26/07/2021
ENERGY USE INTENSITY OF A BUILDING
According to the Energy Benchmarking Report by IOTA of the Department of Energy in the USA, the chart below shows the energy use intensity (EUI) for different industries, (measured in kilowatt hours per square foot (kWh/sf)).
The EUI level is a factor of:
• Reliance on the operational equipment used in the bank
• The energy required by the equipment
• Hours of operation
The image which shows the EUI Benchmark for different industries indicates the EUI for a Mercantile (Bank) is 20 kWh/Sf.
When converted, this gives 215.28 kWh/m2 (1Sf = 0.092903 m2) EUI Benchmark.
For example,
A bank building with total floor area of 506 m2 consumed a total gross energy in one year equivalent to 99,863 kWh.
The EUI is calculated by dividing the total annualized energy consumed by the entire building floor area.
i.e. EUI = (Total Energy Consumed)/(Floor Area)
The building annual Energy Use Index is 197 kWh/m2/annum.
As compared to the IOTA, Department of Energy EUI benchmark of 215.28 kWh/m2 in Figure 1 above, this shows that the calculated EUI level comparing the annualized energy consumption shows the building has a good level of Energy Efficiency Measures being put in place.
To further reduce the EUI, the system can be improving by reducing consumption through retrofitting and using occupancy sensor for lighting and using more energy efficient devices, let’s say this was reduced to 84,144 kWh over the same floor area of 506m2.
The EUI using the new consumption after the energy investment will be166.29 kWh/m2/year. This resulted in a 16% reduction in energy consumption.
As compared to the IOTA, Department of Energy EUI benchmark of 215.28 kWh/m2 in Figure 1 above, this show that the calculated EUI level comparing the energy consumption before the retrofits and the value after the retrofit were lower and showed a good level of EEMs being put in place.
