In the fight for energy efficiency, technology allows us to take advantage of energy sources such as the sun, wind or water to light, move and heat or cool our homes. The next step could be to look down, below our feet, a few meters above the ground, where the temperature is warm and constant at all times. Again, it is about harnessing the energy that surrounds us. Most of the heat that reaches us from the sun is absorbed by the earth's crust and remains underground. Thanks to the geothermal heat pumps we can take advantage of the heat from the subsoil to heat or cool our home.
In this article we are going to explain what geothermal heat pumps are, their characteristics, operation, efficiency and much more.
What are geothermal heat pumps
A geothermal heat pump is a heating and cooling system that uses heat energy stored in the Earth to regulate the temperature in a building or home. Unlike traditional systems that burn fossil fuels or use electricity to generate heat or cold, geothermal heat pumps are more efficient and friendly to the environment.
How do they work
Its operation shares technology with other types of heat pumps present in the usual air conditioning equipment; the functions performed by the working fluid (heat transfer fluid) of these systems, and the roles played by the rest of the elements that make up the circuit:
- Compressor: Device responsible for increasing the pressure of a fluid, thus increasing its temperature.
- Evaporator: Device responsible for reducing pressure and lowering temperature.
Through this set of pressure changes, the required temperature is transferred from the interior of the earth to the distribution system of the house or room. Once you have done the work of exchanging or obtaining the desired temperature, it is time to distribute said temperature throughout the room to be heated.
The process is carried out in the same way as a normal heat distribution system. There is a sufficient range of soil temperatures for geothermal heating is compatible with new and existing radiators and underfloor heating installations.
Another function of the geothermal installation is to capture heat for the ACS to generate electricity. Currently, manufacturers have models of geothermal heat pumps with sufficient working power to cover the future needs of air conditioning and domestic hot water for each type of home. For these situations, you can count on the water tank without any inconvenience.
Installations with geothermal pumps
There are many types of geothermal installations, which vary depending on what the exchange pipes receive.
horizontal catchment
The main characteristic of this type of facility is the horizontal distribution of the collectors that distribute the heat transfer fluid. These seem to extend the length and breadth of the plot. It is the most widely used format in geothermal models. Its position is about a meter and a half deep, and this is the only condition where the outside climate can be regulated. For this approach to be effective, there needs to be enough expansion area.
In general, its application is more frequently found in plots corresponding to single-family homes or other types of isolated buildings with sufficient surfaces to capture the necessary thermal energy for its use. In small plots with large buildings it will not be entirely effective.
Vertical geothermal collection using probes or wells
To overcome the previously assumed lack of surface problem, there is the option of placing the exchange system (pipes) vertically. This alternative compensates for the lack of space with a higher perforation. The work involved using more sophisticated preparation machinery, but the results were more efficient when reach warmer sediments at depths ranging from 25 to 150 meters. The diameter of the probe well is relatively small, around 10-15 cm.
Geothermal capture in lakes or rivers
Geothermal water harvesting involves introducing exchange systems (heat transfer fluid pipes) directly into hot lakes or rivers or hot water reservoirs. The heat exchange occurs directly in the aqueous medium.
It is a very simple system without excessive technical complexity, more economical and efficient. Of course, its disadvantage is that this aqueous resource is not available everywhere. According to the installation depth of the fluid collector and the required heat demand, the power or type of geothermal pump It should be the right one for each case.
Advantages and disadvantages of geothermal heat pumps
Advantages:
- Energy efficiency: Geothermal heat pumps are highly efficient compared to conventional heating and cooling systems. They can provide up to four units of heating or cooling for every unit of electricity used, making them economically attractive in the long run.
- Sustainability: They are an environmentally friendly option because they take advantage of a renewable and constant source of energy: the subsoil temperature. This reduces dependence on fossil fuels and decreases greenhouse gas emissions.
- Versatility: In addition to heating and cooling, ground source heat pumps can be used to heat water, which saves energy in domestic hot water production.
- Durability: These systems tend to be durable and require less maintenance compared to other heating and cooling systems.
- Independence from external weather conditions: Unlike solar thermal systems or photovoltaic panels, geothermal heat pumps do not depend on solar radiation or external weather conditions, so they work constantly and predictably throughout the year.
Disadvantages:
- Initial investment: The initial investment to install a geothermal heat pump is usually higher than that of conventional systems. This is due to the need to bury the geothermal loop or submerge it in water, which requires specialized excavation and equipment.
- requires space: Installation of a geothermal system requires space for the geothermal loop, either in the ground or underwater. On properties with limited space or zoning restrictions, this can be challenging.
- Need for permits and regulations: Regulations and permits for the installation of geothermal systems may vary by geographic location, which could add complexity to the installation process.
- Payback time: Despite their efficiency, the time needed to recover the initial investment can be longer than with cheaper systems, depending on local energy prices and available tax incentives.
I hope that with this information you can learn more about geothermal heat pumps and how they can help heat or cool our home.