11.17 - Common Refrigerant Quick Reference
Module: Standalone Reference Appendices and Instructor Resources
Purpose: One-table refrigerant-by-refrigerant comparison for the common legacy, current, transition, low-GWP, natural, chiller, commercial-refrigeration, and specialty refrigerants most relevant to this course and U.S. HVAC/R practice
Verification date: August 14, 2026
Design requirement: This file intentionally uses one master table only so a student can compare refrigerants without moving among separate property tables.
Pressure-class authority: Current 40 CFR §82.152 definitions at 104°F (40°C)
Safety-class basis: Current ANSI/ASHRAE Standard 34-2024 framework plus current published addenda and current EPA SNAP listings where applicable
GWP basis: EPA Technology Transitions GWP Reference Table where a current value is listed; established EPA/IPCC AR4 values for legacy ODS; calculated blend values are explicitly marked
Scope: This is a refrigerant quick reference, not a complete equipment-design database or a substitute for the refrigerant manufacturer’s SDS, approved equipment instructions, current codes, or the full P-T tables in Section 11.18.
How to Read the Master Table
Use the row as a complete first-pass identification check:
REFRIGERANT
→ COMPOSITION / FAMILY
→ PURE OR BLEND
→ ODP / GWP
→ SAFETY CLASS
→ SECTION 608 PRESSURE CLASS
→ APPLICATION
→ CURRENT / LEGACY CONTEXT
→ LUBRICANT
→ CHARGING / P-T RULE
→ CERTIFICATION CONTEXT
→ SERVICE WARNING
Keep these distinctions separate:
PRESSURE CLASS
≠
SAFETY CLASS
≠
ENVIRONMENTAL CLASS
≠
CERTIFICATION TYPE BY ITSELF
Important use rules:
- Section 608 certification depends on the appliance, activity, refrigerant, and whether the refrigerant/end use is exempt from Subpart F. For non-exempt refrigerants, a medium-, high-, or very-high-pressure stationary appliance is normally Type II, but a qualifying factory-sealed small appliance may be Type I; low-pressure appliances are Type III. Current §82.154(a)(1) exempts specified substitutes/end uses, including CO2 and water in any application, ammonia in commercial or industrial process refrigeration or absorption units, and specified R-290/R-600a end uses. Ordinary paid MVAC service is governed separately by Section 609.
- A1 does not mean harmless. Pressure, oxygen displacement, frostbite, decomposition, machinery-room, and other hazards can still exist.
- A2L, A2, A3, B1, and B2L require their applicable safety controls. Tool suitability, charge limits, ventilation, ignition-source control, listing, code, and manufacturer instructions can change the permitted procedure.
- For zeotropic blends, charge as liquid unless the approved manufacturer procedure states otherwise. For P-T interpretation, use dew / saturated vapor for superheat and bubble / saturated liquid for subcooling.
- Lubricant entries are typical orientation only. The exact compressor, lubricant grade, viscosity, additive package, retrofit procedure, and miscibility requirement are controlled by the equipment/compressor/refrigerant manufacturer.
- SNAP acceptability and AIM Technology Transitions restrictions are end-use specific. A refrigerant being acceptable in one application does not make it acceptable in every application.
- Do not mix refrigerants or perform a “drop-in” retrofit based only on similar pressure. Follow an approved retrofit procedure and relabel the equipment.
- Detailed P-T values belong in
11.18 - Common Refrigerant Pressure-Temperature Tables.md. Section 11.9 remains the smaller verified dataset needed by existing course questions.
Master Common-Refrigerant Comparison
| Refrigerant | Chemical name / composition (% by mass) | Family | Pure / blend and glide | ODP / ODS status | 100-year GWP | ASHRAE safety class | Thermodynamic §82.152 pressure category at 104°F | Typical applications | U.S. status / transition context | Typical lubricant compatibility | Charging / P-T handling | Common certification / exam association | Key service / safety warning | P-T cross-reference |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| R-11 | Trichlorofluoromethane, CCl3F | CFC | Pure; no glide | 1.0; Class I ODS | 4,750 (AR4) | A1 | Low | Legacy low-pressure centrifugal chillers; older large A/C systems | Legacy ODS. U.S. Class I production/import phaseout; existing equipment relies on recovered/reclaimed/stockpiled material as allowed. | Mineral oil common in legacy systems; OEM controls | Single saturation relationship. Low-pressure/vacuum behavior is important; charge per OEM. | Typical low-pressure chiller context -> Type III | System may operate below atmospheric pressure, so air/moisture can leak inward. Ozone-depleting CFC; recover, do not vent. | 11.18 low-pressure/chiller group |
| R-12 | Dichlorodifluoromethane, CCl2F2 | CFC | Pure; no glide | 1.0; Class I ODS | 10,900 (AR4) | A1 | Medium | Legacy household/commercial refrigeration; older MVAC; older small appliances | Legacy ODS. U.S. Class I production/import phaseout; remains in legacy equipment and recovered/reclaimed inventories. | Mineral oil common in legacy stationary systems; OEM controls | Single saturation relationship. Charge by the approved/OEM procedure. | Stationary medium-pressure -> typically Type II unless small appliance -> Type I; MVAC -> Section 609 | Do not confuse old automotive R-12 service with Section 608 stationary work. High ODP and high GWP. | 11.18 legacy/medium-pressure group |
| R-113 | 1,1,2-Trichloro-1,2,2-trifluoroethane, C2Cl3F3 | CFC | Pure; no glide | 0.8; Class I ODS | 6,130 (AR4) | A1 | Low | Legacy low-pressure refrigeration/chiller and specialty applications | Legacy ODS. Class I production/import phaseout; encountered mainly in older equipment or historical references. | Mineral oil historically common; OEM controls | Single saturation relationship; low-pressure/absolute-pressure concepts matter. | Low-pressure appliance -> Type III | Legacy CFC with significant ozone impact. Air/moisture ingress is possible in low-pressure operation. | 11.18 low-pressure/chiller group |
| R-114 | 1,2-Dichloro-1,1,2,2-tetrafluoroethane, C2Cl2F4 | CFC | Pure; no glide | 1.0; Class I ODS | 10,000 (AR4) | A1 | Medium | Legacy specialty refrigeration, process cooling, and older equipment | Legacy ODS. Class I production/import phaseout; uncommon except in older systems. | Mineral oil historically common; OEM controls | Single saturation relationship; charge per OEM. | Stationary medium-pressure -> typically Type II unless small appliance -> Type I | Legacy CFC with high ODP/GWP. Do not treat historical availability as current new-equipment suitability. | 11.18 legacy/medium-pressure group |
| R-22 | Chlorodifluoromethane, CHClF2 | HCFC | Pure; no glide | 0.055; Class II ODS | 1,810 (AR4) | A1 | High | Large installed base of legacy residential/light-commercial A/C, heat pumps, commercial refrigeration | Legacy Class II ODS. U.S. production/import of virgin HCFC-22 for servicing ended in 2020; existing systems may use recovered/reclaimed/previously produced material as allowed. | Mineral oil or alkylbenzene common in legacy systems; retrofit lubricant depends on replacement/OEM | Single saturation relationship. Do not mix a retrofit refrigerant with R-22 unless an approved retrofit procedure explicitly provides for it. | High-pressure stationary -> Type II; R-22 bus/passenger-compartment A/C remains a Section 608 example rather than ordinary R-12 MVAC | ODS plus high GWP. Retrofit requires refrigerant, lubricant, metering-device, capacity, and labeling evaluation. | 11.18 comfort A/C and legacy HCFC group |
| R-123 | 2,2-Dichloro-1,1,1-trifluoroethane, CHCl2CF3 | HCFC | Pure; no glide | 0.02; Class II ODS | 77 (AR4) | B1 | Low | Legacy low-pressure centrifugal chillers | Legacy Class II ODS. Existing chillers remain in service; lower-ODP/lower-GWP chiller alternatives include R-1233zd(E) and R-514A in applicable designs. | OEM-specific chiller oil; mineral/alkylbenzene historically used in some designs | Single saturation relationship. Low-pressure charging/recovery procedures and absolute vacuum units are important. | Low-pressure chiller -> Type III | B1 means higher toxicity with Class 1 flammability classification. Low-pressure systems can draw air/moisture inward. | 11.18 low-pressure/chiller group |
| R-124 | 2-Chloro-1,1,1,2-tetrafluoroethane, CHClFCF3 | HCFC | Pure; no glide | ~0.022; Class II ODS | 609 (AR4) | A1 | Medium | Legacy refrigeration/chiller and blend component | Legacy Class II ODS; increasingly uncommon as a primary refrigerant. | Mineral oil, alkylbenzene, or POE depending system/retrofit; OEM controls | Single saturation relationship; charge per OEM. | Stationary medium-pressure -> typically Type II unless small appliance -> Type I | Contains chlorine and has nonzero ODP. Do not infer current retrofit acceptability from pressure similarity. | 11.18 legacy/medium-pressure group |
| R-500 | R-12/R-152a = 73.8/26.2% by mass | CFC/HFC blend | Azeotropic designation; negligible/very small practical glide; use manufacturer P-T data | ~0.738 calculated; contains Class I ODS | ~8,077 calculated (AR4 components) | A1 | Medium | Legacy air conditioning and refrigeration | Legacy ODS-containing blend; largely obsolete except historical/legacy service. | Mineral oil historically common; OEM controls | Azeotropic blend; follow manufacturer charging and P-T data rather than assuming pure-fluid behavior under every condition. | Stationary medium-pressure -> typically Type II unless small appliance -> Type I | Contains CFC-12. Do not treat it as a modern HFC blend merely because one component is HFC-152a. | 11.18 legacy blend group |
| R-502 | R-22/R-115 = 48.8/51.2% by mass | HCFC/CFC blend | Azeotropic designation; negligible/very small practical glide; use manufacturer P-T data | ~0.334 calculated; contains Class I/II ODS | ~4,660 (AR4/EPA legacy basis) | A1 | High | Legacy low-temperature commercial refrigeration | Legacy ODS-containing blend; largely replaced by non-ODS refrigerants in newer equipment. | Mineral oil or alkylbenzene historically common; OEM controls | Azeotropic blend; follow manufacturer charging and P-T data rather than assuming pure-fluid behavior under every condition. | High-pressure stationary -> Type II | Contains both HCFC-22 and CFC-115. Historical replacement relationships do not make drop-in mixing acceptable. | 11.18 legacy commercial-refrigeration group |
| R-23 | Trifluoromethane, CHF3 | HFC | Pure; no glide | 0 | 14,800 (EPA TT basis) | A1 | Very high | Ultra-low-temperature and cascade refrigeration; specialty process systems | Specialty high-GWP HFC. Use is increasingly constrained by HFC climate policy and end-use rules. | POE commonly used in modern systems; OEM controls | Single saturation relationship; very-high-pressure equipment and components must be specifically rated. | Very-high-pressure stationary -> Type II | Extremely high pressure and very high GWP. Do not use ordinary pressure-rated tools/components unless specifically suitable. | 11.18 very-low-temperature / very-high-pressure group |
| R-32 | Difluoromethane, CH2F2 | HFC | Pure; no glide | 0 | 675 (EPA TT basis) | A2L | Very high | Newer residential/light-commercial A/C and heat pumps; major component of many blends | Current lower-GWP alternative in specified end uses, subject to applicable SNAP use conditions, listings, codes, and Technology Transitions requirements. | POE or PVE commonly used depending OEM | Single saturation relationship. Use A2L-rated service procedure/tools and OEM charging method. | Very-high-pressure stationary -> Type II unless appliance qualifies as Type I | A2L flammable refrigerant. At 104°F its saturation pressure places it in the very-high-pressure Section 608 category; do not assume R-410A tooling/procedure is automatically suitable. | 11.18 comfort A/C / A2L group |
| R-125 | Pentafluoroethane, CHF2CF3 | HFC | Pure; no glide | 0 | 3,500 (AR4/EPA basis) | A1 | High | Primarily a blend component in R-404A, R-407 series, R-410A, R-507A, R-452A, and others | High-GWP HFC component subject to AIM phasedown controls; uncommon as a stand-alone HVAC refrigerant. | POE common in systems containing R-125; OEM controls | Pure-fluid P-T behavior by itself, but most technicians encounter it inside blends whose bubble/dew rules control. | If used as a stationary high-pressure refrigerant -> Type II; normally encountered as a blend component | Do not use component properties to substitute for the P-T or safety data of the finished blend. | Component/reference only; blend tables govern |
| R-134a | 1,1,1,2-Tetrafluoroethane, CH2FCF3 | HFC | Pure; no glide | 0 | 1,430 (EPA TT basis) | A1 | Medium | Stationary chillers/refrigeration; older/newer legacy MVAC fleet; many appliances and blend formulations | Large installed base; high-GWP HFC subject to AIM phasedown and end-use-specific Technology Transitions restrictions for new equipment. | POE common in stationary systems; PAG common in MVAC; OEM controls | Single saturation relationship. Current course P-T examples use R-134a. | Stationary medium-pressure -> Type II unless small appliance -> Type I; MVAC -> Section 609 | Same refrigerant can appear under different certification programs depending on appliance. Do not infer Section 608/609 from refrigerant alone. | 11.9 selected course data; 11.18 medium-pressure group |
| R-143a | 1,1,1-Trifluoroethane, CH3CF3 | HFC | Pure; no glide | 0 | 4,470 (EPA TT basis) | A2L | High | Primarily a blend component in R-404A and R-507A | Very high-GWP HFC component subject to AIM phasedown; rarely used alone in ordinary HVAC service. | POE common in systems containing it; OEM controls | Pure-fluid behavior alone; finished-blend charging/P-T rules govern in normal service. | If used alone in stationary high-pressure equipment -> Type II; normally blend-component context | Current safety classification is A2L; older references may show A2. Finished blends such as R-404A/R-507A remain A1. | Component/reference only; blend tables govern |
| R-152a | 1,1-Difluoroethane, CH3CHF2 | HFC | Pure; no glide | 0 | 124 (EPA TT basis) | A2 | Medium | Specialty refrigeration; aerosol/foam uses; approved in certain MVAC applications under use conditions; blend component | Lower-GWP HFC with flammability limits; application acceptability is end-use specific. | POE/PAG or other OEM-specified lubricant depending application | Single saturation relationship; flammable-refrigerant procedures apply. | Stationary medium-pressure -> Type II unless small appliance -> Type I; MVAC use -> Section 609 | A2 is flammable and is not the same as A2L. Use only in equipment/end uses specifically designed and allowed for it. | 11.18 medium-pressure specialty group |
| R-245fa | 1,1,1,3,3-Pentafluoropropane, CHF2CH2CF3 | HFC | Pure; no glide | 0 | 1,030 (EPA TT basis) | B1 | Low | Low-pressure chillers, heat-transfer/ORC and specialty applications | High-GWP HFC low-pressure alternative; new-use status is end-use specific and has been restricted in some sectors. | POE or other OEM-specific lubricant depending machine | Single saturation relationship; low-pressure/vacuum behavior matters. | Non-exempt low-pressure stationary appliance -> Type III | B1 indicates higher toxicity with Class 1 flammability classification. Low-pressure equipment can draw air/moisture inward; follow the SDS, ventilation, and OEM requirements. | 11.18 low-pressure/chiller group |
| R-404A | R-125/R-143a/R-134a = 44/52/4% by mass | HFC blend | Zeotropic; near-azeotropic behavior with small glide | 0 | 3,922 (EPA TT basis) | A1 | High | Large installed base in commercial refrigeration, freezers, ice machines, transport refrigeration | Legacy high-GWP HFC blend. Existing equipment remains important, but many new-equipment/end-use applications have transitioned or are restricted. | POE common; OEM controls | Charge as liquid to preserve composition. Small glide; use manufacturer P-T data. | High-pressure stationary -> Type II; factory-sealed ≤5 lb small appliance may be Type I | Very high GWP. Do not top off with a different replacement blend; retrofit requires a complete approved procedure. | 11.18 commercial-refrigeration group |
| R-407A | R-32/R-125/R-134a = 20/40/40% by mass | HFC blend | Zeotropic; measurable glide | 0 | ~2,107 calculated (AR4 components) | A1 | High | Commercial refrigeration; R-22/R-404A transition and retrofit applications where specifically approved | A1 HFC transition blend with lower GWP than R-404A but still subject to HFC phasedown/end-use restrictions. | POE common; OEM/retrofit procedure controls | Charge liquid. Superheat -> dew; subcooling -> bubble. | High-pressure stationary -> Type II | Glide matters. Do not use an average saturation temperature when calculating superheat/subcooling. | 11.18 commercial-refrigeration zeotrope group |
| R-407C | R-32/R-125/R-134a = 23/25/52% by mass | HFC blend | Zeotropic; measurable glide | 0 | 1,774 (EPA TT basis) | A1 | High | Air conditioning, heat pumps, chillers, and many R-22 replacement/retrofit applications | Common installed A1 HFC blend; still high-GWP relative to newer alternatives and subject to current HFC transition policy. | POE common; retrofit/OEM controls | Charge liquid. Superheat -> dew; subcooling -> bubble. | High-pressure stationary -> Type II | Strong exam example for bubble/dew/glide. Fractionation can occur if improperly charged or after some leak scenarios. | 11.9 selected bubble/dew data; 11.18 comfort A/C group |
| R-407F | R-32/R-125/R-134a = 30/30/40% by mass | HFC blend | Zeotropic; measurable glide | 0 | ~1,825 calculated (AR4 components) | A1 | High | Commercial refrigeration; lower-GWP alternative to R-404A/R-507A in appropriate systems | Transition HFC blend; new-use status and GWP limits are end-use specific. | POE common; OEM controls | Charge liquid. Superheat -> dew; subcooling -> bubble. | High-pressure stationary -> Type II | Zeotropic composition/glide must be respected; not a drop-in substitute solely because pressures are similar. | 11.18 commercial-refrigeration zeotrope group |
| R-410A | R-32/R-125 = 50/50% by mass | HFC blend | Zeotropic; near-azeotropic with very small glide | 0 | 2,088 (EPA TT basis) | A1 | High | Very large installed base in residential/light-commercial A/C and heat pumps | Legacy/current installed-base refrigerant. High GWP drives transition of new equipment toward lower-GWP alternatives such as R-32 and R-454B where applicable. | POE common; OEM controls | Liquid charging is preferred for the blend. Manufacturer P-T data may present essentially one practical saturation curve because glide is small. | High-pressure stationary -> Type II unless appliance qualifies as Type I | High operating pressure. R-410A equipment is not automatically suitable for R-32 or R-454B retrofits. | 11.9 selected comparison data; 11.18 comfort A/C group |
| R-507A | R-125/R-143a = 50/50% by mass | HFC blend | Azeotropic designation; negligible/very small practical glide; use manufacturer P-T data | 0 | 3,985 (EPA TT basis) | A1 | High | Legacy/commercial low-temperature refrigeration and industrial refrigeration | High-GWP installed-base HFC blend; many new applications have transitioned toward lower-GWP refrigerants. | POE common; OEM controls | Azeotropic blend; follow manufacturer charging and P-T data; controlled liquid transfer is commonly used for blend charging. | High-pressure stationary -> Type II | Very high GWP. Do not confuse azeotropic behavior with permission to mix with R-404A or another refrigerant. | 11.18 commercial-refrigeration group |
| R-508B | R-23/R-116 = 46/54% by mass | HFC/PFC blend | Azeotropic designation; negligible/very small practical glide; use manufacturer P-T data | 0 | 13,396 (EPA TT basis) | A1 | Very high | Ultra-low-temperature cascade refrigeration and specialty process systems | Specialty extremely high-GWP refrigerant; climate policy strongly limits desirability and use is specialized. | POE or OEM-specific lubricant | Very-high-pressure refrigerant; use equipment, cylinders, hoses, and recovery machinery specifically rated. | Very-high-pressure stationary -> Type II | Extremely high GWP and pressure. Very-high-pressure classification is an EPA exam recognition point. | 11.18 very-low-temperature / very-high-pressure group |
| R-448A | R-32/R-125/R-134a/R-1234yf/R-1234ze(E) = 26/26/21/20/7% by mass | HFC/HFO blend | Zeotropic; significant glide | 0 | 1,386 (EPA TT basis) | A1 | High | Supermarkets, commercial refrigeration, cold storage, food processing, transport refrigeration | A1 lower-GWP transition blend relative to R-404A/R-507A; acceptability and Technology Transitions restrictions remain end-use specific. | POE common; OEM/retrofit procedure controls | Charge liquid. Superheat -> dew; subcooling -> bubble. | High-pressure stationary -> Type II | Significant glide. Retrofit requires evaluation of capacity, discharge temperature, controls, oil return, and labels. | 11.18 commercial-refrigeration zeotrope group |
| R-449A | R-32/R-125/R-134a/R-1234yf = 24.3/24.7/25.7/25.3% by mass | HFC/HFO blend | Zeotropic; significant glide | 0 | 1,396 (EPA TT basis) | A1 | High | Supermarkets, commercial refrigeration, cold storage and retrofit/new applications where approved | A1 lower-GWP transition blend relative to R-404A/R-507A; current use is end-use and rule specific. | POE common; OEM/retrofit procedure controls | Charge liquid. Superheat -> dew; subcooling -> bubble. | High-pressure stationary -> Type II | Do not ignore glide or assume it is a drop-in R-404A replacement. | 11.18 commercial-refrigeration zeotrope group |
| R-450A | R-134a/R-1234ze(E) = 42/58% by mass | HFC/HFO blend | Zeotropic; small/moderate glide | 0 | 601 (EPA TT basis) | A1 | Medium | Chillers, medium-temperature refrigeration, vending and selected R-134a replacement applications | Lower-GWP A1 alternative to R-134a in compatible equipment; end-use restrictions/use conditions still control. | POE common; OEM controls | Charge liquid. Use manufacturer bubble/dew data where separate values are given. | Stationary medium-pressure -> Type II unless small appliance -> Type I | Not a universal drop-in replacement for R-134a; equipment and control compatibility must be verified. | 11.18 medium-pressure / chiller-refrigeration group |
| R-452A | R-32/R-125/R-1234yf = 11/59/30% by mass | HFC/HFO blend | Zeotropic; glide | 0 | 2,140 (EPA TT basis) | A1 | High | Refrigerated transport, commercial refrigeration, selected R-404A/R-507A replacement applications | A1 transition blend with pressure/performance similarities useful in some legacy applications, but GWP remains high. | POE common; OEM controls | Charge liquid. Superheat -> dew; subcooling -> bubble. | High-pressure stationary/cargo refrigeration -> Type II; vehicle passenger A/C rules are different | Refrigerated cargo equipment is not ordinary MVAC. Do not let the fact that equipment is mounted on a vehicle automatically move it to Section 609. | 11.18 commercial/transport-refrigeration group |
| R-452B | R-32/R-125/R-1234yf = 67/7/26% by mass | HFC/HFO blend | Zeotropic; small glide | 0 | 698 (EPA TT basis) | A2L | High | Residential/light-commercial A/C, heat pumps, chillers in equipment designed for A2L refrigerants | Current lower-GWP R-410A alternative in specified end uses, subject to SNAP use conditions, listings, and code requirements. | POE commonly specified; OEM controls | Charge liquid. Use A2L-compatible equipment/tools; dew for superheat and bubble for subcooling. | High-pressure stationary -> Type II unless small appliance -> Type I | A2L ignition-source, ventilation, leak-detection, tool, and recovery-equipment requirements must be respected. | 11.18 comfort A/C / A2L group |
| R-454A | R-32/R-1234yf = 35/65% by mass | HFC/HFO blend | Zeotropic; glide | 0 | 237 (EPA TT basis) | A2L | High | Commercial refrigeration and selected A/C/heat-pump applications designed for A2L refrigerants | Current low-GWP A2L alternative in specified end uses; use conditions and equipment standards apply. | POE common; OEM controls | Charge liquid. Superheat -> dew; subcooling -> bubble. Follow A2L service requirements. | High-pressure stationary -> Type II unless small appliance -> Type I | Low GWP does not mean nonflammable. Do not use A1 procedures/tools automatically. | 11.18 A2L refrigeration/AC group |
| R-454B | R-32/R-1234yf = 68.9/31.1% by mass | HFC/HFO blend | Zeotropic; small glide | 0 | 465 (EPA TT basis) | A2L | High | Major current residential/light-commercial A/C and heat-pump replacement path for R-410A in newly designed equipment | Current lower-GWP A2L alternative in specified new equipment; SNAP use conditions, listing standards, codes, and Technology Transitions rules apply. | POE commonly specified; OEM controls | Charge liquid. Dew for superheat; bubble for subcooling. Use A2L-rated recovery/service equipment. | High-pressure stationary -> Type II unless small appliance -> Type I | Do not retrofit R-410A equipment merely by changing refrigerant. A2L design, charge limits, components, sensors, and service procedures can differ. | 11.18 comfort A/C / A2L group |
| R-454C | R-32/R-1234yf = 21.5/78.5% by mass | HFC/HFO blend | Zeotropic; glide | 0 | 146 (EPA TT basis) | A2L | High | Low- and medium-temperature commercial refrigeration; selected A2L equipment | Very-low-GWP A2L blend for specified applications; end-use SNAP/use-condition and equipment standards control. | POE common; OEM controls | Charge liquid. Dew for superheat; bubble for subcooling. | High-pressure stationary -> Type II unless small appliance -> Type I | A2L flammability plus blend glide. Verify charge limits, ventilation, ignition controls, and tool suitability. | 11.18 A2L commercial-refrigeration group |
| R-455A | R-32/R-1234yf/R-744 = 21.5/75.5/3.0% by mass | HFC/HFO/CO2 blend | Zeotropic; substantial glide | 0 | 146 (EPA TT basis) | A2L | High | Commercial refrigeration, condensing units, cold storage, ice machines, refrigerated transport | Very-low-GWP A2L alternative in specified refrigeration end uses; use conditions and equipment standards apply. | POE commonly specified; OEM controls | Charge liquid. Significant glide: dew for superheat, bubble for subcooling. | High-pressure stationary/cargo refrigeration -> Type II unless small appliance -> Type I | Significant glide and A2L flammability. Component sizing/pressure-drop behavior can differ materially from R-404A. | 11.18 A2L commercial-refrigeration group |
| R-513A | R-134a/R-1234yf = 44/56% by mass | HFC/HFO blend | Azeotropic designation; negligible/very small practical glide; use manufacturer P-T data | 0 | 630 (EPA TT basis) | A1 | Medium | Chillers, commercial refrigeration, vending, dehumidification and R-134a replacement applications | Lower-GWP A1 alternative to R-134a in compatible equipment; Technology Transitions and SNAP status are end-use specific. | POE common; OEM controls | Azeotropic blend; follow manufacturer charging and P-T data; controlled liquid transfer is commonly used for blend charging. | Stationary medium-pressure -> Type II unless small appliance -> Type I | A1 makes service transition easier than A2L alternatives, but it is not a universal drop-in R-134a replacement. | 11.18 medium-pressure / chiller-refrigeration group |
| R-514A | R-1336mzz(Z)/R-1130(E) = 74.7/25.3% by mass | HFO/HCO blend | Azeotropic designation; negligible/very small practical glide; use manufacturer P-T data | ~0.00006; very low nonzero | 3 (EPA TT basis) | B1 | Low | Low-pressure centrifugal chillers; replacement path for R-123 in compatible new/converted equipment | Current very-low-GWP low-pressure alternative in applicable chiller designs. | OEM-specific chiller lubricant | Azeotropic low-pressure blend; use OEM P-T data and the approved low-pressure recovery/charging procedure. | Low-pressure chiller -> Type III | B1 higher-toxicity classification. Very low GWP does not mean zero hazard; low-pressure air/moisture ingress remains important. | 11.18 low-pressure/chiller group |
| R-515B | R-1234ze(E)/R-227ea = 91.1/8.9% by mass | HFO/HFC blend | Azeotropic designation; negligible/very small practical glide; use manufacturer P-T data | 0 | 287 (EPA TT basis) | A1 | Medium | Chillers and selected medium-temperature applications requiring an A1 lower-GWP option | Current lower-GWP A1 alternative in specified applications. | POE/OEM-specific chiller lubricant | Azeotropic blend; follow manufacturer charging and P-T data rather than assuming pure-fluid behavior under every condition. | Stationary medium-pressure -> Type II unless small appliance -> Type I | Do not confuse chiller application with Type III automatically; pressure category, not the word ‘chiller,’ controls. | 11.18 medium-pressure/chiller group |
| R-1234yf | 2,3,3,3-Tetrafluoroprop-1-ene, CF3CF=CH2 | HFO | Pure; no glide | 0 | 1 (EPA TT basis) | A2L | Medium | Modern MVAC; selected refrigeration applications and blend component | Current very-low-GWP alternative, especially in MVAC; application/use conditions and equipment design control. | PAG common in MVAC; POE or other OEM-specified lubricant in stationary equipment | Single saturation relationship. Use A2L-compatible service procedures and the exact vehicle/equipment specification. | MVAC passenger-compartment service -> Section 609; stationary medium-pressure -> Type II unless small appliance -> Type I | Major 608/609 boundary example. A2L flammability and unique fittings/service equipment matter in MVAC. | 11.18 HFO/MVAC-medium-pressure group |
| R-1234ze(E) | trans-1,3,3,3-Tetrafluoroprop-1-ene, trans-CF3CH=CHF | HFO | Pure; no glide | 0 | 1 (EPA TT basis) | A2L | Medium | Chillers, heat pumps, medium-temperature refrigeration, blend component | Current very-low-GWP HFO used in equipment designed for its pressure/capacity and A2L characteristics. | POE commonly used; OEM controls | Single saturation relationship; A2L service procedures apply. | Stationary medium-pressure -> Type II unless small appliance -> Type I | Lower pressure/capacity characteristics differ from R-134a; do not treat as a pressure-equivalent drop-in. | 11.18 HFO/chiller-medium-pressure group |
| R-1233zd(E) | trans-1-Chloro-3,3,3-trifluoroprop-1-ene, trans-CHCl=CHCF3 | HCFO | Pure; no glide | <0.0004; very low nonzero | 4 (EPA TT basis) | A1 | Low | Low-pressure centrifugal chillers and specialty heat-transfer/ORC applications | Current very-low-GWP/very-low-ODP chiller alternative in compatible equipment. | OEM-specific chiller lubricant | Single saturation relationship. Low-pressure/absolute-pressure procedures are important. | Low-pressure chiller -> Type III | Contains chlorine and has a very small nonzero ODP; do not label it simply ‘zero ODP.’ Low-pressure air/moisture ingress remains important. | 11.18 low-pressure/chiller group |
| R-1336mzz(Z) | cis-1,1,1,4,4,4-Hexafluoro-2-butene, CF3CH=CHCF3 | HFO | Pure; no glide | 0 | 2 (EPA TT basis) | A1 | Low | Specialty chillers, high-temperature heat pumps/ORC and blend component in R-514A | Current very-low-GWP specialty refrigerant/working fluid in compatible designs. | OEM-specific lubricant | Single saturation relationship; low-pressure behavior in applicable chiller/ORC systems. | Low-pressure stationary refrigerant context -> Type III when appliance falls within Section 608 low-pressure scope | Specialty fluid. Use manufacturer-specific property data; do not substitute R-514A blend data for pure R-1336mzz(Z). | 11.18 low-pressure/specialty HFO group |
| R-290 | Propane, C3H8 | Hydrocarbon | Pure; no glide | 0 | 3.3 (EPA TT basis) | A3 | High | Stand-alone retail-food refrigeration, household refrigeration, self-contained room A/C/heat pumps, vending, ice machines, water coolers, very-low-temperature equipment, refrigerated food processing/dispensing, and other specifically approved uses | Current very-low-GWP natural refrigerant in specified applications, subject to charge limits, listings, SNAP use conditions, and codes. | Mineral oil, alkylbenzene, or POE depending compressor/OEM | Single saturation relationship. Use hydrocarbon-rated tools/procedures; exact charge mass is critical. | Many common listed R-290 end uses are exempt from Section 608 Subpart F under §82.154(a)(1)(viii); hydrocarbon industrial-process refrigeration used in processing hydrocarbons is also exempt under §82.154(a)(1)(vi). For a non-exempt use, determine certification from the appliance/activity and applicable pressure class. | A3 highly flammable. Control ignition sources and use equipment specifically designed/listed for R-290; never improvise with ordinary tools. | 11.18 natural-refrigerant group |
| R-600a | Isobutane (2-methylpropane), i-C4H10 | Hydrocarbon | Pure; no glide | 0 | 1 (EPA TT basis) | A3 | Medium | Household refrigerators/freezers, stand-alone retail-food refrigerators/freezers, vending machines, and other specifically approved equipment | Current very-low-GWP natural refrigerant in specifically designed/listed equipment. | Mineral oil or POE commonly used depending compressor/OEM | Single saturation relationship. Very small charge masses are common; use hydrocarbon-rated tools and exact weighing. | The common R-600a household, stand-alone retail-food, and vending-machine end uses listed in §82.154(a)(1)(ix) are exempt from Section 608 Subpart F. For a non-exempt use, determine certification from the appliance/activity and applicable pressure class. | A3 highly flammable. Small charge does not remove ignition risk; follow SNAP use conditions, listing/code requirements, and manufacturer-approved service procedures. | 11.18 natural-refrigerant group |
| R-717 | Ammonia, NH3 | Natural inorganic refrigerant | Pure; no glide | 0 | 1 (EPA TT reference basis) | B2L | High | Industrial refrigeration, cold storage, food processing, ice rinks, and ammonia absorption systems | Current high-efficiency natural refrigerant with long-established industrial use; code/training requirements are substantial. | Mineral, PAO, PAG or other system-specific lubricant depending compressor/design | Single saturation relationship. Use ammonia-dedicated materials, tools and procedures. | Ammonia in commercial or industrial process refrigeration and in absorption units is exempt from Section 608 Subpart F under §82.154(a)(1)(iv). For an unusual non-exempt application, determine certification from the actual appliance/activity. | B2L combines higher toxicity and lower flammability. Copper/copper alloys are generally unsuitable for ammonia refrigerant piping; emergency planning, ventilation, materials compatibility, and site procedures are critical. | 11.18 natural-refrigerant/ammonia group |
| R-744 | Carbon dioxide, CO2 | Natural inorganic refrigerant | Pure; no glide | 0 | 1 (reference gas) | A1 | Very high | Transcritical/subcritical supermarket refrigeration, heat pumps, transport refrigeration, and some MVAC systems | Current ultra-low-GWP natural refrigerant with growing use in compatible high-pressure systems. | POE/PAG or other CO2-specific lubricant depending compressor/OEM | Below critical temperature a saturation relationship exists; above ~87.8°F critical temperature there is no liquid-vapor saturation line and transcritical systems use a gas cooler. | CO2 is exempt from Section 608 Subpart F in any application under §82.154(a)(1)(i). Passenger-compartment MVAC service remains subject to the separate Section 609 framework and its applicable requirements. | Very high pressure is the dominant service hazard. Dry ice can form during rapid depressurization; use CO2-rated components and procedures. | 11.18 R-744 special transcritical group |
| R-718 | Water, H2O | Natural inorganic refrigerant | Pure; no glide | 0 | 0 | A1 | Low | Absorption/adsorption chillers and vacuum refrigeration concepts; not a conventional direct-expansion field refrigerant | Natural zero-ODP/zero-GWP refrigerant used in specialized systems. | System-specific; absorption systems do not use the same compressor/lubricant arrangement as ordinary vapor-compression systems | Very low vapor pressure; vacuum-system concepts dominate. | Water is exempt from Section 608 Subpart F in any application under §82.154(a)(1)(iii). | Do not use water-refrigerant behavior as a model for halocarbon service. Vacuum integrity and system chemistry are application-specific. | 11.18 natural/low-pressure specialty group |
Notes on Values and Terminology
GWP: Values in the table are 100-year values on the stated EPA reference basis. Because regulatory programs can specify a particular GWP source/method, a different historical document may display a different numerical GWP for the same refrigerant. For this course, the value and basis shown in this table control unless a later verified course revision replaces it.
Calculated legacy blends: R-500 GWP/ODP and R-502 ODP are approximate composition-weighted teaching values. R-502 GWP is rounded to the EPA legacy value of approximately 4,660. R-407A and R-407F GWP values are composition-weighted from the component AR4 values used by the course. These calculated values are provided for comparison, not as a substitute for a regulatory program’s specified GWP table.
Pressure category: Current §82.152 definitions use the refrigerant’s liquid-phase saturation pressure at 104°F (40°C), with a separate critical-temperature criterion for very-high-pressure appliances. The regulatory thresholds are stated in psia, not psig. In this table the column is a thermodynamic classification using those thresholds. It does not, by itself, establish that Subpart F applies to an exempt substitute/end use.
Safety class: The first letter indicates toxicity class and the number/2L designation indicates flammability class under Standard 34. The current course uses the current A2L reclassification for refrigerants such as R-32 and R-143a rather than older A2 listings.
Blend behavior: R-400-series refrigerants are generally zeotropic blends. Some have sufficiently small glide to be described as near-azeotropic in practical service. R-500-series designations are azeotropic blends. Always use the actual manufacturer P-T data rather than relying only on the series number.
Current/legacy status: “Legacy” does not mean that every existing appliance is illegal to operate. It generally means the refrigerant is associated with older equipment, ODS phaseout, high-GWP transition, or older end-use designs. Existing-equipment service, recovered/reclaimed refrigerant, and end-use restrictions must be evaluated under the current applicable rule.
Trade names: Trade names are intentionally omitted from the master table because multiple suppliers may sell the same ASHRAE-designated refrigerant and trade names can change. Identify the refrigerant by its R-number, cylinder/product label, SDS, and equipment documentation.
References
Current Regulatory and EPA Sources
-
Electronic Code of Federal Regulations, 40 CFR §82.152 - Definitions, current version accessed August 14, 2026.
https://www.ecfr.gov/current/title-40/chapter-I/subchapter-C/part-82/subpart-F/section-82.152 -
U.S. Environmental Protection Agency, Technology Transitions GWP Reference Table, accessed August 14, 2026.
https://www.epa.gov/hfcs/technology-transitions-gwp-reference-table -
U.S. Environmental Protection Agency, Ozone-Depleting Substances, accessed August 14, 2026.
https://www.epa.gov/ozone-layer-protection/ozone-depleting-substances -
U.S. Environmental Protection Agency, Phaseout of Ozone-Depleting Substances, accessed August 14, 2026.
https://www.epa.gov/ods-phaseout -
U.S. Environmental Protection Agency, Technology Transitions HFC Restrictions by Sector, accessed August 14, 2026.
https://www.epa.gov/hfcs/technology-transitions-hfc-restrictions-sector -
U.S. Environmental Protection Agency, Significant New Alternatives Policy (SNAP) refrigeration and air-conditioning substitute listings, current pages accessed August 14, 2026.
https://www.epa.gov/snap/substitutes-refrigeration-and-air-conditioning -
U.S. Environmental Protection Agency, Acceptable Refrigerants and their Impacts - MVAC, last updated April 28, 2026; accessed August 14, 2026.
https://www.epa.gov/mvac/acceptable-refrigerants-and-their-impacts
Current Safety-Classification Source
-
ASHRAE, ANSI/ASHRAE Standard 34-2024 - Designation and Safety Classification of Refrigerants, with current published addenda, verification basis August 14, 2026.
https://www.ashrae.org/technical-resources/standards-and-guidelines -
ASHRAE, Refrigerant Designations, composition/designation reference used together with the current Standard 34/addenda.
https://www.ashrae.org/technical-resources/standards-and-guidelines/ashrae-refrigerant-designations
Property / P-T Cross-Check Sources
-
Arkema, Forane Refrigerants Pressure Temperature Chart, 2025 edition, accessed August 14, 2026. The chart states that its data were generated using NIST REFPROP Version 10.0.
https://forane.arkema.com/files/live/sites/shared_arkema/files/downloads/fluorochemicals/Forane%20Ref%20PT%20Regular%20Chart%20EN -
National Institute of Standards and Technology, Thermophysical Properties of Fluid Systems / REFPROP context, accessed August 14, 2026.
https://webbook.nist.gov/chemistry/fluid/
Course Cross-References
-
11.4 - Refrigerant Pressure and Safety Classification Reference
-
11.18 - Common Refrigerant Pressure-Temperature Tables.md- full technician P-T tables when completed.