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

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## 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:**

- First, determine the absorbed heat (J). In this example, the absorbed heat (J) is given as 40.
- Next, determine the input heat (J). For this problem, the input heat (J) is given as 50.
- 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 (%)