Video · HVAC Installation Craft
R-454B Refrigerant Install on a Long Line Set, With a Job Site Check-In
A new R-454B refrigerant system shouldn't run on line set sized for an old R-22 unit. On this install the undersized liquid line came out and a new 3/8 inch line went in before charging.
Job footageSwiftPro
- Topic
- HVAC Installation Craft
- Length
- 1:23
- Posted
- September 2, 2026
- Shot by
- The SwiftPro crew, Northern Virginia
What you’re seeing in this video
Behind a house, Tyler Griffin, SwiftPro's owner, checks in by face cam with a young installer in a black SwiftPro polo. The tech is at the outdoor condenser with digital manifold gauges connected, charging the system and pointing out the line set.
He explains that the old line was 1/4 inch, sized for an R-22 unit and badly undersized for the new R-454B system, so they ran a new 3/8 inch line. The disconnect and the electrical whip, the flexible conduit feeding the unit, are new too. He plans to let the system settle before adjusting the charge.
All right, walking around the backside of the house here to go check out Elijah. What's going on with Elijah? We are just charging up the unit to because this is a pretty long line set. We actually just installed the 3/8 line set today.
What was the previous size? 1/4. 1/4 and that was undersized, correct? Incredibly so.
Yeah, that's for a R22 unit. We have the R454B. You put a new disconnect on here, too? New disconnect here.
Okay. The feed Everything when we replace units, we don't reuse any of this stuff. We don't want any carryover that could cause a problem. So, everything from the disconnect out to the unit is all new.
The whip there, electrical line that's running there. So, how much longer is it going to take you to get this charging completed? Well, I'm going to make sure in about 20 minutes before I change anything in the system. So, 20 minutes, probably.
Anything that you enjoy about HVAC in particular? It makes you think. And I like taking something that doesn't work right and getting a new one and making it work. Love that.
All right. If you guys need a HVAC system installed at your place, have our team do it and you can request Elijah and Oscar. They are an awesome install team and they love serving and they love making sure that the system is installed correctly and will last for for many, many years to come.
Why it matters in your house
- R-454B is the refrigerant replacing R-410A in new systems, and R-22 is long phased out. If your current system is old enough to run R-22, plan on a full line set check at replacement.
- Reusing the old line set can be fine if it's the right size, clean and leak free. If it isn't, a new one is far easier to live with than a compressor failure down the road.
- Long line sets need extra refrigerant beyond the factory charge. A tech who charges by gauge readings and measured weight gets it right instead of guessing.
Do you have to replace the line set with a new R-454B system?
Not always. A line set can be reused if it's the correct size for the new equipment, in good shape, and cleaned and tested properly. Lines left from an old R-22 system are often undersized or contaminated with old oil, and that's when replacement is the safer call, like on this job.
Want it done at your place? See HVAC Installation Craft at SwiftPro or call (703) 997-9757.
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