Enthalpy

Enthalpy, abbreviated as H, measures the sum of internal energy changes in heat under constant pressure of the system.

 

Enthalpy formula

\(\large{ H =  U + p \; V   }\)

Where:

Units	English	Metric
\(\large{ H }\) = enthalpy of a system	\(\large{\frac{Btu}{lbm}}\)	\(\large{\frac{kJ}{kg}}\)
\(\large{ U }\) = internal energy of work done in a system	\(\large{Btu}\)	\(\large{J}\)
\(\large{ p }\) = pressure	\(\large{\frac{lbf}{in^2}}\)	\(\large{Pa}\)
\(\large{ V }\) = volume of a system	\(\large{ft^3}\)	\(\large{m^3}\)