Heating a cottage or summer house is not an easy task, requiring careful attention, a competent and rational approach. Given the intensive growth in energy prices, even economical gas appliances are sometimes not the best choice. In terms of lack of operating costs, do-it-yourself geothermal home heating looks the most advantageous. This scheme involves the use of underground heat generated naturally. This option, for sure, will appeal to people who are not indifferent to environmental issues, there is simply no harm to the environment.
For the first time, such methods were tested in the 70s of the last century in the United States, when the first economic crises broke out. Of course, these systems could hardly be called perfect, which was reflected both in efficiency and in the cost of arrangement. In today’s world, fortunately, things are quite different.
There is an opinion that geothermal heating of a private house can be created only in fairly warm regions, where hot springs and springs beat around. This is absolutely not true. A clear example of this is Greenland, an island with harsh climatic conditions, most of whose territory is hidden by snow. However, the vast majority of local houses, farms and agricultural land is heated by underground heat.
You can compare the operation of such a heating system with a refrigerator, but vice versa. The inner layers of the earth maintain a sufficiently high temperature constantly, heating up from the core, regardless of external conditions. It remains only to understand how to “extract” this thermal energy.
For this purpose, a heat pump is mounted at the top, a shaft is pulled out into which the heat exchanger is immersed. Groundwater passes through pumps, heats up, and by entering pipes and radiators heats the air in the premises. The system includes two circuits:
- Internal circuit — a classic building heating system, consisting of radiators, pipes, batteries and other things;
- The outer circuit is directly a heat exchanger located deep in the ground.
It is worth noting that both ordinary water and antifreeze can be used as a coolant.
You can heat your home according to one of the following schemes:
- Pump and heat exchanger of vertical type. The depth of the well in this case varies from 50 to 200 meters, so drilling is associated with significant financial investments. Thermal energy is taken from deep groundwater, the temperature of which is very high. The heat pump provides the movement of the liquid, the heat exchanger takes energy, then the water is discharged back. Do not be afraid of the initial investment, the calculations clearly show that the result justifies the means, the duration of operation reaches a century.
- A technique based on the installation of a reinforced tank with antifreeze heated by soil in a mine about a hundred meters deep has a lot in common with the described scheme. A heat pump is also used to keep the antifreeze moving.
- A horizontal heat exchanger is a less expensive and more structurally simple scheme. The main requirement is that the pipes are below the mark at which the soil freezes during the cold season. The heating efficiency in such a situation is less, and therefore it has to be compensated for by the total collector area, which should be approximately 2 times the area of the heated room. Of course, this value is approximate, the exact coefficient depends on many factors.
- Finally, the last scheme is suitable if there is no more than a hundred meters between the heated building and the nearest body of water. The advantage of this technology is a small financial investment, the absence of significant volumes of earthworks. The heat exchange circuit is located so that freezing is not observed at depth, there must be at least a meter of water under the ice. Ideally, there should be no current in the pond that could damage the probes located at the bottom. It is these probes that are absorbers of thermal energy.
Polyethylene-based pipes are excellent for forming the outer contour. When calculating, it should be assumed that from 40 to 50 W of thermal energy should fall on the meter of the collector. It turns out that in a situation where the pump capacity is 10 kW, the drilling depth will be up to 200 meters.
It is worth remembering that in some situations it is more rational to drill not one deep well, but several smaller ones. So that in such a situation the appearance of the site is not spoiled, the cluster method is used — several pillars diverge from one starting point in depth.
So, the geothermal method is characterized by the following set of positive features:
- Inexhaustible free thermal energy is used.
- There is no risk of fire, detonation, short circuit and other dangerous phenomena.
- There is no need to erect a separate building for the organization of the boiler room, the unit itself takes up little space, there is no need for additional space for fuel storage.
- The scheme is ideal from the point of view of environmental safety. In the process of use, there are no combustion products and emissions that provoke air, soil and water pollution.
- The system does not need regular maintenance and control, the correctness of the parameters is maintained by automation. Economy is also ensured by this feature.
- Variability. The heating circuit, located directly in the building, is no different in its design from traditional water heating systems. The owners can bring to life both the modern idea of \u200b\u200bunderfloor heating, and the more traditional radiator scheme.
The main problem of this technology is the high price, due to the significant amount of excavation. However, given the further advantages, this disadvantage seems insignificant. Practice shows that full payback is achieved in just a few seasons!