Brief Summary of ECBC

The Energy Conservation Building Code (ECBC) set minimum energy performance standards for commercial buildings. Under section 14 (p) of the Energy Conservation Act, 2001, Central Government has powers to prescribe ECBC for non-residential buildings, having connected load of 100 KW and above or a contract demand of 120 KVA and above or recommended built-up area of 1000 sqm and above. or building complex for efficient use of energy and its conservation. The state governments have the flexibility to modify ECBC to suit local or regional needs. Energy performance standards for the following building systems will be included in the ECBC:

  1. Building Envelope
  2. Heating Ventilation and Air Conditioning
  3. Lighting
  4. Service Water Heating
  5. Electric Power and Distribution

The salient features of the ECBC for the Composite Climate Zone are as under:

1. Building Envelope:

ECBC compliant design strategy for a building is as under:

Heat/Moisture Losses Walls Roof Window
Minimize Conduction Losses Use insulation with low U-value Use insulation with low U-value Use material with low U-factor
Minimize Convection Losses & Moisture Penetration Reduce air leakage & use vapor barrier Reduce air leakage & use vapor Barrier Use prefabricated windows and seal the joints between windows and walls.
Minimize Radiation Losses Use light colored coating with high reflectance Use light colored coating with high reflectance Use glazing with low Solar Heat Gain Coefficient (SHGC)

Roof Requirement:

Climate Zone Hospitals, Hotels, Call Centres, (24-hours) Other Building types (Daytime)
  Maximum U-factor of the overall assembly (W/sq.m-0 C) Minimum R-value of insulation alone (W/sq.m-0 C) Maximum U-factor of the overall assembly (W/sq.m-0 C) Minimum R-value of insulation alone (W/sq.m-0 C)
Composite U-0.261 R-3.5 U-0.409 R-2.1

Wall Requirement:

Climate Zone Hospitals, Hotels, Call Centres, (24-hours) Other Building types (Daytime)
  Maximum U-factor of the overall assembly (W/sq.m-0 C) Minimum R-value of insulation alone (W/sq.m-0 C) Maximum U-factor of the overall assembly (W/sq.m-0 C) Minimum R-value of insulation alone (W/sq.m-0 C)
Composite U-0.440 R-2.10 U-0.440 R-2.10

Glazing requirements:

Climate Maximum U-factor Maximum SHGC WWR < 40% Maximum SHGC 40% < WWR <60%
Composite 3.3 0.25 0.20
3.3 0.25 0.20
Minimum Visible Light Transmittance
Window –Wall-Ratio Minimum VLT
<30% 0.27
31%-40% 0.20
41%-50% 0.16
51%-60% 0.13

Defaults for Unrated Vertical Fenestration (Overall Assembly including the Sash and Frame)

  Clear Glass Tinted Glass
Frame Type Glazing Type U- Factor(W/m2-0C) SHGC VLT U-Factor SHGC VLT
All frame types Single Glazing 7.1 0.82 0.76 7.1 0.70 0.58
Wood, vinyl, of fiberglass frame Double Glazing 3.3 0.59 0.64 3.4 0.42 0.39
Metel and other frame type Double Glazing 5.1 0.68 0.66 5.1 0.50 0.40

Envelope Performance Factor Coefficients for Composite Climate (under review)

  Daytime Occupancy 24- Hour Occupancy
U - Factor SHGC U - Factor SHGC
Mass Walls 6.01 -- 13.85 --
Curtain Walls, Other 15.72 -- 20.48 --
Roofs 11.93 -- 24.67 --
North Windows -1.75 40.65 -4.56 58.15
Non-North Windows -1.25 54.51 0.68 86.57
Skylights -96.35 311.71 -294.66 918.77

Comfort requirements and Physical manifestations in Buildings of Composite Climate Zone

Thermal Requirements Physical Manifestation
Reduce Heat Gain in Summer and Reduce Heat Loss in Winter
Decrease exposed surface area Orientation and shape of building. Use of trees as wind barriers
Increase thermal resistance Roof insulation and wall insulation
Increase thermal capacity (Time lag) Thicker walls
Increase buffer spaces Air locks/Balconies
Decrease air exchange rate Weather stripping
Increase shading Walls, glass surfaces protected by overhangs, fins and trees
Increase surface reflectivity Pale color, glazed china mosaic tiles, etc.
Reduce solar heat gain Use glazing with lower SHGC and provide shading for windows. Minimize glazing in East and West
Promote Heat Loss in Summer/Monsoon
Increase air exchange rate ( Ventilation) Courtyards/wind towers/ arrangement of openings
Increase humidity levels in dry summer Trees and water ponds for evaporative cooling
Decrease humidity in monsoon Dehumidifiers/ desiccant cooling

Source:- Nayak and Prajapati (2206), Handbook on Energy Conscious Buildings.

2. Heating, Ventilation and Air Conditioning (HVAC):

i) Minimum Efficiency for Chillers:

Equipment Class Minimum COP Minimum IPLV Test Standard
Air Cooled Chiller <530KW (<150 tons) 2.90 3.16 ARI 550/590-1998
Air Cooled Chiller>=530KW(>=150 tons) 3.05 3.32 ARI 550/590-1998
Centrifugal Water Cooled Chiller <530KW(<150 tons) 5.80 6.09 ARI 550/590-1998
Centrifugal Water Cooled Chiller >=530KW and <1050KW(>=150 tons and <300 tons) 5.80 6.17  
Centrifugal Water Cooled Chiller >=1050KW(>=300 tons) 6.30 6.61 ARI 550/590-1998
Reciprocating Compressor, Water Cooled Chiller all sizes 4.20 5.05  
Rotary Screw and Scroll Compressor, Water Cooled Chiller <530KW(<150 tons) 4.70 5.49 ARI550/590-1998
Rotary Screw and Scroll Compressor, Water Cooled Chiller>=530 and <1050KW (>=150 and <300 tons) 5.40 6.17  
R Rotary Screw and Scroll Compressor, Water Cooled Chiller>=1050KW(>=300 tons) 5.75 6.43 ARI 550/590-1998

ii) Unitary Air

Conditioning Equipment:

Equipment Class Minimum COP Minimum IPLV Test Standard
Unitary Air Cooled Air Conditioner >=19 and <40KW(>=5.4 and <11 tons) 3.08   ARI 210/240
Unitary Air Cooled Air Conditioner >=40 to <70KW(>=11 to <20 tons) 3.08   ARI 340/360
Unitary Air Cooled Air Conditioner >=70KW(>=20 tons) 2.93 2.99 ARI 340/360
Unitary Water Cooled Air Conditioner<19KW(<5.4 tons) 4.10   ARI 210/240
Unitary Water Cooled Air Conditioner>=19 and <40KW(>=5.4 and <11 tons) 4.10 +++ ARI 210/240
Unitary Water Cooled Air Conditioner>=<40KW (>=11 tons) 3.22 3.02 ARI 210/240

3. Lighting:

i) Lighting Power Requirement: Table 7.3.1 Interior Lighting Power-Building Area Method

Building Area Type LPD (W/sq.m) Building Area Type LPD (W/sq.m)
Automotive facility 9.7 Multifamily 7.5
Convention Center 12.9 Museum 11.8
Court House 12.9 Office 10.8
Dining: Bar Lounge/Leisure 14.0 Parking Garage 3.2
Dinging: Cafeteria/Fast Food 15.1 Performing Arts Theater 17.2

Table 7.3.2 Interior Lighting Power –Space Function Method

Space Function LPD (W/sq.m) Space Function LPD (W/sq.m)
Lobby 14.0 Hospital  
For Hotel 11.8 Emergency 29.1
For Performing Arts Theater 35.5 Recovery 8.6
For Motion Picture Theater 11.8 Nurse Station 10.8

ii) Exterior Building Lighting Power:

Exterior Lighting Applications Power Limits
Building entrance (with canopy) 13 W/m2 (1.3 W / ft2) of canopied are
Building entrance (without canopy) 90 W/lin m (30 W/lin f) of door width
Building exit 60 W/lin m (20 W/lin f) of door width
Building facades 2 W/m2 (0.2 W/ ft2) of vertical facade area

iii) Interior Lighting Power - Space Function Method:

Space Function LPD (W/m2) Space Function LPD (W/m2)
Office-enclosed 11.8 · For Reading Area 12.9
Office- open plan 11.8 Hospital  
Conference/Meeting/Multipurpose 14.0 · For Emergency 29.1
Classroom/Lecture Training 15.1 For Recovery 8.6
Lobby* 14.0 ·For Nurse Station 10.8
· For Hotel 11.8 · For Exam Treatment 16.1
· For Performing Arts Theater 35.5 · For Pharmacy 12.9
· For Motion Picture Theater 11.8 ·   For patient Room 7.5
Audience/Seating Area* 9.7 ·   For Operating Room 23.7
·For Gymnasium 4.3 ·   For Nursery 6.5
· For Convention Center 7.5 .    For Medical 15.1
Space Function LPD (W/m2) Space Function LPD (W/m2)
Atrium –first three floors 6.5 · For Low Bay (<8m celling) 12.9
Atrium-each additional floor 2.2 · For High Bay (>8m ceiling) 18.3
Lounge/Recreation* 12.9 .  For Detailed Manufacturing 22.6
· For Hospital 8.6 .   For Equipment Room 12.9
Dining Area* 9.7 ·   For Control Room 5.4
· For Hotel 14.0 Hotel/Motel Guest Rooms 11.8
· For Motel 12.9 Dormitory- Living Quarters 11.8
· For Bar Lounge/Leisure Dining 15.1 Museum  
· For Family Dining 22.6 · For General Exhibition 10.8
· Food Preparation 12.9 ·  For Restoration 18.3
Laboratory 15.1 Bank office- Banking Activity Area 16.1
Restrooms 9.7 Retail  
Dressing/Locker/Fitting Room 6.5 For Sales Area 18.3
Corridor/Transition* 5.4 · For Mall Concourse 18.3
· For Hospital 10.8 Sports Arena  
·For Manufacturing Facility 5.4 · For Ring Sports Area 29.1
Stairs-active 6.5 · For Court Sports Area 24.8
Active Storage* 8.6 · For Indoor Field Area 15.1
·For Hospital 9.7 Warehouse  
Inactive Storage* 3.2 ·For Fine Material Storage 15.1
· For Museum 8.6 · For Medium /Bulky Material Storage 9.7
Electrical /Mechanical Facility 16.1 Parking Garage- Garage Area 2.2
Workshop 20.5 Transportation  
Convention Center- Exhibit Space 14.0 · For Airport- Concourse 6.5
Library ·  For Air/Train/Bus- Baggage Area 10.8  
· For Card File & Cataloging 11.8 · For Ticket Counter Terminal 16.1
· For Stacks 18.3    

4. Service Water Heating:

Mandatory Requirements

a) Solar water heater or heat recovery for at least 20% of the design capacity

Minimum efficiency for service water heating equipment

Piping insulation