Presentation showing the incredible energy savings potential of geoexchange / ground source heat pumps for heating and cooling commercial buildings. This presentation was delivered at the AIRAH Pre-loved Buildings Conference in Brisbane, Australia in October 2014. Titled Small Council, Big Vision, Bigger Savings, it takes the audience on the journey of this project from initial concept through to completion. It discussed both the incredible energy and dollar savings while also addresses the importance of the project team and their importance in delivering what was a truly great project.

2. Small Council, Big Vision, Bigger Savings: The Transformation of the RiverinaHighlands Building
Yale Carden (M.AIRAH, M.IGSHPA) and Cameron Hutchison (M.IGSHPA)

3. Presentation Overview
•The Small Council:
–TumutShire and the RiverinaHighlands Building
•The Big Vision:
–The RiverinaHighlands Building Energy Efficiency Project (RHBEEP)
•GeoexchangeProject Cycle
•Bigger Savings:
–The Story So Far
•Conclusions

4. Introduction
•Client: TumutShire Council
•Population: 11 000
•Elevation: 305 m
•Monthly Minimum: 1.2 C in July
•Monthly Maximum: 31 C in January

5. Location

6. The RiverinaHighlands Building
•Built in early 1980s by TumutCounty Electricity Authority
•NLA of 2326 sqmover 3 floors
•Brick, iron roof, single glazing, minimal insulation
•Tenants: Council, State Government Departments, Emergency Operations Centre
•Purchased by TumutCouncil in 2008

7. Stewardship Commences
•2008: First AC Audit
–Replacement required
•2011: Level 2 Energy Audit
–January 2009 to October 2011
–Daily peaks of >200 kWh from June to August
–Monday winter peak from 0630 to 0800
–Daily peak in summer of 100-150 kWh from 1430 to 1700

8. Electricity Use Breakdown (2010)
Usage
kWh pa
Percent
Lighting
130 341
24 %
HVAC
283 302
51 %
Refrigeration
--
--
Appliances
134 410
24 %
Pumps and Motors
--
--
Hot Water
7621
1 %
Other
--
--
TOTAL
555 673
100 %

9. Energy Audit: The Business Cases
•Upgrade and Retrofit Lighting (T8-T5);
•HVAC Retrofit / Upgrade; and
•Solar PV Installation (30 kW)
•Plus
–Installation of insulation;
–Power Factor Correction; and
–Metering Optimisation

10. The Big Vision -RHBEEP
•Reduce electricity
•Lead by example
•Educate others
•Future proof
•Build local capacity

11. The Big Vision -Finance
•Community Energy Efficiency Program (CEEP): $877 516
•Clean Energy Finance Corporation (CEFC): $1.18 million low interest loan

12. Transforming the HVAC
•Existing / original:
–Air cooled central plant with electric duct heaters
–Split DX units in meeting rooms, server room and Emergency Operations Centre

13. Transforming the HVAC
•Upgrade Options
–Optimiseexisting system
–Variable Refrigerant Volume (VRV) system
–Geoexchange/ GSHP system

14. The GeoexchangeProject Cycle
•Pre-feasibility and Concept Design
•In-situThermal Response Test
•GeoexchangeDesign
•Building Services and GSHPs
•Ground Heat Exchanger
•Pumping Strategies

15. Pre-feasibility and Concept Design
•Desktop Study Identified:
–Client Commitment
–Climate
–Car Park for Ground Heat Exchanger (GHX)
–Internal space suitable for GSHPs

16. Thermal Response Test
•Thermal Conductivity
•Thermal Diffusivity
•Mean Earth Temperature
•Practicalities

17. GeoexchangeDesign Process
•Building:
–Annual hourly load profile
•Ground:
–Thermal properties -TRT
•Distribution:
–Building services and GSHPs
•Integrate:
–Building annual heat flux with ground capacity

18. GeoexchangeDesign Process
•Finalise:
–GHX design re borehole quantity, depth and spacing
•Pumping:
–Optimiseheat transfer and minimisepumping costs

19. Building Services and GSHPs
•Distributed ‘water to air’ GSHPs
•26 GSHPs in individual zones
•DC inverter compressor
•Variable speed fans
•Modulating water valve

20. The Ground Heat Exchanger
•35 boreholes at 92 m deep, 7 m spacings
•Bentonite / silica grout (enhanced)
•Reverse return manifoldedas 5 sets of 7
•Material:PE100, DN40 (boreholes)
•Material: PE100, DN40-180 (manifolds)
•Electrofusionjoints

21. The Ground Heat Exchanger

22. Pumping Strategies
•Low pressure drop
•No balancing valves
•3 circulating pumps with VS drives (1 standby)
•Additional small pump for very low loads such as Emergency Operations Centre

23. Bigger Savings: The Story So Far
Summary of Energy Savings Across the RHB (MWh)
Lighting
HVAC
Other
Total
Baseline Data
121.9
267.1
142.1
531.2
Jan-May 2014
51.2
37.6
135.0
223.8
Savings
70.7
229.5
7.1
307.3
% of System
58 %
86 %
5 %
58 %
% of RHB
13 %
43 %
1 %
58 %

24. Bigger Savings: The Story So Far
•86 % HVAC savings includes insulation and lighting upgrades
•Level 2 Audit predicted 79 % saving with geoexchange
•Does not yet include the heating season, which has predicted savings of 88 %
•Annual maintenance costs were ~$80 000

25. Bigger Savings: The Story So Far
•The simple economics:
–~$217 00 in annual savings
–Simple payback is ~8 years
–Simple payback with funding is <4 years
–ROI is 11-12 %
•Increased plant room space
•Higher comfort levels
•Greater temperature and humidity control

26. Bigger Savings: The Story So Far

27. Conclusions
•The value of a big vision
•Power of a small team with a purpose
•A template for similar buildings
•Importance of finance structures

28. Finalist Awards
•AIRAH 2014 Award for Excellence:
–Best HVAC and Refrigeration Retrofit or Upgrade (National Award)
•Banksia Foundation:
–Innovator of the Year (National Award)
•Local Government NSW:
–Climate Change Action (State Award)
•Local Government Management Association Excellence Awards 2013:
–Excellence in Environmental Leadership and Sustainability (State Award)
•Office of Environment and Heritage Green Globe Awards:
–Local Government Sustainability (State Award)