Adopting Low-cost Alternative for Energy Saving
Energy Saving Potential

This section showcases the energy conservation measures in a low energy design building. The measures considered here are, Shaded envelope, Daylight integration, and optimum Window Wall Ratio (WWR). Although there are several low energy design strategies for energy conservation as explained in the technical section, the overall energy saving potential from the following low energy design strategies are quantified under the project ‘High Performance Commercial buildings in India’:

  • Shaded envelope
  • Daylight integration
  • Window design optimisation

For more information on the low energy design strategies, refer Technical Information Section.

     
Shading
Daylight integration
Window Wall Ratio

Walls, Roof (shaded) and Windows shaded

Daylight integration

(20- 30)%

     
   

Impact of Energy Conservation Measures-1 design Strategies:

Energy Performance Index of a low energy day use and 24 hour use building with above mentioned energy conservation measures is in the following range:

Dayuse Building

24 Hour use Building

Lighting: 60.86 (kWh/m2/annum)
HVAC: 80.51 (kWh/m2/annum)
EPI of the building (including lighting & HVAC consumption only): 141.36 (kWh/m2/annum)

Lighting: 166.4 (kWh/m2/annum)
HVAC: 190.6(kWh/m2/annum)
EPI of the building (including lighting & HVAC consumption only):
357.1 (kWh/m2/annum)

   
ENERGY SAVING POTENTIAL: 24%** (IN COMPARISON TO CONVENTONAL BUILDING CASE)
ENERGY SAVING POTENTIAL: 21.6%** (IN COMPARISON TO CONVENTONAL BUILDING CASE)

It is observed that in air-conditioned buildings for both day-use and 24 hour-use, adopting low energy design strategies has high energy saving potential. It is also observed that day time occupied buildings have a higher energy reduction potential when compared to 24 hour occupied building. The below graphs show the reduction in energy consumption in day time and 24 hour-use buildings by adopting low energy strategies.

Fig 1: Energy saving potential due to low energy design strategies (shaded envelope + Daylight integration and optimum WWR) in a day use building Fig 1: Energy saving potential due to low energy design strategies (shaded envelope + Daylight integration and optimum WWR) in a 24 hour use building
   

**Note: The energy saving potential of Energy Conservation Measures (ECM1), is calculated with low energy design strategies against Base case (conventional building). Building Envelope, lighting and HVAC systems in ECM1 are same as in Base case/Conventional Building

It is noted that adopting low energy strategies, the energy saving potential in a day use building is more than that in a 24 hour use building
   

Life Cycle Cost Analysis:

The Life Cycle Cost Analysis (LCC) of this Low energy solar passive design strategies (shaded envelope and daylight integration with optimum WWR of 0.30) was carried out under this project. The LCC of a day-use building considering 25 years is 226 Million Rupees. The pay back for incorporating the solar passive design strategies is found out to be three years for a day use building and less than two years for a 24 hour use buildings.

     
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