Useful boiler efficiency calculator

Keep efficiency and heating value on the same HHV/LHV and output basis.

Units

\eta_{\text{boiler}} = \frac{q_{\text{useful}}}{q_{\text{fuel}}}

Calculator

Enter the values you know and leave one box empty. Calculate finds the empty one, the result or any input.

Given

\eta_{\text{boiler}} = \frac{8{,}200{,}000}{10{,}000{,}000} = 0.82

Symbol	Meaning	Unit
$\eta_{\text{boiler}}$	useful output divided by fuel input	—
$q_{\text{useful}}$	net useful steam heat	Btu/h
$q_{\text{fuel}}$	fuel heat input on chosen HHV/LHV basis	Btu/h

Symbol	Meaning	Unit
$\eta_{\text{boiler}}$	useful output divided by fuel input	—
$q_{\text{useful}}$	net useful steam heat	kW
$q_{\text{fuel}}$	fuel heat input on chosen HHV/LHV basis	kW

Results are estimates for study and screening. Check the inputs, units and assumptions before you use them for design, billing or contract decisions.