This presentation looks at the technical perspectives of delivering an energy model for both the purposes of different regulatory frameworks; LEED and BREEAM. The technical focus will be upon the metrics used and design strategies that affect the performance, certification and rating of buildings.

1. Delivering an Energy Model for BREEAM and LEED
– Exposing What Really Matters
John Gleeson
B.Sc. Eng., C.Eng. MIEI,
IES Ltd. (Dublin)
John.Gleeson@iesve.com
Liam Buckley
ASHRAE Member, M.Eng., C.Eng. MIEI, BEMP
IES Ltd. (Boston)
Liam.Buckley@iesve.com

2. Delivering an Energy Model for BREEAM and LEED
– Exposing What Really Matters

3. The Energy Model
• Efficiencies & Inefficiencies
• Equivalencies & Synergies
• Opportunities
Delivering an Energy Model for BREEAM and LEED
– Exposing What Really Matters

4. Delivering an Energy Model for LEED
1. The Model Geometry

5. Delivering an Energy Model for LEED
1. The Model Geometry
Proposed Model 4 Baseline Models
• 40% glazing maximum
• No Shading
• Fixed Envelope U-values
• Fixed Lighting (W/m2)
• Fixed HVAC based on heating fuel source,
number of floors and conditioned floor
area of building
• No Renewable Energy
• As designed (almost)

6. Delivering an Energy Model for LEED
1. The Model Geometry
Solar Tracking & Shading
Detailed Solar Tracking for Solar Gain Calculations
Linked to HVAC Loads Sizing & Energy Simulation

7. Delivering an Energy Model for LEED
1. The Model Geometry
Abu Dhabi Financial Centre, UAE
• 6,100,000 square foot development, 8 buildings
• Double-Skin Façades
• Daylight Harvesting
• Automated Shades & Blinds
• Underfloor Air Distribution
• CDQ Desiccant Dehumidification
• PV Panels

8. Delivering an Energy Model for BREEAM
1. The Model Geometry

9. Delivering an Energy Model for LEED
2. The Climate / Weather Data
• Dry-bulb temperature
• Wet-bulb temperature
• External Dew-Point Temperature
• Wind Speed
• Wind Direction
• Direct Radiation
• Diffuse Radiation
• Global Radiation
• Solar Altitude
• Cloud Cover
• Atmospheric Pressure
• External Relative Humidity
• External Moisture Content
Weather Data (8,760)

10. Delivering an Energy Model for LEED
2. The Climate / Weather Data
Q: What Weather Data do you use?
• TMY, TMY2, TMY3, IWEC, CWEC, TRY, DSY, TMY (7), TMY (15), AMY?
1960 1970 1980 1990 2000 2010 2020 2030 2040 2050 2060 2070 2080
TMY2 Building Lifecycle if built today
1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020
TMY2 [1961-1990]
TMY (7)
TMY (15)
2014
TMY3 [‘91-’05]
IWEC [1982-1999]

11. Dublin89
IWEC
TMY(15)
TMY(7)
Delivering an Energy Model for LEED
2. The Climate / Weather Data
Dublin Weather Heat Maps
JAN FEB MAY APR MAY JUN JUL AUG SEP OCT NOV DEC

12. Delivering an Energy Model for LEED
2. The Climate / Weather Data
Dublin Temperature Distribution
IWEC TMY(7)
Δ = 1,537
hours < 8°C

13. Delivering an Energy Model for BREEAM
2. The Climate / Weather Data
• Ireland –
• Monthly weather data from with SBEM
• Dynamic thermal simulation average IWEC
file used (8760hrs)
• UK
• Monthly weather data from with SBEM
• Dynamic thermal simulation average TRY
file used (8760hrs)

14. Delivering an Energy Model for LEED
3. The Building Envelope
Envelope Analysis; Fabric &
Infiltration:

15. Delivering an Energy Model for BREEAM
3. The Building Envelope
• U-Values
• Thermal Bridging
• Infiltration
• Refurbishment – Oct 2014

16. Delivering an Energy Model for LEED
4. Internal Gains

17. 0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
LightingEnergy(MBH)
Time (Hrs)
Delivering an Energy Model for LEED
4. Internal Gains
Typical Daily Usage
of Lighting Energy

18. Delivering an Energy Model for BREEAM
4. Internal Gains
• National Calculation Methodology

19. Delivering an Energy Model for LEED
5. HVAC Systems
HVAC Baseline System Selection
• Based on heating fuel source, number of floors and conditioned floor area of building

20. Delivering an Energy Model for LEED
5. HVAC Systems
Part-Load Performance Curves

21. Delivering an Energy Model for LEED
5. HVAC Systems
Naturally Ventilate…. Or not?

22. Delivering an Energy Model for BREEAM
5. HVAC Systems

23. Delivering an Energy Model for LEED
6. Other End-Uses
Elevators, DHW,
Exterior Lighting, etc.

24. Delivering an Energy Model for BREEAM
6. Other End-Uses
Dependant on building type

25. Delivering an Energy Model for LEED
7. The Simulation Metrics
Cost of Energy Consumption,
Unmet load hours, etc.

26. Delivering an Energy Model for LEED
7. The Simulation Metrics
Walgreens Net-Zero Store
• PV Roof
• Daylight Harvesting
• Automated Shades
• Geothermal
• CO2 refrigeration
• Energy recovery
Courtesy: Cyclone Energy Group

27. Delivering an Energy Model for BREEAM
7. The Simulation Metrics
EN01 Energy Efficiency
• Notional building comparison
• Translation into the ratio
• Weighting
Building energy comparison BREEAM vs LEED

28. Delivering an Energy Model for LEED
Summary
 Detailed & Robust
- Better Accuracy.
 Updated/improved
every 3 years.
 Influential factors can
be identified early.
- Favours Airside HVAC
Systems.
- Assumes sealed, fully
conditioned buildings.
- Documentation.
• Efficiencies are Improving
• Baseline HVAC Becoming Regional
• More Simulations (DL) Required

29. Delivering an Energy Model for BREEAM
Summary
Key Objectives
• Provide consistency and comparability
• Comparison against national baseline
• Use of national best practice standards
• Adds value

30. Delivering an Energy Model for BREEAM
Summary
BREEAM EQUIVALENCY FOR LEED

31. A Presentation by:
Integrated Environmental Solutions
To find out more, please contact:
John Gleeson
B.Sc. Eng., C.Eng. MIEI,
IES Ltd. (Dublin)
+353 1 8750104
John.Gleeson@iesve.com
Questions / Comments
Liam Buckley
ASHRAE Member, M.Eng., C.Eng. MIEI, BEMP
IES Ltd. (Boston)
+1 617 840 6101
Liam.Buckley@iesve.com