The SAGS Project will install 2 types of different geothermal collectors at the site of a new build residential dwelling at Druids Glen, Wicklow, Ireland during the Summer of 2016 . This consists of a single U pipe type collector of 100m and 2 GeoKoax of 50m each. All three of these holes are backfilled with thermal grout.
Before connection to the house, the collectors will be tested using a Thermal Response Test in the same ground conditions and based on the individual results, the range in ground temperature over 25 years of operation will be simulated. This is typical best practice in the design and sizing of ground collectors. The results of the test will show the most efficient collector that will be matched with the solar thermal collector and will also help size the solar thermal collector (estimated at 3kW solar thermal capacity (c. 6m2) of evacuated tubes).
The results of this Thermal Response Test will be used to build an operational model to simulate the performance of the system with and without the solar assistance to the ground loop. This will be done by a combination of the commercially available EED and GLD softwares.
The house involved in this project is two storey new build home , located on sandstone and slate bedrock formations of the Bray Head Group (GSI, 1999). A total heating demand on 9kW has been estimated for the dwelling, comprising 3kW of domestic hot water and 6kW of space heating. The building fabric is planned to achieve A2 rating or better.
House under construction as of September 2016
Based on the computer modelling and Thermal Response Testing the 100 m double U collector or the 2x50M GeoKoax will be included as part of the house development. Detailed monitoring services will be installed and will cover:
- Heat meters – independent meters for the solar thermal system, the ground source heat pump and the brine collector heat These will measure individually the energy delivered by each component of the system;
- Energy meters – will be included in the system with all the individual electrical components that will include the heat pump, individual circulation pumps for the solar thermal and heating system
- Management control unit – to provide data on the house demand and delivery to the independent zones of the house.
- Additionally, a down hole temperature measuring sensor has been developed in house and will be permanently emplaced in the a GeoKoax borehole and the U pipe borehole. These will be used to provide year long subsurface temperature data at 15 minute intervals. This will be especially useful in monitoring the evolution of ground temperature as the system operates.
The outputs and interpretation of this data collection will be made available as part of a web based interface, particularly of the 2016/2017 heating season.
The project partners expect to provide case study data from these trials at the Energy Show in 2017.