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🧊 Thermal

🕯️Phase-change material

Latent-heat packets that flatten temperature swings — not a substitute for λ insulation, a complement.

Also called: PCM · salt hydrate PCM · paraffin PCM

Phase-change material — Wikimedia lead image
Suricata · CC BY-SA 3.0
At a glance
Score intensity

Darker cells mean a higher score for this topic on that metric.

Score profile

Each bar is a 0-100 atlas score for this topic, not a timeline.

102224525848
Fire
Heat
Specs
Timeline

Milestones in order. This is history, not a weekly activity grid.

c. 1948 Telkes Dover house1960s NASA PCM1970s Salt-hydrate R&D1990s Microencapsulated paraffin2000s PCM gypsum boards2010s EN / ASTM test methods2010s Cold-chain packs2010s Graphite composite PCM2020s Battery packs2020s Bio-based waxes
  1. Telkes Dover house
  2. NASA PCM
  3. Salt-hydrate R&D
  4. Microencapsulated paraffin
  5. PCM gypsum boards
  6. EN / ASTM test methods
  7. Cold-chain packs
  8. Graphite composite PCM
  9. Battery packs
  10. Bio-based waxes
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18 min read

Last reviewed Sources & creditsMedia creditsMethodology

heat 22 · fire 24

Start with this section - Origins & milestones

Fire role or insulation role

Pick the fire-performance reading or the insulation reading already scored on this material. Teaching marks — not a specification.

Atlas scores and on-page facts only. A named product test, thickness and assembly decide any real wall or garment. No lab stamp.

Open compare lab

Quick facts

Latent heatJob
comfort band ~21–26 °CTm
Paraffin burnsFire
Glauber’s salt loreIcon
With wool/PIR, not insteadPair
thermalFamily

Phase-change material is one of 32 materials in this atlas, grouped under thermal: history, structure, measured properties, process routes, uses, safety and market — not a product catalogue.

Scores compare Phase-change material with the rest of the atlas on strength, heat, fire behaviour, insulation, workability and circularity. They are editorial, not certificates.

Seven chapters follow. Fire and insulation claims name test families (Euroclass, ASTM E84, ISO 5660, KS F) rather than inventing a single safety number.

Deep introduction

Deep dive: Phase-change material

Phase-change material (paraffins / salt hydrates / bio-waxes) is a family of grades whose density ~0.8–1.6 g/cm³, heat band designed 18–28 °C for buildings, and fire letter paraffin = combustible; salts vary.

What “the material” actually is

Phase-change material is sold as grades, not as a single substance. Chemistry paraffins / salt hydrates / bio-waxes, density ~0.8–1.6 g/cm³, heat band designed 18–28 °C for buildings.

This atlas treats Phase-change material as a system: mill route, coatings, tests and the cavity it sits in.

Heat, fire and insulation

Conductivity note: low-to-moderate; often needs fins or graphite. Insulation score 52/100 is relative to 32 entries — metals lose, VIPs and aerogels win.

Fire letter in editorial use: paraffin = combustible; salts vary. Do not equate A1 with “safe in a blaze” or E with “illegal”. Assemblies decide.

How it is made and used

Origin: NASA / Telkes 1940s–70s; building PCM 2000s, United States / Germany. The process chapter follows feedstock → conversion → forming → finish → install.

Uses span buildings to defence / safety. Pairings matter: mineral-wool.

Market and circularity

Producers below are landmarks, not an endorsement ranking. Prices are bands, not live quotes.

Circularity mark 48/100. Ask which scrap, which certificate, which year.

The profile

102224525848
Strength 10
Heat resistance 22
Fire performance 24
Insulation 52
Workability 58
Circularity 48

Fire role or insulation role

Pick the fire-performance reading or the insulation reading already scored on this material. Teaching marks — not a specification.

Atlas scores and on-page facts only. A named product test, thickness and assembly decide any real wall or garment. No lab stamp.

Seven chapters

Fire mark or insulation mark first?

Decision walkthrough on Phase-change material: fire 24, insulation 52, and one fact already on file — not a code stamp.

  1. Read the fire-performance mark — Fire on this hub is 24/100 — teaching comparison among atlas materials.
  2. Read the insulation mark — Insulation is 52/100 — heat-flow story, not the same question as flame.
  3. Sit one published fact beside them — Quick fact on file: Job: Latent heat.
  4. Sustainability is not a fire skip — A high sustainability mark does not replace fire protection in a real assembly.
  5. Not a building-code rating — Named tests, thickness and build-up still decide compliance — this page is literacy only.

On Phase-change material, fire 24 and insulation 52 answer different jobs; Job: Latent heat grounds one real detail.

Editorial atlas marks. Not a code certificate or product approval.

Thermal mark or safety fact first?

Second lab decision on Phase-change material: heat-resistance 22 beside published thermal fact Conductivity — literacy, not a code stamp.

  1. Read the heat-resistance mark — Heat resistance on this hub is 22/100 — a thermal story, different from the fire/insulation pair.
  2. Sit one thermal fact beside it — Properties chapter lists Conductivity among published thermal rows.
  3. Heat resistance is not a fire skip — A high thermal mark does not replace named fire tests in a real assembly.
  4. Still not a building-code rating — Thickness, build-up and named tests decide compliance — this page teaches axes only.

On Phase-change material, heat 22 and Conductivity are a second thermal/safety reading after fire vs insulation.

Editorial atlas marks. Not a code certificate or product approval.

Heat line to keep

Choose the heat reading for Phase-change material.

Keep heat resistance 22.

A decision from printed marks. Not a building permit.

Frequently asked questions

Is Phase-change material non-combustible?
Declared reaction class in this atlas: paraffin = combustible; salts vary. Assemblies still need resistance tests.
Does Phase-change material insulate?
Thermal mark 52/100 versus the atlas. Conductivity note: low-to-moderate; often needs fins or graphite.
What is the density band?
~0.8–1.6 g/cm³
How is it made?
Origin story: NASA / Telkes 1940s–70s; building PCM 2000s (United States / Germany).
Can it be recycled?
Circularity mark 48/100 — editorial, route-specific.
Typical melting or failure heat?
designed 18–28 °C for buildings
What should it be paired with?
mineral-wool: Blocks heat flow; PCM stores it.
Where is it specified?
Buildings, transport, energy and consumer goods — see the uses chapter.
Is the fire-performance score a building-code rating?
No. It is an editorial 0–100 teaching mark among materials in this atlas. A real wall or garment needs a named product test, thickness and assembly. This page is not a lab stamp.
When should I read insulation instead of fire?
Use the insulation pick when the question is heat flow — lining, loft, or a cold-bridge — and the fire pick when the question is how the same material behaves in flame. Both numbers already sit on this hub; they answer different jobs.
Does a high sustainability score mean I can skip fire protection?
No. Sustainability here is a relative atlas mark (growth, reuse, embodied story). Bamboo and timber can still char like wood. Fire protection stays a separate specification.
Why is bamboo missing in some languages?
A language URL is published only when the seven chapters are real prose in that language. Bamboo exists in English, Korean, Japanese, Chinese and Spanish. French, German, Portuguese and Russian stay withheld — earlier machine drafts leaked English, so those URLs are not opened.

Icons

Maria Telkes

Maria Telkes

United States · 1948

Maria Telkes is a reference point in the public image of Phase-change material.

Glauber’s salt

Glauber’s salt

Europe · historic

Glauber’s salt is a reference point in the public image of Phase-change material.

Micronal board

Micronal board

Germany · 2000s

Micronal board is a reference point in the public image of Phase-change material.

Ice pack

Ice pack

Global · 20th c.–

Ice pack is a reference point in the public image of Phase-change material.

NASA PCM vest

NASA PCM vest

United States · 1990s–

NASA PCM vest is a reference point in the public image of Phase-change material.

Cold-chain box

Cold-chain box

Global · 2010s–

Cold-chain box is a reference point in the public image of Phase-change material.

Paraffin candle physics

Paraffin candle physics

Global · historic

Paraffin candle physics is a reference point in the public image of Phase-change material.

Battery PCM pad

Battery PCM pad

Global · 2020s

Battery PCM pad is a reference point in the public image of Phase-change material.

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5 / 8

Head-to-head

Same family or rival physics — pick a duel.

Similar materials

Closest neighbours on the six atlas axes — strength, heat, fire, insulation, workability and circularity.

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