Functioning and performance of the geothermal system in Amadeo

08 November 2009 - Comments (3)

Construction

In the previous article we detailled the installation of the geothermal system. We now look at its functioning and performance, showing that almost 80% of the geothermal heat pump energy output, comes from the ground for free. That is saving money and reducing CO2 emissions. Vaillant engineer, Saša Tasić, gives us a complete walkthrough.

Note for our English speaking readers: the videos below are all in Serbian language. We do not have English subtitles at this time.

Vaillant geothermal heat pump GeoTHERM VWS 300/2 and buffer (Photo Beodom).

General presentation of the geothermal system

This first video covers the presentation of the geothermal system and of its 3 main functions :

• heating water for the underfloor and fancoil distribution to provide heat in the building
• heating water to provide a secondary source of energy for the sanitary hot water in the building (the primary energy being the solar system)
• cooling water for the underfloor and fancoil distribution to provide freshness in the building in the summer months.

One of the important element in the system is the main circulation pump, that is working synchronously with the heat pump, and the switching valve that directs hot water from the heat pump, either to the cylinders for the sanitary hot water preparation or in the buffer for the underfloor heating distribution.

Switching valve and circulation pump at the back of the buffer. The Vaillant switching valve determines whether the outgoing flow of hot water from the pump goes to the buffer (for the underfloor heating system) or directly to the hot water cyclinders (for the preparation of sanitary hot water). The main circulation pump (in red) circulates the hot water from the heat pump. At the bottom is the expansion tank for the underfloor heating system. (Photo Beodom).

Performance and C.O.P.

The geothermal heat pump efficacy is given using the coefficient of performance (C.O.P.). That coefficient gives the energy output of the pump based on the energy input. A C.O.P. of 5 means that for every 1 kW of electricity used to operate the system, 5 kW comes out of the unit in the form of heat.

Our geothermal heat pump has shown excellent performance so far with a COP of 5 or greater. The pump uses from 7 to 8 kW of electric energy to run the compressor and gets around 30 kW from the ground. That is around 38 kW of heat energy out of the heat pump.

Vaillant geothermal heat pump GeoTHERM VWS 300/2 and distribution loops (Photo Beodom).

Functioning of the heat pump

This second video covers the functioning of the geothermal heat pump and the performance of the installation. It also explains the use of the external electric resistance during the coldest days.

External backup resistance for the geothermal system (Photo Beodom).

Zoom on the distribution loops

In this last video, Saša Tasić explains in details the distribution loops of the geothermal installation. He shows the role of the different switching and mixing valves and of the circulation pumps. In particular concerning the regulation of the temperature in the underfloor heating and cooling system.

Distribution loops of the geothermal system (Photo Beodom).