the suction. Didn't want to make a mess out of a brand new unit either

Dave0176

mattmia2 said:

It seems to me that copper is pretty thoroughly annealed at soft soldering temps but I'm not a metallurgist.

ChrisJ said:

mattmia2 said:

It seems to me that copper is pretty thoroughly annealed at soft soldering temps but I'm not a metallurgist.

I think it depends on how long it's at the temperature etc.

That said..........why is annealing a bad thing for copper tubing? Most linesets are soft copper already.

Just like in welding the welded portion of the joint is the strongest, it’s the leading portions that get weakened from the heat. I’ve never seen a brazed joint break or blow, however I have seen the joint break just before the brazed joint.

SuperTech

I've only seen one solder joint fail on a refrigeration system. It was on the liquid line connection to a compressor that was replaced on a rooftop unit. Condenser coil was plugged, system was running very hot and it appeared as if the connection got hot enough to cause the joint to fail.
I asked the tech who had replaced the compressor a few years prior if he used Stay Brite and he claimed he always does, but who knows for sure. The joint could have failed for other reasons. I like Stay Brite, but I would never use it on a compressor.

ChrisJ

> @SuperTech said:
> I've only seen one solder joint fail on a refrigeration system. It was on the liquid line connection to a compressor that was replaced on a rooftop unit. Condenser coil was plugged, system was running very hot and it appeared as if the connection got hot enough to cause the joint to fail.
> I asked the tech who had replaced the compressor a few years prior if he used Stay Brite and he claimed he always does, but who knows for sure. The joint could have failed for other reasons. I like Stay Brite, but I would never use it on a compressor.

If your discharge line gets hot enough to soften solder I think there are much much bigger issues at hand than the joint failing.

You're already at 700 psi by 160 degrees, no idea what pressure 400F would be.

SuperTech

For what its worth it was an R22 system. Perhaps it was poor soldering/cleaning that caused the joint to fail more than heat or pressure. I just remember it leaked right at the joint suddenly, the compressor was changed several years prior and never leaked.

ChrisJ

SuperTech said:

For what its worth it was an R22 system. Perhaps it was poor soldering/cleaning that caused the joint to fail more than heat or pressure. I just remember it leaked right at the joint suddenly, the compressor was changed several years prior and never leaked.

Maybe there is something to the whole vibration thing.
My concern was flux.

So far......every HVAC joint I've done has been with Staysilv 15 with N2 flowing. I like how there's no flux to deal with as well as the fact it can be used to fill voids and holes.

But the Stay Brite has maybe me wonder a few times.

Sorry for getting things sidetracked. @Dave0176 Beautiful work as always.

mattmia2

Vibration would be my concern. Tin/lead solder joints have a tendency to fatigue and shear apart at the solder if it gets enough repeated force. This especially happens in electronics with connectors that don't have additional mechanical support.

pecmsg

Dave0176 said:

ChrisJ said:

Since it was kind of mentioned, but kind of not.

What's the downside to Staybrite 8 vs Silphos? My guess is the flux but I really don't know.

If you call Harris and ask them if you can use staybrite 8 they won’t tell it’s recommended however they will tell you stay brite produces a stronger joint then brazing because your not annealing the copper so much. From what I understand soft soldering is not recommended by certain towns due to the lower melting point. I’m guessing their thoughts are in a fire situation where it could get over 1000 degrees their worries is the lines could melt and separate causing a blowoff.

The copper will rupture long before getting to that temperature!

EBEBRATT-Ed

I agree with @SuperTech I wouldn't soft solder a discharge line.

The only time you work on a discharge line is a compressor replacement (usually) Liquid and suction on a split.

My old boss had a 1 5/8" discharge valve blow off a compressor and it just missed his head and it was stay brite

We can't control jobs that are overcharged, pumping oil, dirty condenser, bad condenser fan motor etc that can send discharge temps high enough to potentionally cause issues with soft solder

EdTheHeaterMan

Looks like everybody agrees that the Job looks great, but...

@Dave0176: Let me just say that I'm sorry I asked about the Mapp Gas. The job looks Great ... no buts about it!

ChrisJ

> @EdTheHeaterMan said:
> Looks like everybody agrees that the Job looks great, but...
>
> @Dave0176: Let me just say that I'm sorry I asked about the Mapp Gas. The job looks Great ... no buts about it!

I'm almost positive you can braze with Mapp or LPG with the proper torch.

SuperTech

Lol, this thread is set to go off topic a second time. I might have to try brazing with Mapp next time I'm bored.

ChrisJ

> @SuperTech said:
> Lol, this thread is set to go off topic a second time. I might have to try brazing with Mapp next time I'm bored.

Oxy Mapp and oxy propane are more than hot enough. I promise.

Also Turbotorch makes lpg and Mapp torches.

https://www.zoro.com/turbotorch-air-propanemapp-kit-0386-1397/i/G2896381/

HVACNUT

I worked at a shop in the mid 90's and Carrier Puron 410A was out. The installers used flux and lead free solder instead of brazing, and hard pipe copper L for the suction lines. I still don't get it.

Dave0176

ChrisJ said:

> @EdTheHeaterMan said:

> Looks like everybody agrees that the Job looks great, but...

>

> @Dave0176: Let me just say that I'm sorry I asked about the Mapp Gas. The job looks Great ... no buts about it!



I'm almost positive you can braze with Mapp or LPG with the proper torch.

I braze with the Mapp gas torch it’s a turbo type tip it’ll work on the 3/8 3/4” line sets, 7/8” starts pushing it. Usually I got my MC tank with No 14 turbo tip for the big stuff. The B tank almost never comes outta the truck anymore.

EBEBRATT-Ed

I agree with @Dave0176

You can braze with Air/Mapp or Air/acytelene but only in the smaller sizes. Turbo torch may say there big tips may braze large sizes but good luck with that....it's not practical takes a long time and burns too much fuel. Valves and speciality items shouldnt be over heated

Like Dave said 7/8-1 1/8 is about it and it depends on where you are outside in the cold with the wind blowing or on a roof top at 100 degrees ambient it make a big difference

Oxy acytelene and map or propane acytelene are the way to go 1 1/8 and larger for best results

EBEBRATT-Ed

One place I worked at we did a fair amount of cutting with oxy/acytelene but switched to Mapp & oxy because at the time it was (and maybe still is) much cheaper. What we found was Mapp cut fine on new steel but didn't seem to cut as well on dirty, painted or rusty stuff so we switched back to acytelene