The damping rate is the ratio between the amplitude of the thermal wave observed inside Delta T inside and the amplitude of the thermal wave observed outside Delta T outside It is generally expressed as a percentage.
The higher this percentage, the more the wall will absorb the heat wave and provide summer comfort.
Thermal phase shift:
The Thermal phase shift, also called thermal inertia , represents the response time between an outdoor heat peak and that generated inside a given wall. It is expressed in hours. A Thermal phase shift of at least 12 hours corresponds to the heat peak effect felt in the evening having the heat accumulated in the wall during the day being dissipated inside and outside during the night.