RefrigerantASHRAE R-1233zd(E)

R-1233zd(E)

A1Non-flammableHFO (pure)

CF3CH=CHCl (E isomer)

Hydrochlorofluoroolefin (HCFO) — A1 non-flammable, GWP 1, near-zero ODP. The low-pressure replacement for R-123 in centrifugal chillers. Honeywell Solstice zd; very low operating pressures (sub-atmospheric on chiller evaporator).

Saturation @ 70°F

1.6PSIG

GWP (IPCC AR5)

1100-yr

Temperature glide

≈0°F

Boiling point

64.9°F

Sourced facts

ASHRAE safety class: A1[src]
Chemical formula: CF₃CH=CHCl (E)[src]
GWP (100-yr): 1IPCC AR5[src]
ODP: 0.00034[src]
Normal boiling point: 64.9°F (18.3°C)[src]
Temperature glide: 0°F[src]
Required lubricant: POE[src]
Trade name: Solstice zd[src]

R-1233zd(E) PT calculator Superheat

Non-flammable

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

Pressure

Temperature

Highlight at°F

Quick lookup — R-1233zd(E)

Temp:°F

1.6PSIG(11 kPa)

Range: -40 to 150°FOpen full PT calculator →

Common service temperatures

32°F

-8PSIG

Freezing

45°F

-5PSIG

Heat-pump heat

70°F

2PSIG

Standard

75°F

3PSIG

Test ref

80°F

5PSIG

Warm

95°F

12PSIG

Summer peak

Saturation values from CoolProp 7.2.0 R1233zd(E). Operating pressure on a running system differs — see the operating-pressure references for in-use values.

R-1233zd(E) PT chart PDF — printable saturation table

Looking for the R-1233zd(E) PT chart PDF for shop reference? The complete pressure-temperature saturation table is below — every 1° increment from −40°F to 150°F (or to the refrigerant's critical temperature). Use the Print / Save as PDF button in the table header to download a clean, table-only PDF (the rest of the page is hidden from the print output). Important service temperatures (normal boiling point, freezing point of water, residential AC evap and condenser targets) are tinted and tagged in the table for at-a-glance shop reference.

R-1233zd(E) PT Chart — Pressure-Temperature Saturation Table

1° increments · Source: CoolProp 7.2.0 / manufacturer datasheet · hvacptcharts.com

R-1233zd(E) · 1° increments · °F / PSIG

Tinted rows: NBP atmospheric crossover · 32°F H₂O freeze · 40°F Chiller evap LCHW · 100°F Cond saturation · 130°F High-side limit

R-1233zd(E) pressure-temperature saturation table in Fahrenheit and PSIG
Temp (°F)	Pressure (PSIG)
-40°F	-13.9
-39°F	-13.8
-38°F	-13.8
-37°F	-13.8
-36°F	-13.7
-35°F	-13.7
-34°F	-13.7
-33°F	-13.6
-32°F	-13.6
-31°F	-13.6
-30°F	-13.5
-29°F	-13.5
-28°F	-13.4
-27°F	-13.4
-26°F	-13.4
-25°F	-13.3
-24°F	-13.3
-23°F	-13.2
-22°F	-13.2
-21°F	-13.1
-20°F	-13.1
-19°F	-13.0
-18°F	-13.0
-17°F	-12.9
-16°F	-12.8
-15°F	-12.8
-14°F	-12.7
-13°F	-12.7
-12°F	-12.6
-11°F	-12.5
-10°F	-12.5
-9°F	-12.4
-8°F	-12.3
-7°F	-12.3
-6°F	-12.2
-5°F	-12.1
-4°F	-12.0
-3°F	-12.0
-2°F	-11.9
-1°F	-11.8
0°F	-11.7
1°F	-11.6
2°F	-11.5
3°F	-11.4
4°F	-11.3
5°F	-11.3
6°F	-11.2
7°F	-11.1
8°F	-11.0
9°F	-10.8
10°F	-10.7
11°F	-10.6
12°F	-10.5
13°F	-10.4
14°F	-10.3
15°F	-10.2
16°F	-10.1
17°F	-9.9
18°F	-9.8
19°F	-9.7
20°F	-9.5
21°F	-9.4
22°F	-9.3
23°F	-9.1
24°F	-9.0
25°F	-8.8
26°F	-8.7
27°F	-8.5
28°F	-8.4
29°F	-8.2
30°F	-8.1
31°F	-7.9
32°FH₂O freeze	-7.7
33°F	-7.5
34°F	-7.4
35°F	-7.2
36°F	-7.0
37°F	-6.8
38°F	-6.6
39°F	-6.4
40°FChiller evap LCHW	-6.2
41°F	-6.0
42°F	-5.8
43°F	-5.6
44°F	-5.4
45°F	-5.2
46°F	-5.0
47°F	-4.8
48°F	-4.5
49°F	-4.3
50°F	-4.1
51°F	-3.8
52°F	-3.6
53°F	-3.3
54°F	-3.1
55°F	-2.8
56°F	-2.5
57°F	-2.3
58°F	-2.0
59°F	-1.7
60°F	-1.4
61°F	-1.2
62°F	-0.9
63°F	-0.6
64°F	-0.3
65°FNBP (atmospheric)	0.0
66°F	0.3
67°F	0.7
68°F	1.0
69°F	1.3
70°F	1.6
71°F	2.0
72°F	2.3
73°F	2.7
74°F	3.0
75°F	3.4
76°F	3.8
77°F	4.1
78°F	4.5
79°F	4.9
80°F	5.3
81°F	5.7
82°F	6.1
83°F	6.5
84°F	6.9
85°F	7.3
86°F	7.7
87°F	8.2
88°F	8.6
89°F	9.1
90°F	9.5
91°F	10.0
92°F	10.4
93°F	10.9
94°F	11.4
95°F	11.9
96°F	12.4
97°F	12.9
98°F	13.4
99°F	13.9
100°FCond saturation	14.4
101°F	14.9
102°F	15.5
103°F	16.0
104°F	16.6
105°F	17.1
106°F	17.7
107°F	18.3
108°F	18.9
109°F	19.4
110°F	20.0
111°F	20.6
112°F	21.3
113°F	21.9
114°F	22.5
115°F	23.1
116°F	23.8
117°F	24.4
118°F	25.1
119°F	25.8
120°F	26.5
121°F	27.1
122°F	27.9
123°F	28.6
124°F	29.3
125°F	30.0
126°F	30.7
127°F	31.5
128°F	32.2
129°F	33.0
130°FHigh-side limit	33.8
131°F	34.5
132°F	35.3
133°F	36.1
134°F	36.9
135°F	37.8
136°F	38.6
137°F	39.4
138°F	40.3
139°F	41.1
140°F	42.0
141°F	42.9
142°F	43.8
143°F	44.7
144°F	45.6
145°F	46.5
146°F	47.4
147°F	48.4
148°F	49.3
149°F	50.3
150°F	51.3

R-1233zd(E) pressure-temperature saturation table in Celsius and kPa
Temp (°C)	Pressure (kPa)
-40°C	-96
-39°C	-95
-38°C	-95
-37°C	-94
-36°C	-94
-35°C	-94
-34°C	-93
-33°C	-93
-32°C	-92
-31°C	-91
-30°C	-91
-29°C	-90
-28°C	-90
-27°C	-89
-26°C	-88
-25°C	-87
-24°C	-87
-23°C	-86
-22°C	-85
-21°C	-84
-20°C	-83
-19°C	-82
-18°C	-81
-17°C	-80
-16°C	-79
-15°C	-78
-14°C	-76
-13°C	-75
-12°C	-74
-11°C	-72
-10°C	-71
-9°C	-69
-8°C	-68
-7°C	-66
-6°C	-65
-5°C	-63
-4°C	-61
-3°C	-59
-2°C	-57
-1°C	-55
0°CH₂O freeze	-53
1°C	-51
2°C	-49
3°C	-46
4°CChiller evap LCHW	-44
5°C	-42
6°C	-39
7°C	-36
8°C	-34
9°C	-31
10°C	-28
11°C	-25
12°C	-22
13°C	-19
14°C	-15
15°C	-12
16°C	-8
17°C	-5
18°CNBP (atmospheric)	-1
19°C	3
20°C	7
21°C	11
22°C	15
23°C	19
24°C	24
25°C	29
26°C	33
27°C	38
28°C	43
29°C	48
30°C	53
31°C	59
32°C	64
33°C	70
34°C	76
35°C	82
36°C	88
37°C	94
38°CCond saturation	101
39°C	107
40°C	114
41°C	121
42°C	128
43°C	136
44°C	143
45°C	151
46°C	159
47°C	167
48°C	175
49°C	183
50°C	192
51°C	201
52°C	210
53°C	219
54°CHigh-side limit	228
55°C	238
56°C	248
57°C	258
58°C	268
59°C	279
60°C	290
61°C	300
62°C	312
63°C	323
64°C	335
65°C	347

CoolProp 7.2.0 · PSIG/kPa = gauge · PSIA = PSIG + 14.696 · kPa(abs) = kPa(gauge) + 101.325

Full saturation values at 1° increments — toggle between °F / PSIG and °C / kPa. Use Print / Save as PDF for laminated shop reference, or download the CSV / JSON below for use in other tools. R-1233zd(E) PT chart data: CoolProp 7.2.0 (REFPROP-compatible Helmholtz EOS) or manufacturer datasheet, validated against AHRI Standard 700-2019.

At a glance

Chemistry

CF3CH=CHCl (E isomer)

(E)-1-Chloro-3,3,3-trifluoro-1-propene

Lubricant compatibility

POEPVEMO

Low-pressure HCFO with very low GWP and short atmospheric lifetime. Engineered as a long-term R-123 replacement.

Trade names

Solstice 1233zdHoneywell
Solstice LBAHoneywell

Common applications

Low-pressure centrifugal chillers
Foam blowing agent (polyurethane insulation)
Organic Rankine cycle working fluid

Properties

Boiling point (1 atm)
18.3°C / 64.9°F
Critical point
331.6°F at 511 PSIG
Molar mass
130.49 g/mol
Temperature glide
Negligible (0.00°F)
ODP
0.00034
GWP (AR5, 100-yr)
1
GWP (AR6, 100-yr)
4
Atmospheric lifetime
0.07 years

What is R-1233zd(E)?

R-1233zd(E) is a hydrochlorofluoroolefin (HCFO) — chemically related to HFOs but with one chlorine atom in the molecular structure. The compound is trans-1-chloro-3,3,3-trifluoro-1-propene [ashrae34]. The single chlorine gives R-1233zd(E) very small but non-zero ozone-depletion potential (0.00034) — far below R-22's 0.055, below Montreal Protocol de-minimis thresholds, but technically not zero.

R-1233zd(E) was developed by Honeywell as a near-drop-in replacement for R-123 in low-pressure centrifugal chillers. The pressure envelope closely matches R-123; the safety class (A1) is preserved; the GWP (1) is dramatically lower than R-123's 79.

Where R-1233zd(E) is used

Low-pressure centrifugal chiller R-123 replacement (Trane, others)
New low-pressure chiller equipment installations
High-temperature heat pumps (some applications)
Foam blowing agent in polyurethane insulation

Regulatory & phase-down status

R-1233zd(E)'s very-low ODP (0.00034) is below the de-minimis threshold most regulatory frameworks apply; the refrigerant is treated as effectively zero-ODP for practical purposes [montrealprotocol]. GWP 1 places it below every regulatory threshold.

R-1233zd(E) faces no meaningful phase-down pressure under EU F-Gas, EPA AIM Act, or Montreal Protocol HCFC schedules. It is the long-term low-GWP destination for low-pressure centrifugal chiller applications.

Service notes

POE oil typical for chiller applications [ahri700]. Verify against equipment OEM service literature for specific viscosity grade. A1 classification means no A2L procedures required.

R-1233zd(E) operates at very low pressures — sub-atmospheric on the evaporator side at typical chilled-water temperatures. Equipment is designed for sub-atmospheric operation with purge units to remove non-condensable atmospheric contamination.

Operating cycle

Phase-down timeline

R-1233zd(E) is not subject to AIM Act or EU F-Gas phase-down regulation. With a 100-year GWP of 1 (HFO) and low 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.

Properties: GWP (AR5) 1 · ODP 0.00034 · Not AIM Act-affected · type: hfo-pure

Global warming potential, in context

Low-pressure centrifugal chillers

Retrofit and replacement paths

R-1233zd(E) replaces

Reading the R-1233zd(E) PT chart — sub-atmospheric operation on the low side

R-1233zd(E)'s PT chart shows very low pressures across the chiller operating range. At 70°F R-1233zd(E) saturation is approximately 4 PSIG (CoolProp 7.2.0); at typical chiller evaporator temperatures (35-45°F), saturation is well below atmospheric pressure — the chiller evaporator runs at vacuum.

Single saturation curve (pure refrigerant, no glide). Standard 500 PSI manifold gauges have more than enough range; the operational concern is at the low end, where vacuum-rated gauges and procedures are needed.

Sub-atmospheric operation requires purge units

Low-pressure centrifugal chillers operating below atmospheric pressure on the evaporator face air ingress through any leak path. The chillers include purge units to remove non-condensable atmospheric contamination that accumulates over time. This is a normal feature of low-pressure chiller operation, not a fault — but service technicians need to understand the purge-unit role and operation.

HCFO chemistry — single chlorine, very-short atmospheric lifetime

R-1233zd(E) is a hydrochlorofluoroolefin: CF₃CH=CHCl. The carbon-carbon double bond (the "ene" / "olefin" feature) is what gives the molecule its very short atmospheric lifetime (~26 days) and resulting very low GWP (1). The single chlorine atom adds a small ozone-depletion potential (0.00034) that HFOs (without chlorine) don't have.

The "E" designation refers to the trans (entgegen) geometric configuration around the double bond. The cis (zusammen, "Z") isomer R-1233zd(Z) has different physical properties and is rarely used as a standalone refrigerant.

The HCFO chemistry is the modern engineering solution for low-pressure chiller applications where R-123's HCFC chemistry (ODP 0.02) needed replacement without losing the favorable pressure envelope and safety class.

GWP 1 and effectively zero ODP — long-term regulatory positioning

R-1233zd(E) has GWP 1 (IPCC AR5) — among the very lowest of commercial refrigerants alongside R-744 (CO₂) [ipccar5]. ODP is 0.00034 — technically non-zero but below the de-minimis threshold most regulatory frameworks apply [montrealprotocol]. EPA SNAP has approved R-1233zd(E) for R-123 chiller replacement [snap].

The combination of very-low GWP and effectively-zero ODP eliminates phase-down risk under all current and reasonably-foreseeable regulatory frameworks. R-1233zd(E) is structurally a long-term destination refrigerant for low-pressure chiller applications.

For R-123 replacement specifically, R-1233zd(E) provides the clear path forward — operationally equivalent in equipment terms, dramatically lower environmental impact (GWP 1 vs R-123's 79, ODP 0.00034 vs R-123's 0.02).

A1 safety class — easier than R-1234ze A2L for chillers

R-1233zd(E)'s A1 safety classification is a meaningful advantage over A2L alternatives for chiller applications. A1 chillers don't require sealed motors, A2L-rated leak detection, or charge limits per ASHRAE 15 A2L provisions. Equipment-room and code compliance is simpler.

For chiller OEMs choosing between A1 R-1233zd(E) and A2L R-1234ze for new low-GWP equipment, R-1233zd(E)'s A1 classification often makes it the preferred choice in installations where A2L equipment-room provisions add cost or complexity. Trane has standardized R-1233zd(E) for several centrifugal chiller product lines [trane]; other chiller OEMs offer R-1233zd(E) options.

How to think about R-1233zd(E) in 2026 and beyond

R-1233zd(E) is the dominant R-123 replacement refrigerant for low-pressure centrifugal chillers. Existing R-123 chillers facing the HCFC phase-down (US R-123 production banned January 2020) can be retrofitted to R-1233zd(E) with operational equivalence. New low-pressure chiller installations from 2020+ predominantly specify R-1233zd(E).

The A1 safety class is the primary differentiator from R-1234ze (A2L) for chiller applications. For installations where A2L equipment-room provisions are inconvenient or where A1 classification is required by code or insurance, R-1233zd(E) is the natural choice.

Service technicians familiar with R-123 chiller service can work R-1233zd(E) with minimal procedural adjustment — same pressure envelope, same safety class, same lubricant family. The retrofit transition is among the smoothest in the chiller refrigerant landscape.

Frequently asked

›What is R-1233zd(E) used for?

Low-pressure centrifugal chiller R-123 replacement primarily. Trane offers R-1233zd(E) chillers (CenTraVac product line); other chiller OEMs also offer R-1233zd(E) options. Honeywell markets the refrigerant as Solstice zd [honeywellsolstice].

›Why is R-1233zd(E) called HCFO instead of HFO?

HCFO = hydrochlorofluoroolefin. The "C" denotes the one chlorine atom in the molecule. R-1233zd(E)'s structure is CF₃CH=CHCl — three fluorines, one chlorine, plus hydrogen and the carbon-carbon double bond. HFOs (hydrofluoroolefins) have no chlorine; R-1234yf and R-1234ze are HFOs. The chlorine atom in R-1233zd(E) gives it the very small ODP (0.00034) that HFOs don't have.

›What's R-1233zd(E)'s GWP?

1 per IPCC AR5 — very low [ipccar5]. The 26-day atmospheric lifetime drives the low GWP. R-1233zd(E) sits alongside R-744 (CO₂) as one of the lowest-GWP commercial refrigerants.

›Is R-1233zd(E) ozone-depleting?

Technically yes — ODP 0.00034 — but far below regulatory de-minimis thresholds. For practical purposes R-1233zd(E) is treated as zero-ODP. EPA SNAP has approved R-1233zd(E) for R-123 chiller replacement without ozone-depletion concerns [snap].

›Is R-1233zd(E) flammable?

No — ASHRAE class A1 (non-toxic, non-flammable) [ashrae34]. This is a primary advantage over R-1234ze (A2L) for chiller applications where A1 safety simplifies equipment-room and code compliance.

›What lubricant does R-1233zd(E) use?

POE oil typically [ahri700]. Verify against equipment OEM service literature. Some chiller OEMs may specify specific viscosity grades or alternative synthetic oils for particular compressor designs.

›Can R-1233zd(E) retrofit R-123 chillers?

Yes — R-1233zd(E) was designed as a near-drop-in R-123 replacement. The pressure envelope closely matches R-123; safety class (A1) is preserved; lubricant chemistry is compatible. Major chiller OEMs (Trane, others) have documented R-123 to R-1233zd(E) retrofit procedures.

›What is Solstice zd?

Honeywell's trade name for R-1233zd(E) [honeywellsolstice]. Honeywell is the primary commercial manufacturer; the refrigerant is supplied to multiple chiller OEMs for new equipment and retrofit applications.

Download this dataset

Full PT chart for R-1233zd(E) · CC BY 4.0 · attribute the source

CSV JSON

Sources & citations

[1]
ASHRAE Standard 34-2022
2022https://www.ashrae.org/technical-resources/standards-and-guidelines
[2]
IPCC AR5 (2014) Working Group I, Chapter 8, Table 8.A.1
2014https://www.ipcc.ch/report/ar5/wg1/
[3]
CoolProp 7.2.0
2014 (continually updated)http://www.coolprop.org/doi:10.1021/ie4033999
[4]
EPA SNAP — R-1233zd(E) acceptable for chiller R-123 replacement
https://www.epa.gov/snap
[5]
Montreal Protocol — HCFO de-minimis ODP threshold provisions
https://ozone.unep.org/treaties/montreal-protocol
[6]
AHRI Standard 700-2019
2019https://www.ahrinet.org/search-standards
[7]
Honeywell Solstice zd (R-1233zd(E)) Technical Information
https://www.honeywell-refrigerants.com/americas/
[8]
Trane R-1233zd chiller equipment documentation
https://www.trane.com/commercial/north-america/us/en/products-systems/chillers.html