R-1233zd(Z)
Pure HFO — the cis (Z) isomer of 1-chloro-3,3,3-trifluoro-1-propene. Substantially less common than the E-isomer (R-1233zd(E), Honeywell Solstice zd). Specialty applications only: select foam blowing and research/heat-transfer use. Not used in conventional HVAC.
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 commercial PT chart published for this refrigerant. No published commercial PT chart exists for R-1233zd(Z). The site never fabricates values. See the citation below for the closest related commercial refrigerant where applicable.
- isomer-noteASHRAE Standard 34-2022 distinguishes R-1233zd(E) (commercial, in Solstice ZD chillers) from R-1233zd(Z) (cis-isomer, research-only).https://www.ashrae.org/technical-resources/standards-and-guidelines
- isomer-equivalentFor commercial PT chart data of R-1233zd, see the (E)-isomer entry: Hulse, R.J. et al. (2012), "Physical Properties of HCFO-1233zd(E)", J. Chem. Eng. Data 57(12), 3581-3586. doi:10.1021/je300776s.https://pubs.acs.org/doi/10.1021/je300776s
- research-measurementLimited measurements for R-1233zd(Z) appear in molecular-simulation and isomerization-equilibrium research literature; no commercial PT chart has been published as of 2026.
At a glance
Chemistry
Lubricant compatibility
Z-isomer of R-1233zd. Less common than the E-isomer; specialty foam blowing agent and low-GWP heat-transfer fluid applications.
Common applications
- Foam blowing agent (specialty applications)
- Heat-transfer fluid (research/specialty)
Properties
- Molar mass130.50 g/mol
- Temperature glideNegligible (0.00°F)
- ODP—
- GWP (AR5, 100-yr)—
What is R-1233zd(Z)?
R-1233zd(Z) is the cis isomer of 1-chloro-3,3,3-trifluoro-1-propene (CF₃CH=CHCl). The E-isomer (R-1233zd(E)) is the commercially dominant form — sold as Honeywell Solstice zd and used as a low-pressure centrifugal chiller refrigerant and foam blowing agent. The Z-isomer is rare in HVAC applications; it exists primarily as a research compound and in select specialty foam-blowing applications where its slightly different volatility profile is useful.
For the common form of this refrigerant family — the commercially deployed one in centrifugal chillers — see the R-1233zd(E) page.
Where R-1233zd(Z) is used
- Specialty foam blowing applications
- Research and small-scale heat transfer fluid applications
- Not used in HVAC chillers or refrigeration
Regulatory & phase-down status
R-1233zd(Z) is not subject to any active phase-down. Its commercial volume is too small to be regulatory-significant. No SNAP or AIM Act listing applies in HVAC contexts.
Service notes
R-1233zd(Z) is not a service refrigerant. Reference data on this page is for completeness. Field technicians who encounter equipment labeled "R-1233zd" should verify the isomer — the (E) form is the chiller refrigerant; encountering the (Z) form in HVAC equipment is unusual and should prompt verification of the equipment specification.
Phase-down timeline
R-1233zd(Z) is not currently regulated by AIM Act or EU F-Gas phase-down. Its very low GWP (<1) places it below regulatory thresholds. No published phase-down milestones exist for this refrigerant — it is a forward-compatible option for the current low-GWP transition rather than a refrigerant being phased out.
Global warming potential, in context
No peer-comparison group is defined for R-1233zd(Z). The refrigerant's GWP is not published in this dataset.
Peer-comparison groups are defined for refrigerants that compete in the same application sector (residential AC, commercial MT/LT, chillers, mobile AC). Specialty or research-grade refrigerants without a clear peer set don't appear in any group; their GWP is shown above in absolute terms instead.
Frequently asked
›Is R-1233zd(Z) used in any commercial refrigeration or HVAC equipment?
Not in any significant commercial deployment. The commercially used 1-chloro-3,3,3-trifluoro-1-propene is the E-isomer (R-1233zd(E), Honeywell Solstice zd) used in low-pressure centrifugal chillers as a long-term R-123 replacement. The Z-isomer is specialty only.
›What's the difference between R-1233zd(E) and R-1233zd(Z)?
Geometric isomerism around the carbon-carbon double bond. The E-isomer (trans) is the commercially relevant form for HVAC applications; it has the right pressure envelope for low-pressure centrifugal chillers replacing R-123 and is sold by Honeywell as Solstice zd. The Z-isomer (cis) has different physical properties and is not used as a chiller refrigerant. Both are HFOs with very low GWP and zero ozone-depletion potential.
›Should I be concerned if I see R-1233zd(Z) on a refrigerant cylinder?
Verify the specification with the equipment OEM. Most "R-1233zd" cylinders are the E-isomer. A cylinder labeled R-1233zd(Z) is unusual for HVAC service — either it's a specialty industrial application (verify with the system designer) or there's a labeling error worth confirming.