What is the Q Max value in the cooling fabric?
Mar 24, 2026
The Q max value in a "cooling fabric" is the material's maximum heat-storage (thermal energy) capacity-i.e., the most heat it can absorb during its cooling/phase-change process (commonly when a PCM-phase change material-melts).
What it tells you
Higher Q max = the fabric can absorb/store more heat before the cooling effect is used up.
Lower Q max = the cooling effect typically doesn't last as long (under the same test conditions).
Units & common interpretation
Q max is usually given in J/g (joules per gram) (sometimes similar energy-per-mass units). But the exact meaning can depend on the test method used by the manufacturer.
Important caveat
"Cooling fabric" claims can come from different technologies (PCM phase-change vs. moisture wicking vs. "cool-touch" finishes). Q max is specifically meaningful when the cooling is due to thermal storage/PCM behavior.
