Australian Geological Survey Offices - Canberra - Australia

SYSTEM COMPARISON - Geoexchange Vs Conventional

Building Area:

19 000 square metres

System Capacity:

2.5 M Watts

Equipment:

230 WaterFurnace Premier AT heat pumps of varying capacities

Ground Loops:

350 x 104 metre x 32 mm loops connected by 50 x 50 mm headers

Common pumping via variable speed pumping station.

Capital Cost:

Additional $500,000.00*

Operating Cost:

$15.00/sqm compared to $4.50/sqm for Geoexchange

Annual Operating Cost:

Additional $199,500.00

Pay-back:

Immediate

* Original conventional plant design incorporated a stand-by chiller/boiler plant (full capacity), if this had not been costed into the design, there would have been a two year payback.

Other Advantages:

• Modular plant
• Long equipment life
• Can operate minimum plant for areas required 
• Minimal Maintenance
• No outdoor equipment 
• Minimal plant room
• Reduced CO2 emissions