| Title | Implementing a Geothermal Heat Pump in a School in Coyhaique, Chile |
|---|---|
| Authors | Nicolás HURTADO, Nicolás PEREZ-ESTAY, Pablo VALDENEGRO, Diego ARAVENA, Diego MORATA |
| Year | 2020 |
| Conference | World Geothermal Congress |
| Keywords | southern Chile, geothermal heat pump, geothermal open loop, school, electrical resistivity methods |
| Abstract | Coyhaique is the most populated city of the Aysén region in southern Chile. With nearly 60,000 inhabitants, it has been catalogued as one of the most polluted cities in Latin America. This environmental issue is caused by the use of firewood as a heating source. In 2017, the Andean Geothermal Center of Excellence (CEGA) along with several regional entities obtained a regional government funding for the design and installation of a heating system with a geothermal heat pump for a public school. The prototype replaced the wood burning system in ~50% of the school’s infrastructure, and it is intended to serve as an example for others schools in the region, contributing to the regional plan for reducing PM emissions. In order to characterize the aquifer and quantify the available resource, electrical resistivity tomography (ERT) and transient electro-magnetic (TEM) surveys were performed. The aquifer’s electrical resistivity was interpreted to range between 70 – 250 Ωm, showing the water table at 7 m depth underneath the school. The drilling of two shallow wells (extraction and reinjection) confirmed that the aquifer could be reached at 9 m depth and correlated with a resistivity of ~200 Ωm. The extracted groundwater flow is around 5 L/s, but the pumping test showed a much higher capacity (over 20 L/s). School’s infrastructure thermal insulation was inspected before the design of the system, which is based on environmental temperature and focuses on improvements to reach national norms. The final installation consists of a 50 kWt heating system powered by two geothermal heat pumps, covering 11 classrooms through a distributed fan-coil array. The use of fan-coils results in a higher overall efficiency than the use of radiators, since they allow the heat pump to work with lower temperatures. |