Table 2.

Main advantages and disadvantages of each type of PCMs.

Type of PCM	Advantages	Disadvantages
Organic	▪Available in a large temperature range; ▪Chemically inert; ▪Do not undergo phase segregation; ▪Thermally stable for repeated freeze/melt cycles; ▪Low vapor pressure in the melt form; ▪Relatively small melting heat; ▪Non-corrosive, or mildly corrosive (fatty acids); ▪Compatible with construction materials; ▪Small volume change during phase transitions; ▪Little or no super-cooling effect during freezing; ▪Innocuous (usually non-toxic and non-irritant; non-paraffin type may have various levels of toxicity); ▪Stable below 500 °C (non-paraffin type shows instability at high temperatures; ▪Recyclable.	▪Low thermal conductivity (around 0.2 W/m K); ▪Moderately flammable; ▪Non-compatible with plastic containers.
Inorganic	▪High volumetric storage heat; ▪High melting heat; ▪High thermal conductivity (0.5 W/m K); ▪Cheap and readily available; ▪Nonflammable; ▪Compatible with plastic containers; ▪Sharp phase change; ▪Low environmental impact; ▪Potentially recyclable.	▪Super-cooling during freezing; ▪Phase segregation during transitions; ▪Corrosive to metals; ▪Irritant; ▪High vapor pressure (inducing water loss and progressive changes in thermal behavior during thermal cycles); ▪Low durability (possible long term degradation when exposed to environmental agents); ▪Moderate chemical stability; ▪High volume change.
Eutectic	▪Sharp melting temperature; ▪High volumetric thermal storage capability (slightly lower than organic PCMs).	▪Limited data available on their thermo-physical properties.