Arkansas HVACR NewsMagazine November 2024

HVACR NewsMagazine November 2024 Tech News What’s Up With

GWP: The lower GWP of 466 for R 454B is ~22% of R-410A's GWP (2088). Safety Classification: Both are Class A (lower toxicity) refrigerants, with R 454B being Class 2L (lower flammability) compared to R-410A's Class 1 (no flame propagation). Servicing: R-454B is to be used only in new systems designed for R-454B. Legacy systems designed for R-410A should only be serviced with R-410A. Temperature Glide: Both refrigerants have minimal glide: R-454B ~2°F and R-410A ~1°F. Topping Off: It is acceptable to top off systems with either gas after repairing leaks. Lubricants: Both R-454B and R-410A systems will use POE-based lubricants, which should be handled carefully to avoid introducing moisture to the system. Best Practices: Many best practices recommended for R-410A, such as purging, leak checks, and evacuation, are now required for R-454B and other A2L refrigerants. Recovery Machines and Vacuum Pumps: For servicing R-454B or other A2L systems, use A2L-rated equipment. This article and subsequent page of refrigerant charts was furnished by Brian Orr and HVAC School For Techs by Techs. We appreciate them sharing their excellent articles and encourage our readers to subscribe to their site at https://hvacrschool.com/start/

All This A2L Stuff As the ramp-up of new AC units and heat pumps with low-GWP refrigerant R-454B accelerates, it may be useful to look at some of the basic properties of R-454B refrigerant as compared to the legacy gas it's replacing: R-410A. This tech tip is a brief review of some of the more important aspects of R-454B vs. R 410A—compared side by side. Head to Head: R-454B vs. R-410A Refrigerant Cylinders : While R-410A jugs were pink, the R-454B will be off white, with a red strip (denoting the A2L (lower flammability) class. R-454B cylinders will come with left -hand threads and a pressure relief valve instead of the old rupture disk. The fill weight will be 20 lbs, as opposed to 25 lbs for R-410A.

PT Charts: The PT curves for R-454B and R-410A are very similar, but for best performance, use the appropriate chart or app for your specific application.