# Thermal Resistance

Written by Jerry Ratzlaff on . Posted in Thermodynamics

Thermal resistance, abbreviated as R, measures the temperature difference by which an object or material resists a heat flow.

## Thermal Resistance Formula

 $$\large{ R = \frac{ l }{ k\;A } }$$

### Where:

$$\large{ R }$$ = thermal resistance

$$\large{ A }$$ = total area of the heat exchanger

$$\large{ l }$$ = length of material (measured on the path of the heat flow)

$$\large{ k }$$ = thermal conductivity of material