R-1336mzz(Z)
Pure HFO (cis-1,1,1,4,4,4-hexafluoro-2-butene) — A1 non-flammable, GWP 2, very low operating pressures. Chemours Opteon 1100. High-temperature heat pump and process refrigeration applications where high condensing temperatures matter.
Lower toxicity (Occupational Exposure Limit ≥ 400 ppm). No flame propagation in air at standard atmospheric pressure and 60°C. R-134a, R-22, R-410A, R-404A, R-744 (CO2) are A1.
- Flammability
- None (no flame propagation)
- Toxicity
- Lower (OEL ≥ 400 ppm)
Classification per ANSI/ASHRAE Standard 34-2022. See full reference.
Saturation pressure-temperature curve
No PT chart in this build — published primary source exists. A published Helmholtz equation of state exists for R-1336mzz(Z)(cited below), but is not implemented in this site's CoolProp 7.2.0 WASM build. The site never fabricates values to fill gaps; values would need to be computed by transcribing the published Wagner-form ancillary equation coefficients into the dataset. For service work, refer directly to the cited primary source.
- peer-reviewed-eosTanaka, K., Higashi, Y., et al. (2020), "Thermodynamic Properties of cis-1,1,1,4,4,4-Hexafluorobutene [R-1336mzz(Z)]: Vapor Pressure, (p, ρ, T) Behavior, and Speed of Sound Measurements and Equation of State", Journal of Chemical & Engineering Data 65(2).Fundamental Helmholtz EOS with vapor pressure ancillary equation. Valid across the operating range for chiller/HTHP applications.https://pubs.acs.org/doi/10.1021/acs.jced.9b01198
- manufacturer-datasheetChemours Opteon 1100 (R-1336mzz(Z)) Technical Information.https://www.opteon.com/en/products/stationary-refrigerants/1100
At a glance
Chemistry
Lubricant compatibility
Very low GWP HFO designed for high-temperature heat pumps, organic Rankine cycle, and foam blowing. Higher NBP than R-1234ze(E).
Trade names
- Opteon 1100Chemours
Common applications
- High-temperature heat pumps (industrial)
- Organic Rankine cycle working fluid
- Foam blowing agent (polyurethane insulation)
- Centrifugal chillers (low-pressure)
Properties
- Boiling point (1 atm)33.4°C / 92.1°F
- Critical point340.3°F at 400 PSIG
- Molar mass164.06 g/mol
- Temperature glideNegligible (0.00°F)
- ODP0
- GWP (AR5, 100-yr)2
- GWP (AR6, 100-yr)18
- Atmospheric lifetime0.07 years
What is R-1336mzz(Z)?
R-1336mzz(Z) is a pure HFO (4-carbon hydrofluoroolefin) with a higher boiling point and lower vapor pressure than other HFO refrigerants [ashrae34]. The molecular structure (CF₃CH=CHCF₃, Z isomer) places it in a unique niche for high-temperature heat pump and very-low-pressure refrigeration applications where the high normal boiling point (92°F) and A1 safety class are operational advantages.
R-1336mzz(Z) was developed by Chemours as Opteon 1100, targeting industrial heat pump and high-temperature process refrigeration applications. The high NBP means very low operating pressures even at typical condensing temperatures — chillers and heat pumps using R-1336mzz(Z) often operate at sub-atmospheric pressure on the evaporator side.
Where R-1336mzz(Z) is used
- High-temperature industrial heat pumps (process heating applications, up to 150°C delivery temperatures)
- Very low-pressure centrifugal chillers
- Foam blowing agent in polyurethane insulation
- Organic Rankine Cycle (ORC) waste-heat recovery applications
Regulatory & phase-down status
R-1336mzz(Z) faces no phase-down pressure — GWP 2 is below every regulatory threshold. R-1336mzz(Z) is structurally a long-term destination refrigerant for high-temperature heat pump and specialty very-low-pressure applications.
EPA SNAP has approved R-1336mzz(Z) for industrial heat pump applications [snap]. The refrigerant is increasingly specified for new high-temperature heat pump equipment installations as the technology matures.
Service notes
Lubricant choice depends on equipment OEM — POE, PVE, or PAG depending on specific compressor design [ahri700]. Verify against equipment service literature.
Very-low operating pressures mean sub-atmospheric operation on the evaporator side is common. Equipment-OEM service procedures address purge unit operation, vacuum integrity, and the specific service considerations for low-pressure refrigeration systems.
Phase-down timeline
R-1336mzz(Z) is not subject to AIM Act or EU F-Gas phase-down regulation. With a 100-year GWP of 2 (HFO) and zero ozone-depletion potential, it sits below both the EU F-Gas 150 GWP cap and the EPA AIM Act 700 GWP cap. No phase-down schedule applies — it is one of the refrigerants chosen for the transition away from high-GWP HFCs.
Global warming potential, in context
Low-pressure centrifugal chillers
Retrofit and replacement paths
R-1336mzz(Z) replaces
Reading the R-1336mzz(Z) PT chart — very low pressures, sub-atmospheric on evaporator
R-1336mzz(Z)'s PT chart shows very low operating pressures across the typical heat pump and refrigeration range. At 70°F R-1336mzz(Z) saturation is approximately −2 PSIG (slightly sub-atmospheric); at typical chiller evaporator temperatures (45°F), saturation is well into vacuum. At condensing temperatures (120-150°F for high-temperature heat pumps), saturation reaches 30-60 PSIG.
Single saturation curve (pure refrigerant, no glide). The operating envelope is unique among mainstream refrigerants — substantially lower than R-134a, comparable to R-123 / R-1233zd(E) for low-pressure chiller applications.
Sub-atmospheric operation requires careful equipment design — air ingress through any leak causes refrigerant contamination with non-condensables. R-1336mzz(Z) systems include purge units, vacuum-rated isolation valves, and leak-detection systems specific to vacuum-operation refrigeration. Service technicians need OEM-specific training for these systems.
Four-carbon HFO structure for high boiling point
R-1336mzz(Z) is a 4-carbon hydrofluoroolefin (CF₃CH=CHCF₃, Z isomer). The 4-carbon backbone with central carbon-carbon double bond and terminal trifluoromethyl groups produces the molecule's distinctive properties: high normal boiling point (92°F), low vapor pressure across the operating range, A1 safety classification.
The molecular weight (164 g/mol) is the highest among mainstream HFO refrigerants — substantially higher than R-1234yf (114 g/mol) or R-1234ze (114 g/mol). The heavier molecule produces lower vapor density at any given pressure, contributing to the very low operating pressure envelope.
High boiling point enables high-temperature heat pump applications
R-1336mzz(Z)'s 92°F normal boiling point is the key feature for high-temperature heat pump applications. At typical industrial process heating delivery temperatures (100-150°C / 212-302°F), R-1336mzz(Z) operates at moderate condensing pressures (30-60 PSIG) — within compressor design tolerances.
For comparison, R-134a or R-410A at the same condensing temperatures would operate at very high pressures — well above standard equipment design ratings or requiring transcritical operation. R-1336mzz(Z) extends the temperature range of practical vapor-compression heat pumps significantly above conventional HFC refrigerants.
This makes R-1336mzz(Z) the enabling refrigerant for industrial decarbonization applications where heat pumps replace natural-gas-fired process heating. The EU REPowerEU initiative and US Inflation Reduction Act industrial efficiency provisions both drive growth in this segment through 2025-2035.
GWP 2 — among the lowest commercial refrigerants
R-1336mzz(Z)'s GWP of 2 (IPCC AR5) places it in the very-low tier alongside R-744 (1), R-1234ze (7), R-1234yf (4), R-290 (3) [ipccar5]. The combination of very-low GWP and A1 safety classification gives R-1336mzz(Z) excellent regulatory positioning for the foreseeable future.
EPA SNAP has approved R-1336mzz(Z) for high-temperature heat pump applications [snap]. EU F-Gas Regulation provides clear positioning under all current thresholds. No phase-down risk through any plausible future regulatory scenario.
How to think about R-1336mzz(Z) in 2026 and beyond
R-1336mzz(Z) occupies a specialty niche in 2026 — industrial high-temperature heat pumps and specialty low-pressure refrigeration. Market growth is significant as industrial decarbonization initiatives accelerate.
For technicians, R-1336mzz(Z) work is unusual — very low operating pressures, vacuum operation on the evaporator side, equipment-OEM-specific service procedures. The refrigerant ecosystem is smaller than mainstream HFCs; service expertise is concentrated in OEM-trained networks rather than general HVAC service technicians.
For equipment specifiers, R-1336mzz(Z) is increasingly the choice for industrial high-temperature heat pumps where conventional HFC refrigerants don't reach the required delivery temperatures efficiently. The application growth is driven by industrial decarbonization economics and regulatory pressure on fossil-fuel-fired process heating.
Frequently asked
›What is R-1336mzz(Z) used for?
High-temperature industrial heat pumps and specialty low-pressure chillers. Chemours markets the refrigerant as Opteon 1100 [chemoursopteon]. The high boiling point (92°F) suits applications where typical refrigerant operating temperatures fall in ranges other refrigerants can't reach efficiently — industrial process heating, ORC waste-heat recovery, high-condensing-temperature heat pumps.
›What's R-1336mzz(Z)'s GWP?
2 per IPCC AR5 — very low [ipccar5]. The short atmospheric lifetime drives the low GWP. R-1336mzz(Z) sits in the same low-GWP tier as R-744 (CO₂), R-1234yf, R-1234ze.
›Why does R-1336mzz(Z) have such high boiling point?
The 4-carbon molecular structure produces lower vapor pressure than smaller HFOs like R-1234yf or R-1234ze. The higher molecular weight (164 g/mol vs R-1234yf's 114) and the specific molecular geometry both contribute to the higher NBP (92°F vs R-1234yf's −21°F).
›Is R-1336mzz(Z) flammable?
No — ASHRAE class A1 (non-toxic, non-flammable) [ashrae34]. The 4-carbon HFO structure is large enough that combustion in air is not sustained under normal conditions.
›What lubricant does R-1336mzz(Z) use?
Equipment-OEM dependent — POE, PVE, or PAG depending on compressor design [ahri700]. Verify against equipment service literature for the specific application.
›What is Opteon 1100?
Chemours' trade name for R-1336mzz(Z) [chemoursopteon]. Chemours is the primary commercial manufacturer.
›Where will R-1336mzz(Z) grow in the future?
Industrial high-temperature heat pumps are the primary growth area as the EU and global industrial decarbonization initiatives accelerate. R-1336mzz(Z) enables electric-driven heat pump replacement of natural-gas-fired industrial process heating in applications up to ~150°C delivery temperature. Demand will grow significantly through the 2025-2035 decade.
Sources & citations
- [1]ASHRAE Standard 34-2022
- [2]IPCC AR5 (2014) Working Group I, Chapter 8, Table 8.A.1
- [3]CoolProp 7.2.0
- [4]EPA SNAP — R-1336mzz(Z) acceptable for high-temperature heat pumps
- [5]AHRI Standard 700-2019
- [6]Chemours Opteon 1100 (R-1336mzz(Z)) Product Data Sheet