How a ventilation system impacts a geothermal installation
superadmin
December 29, 2016
When identifying how a balanced ventilation system impacts a geothermal installation (known as ground-air geothermal exchanger, Provençal well or Canadian well), first the concept of geothermal energy must be considered, what it represents and how it varies according to the seasons.
The geothermal energy is a renewable energy that utilizes the heat from the subsoil for ecological climate control, with low energy consumption and significantly reducing CO2 emissions. On average, the temperature increases between 2 and 4° C as the depth of the Earth increases by 100 meters. This temperature gradient is what allows for energy capture through different systems:
- Subsurface open capture: it consists of making one or more vertical boreholes until reaching the depth where an underground aquifer is located. Traditional water pumps are introduced in these boreholes, extracting heat from the water to introduce it into the interior of the house or building. The extracted water flow is returned to the ground by means of an injection well separated 20 m from the extraction wells.
- Vertical geothermal capture: it consists of extracting or giving heat from the Earth using probes that form a closed circuit and act as heat exchangers. Depending on the characteristics of the terrain, the depth of the borehole varies between 80 and 150 m.
- Horizontal geothermal capture: the capture probes are buried 1.5 to 2 m. deep to extract energy from the ground. By means of a network of polyethylene pipes through which water with glycol circulates, a heat exchanger is formed that climatizes and supplies ACS to the house.
You can learn more about geothermal energy through this video:
The operation of geothermal energy capture systems varies depending on the time of year. In summer, heat is given up to the interior of the ground through probes or collectors. In winter, the process is reversed to extract heat from the ground and heat the interior of the building. This process repeats throughout the year to supply domestic hot water. When heat capture is carried out through air conduction from the subsoil, the installation of a Provençal or Canadian well is often chosen. These wells can be connected to a double flow ventilation system, especially efficient in recovering the heat from contaminated air to maintain constant indoor temperature. When this ventilation system is connected to air wells from the subsoil, the entire geothermal installation undergoes a series of impacts that must be considered when designing it:- A loss of pressure occurs in the air circulation through the perforated ducts within the ground. This naturally increases with depth and if not taken into account, it can significantly reduce the energy efficiency of the entire installation.
- The connection of a Provençal well for extracting geothermal energy with a double flow ventilation system makes it essential that all air extraction points are hermetically sealed. Otherwise, the heat contribution in winter may drastically reduce compared to the initial calculations.
Siber Ventilation
Manufacturer of High Energy Efficiency Ventilation Systems. Siber provides a set of high energy efficiency solutions in wind and mechanically intelligent ventilation, improving the Health, Hygiene, and Comfort of people, being respectful of the environment.