88 — April/May 2015 — Build 147

Departments/Innovation

A SYSTEM DESIGNED and implemented by Beca uses the artesian water flowing underneath Christchurch and the Canterbury Plains to both heat and cool Christchurch’s new international airport.

By tapping into wells to access ground-water, the airport is provided with a sustain-able, reduced-cost energy-efficient source.

Many benefits

The benefits are huge. LPG, diesel and cooling tower requirements are eliminated,

Tapping intonature’s gift

A pioneering, award-winning artesian heating and cooling system developed for Christchurch International Airport is already being used in

other large-scale projects here and has scope internationally.

By Dael Climo, Build Deputy Editor

maintenance costs are reduced, and as the same energy is used for both heating and cooling, it is five times more efficient than standard systems. For every 1kW that is put in, 5 kW of energy is transferred.

Chillers, acting as geothermal heat pumps, provide both mechanical cooling and heating, and 12°C artesian water is used for direct cooling. Apart from enabling artesian water to heat or cool the building at any one time, the system can also recover and redistribute heat energy.

Has huge potential internationally

Beca Business Director Keith Paterson says the model is already being applied in other large-scale commercial buildings throughout New Zealand, and other coun-tries are expected to follow.

‘It has changed the market – people worldwide are recognising that this is the most energy-efficient system, and they are following our lead.

‘There are great benefits in terms of reducing pressure on recurrent costs and

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moving forward. I think it will be the system of choice for all temperate countries. If arte-sian water is not available, then seawater is a good alternative.’

Peer recognition

The project won the building and con struc-tion category in the 2014 New Zealand Engineering Excellence awards and, recently, the international project of the year at the Chartered Institution of Building Service Engineers (CIBSE) 2015 building performance awards. The CIBSE

is an international professional engineering society based in London.

Beca Technical Director and Christchurch Building Services Manager Justin Hill says Beca was proud to be involved in the project.

‘This project epitomises excellent engi-neering in almost every aspect of the design and construction.

‘I believe Beca’s holistic approach to the system design played a major role in the project’s success. Cost-effectiveness, energy efficiency and future flexibility were high on the priority list.’

HEAT EXCHANGER

6–17.5°C WATER FOR COOLING

40°C WATER FOR HEATING

COOLING WATER LOOP HEATING WATER LOOP

HEAT EXCHANGER

WATER–COOLED CHILLERS

WELLS EXTRACTING 12°C ARTESIAN WATER FROM

AQUIFER

7–20°C ARTESIAN WATER RETURNED TO AQUIFER

WATER–COOLED CHILLERS

CHRISTCHURCH INTERNATIONAL AIRPORT TERMINAL