Thermal Efficiency

Thermal efficiency, abbreviated as \(\eta_{th}\) (Greek symbol eta), a dimensionless number, is the fraction of heat that is converted to work or desired output divided by required input.

 

Thermal efficiency Formula
\(\large{ \eta_{th}  =  \frac{ W }{ Q_H }  }\)
Symbol	English	Metric
\(\large{ \eta_{th} }\)  (Greek symbol eta) = thermal efficiency	\(\large{dimensionless}\)
\(\large{ W }\) = work out	\(\large{ ft-lbf }\)	\(\large{J}\)
\(\large{ Q_H }\) = heat input	\(\large{\frac{Btu}{lbm}}\)	\(\large{\frac{J}{kg}}\)