Refrigerants
Refrigerant types, phase-downs and the A2L transition.
28 entries
- 01R-448A Refrigerant: What It Is, What It Replaces, and What Section 608 SaysR-448A is the nonflammable HFC/HFO blend that has taken over from R-404A in many walk-ins and supermarket racks. Here is what it is, how it differs from R-404A and R-449A, how to charge it, and which rules apply.7 min read
- 02R-1234yf vs R-134a: What Actually Differs, and What It Means for CertificationR-1234yf and R-134a are both car air conditioning refrigerants, but they are not interchangeable. Here is how they differ, why newer vehicles use R-1234yf, and which EPA certification applies.5 min read
- 03R-407C Refrigerant: What It Is, What It Replaces, and What Section 608 SaysWhat R-407C is made of, why it was built as an R-22 replacement, what changes when you retrofit, and which Section 608 and AIM Act rules apply when you service it.7 min read
- 04R-404A Refrigerant: Is It Being Phased Out, and What Replaces It?R-404A is the HFC blend inside most older walk-in freezers and supermarket cases. Here is what it is, what is and is not restricted, what replaces it, and which leak and recovery rules still apply.7 min read
- 05R-422B Refrigerant: What It Is, How It Runs, and What Section 608 SaysR-422B (NU-22B) is an A1 HFC blend built to retrofit R-22 air conditioners. Here is what is in it, how its pressures compare to R-22, and which recovery and leak rules still apply.8 min read
- 06R-407A PT Chart: How to Actually Read the PressuresReal R-407A pressure-temperature values in °F and °C, why the liquid and vapor columns sit so far apart, which one to use for superheat and subcooling, and which leak repair rules bind an R-407A system.8 min read
- 07R-513A Refrigerant: What It Is, What It Replaces, and What Section 608 SaysR-513A is an A1, non-flammable blend of R-1234yf and R-134a with a GWP of 630. It is built to replace R-134a, it is not an A2L, and it is still covered by the Section 608 venting prohibition.6 min read
- 08R-22 vs R-410A: What Actually Differs, and Why You Can't Mix ThemR-410A runs at roughly 60% higher pressure than R-22, uses POE oil instead of mineral oil, and has no ozone-depleting potential. Here is what that means for the equipment, the tools and the law.7 min read
- 09R-32 Refrigerant: What It Is, Who Can Buy It, and What Changes on the JobR-32 is a single-compound A2L refrigerant with a GWP of 675 that is legal in new US air conditioners and heat pumps. It is not banned, it is not a retrofit option for R-410A, and it is not sold to anyone without a Section 608 card.7 min read
- 10R-290 PT Chart: How to Actually Read the PressuresReal R-290 propane pressure-temperature values, why a pure hydrocarbon needs only one column, why you charge it by weight rather than by gauge, and exactly where the Section 608 venting exemption does and does not apply.8 min read
- 11R-407C PT Chart: How to Actually Read the PressuresReal R-407C pressure-temperature values, why its two columns sit about 10 °F apart, which one to use for superheat and subcooling, and what that glide means when you charge a converted R-22 system.9 min read
- 12R-448A PT Chart: How to Actually Read the PressuresReal R-448A pressure-temperature values in °F and °C, why its two columns sit so far apart, which one to use for superheat and subcooling, and the leak repair rule that now reaches R-448A systems.9 min read
- 13R-134a Pressure Chart: How to Actually Read the PressuresReal R-134a pressure-temperature values, why the numbers look so low next to R-22 and R-410A, and why the same refrigerant falls under Section 609 in a car and Section 608 in a refrigerator or chiller.9 min read
- 14R-32 PT Chart: How to Actually Read the PressuresReal R-32 pressure-temperature values, why a single-compound refrigerant needs only one column, how R-32 compares to R-410A and R-454B on the gauges, and what standing pressure actually tells you.8 min read
- 15R-404A PT Chart: How to Actually Read the PressuresReal R-404A pressure-temperature values in °F and °C, which of the two columns to use for superheat and subcooling, and why the leak repair rules that bind an R-404A freezer are not the Section 608 ones.9 min read
- 16R-22 PT Chart: How to Actually Read the PressuresReal R-22 pressure-temperature values, why R-22's single column is exact rather than an approximation, and the retrofit trap that makes an R-22 chart give the wrong answer on an old system.9 min read
- 17R-410A PT Chart: How to Actually Read the PressuresReal R-410A pressure-temperature values, why the chart prints one saturation column when an R-454B chart prints two, and why a gauge reading on its own tells you almost nothing about the charge.8 min read
- 18Superheat and Subcooling: What Each Reading Actually Tells YouSuperheat and subcooling only diagnose a system when you read them together. Here is what each of the four combinations points at, which one to charge by, and why none of it is a Section 608 requirement.8 min read
- 19R-454B PT Chart: How to Actually Read the PressuresA PT chart for R-454B prints two saturation numbers, not one, and using the wrong one throws your superheat or subcooling off before you touch a valve. Here are the real pressures and which column each calculation needs.8 min read
- 20How to Find a Refrigerant Leak (and What Section 608 Requires Next)Most leak-detection guides stop at the bubbles. Here is how the methods actually rank on a real system, and what federal law obliges you to do once you find the leak.9 min read
- 21R-22 Replacement Refrigerant: What Actually Works and What Doesn'tEPA's SNAP program lists more than a dozen refrigerants as acceptable R-22 retrofits, and none of them is a true drop-in. Here is what changes on the job and what Section 608 requires while you do it.8 min read
- 22Is R-22 Still Available? What You Can Legally Do With ItVirgin R-22 stopped being made or imported on January 1, 2020, but R-22 was never banned to use. Reclaimed and pre-2020 stock keeps existing systems running legally.8 min read
- 23Refrigerant Safety: Why a Large Leak Can Cause SuffocationA large refrigerant leak kills by displacing oxygen, not by poisoning you. Here are the four physical hazards the Core exam tests, the PPE that actually works, and which of the controls come from Section 608 rather than from OSHA or ASHRAE.8 min read
- 24Types of Refrigerant: The Classes You Actually Need to KnowRefrigerants get sorted three separate ways — by chemistry, by appliance pressure, and by ASHRAE safety group. None of them is the same thing as EPA 608 Type I, II and III.8 min read
- 25R-32 vs R-454B: What Actually Changes on the JobR-32 and R-454B are both A2L refrigerants replacing R-410A, but they are not interchangeable and they do not sit the same distance from EPA's GWP limit. Here is the difference that matters in the field.7 min read
- 26R-454B Explained: What It Is and What Changes on the JobR-454B is a mildly flammable zeotropic blend that has replaced R-410A in most new residential equipment. Here is what it is made of, how it behaves on the gauges, and which of the handling rules actually come from Section 608.7 min read
- 27A2L Refrigerant Certification: What EPA Actually RequiresSearch for A2L certification and every result sells you a course. The federal requirement is Section 608 — here is what is regulation, what is building code, and what is only your employer.7 min read
- 28The R-410A Phase-Out: What It Actually Means If You Service HVACThe phase-down restricts what may be manufactured and imported, not what you may service. R-410A is not banned, and EPA removed the installation deadline in 2026.7 min read