Energy Use Index Calculator

Formula

The formula to calculate the Energy Use Index (EUI) is:

\[ EUI = \frac{E}{A} \]

Where:

\( EUI \) is the Energy Use Index (kBtu/ft²)
\( E \) is the Total Energy Consumed in a Year (kBtu)
\( A \) is the Total Floor Area of the Building (ft²)

What is an Energy Use Index?

The Energy Use Index (EUI) is a benchmarking tool that measures the energy efficiency of a building by calculating the amount of energy used per square foot per year. It is expressed in units of energy per square foot per year and it’s used to compare the energy efficiency of different buildings or the same building over time. A lower EUI indicates better energy efficiency. It is a crucial component in energy management and sustainability strategies for commercial and residential properties.

Example

Let's say the total energy consumed (E) is 500,000 kBtu, and the total floor area (A) is 50,000 ft². Using the formula:

\[ EUI = \frac{500,000}{50,000} = 10 \]

So, the Energy Use Index (EUI) is 10 kBtu/ft².

Energy Performance Index Calculator

Formula: \( \text{EPI} = \frac{\text{Total Energy Consumption}}{\text{Total Floor Area}} \)

EPI: Energy Performance Index
Total Energy Consumption: Total energy used (in kWh)
Total Floor Area: Total area of the building (in square meters)

Example: \( \text{EPI} = \frac{50000}{2000} \)

Total Energy Consumption: 50,000 kWh
Total Floor Area: 2,000 m²

Estimated Energy Usage Calculator

Formula: \( \text{Estimated Energy Usage} = \text{Power} \times \text{Time} \)

Estimated Energy Usage: Total energy used (in kWh)
Power: Power consumption (in watts)
Time: Duration of usage (in hours)

Example: \( \text{Estimated Energy Usage} = 100 \times 5 \)

Power: 100 W
Time: 5 hours

Energy Use Intensity Calculator

Formula: \( \text{EUI} = \frac{\text{Total Energy Consumption}}{\text{Total Floor Area}} \)

EUI: Energy Use Intensity
Total Energy Consumption: Total energy used (in kWh)
Total Floor Area: Total area of the building (in square meters)

Example: \( \text{EUI} = \frac{60000}{3000} \)

Total Energy Consumption: 60,000 kWh
Total Floor Area: 3,000 m²

Annual Energy Use Calculator

Formula: \( \text{Annual Energy Use} = \text{Daily Energy Use} \times 365 \)

Annual Energy Use: Total energy used in a year (in kWh)
Daily Energy Use: Energy used per day (in kWh)

Example: \( \text{Annual Energy Use} = 50 \times 365 \)

Daily Energy Use: 50 kWh

How to Calculate Energy Performance Index

Formula: \( \text{EPI} = \frac{\text{Total Energy Consumption}}{\text{Total Floor Area}} \)

EPI: Energy Performance Index
Total Energy Consumption: Total energy used (in kWh)
Total Floor Area: Total area of the building (in square meters)

Example: \( \text{EPI} = \frac{45000}{1500} \)

Total Energy Consumption: 45,000 kWh
Total Floor Area: 1,500 m²