# thermal conductance

thermal conductancenoun

- A measure of the ability of an object to allow the flow of heat from its warmer surface through the object to its colder surface, determined as the heat energy transferred per unit of time divided by the temperature difference between the two surfaces, expressed in watts per kelvin. The conductance of an object equals the conductivity of its material times its surface area (cross-section) divided by the distance between the two surfaces (thickness).
- The reciprocal of thermal resistance, usually measured in units of watts per kelvin.

## thermal-conductance

(*plural* thermal conductances)

The heat (thermal energy) flow *P _{th}* through a given body depends on the thermal conductance

*C*of that body, and the temperature difference

_{th}*Î”T*over it, and follows the formula:

Thus, the higher the conductance, the higher the heat flow. The unit of thermal conductance in SI system of units is WÂ·K^{âˆ’1}. For the special case of an ideal plate with area *A*, thickness *d* and thermal conductivity *Î»*, the thermal conductance of the plate is:

The multiplicative inverse of thermal conductance is thermal resistance, denoted as *R _{th}.*