Enter the absorbed heat (J) and the input heat (J) into the calculator to determine the Furnace Efficiency. 

Furnace Efficiency Formula

The following formula is used to calculate the Furnace Efficiency. 

Efurnace = Qa / Qi * 100

  • Where Efurnace is the Furnace Efficiency (%)
  • Qa is the absorbed heat (J) 
  • Qi is the input heat (J) 

How to Calculate Furnace Efficiency?

The following two example problems outline how to calculate the Furnace Efficiency.

Example Problem #1:

  1. First, determine the absorbed heat (J). In this example, the absorbed heat (J) is given as 40.
  2. Next, determine the input heat (J). For this problem, the input heat (J) is given as 50.
  3. Finally, calculate the Furnace Efficiency using the equation above: 

Efurnace = Qa / Qi * 100

Inserting the values from above and solving the equation: 

Efurnace = 40 / 50 * 100 = 80 (%)

Example Problem #2: 

Using the same process as above, first define the variables required by the formula. In this case, these values are:

absorbed heat (J) = 50

input heat (J) = 100

Entering these values yields:

Efurnace = Qa / Qi * 100 = 50 (%)