c. 1948
Telkes Dover house
Maria Telkes’ Glauber’s-salt solar house — leaks and layering taught humility.
Milestones in order. This is history, not a weekly activity grid.
- Telkes Dover house
- NASA PCM
- Salt-hydrate R&D
- Microencapsulated paraffin
- PCM gypsum boards
- EN / ASTM test methods
- Cold-chain packs
- Graphite composite PCM
- Battery packs
- Bio-based waxes
Darker cells mean a higher score for this topic on that metric.
Strength10
Heat resistance22
Fire performance24
Insulation52
Workability58
Circularity48
LessMore
Last reviewed Sources & creditsMedia creditsMethodology
Quick answers
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
heat 22 · fire 24
Phase-change material did not arrive as a finished commodity. NASA / Telkes 1940s–70s; building PCM 2000s around United States / Germany still explains who makes it and which tests it sits in.
Ten dated points, five eras and three milestones below are the spine — not a complete industrial history.
Where it began
NASA / Telkes 1940s–70s; building PCM 2000sUnited States / Germany
Timeline
c. 1948Telkes Dover house
Maria Telkes’ Glauber’s-salt solar house — leaks and layering taught humility.
1960sNASA PCM
Spacesuit and electronics thermal capacitors.
1970sSalt-hydrate R&D
Supercooling and phase separation as the plot.
1990sMicroencapsulated paraffin
BASF Micronal in plaster.
2000sPCM gypsum boards
Comfort claims in lightweight buildings.
2010sEN / ASTM test methods
h(T) curves instead of brochure magic.
2010sCold-chain packs
The market that actually ships.
2010sGraphite composite PCM
Conductivity additives.
2020sBattery packs
Passive buffering between cells.
2020sBio-based waxes
Still combustible.
The eras
1970s
Salt-hydrate R&D
Supercooling and phase separation as the plot.
2000s
PCM gypsum boards
Comfort claims in lightweight buildings.
2010s
Cold-chain packs
The market that actually ships.
2020s
Battery packs
Passive buffering between cells.
Milestones
Microencapsulated paraffin
1990sBASF Micronal in plaster.
Cold-chain packs
2010sThe market that actually ships.
Bio-based waxes
2020sStill combustible.
Knowing this timeline is how to read a mill certificate without treating Phase-change material as timeless.
Keep exploring
More in Thermal
🪨
Mineral wool
Melted rock or glass spun into A1 batts — the default non-combustible insulation of codes.
Overall 69 🧽Polyurethane foam
The low-λ organic foam of fridges and buildings — excellent insulation, a fire design problem unless PIR and coverings are honest.
Overall 46 📦Vacuum insulated panel
A sealed vacuum sandwich — λ around 0.004–0.008 W/m·K until the envelope leaks.
Overall 44