# Exchanged Heat in a Heat Exchanger

Written by Jerry Ratzlaff on . Posted in Thermodynamics

### Exchanged Heat in a Heat Exchanger Formula

$$\large{ S = h \; A \; LMTD }$$

Where:

$$\large{ Q }$$ = exchanged heat duty

$$\large{ A }$$ = exchange area

$$\large{ h }$$ = heat transfer coefficient

$$\large{ LMTD }$$ = logarithmic mean temperature differential