Change from 22 to 410a

[wvabeer]

I am replacing a heat pump and would like to use the old line set. Is it that critical if there is a trace amount of mineral oil. the line set is 15 ft long and real pain to replace. Your thoughts and experiance.
Kenny

[Furnaceguy85]

Whenever I change from r22 to 410a and can't change lines I use a product called rx11 flush. I believe it's made by nu-calogen. There are other brands out there too.

[Saturatedpsi]

I am replacing a heat pump and would like to use the old line set. Is it that critical if there is a trace amount of mineral oil. the line set is 15 ft long and real pain to replace. Your thoughts and experiance.
Kenny

Trace amounts of mineral oil are not a problem. Up to 5% mineral oil has been an acceptable number floating around for some time now. The initial Admonishment of Apocalypse subsided. :grin2:

[Firebird A/C]

I have done several change outs from 22 to 410 and have used the old 22 lines and have never had a problem. Just blow out the old lines with nitrogen and you will be fine. On such a short run that you have, you will be fine. Is there a oil trap on the existing line set?

[wvabeer]

I have done several change outs from 22 to 410 and have used the old 22 lines and have never had a problem. Just blow out the old lines with nitrogen and you will be fine. On such a short run that you have, you will be fine. Is there a oil trap on the existing line set?

This is exactly what I was planning . Thanks guys. :grin2:

[Cosmicmuffin]

This is exactly what I was planning . Thanks guys. :grin2:

STOP! Been to several Factory Seminars on this.,Buy a flush kit.,comes with "tank" you add the flush into.,pressurize it with your nitrogen tank,and flush lines! You are also suppose to be "purging" the lines with a slight flow of nitrogen when you are brazing! You may not have a problem right away,but R-22 & 410 are anything but compatable!

[John Markl]

We re-used dozens of linesets, without a single issue. You will notice at many "classes", that the people who insist that you have to do "this and that", have something to sell....:whistle:

[shaygetz]

You will notice at many "classes", that the people who insist that you have to do "this and that", have something to sell....:whistle:

Noooooooooooooo...perish the thought that such deception exists....:grin2::grin2:

[second opinion]

I am replacing a heat pump and would like to use the old line set. Is it that critical if there is a trace amount of mineral oil. the line set is 15 ft long and real pain to replace. Your thoughts and experiance.
Kenny

As long as the line set is clean and sound reusing it is not a problem.


What does need to be considered, is the oil in the line acidic, if it is there will be a problem down the road.

[AC5096]

The problem I run into is undersized existing line sets. Replacing line sets can be a job, but well worth the effort.

[John Markl]

The problem I run into is undersized existing line sets. Replacing line sets can be a job, but well worth the effort.

Strange.....410A can usually get by with smaller linesets than 22....

[hookspiter]

It's like anything else when you skip steps.

As long as it will runs it's OK. But how long will it run OK, and will you be able to trace a latter problem to oil contamination. If using the line set is OK then why is it suggested to have a separate gauge set for R-410A

[martyinlincoln]

So they can sell more manifolds. The 2-3 drops of clean mineral oil in the manifold isn't going to hurt a thing mixed with 10+lbs of 410A and 70 oz of POE oil in a system.

[marvin]

We re-used dozens of linesets, without a single issue. You will notice at many "classes", that the people who insist that you have to do "this and that", have something to sell....:whistle:

john
you couldnt have said it any better.
i have done many change overs & have yet to replace a line set unless
it was the wrong size lines.

[AC5096]

Strange.....410A can usually get by with smaller linesets than 22....

They can?

The Bryant install instructions state larger line sets than I mostly encounter.

[John Markl]

I don't have it handy, but I've been to 3 Mike Prokup classes in the last two years that covered this in detail....calculating line set length and size, including elbows, valves, etc.

410A uses smaller line sets than 22 for the identical application.

What we DID learn, is that probably 3/4 of the existing R22 linesets are undersized as installed.

[AC5096]

I don't have it handy, but I've been to 3 Mike Prokup classes in the last two years that covered this in detail....calculating line set length and size, including elbows, valves, etc.

410A uses smaller line sets than 22 for the identical application.

What we DID learn, is that probably 3/4 of the existing R22 linesets are undersized as installed.

2 & 2.5 ton R22 units that I'm in the process of replacing have 5/8 suction & 1/4 liquid lines.

Mr. Bryant & the company I work for general manager who also owns a mech. contracting business sez. I'm to use 3/4 & 3/8.

[John Markl]

2 & 2.5 ton R22 units that I'm in the process of replacing have 5/8 suction & 1/4 liquid lines.

Mr. Bryant & the company I work for general manager who also owns a mech. contracting business sez. I'm to use 3/4 & 3/8.

It's always better to robotically do what you're told, rather than understand why, isn't it? :cheers:

[John Markl]

If using the line set is OK then why is it suggested to have a separate gauge set for R-410A

So everyone could go out and buy extra sets of gauges and hoses ;)

On the other hand, there's boatloads of gauge sets out there that have scales for both, don't they? :whistle:

[chillerout1]

let me guess the old units are lennox? change the line set to what the manufacturer says

[AC5096]

let me guess the old units are lennox? change the line set to what the manufacturer says

Bryant, 72 vintage.

[AC5096]

It's always better to robotically do what you're told, rather than understand why, isn't it? :cheers:

When they are paying me. Yes:cheers:

[John Markl]

When they are paying me. Yes

In order to draw your paycheck...yes.

But what self-respecting person would pass on the opportunity to LEARN what the actual calculations are, according to Copeland?

Our trade is full of guys who have been taught WRONG, because they just did what they were told, and called it "experience"....instead of learning the core basics.

After a few years, they become "experienced parts changers", instead of real, knowledgable technicians.....:gah:

[John Markl]

Bryant, 72 vintage.

We've been maintaining a retirement center here for about 25 years, that has close to 150 2 ton Day and Night split systems. They all have 1/4 and 5/8 linesets on R-22 systems.

I'll see if I can find those charts...either in my class stuff, or on line. They're quite enlightening. We spent at least an hour in each class, doing calculations regarding line set lengths, pipe sizes, elbows, valves, etc.....and in EVERY instance, R22 required larger size lines than R410A in indentical applications.

[AC5096]

In order to draw your paycheck...yes.

But what self-respecting person would pass on the opportunity to LEARN what the actual calculations are, according to Copeland?

Our trade is full of guys who have been taught WRONG, because they just did what they were told, and called it "experience"....instead of learning the core basics.

After a few years, they become "experienced parts changers", instead of real, knowledgable technicians.....:gah:

If running new line sets makes me a glorified parts changer so be it. At least I know what I have.You never know in an old line set where joints were soft solderd instead of brazed or if the line is flattened in places.

[AC5096]

Found this.

http://www.upgnet.com/PdfFileRedirect/247077-UAD-H-0209.pdf

[nathytwin]

I just wanna make a point ok.. why not just do the job the RIGHT WAY and not have to worry about it at all.. the only people who stress about this kind of stuff is the unprofessional service techs. Just put the flush through the lines, r-22 and 410-A are not miscible.. AT ALL! look up the word if you don't understand

[kdean1]

I just wanna make a point ok.. why not just do the job the RIGHT WAY and not have to worry about it at all.. the only people who stress about this kind of stuff is the unprofessional service techs. Just put the flush through the lines, r-22 and 410-A are not miscible.. AT ALL! look up the word if you don't understand
I understand both the word and ATTITUDE. Are you trying to make a bad impression as a new guest?

[John Markl]

I just wanna make a point ok.. why not just do the job the RIGHT WAY and not have to worry about it at all.. the only people who stress about this kind of stuff is the unprofessional service techs. Just put the flush through the lines, r-22 and 410-A are not miscible.. AT ALL! look up the word if you don't understand

There's a 'right way' for those who are incompetent, and a 'right way' for those who know what they're doing.....

If you don't make the effort to truly understand the science of our trade, you will forever be relegated to the "parts-changer" pile....

[Saturatedpsi]

I just wanna make a point ok.. why not just do the job the RIGHT WAY and not have to worry about it at all.. the only people who stress about this kind of stuff is the unprofessional service techs. Just put the flush through the lines, r-22 and 410-A are not miscible.. AT ALL! look up the word if you don't understand

You should look it up. :whistle: Mineral oil and R-410A are not miscible.

[vstech]

We've been maintaining a retirement center here for about 25 years, that has close to 150 2 ton Day and Night split systems. They all have 1/4 and 5/8 linesets on R-22 systems.

I'll see if I can find those charts...either in my class stuff, or on line. They're quite enlightening. We spent at least an hour in each class, doing calculations regarding line set lengths, pipe sizes, elbows, valves, etc.....and in EVERY instance, R22 required larger size lines than R410A in indentical applications.

look over these systems... I bet you don't find a piston or a TXV... the old systems used the liquid line as the metering device... follow the lineset to the unit, and you'll find a coil of 1/4" line somewhere... it's a fixed length...

[John Markl]

look over these systems... I bet you don't find a piston or a TXV... the old systems used the liquid line as the metering device... follow the lineset to the unit, and you'll find a coil of 1/4" line somewhere... it's a fixed length...

They're all cap tubes or pistons. That being said, after attending those classes, I'm betting that those line sets are NOT proper for (at least) the third floor units....

[SuperDave89]

Rx-11 flush and nitrogen is what i always use on existing linesets that can't be removed.

[lynden]

look over these systems... I bet you don't find a piston or a TXV... the old systems used the liquid line as the metering device... follow the lineset to the unit, and you'll find a coil of 1/4" line somewhere... it's a fixed length...

I thought lennox were the only one's to use rfc line , did carrier too?

[AC5096]

look over these systems... I bet you don't find a piston or a TXV... the old systems used the liquid line as the metering device... follow the lineset to the unit, and you'll find a coil of 1/4" line somewhere... it's a fixed length...

Correct, but you will find a cap. tube.

[pony]

i heard r410a with higher seer rating require larger lineset then same tonnage then r22,but john mark mention it get smaller some case,i know have to go by manufactured guide,maybe somebody can give mesomemore information,thanks

[keeplearnin]

It's like anything else when you skip steps.

As long as it will runs it's OK. But how long will it run OK, and will you be able to trace a latter problem to oil contamination. If using the line set is OK then why is it suggested to have a separate gauge set for R-410A

as long as it makes it thru the warranty period then I can make some cash.

[keeplearnin]

:gah:
i heard r410a with higher seer rating require larger lineset then same tonnage then r22,but john mark mention it get smaller some case,i know have to go by manufactured guide,maybe somebody can give :gah:mesomemore:gah: information,thanks

mesomemore you got to love it.

[Glennhvac]

I've been lucky so far in that my replacements have had pretty easy line sets to replace. What you also might consider is any joints in the lines that you can see or may be buried and how they were joined. I wouldn't promise that many of the solders used years ago can hold up to the new pressures.
While I have yet to see it I can only imagine what 410a rockets to with a cottonseed packed condenser or dead condenser motor.

Maybe HP cutouts are required on the new units? The ones I install have them but not sure if it is mandatory now.

[dave sulz]

Last summer an exsting soft solder blew out in the attic at night.

[craig1]

While I have yet to see it I can only imagine what 410a rockets to with a cottonseed packed condenser or dead condenser motor.

A joint on a 3/8" liquid line on a system running 400PSI is experiencing about 17 pounds of force pushing the joint apart. You could almost hold that together with bubble gum.

[hvacmike85]

We re-used dozens of linesets, without a single issue. You will notice at many "classes", that the people who insist that you have to do "this and that", have something to sell....:whistle:

so you guys dont use that rx-11 crap, I always do to cover my a%$ but if just nitrogen works heck thats way cheaper than that stuff

[mark beiser]

It is sad that there are still so many misconceptions on this issue.
Quit going by 2nd and 3rd hand information, and by what reps for flushing products say.

There is no incompatibility between mineral and POE oil as far as lubrication and chemistry are concerned. The one and only issue is that mineral oil is not very miscible in HFC refrigerants, so it will tend to collect in parts of the system where the refrigerant is traveling at a relatively low velocity, like the evaporator coil.
If to much of it collects in the evaporator coil, the cooling capacity of the system can be reduced.
That is it as far as "problems" with mineral oil in a HFC system go.

When reusing a line set, try to eliminate any dips in the lines that are likely to have collected oil in them, and blast the lines out with nitrogen to get excess oil out of them, no flush solvents needed.
I've yet to attend a manufacturers training class that recommends flushing the lines with any kind of flush solvent when reusing a line set, except in the case of a bad burnout where there is junk in the lines that is potentially more harmful than any residue left by the solvent.
If you believe the flush solvent manufacturers claim that their products leave no residue, explain why after flushing a lineset with the stuff, blowing the lines out with gobs of nitrogen, and triple evacuating, you can break the vacuum to a positive pressure with nitrogen, you can still smell the solvent when you release the nitrogen from the system.
Or just drizzle some onto a clean piece of glass, and observe the residue left on the glass after the solvent evaporates.

If the refrigerant lines for an existing R-22 system are "under sized" for a new R-410A system, of the same capacity, the old lines were already under sized for a high efficiency R-22 system.
If you delve deeper into piping design than 2nd and 3rd hand word of mouth misinformation, you will find that, R-410A systems can use smaller refrigerant lines than R-22 systems.
The reason some manufacturers want larger refrigerant lines for their R-410A systems is that their system design needs the extra fraction of a percent of capacity from the larger lines to achieve their rated capacity and SEER.
Other manufacturers are able to get their rated SEER and capacity with smaller refrigerant lines.

[1332conn]

I have run into a situation where the line set was not replaced and the unit was going off on low pressure. This happened on a triple digit temperature day. No matter the adjustment in the charge, the unit kept going off. A proposal ws made to the homeowner to change the lineset. But after seeing the costs involved he decided to keep the current lineset and deal with the situation. He did have two systems

[Glennhvac]

I have run into a situation where the line set was not replaced and the unit was going off on low pressure. This happened on a triple digit temperature day. No matter the adjustment in the charge, the unit kept going off. A proposal ws made to the homeowner to change the lineset. But after seeing the costs involved he decided to keep the current lineset and deal with the situation. He did have two systems

I think that would be about the last thing I would blame. I can't say it's impossible but in 35 plus years I have seen my share of POS installations and unless the lines got kinked somehow none ever caused that issue.

[chuckcrj]

I have run into a situation where the line set was not replaced and the unit was going off on low pressure. This happened on a triple digit temperature day. No matter the adjustment in the charge, the unit kept going off. A proposal ws made to the homeowner to change the lineset. But after seeing the costs involved he decided to keep the current lineset and deal with the situation. He did have two systems

How could the wrong lineset cause high head pressure in cooling??

[John Markl]

How could the wrong lineset cause high head pressure in cooling??

:gah:

Amazing, the misconceptions out there.....

[wahoo]

John, could it have been that the installers (and I use that term loosely) left the old plugged pencil strainer inside liquid line and unit kicked off on low or high pressure? Seen it a LOT of times!!!!:gah:

[1332conn]

it was the first and only time i have run into this situation. good luck if you ever do

[catmanacman]

I lie to replace the line set then sell the old one for scrap , makes for some good beer money .especialy the 50 ft 1 1/8