Adopting Low-cost Alternative for Energy Saving
Energy Saving Potential

This section showcases the energy conservation measures in a high performance commercial building in a composite climate. The Energy Conservation Measures considered here are Shaded envelope, Daylight integration applied on ECBC compliant building (envelope, lighting and HVAC) with optimum Window Wall Ratio (WWR). The overall energy saving potential from the following high performing strategies are quantified under the project ‘High Performance Commercial buildings in India’:

  • Shaded envelope
  • Daylight integration
  • Window design optimisation
  • ECBC Complaint Envelope
  • ECBC Complaint lighting design
  • ECBC Complaint HVAC design

For more information on the ECBC envelope, refer Technical Information Section.

 

Shading

Daylight integration

Window Wall Ratio

Walls, Roof (shaded) and Windows shaded

Daylight integration

(20- 30)%

ECBC Envelope

wall

roof

glazing

U-value : 0.391 W/m2°C

U-value : 0.385 W/m2°C

U-value : 2.22 W/m2°C

 

ECBC Compliant lighting design

Lighting Power Density*

   

L.P.D = 6 W/m2

   

   
The LPD considered is lower than ECBC recommended.
 
 

ECBC Compliant HVAC Design

Chiller

AHU

Motor

Centrifugal water cooled chiller COP = 6.3 or EER = 21.49

All AHUs HAVE temperature based Economizer with energy recovery wheel as control with efficiency = 70 %

Variable speed drive

   

Impact of High performing design Strategies:

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

Dayuse Building

24 Hour use Building

Lighting: 17.9 (kWh/m2/annum)
HVAC: 31.2 (kWh/m2/annum)
EPI of the building (including lighting & HVAC
consumption only): 49.2 kWh/m2/annum

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

   
ENERGY SAVING POTENTIAL: 74 %** (IN COMPARISON TO CONVENTONAL BUILDING CASE)
ENERGY SAVING POTENTIAL:** (IN COMPARISON TO CONVENTONAL BUILDING CASE)

It is also observed in air-conditioned buildings for both day use and 24 hour-use, ECBC compliant envelope + efficient lighting with daylight integration & optimum WWR has high energy saving potential. Energy simulation engine was used to quantify energy saving potential in a daytime office and 24 hour buildings. The below graphs shows the reduction in energy consumption in a day time and 24 hour-use buildings by adopting low energy strategies;

Fig 1: Energy saving potential due to Solar passive design strategies (shaded envelope + Daylight integration and optimum WWR) applied on ECBC compliant (envelope, lighting and HVAC) building
   

**Note: The energy saving potential of Energy Conservation Measures (ECM5), is calculated with solar passive design strategies applied on ECBC compliant building against Base case (conventional building)

 
   

Life Cycle Cost Analysis:

The Life Cycle Cost Analysis (LCC) of this high performance design strategy was carried out under this project. The LCC of this case for day use buildings considering 25 yrs is 1077 Million Rs. The Pay back for incorporating the solar passive design strategies is found out to be as less than 3yrs.

     
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