Match phase point to the lane
For 2-8°C shipments, +5°C PCM or carefully conditioned gel packs often reduce freezing risk. For frozen lanes, -18°C PCM, eutectic packs, or dry ice may be more appropriate.
Cold Chain Coolant Tool
Coolant & PCM Reference Table for Cold Chain Packaging
Compare common refrigerants and phase change materials by phase-change point, latent heat, specific heat, freezing expansion, preconditioning need, and typical cold-chain use case before you prepare a packout or quotation request.
°C
Phase-change point for lane matching
Phase-change point for lane matching
kJ/kg
Latent heat reference range
Latent heat reference range
%
Freezing expansion planning range
Freezing expansion planning range
Quick coolant selector
Use the table to compare technical ranges, typical lane fit, and handling notes. Values are planning references; exact specifications vary by formulation, pack size, film structure, and conditioning SOP.
Last reviewed: 18 Jun 2026
| Compare | Coolant / PCM | Phase-change point | Latent heat | Specific heat | Expansion on freezing | Preconditioning | Best-fit lanes | Handling note |
|---|---|---|---|---|---|---|---|---|
|
Water-based flexible gel ice pack Reusable gel pack, soft pouch, water-dominant refrigerant gel. Gel pack0-10°C |
Around 0°C | 300-334 kJ/kg | Liquid approx. 4.18; frozen approx. 2.03 kJ/kg*K | About 8-9%; leave headspace in rigid designs. | Freeze at -18°C or below until fully solid. | Chilled food, grocery, seafood, 0-10°C parcels, buffered 2-8°C lanes. | Use separator layers for freeze-sensitive payloads. Good low-cost starting point for many chilled packouts. | |
|
Rigid ice brick Hard-shell water or gel-filled brick for repeated handling and longer thermal mass. Ice brickReusable |
Around 0°C | 300-334 kJ/kg | Liquid approx. 4.18; frozen approx. 2.03 kJ/kg*K | About 8-9%; shell geometry must allow expansion. | Freeze at -18°C or below; confirm core is fully frozen. | Reusable food distribution, seafood, EPP box programs, insulated delivery boxes. | Higher durability than soft pouches. Check direct-contact freezing risk and payload loading pattern. | |
|
Conditioned 0°C gel pack Frozen gel pack warmed or conditioned before loading to reduce product freezing risk. Conditioned gel2-8°C support |
Around 0°C | 280-330 kJ/kg | Approx. 3.6-4.2 liquid; 1.8-2.4 frozen kJ/kg*K | Typically 6-9%, depending on gel formulation. | Freeze, then condition to the validated loading state before packout. | 2-8°C pharma starter layouts, lab samples, freeze-sensitive chilled goods. | Conditioning and separator placement matter more than the material name. Validate with logger data. | |
|
+5°C PCM pack Positive-temperature PCM designed to release cold near the 2-8°C operating band. PCMPharma |
Approx. +5°C | 160-240 kJ/kg | Approx. 2.0-4.0 kJ/kg*K by formulation | Common planning range 3-8%. | Charge below phase point per supplier SOP; avoid uncontrolled over-freezing for validated lanes. | 2-8°C pharma, biologics, vaccines, lab samples, freeze-sensitive cool-chain payloads. | Often a better starting point than fully frozen gel packs when product freezing is a critical risk. | |
|
+20 to +25°C CRT PCM pack PCM for controlled room temperature shipments where both heat and cold exposure matter. CRT PCM15-25°C |
Approx. +20 to +25°C | 140-220 kJ/kg | Approx. 1.8-3.0 kJ/kg*K | Often below water ice; use supplier expansion data. | Condition within the validated CRT charge window before loading. | 15-25°C controlled room temperature medicines and diagnostics. | Not a chilled or frozen coolant. It buffers ambient excursions around room-temperature limits. | |
|
-5°C PCM or eutectic gel pack Sub-zero coolant for stronger chilled performance where mild freezing risk can be controlled. Sub-zero PCMFreeze risk |
Approx. -5°C | 180-280 kJ/kg | Approx. 2.5-4.0 kJ/kg*K | Common planning range 4-10%. | Freeze below -10°C or per formulation requirement. | Seafood, protein, high thermal-load chilled freight, longer 0-10°C lanes. | Use with caution around vaccines, biologics, leafy produce, and other freeze-sensitive payloads. | |
|
-18°C PCM / frozen eutectic pack Frozen-lane PCM used when the payload must stay near standard frozen distribution temperatures. Frozen PCM≤ -18°C |
Approx. -18°C | 170-260 kJ/kg | Approx. 2.0-3.8 kJ/kg*K | Common planning range 4-12%. | Charge in a -25°C or colder freezer unless supplier specifies otherwise. | Frozen food, frozen seafood, ice cream support, frozen e-commerce parcels. | For deep frozen or long air/export routes, compare with dry ice and route-risk controls. | |
|
Sodium chloride brine eutectic pack Salt-water eutectic refrigerant. Eutectic point is near -21.1°C at about 23.3 wt% NaCl. BrineFrozen |
Near -21.1°C eutectic point | Typical pack planning range 160-240 kJ/kg | Approx. 2.0-3.8 kJ/kg*K by concentration | Often lower than pure water, but container headspace is still required. | Charge below eutectic point, commonly -25°C or colder. | Frozen support, seafood export, high thermal-load cold packs. | Check corrosion compatibility and leakage control. Do not place directly against freeze-sensitive cargo. | |
|
Dry ice pellet or block Solid carbon dioxide coolant that sublimates directly to gas at atmospheric pressure. CO2Vent required |
Sublimes near -78.5°C | About 571 kJ/kg sublimation energy | Approx. 0.8-0.9 kJ/kg*K for solid CO2 | Not a liquid-freezing pack; gas release requires vented packaging. | Use dry ice as supplied; store and handle with ventilation and PPE. | Deep frozen, dry-ice-compatible pharma, lab samples, ice cream, frozen air/export lanes. | Air shipments require dry ice marking, net weight, carrier acceptance, and dangerous-goods review. | |
|
Slurry ice / ice slurry Fine ice crystals suspended in a carrier fluid for direct chilling or process-side cooling. SlurryFood process |
Often -2 to 0°C, depending on solution | Approx. 80-250 kJ/kg by ice fraction | Approx. 3.3-4.2 kJ/kg*K by mixture | Depends on ice fraction and storage method. | Generated by slurry ice system; not normally charged as a sealed pack. | Seafood, fish, produce processing, short direct-contact cooling workflows. | Useful for process cooling, but less common for sealed parcel cold-chain packaging. |
Common coolant and PCM parameter table
Tick up to three rows to compare the real trade-offs: temperature fit, cooling density, freezing risk, conditioning effort, and when each option is usually chosen.
No coolant selected yet.
Coolant choice comparison
Estimate the latent energy available from a selected coolant mass. This is not a thermal qualification result, but it helps compare refrigerant formats quickly.
Estimated latent capacity
0
kJ latent energy
kJ latent energy
0
Wh equivalent
Wh equivalent
0
kJ/kg used
kJ/kg used
Thermal performance also depends on insulation, payload temperature, ambient profile, pack placement, and route time.
Latent cooling energy check
The best coolant is not only the coldest material. Match the phase point to the product temperature band, then check heat capacity, expansion, contact risk, conditioning, and route controls.
Use latent heat as a comparison, not a guarantee
A higher kJ/kg value means more phase-change energy per kilogram, but packout geometry, insulation, payload mass, air gaps, and ambient exposure decide the real hold time.
Leave room for expansion and gas release
Water-rich packs expand when frozen. Dry ice is different: it sublimates into carbon dioxide gas and must never be sealed in airtight packaging.
How cold-chain teams should read the table
Use this page to shortlist the refrigerant family, then continue with pack quantity, route risk, sizing, and shipment-readiness checks.
For chilled lanes
Use the Ice Pack Calculator to estimate starting cold-media mass for 2-8°C or 0-10°C shipments.
For frozen lanes
Use the Dry Ice Calculator when dry ice, deep frozen cargo, air freight, or export handling is part of the route.
For route uncertainty
Use the Route Risk Checker before finalizing packout assumptions for hot ambient, dwell time, or cross-border lanes.