New refrigerants and linesets.

[Michael Brown]

Daikin/Goodman has chosen R32 for their new refrigerant while Carrier has chosen R454b as thier new refrigerant. Both of these are Group A2 refrigerants. Per 2018 IMC 1107.5.1, these refrigerants will require schedule 40 carbon steel liquid lines. Coming from the multi-family side of the industry, I can say that this requirement is being overlooked by everyone. Is there something I am missing here? 1107.5.4 specifies brazed joints for copper tubing carrying A2 refrigerants but that could only be for the suction line. Is there another code section that would allow copper for the liquid lines?

 

[Paul Sweet]

1107.5.3 allows copper tubing. 1107.5.4 allows joints to be soldered (A1) instead of brazed.

1107.5.1 basically says if you use steel it has to be schedule 40 for A1, and schedule 80 for other refrigerants.

 

[Michael Brown]

1107.5.3 allows copper tubing. 1107.5.4 allows joints to be soldered (A1) instead of brazed.

1107.5.1 basically says if you use steel it has to be schedule 40 for A1, and schedule 80 for other refrigerants.

Group A2 are what the new refrigerants are classified. 1107.5.1 specifies that Schedule 80 steel (not 40, my mistake) "shall be used for Group A2...liquid lines for sizes 1.5 inches and smaller"

1107.5.3 seems to be just a specification for copper when used, it does not call out where its use is required like the steel.

1107.5.4 requires brazing for Group A2 refrigerants. Soldering is only allowed with Groups A1 and B1.

As I am reading this, a new system with the Group A2 refrigerant would be required to have a steel liquid line but would be allowed to have a traditional copper suction line. I would expect a significant increase in the cost of material and labor for this installation.

I hope this clarifies my question.

 

[klarenbeek]

If you keep reading 1107.5.1 it goes on to specify Schedule 40 steel for group A1 refrigerants, so I would interpret that section to mean that is the requirements IF you use steel tubing. The 2021 code completely rewrote that whole section, and the new wording seems to match up with that interpretation.

 

[Michael Brown]

If you keep reading 1107.5.1 it goes on to specify Schedule 40 steel for group A1 refrigerants, so I would interpret that section to mean that is the requirements IF you use steel tubing. The 2021 code completely rewrote that whole section, and the new wording seems to match up with that interpretation.

You weren't kidding about the rewrite for 2021. The line requirements moved to 1109.4 where copper pipe is specified for those refrigerants.