| Title | CASE STUDY: GROUND SOURCE THERMAL PILES |
|---|---|
| Authors | T. Sanderson |
| Year | 2017 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | Ground Source Heat Pump, Thermal Piles |
| Abstract | The new Administration Offices building for Hutt City Council is heated and cooled by a ground source heat pump, and for the first time in New Zealand, the use of ground source pipework located within the structural piles of the building, known as thermal piles. The original 1950’s building has been refurbished, including comprehensive seismic strengthening which required around 70 new structural piles. Each pile extends up to 20 metres below the surface of the ground, where the temperature remains constant throughout the year. The piles also pass through a sub-aquifer, above the locally well-known aquifer in this area. The stability of the ground temperature is the key to the use of a ground source heat pump, with a resultant high efficiency. The use of pipework which is lowered into the hollow steel structural piles, provides a good ground loop arrangement, as well as allowing a dual function for the piles. This presentation talks about the initial feasibility analysis and modelling work carried out, the ground properties testing, and the actual installation of the ground loop pipework and equipment. The building was occupied in April 2016, and the installation has been in successful operation since then. The building has won awards for its Architectural significance, and as a heritage building a lack of chimneys or external chiller plant has been of significant importance. An in-use energy rating certification process for the building is also currently under way. |