Before every owner country house such an important question arises as ensuring the supply of heat to all residential premises. Today, various manufacturers offer their own options for individual heating of private cottages outside the city. A new development in this area is geothermal heating. Of course, most home owners are confident that such a convenient and economical heat supply system can only be installed in areas where there are geysers, volcanic formations and hot water springs. Modern installations this type can work successfully in temperate latitudes, with warm springs at low temperatures.
Features of geothermal heating
Geothermal heating refers to alternative types of heat supply in the house. This option for a thermal installation can be called almost ideal for arranging a private home or country house. To work in the system it is used geothermal energy, which is extracted from various natural heat sources. The basic principle of operation in such an installation is similar to the operation of a walking system. The main difference is the following: if in a refrigerator the refrigerator produces cooling for air from the resulting system, then here it produces thermal energy. Coordinated work is possible even with low temperature characteristics.
The main feature of geothermal heating in a house is that during the warm summer season the air in the house is cooled, but in winter it heats up. At the same time, the costs of such heating are very low compared to other thermal installations. In some ways, the operation of such a system is similar to air conditioning. She helps create in the house necessary warmth and comfort, providing the owners with comfortable living conditions in the house.
Geothermal heating principle
The geothermal installation operates autonomously, clearly regulating the required temperature in the room. The principle underlying its operation is the same for all installations, therefore it is independent of various manufacturers of component parts. The main work is assigned to special pumps, which may have some differences among themselves design solution, varieties, but at the same time coefficient data In terms of heat performance, they are all similar. Regarding the energy used, the geothermal system works successfully with various types earth energy.
The system consists of two circuits, namely:
- internal;
- external
The first of those mentioned is presented as familiar to many heating installation from the connection of pipes and radiator elements. The outer contour is dimensional heat exchanger, which is mounted under the thickness of the earth or in a body of water. A special liquid with the addition of antifreeze circulates inside it, and sometimes it is also filled with ordinary water. The coolant is gaining ambient temperature, and the already heated one goes further into the geothermal pump. The heat thus accumulated is transferred further to the internal circuit. This allows water to be heated in radiator elements and pipes throughout the house.
Methods for implementing a geothermal installation
This type of heating differs in the way the heat exchanger is installed. Today there are three varieties in use:
- Vertical heat exchanger: it is compact and has a higher installation cost compared to other types. To install a vertical heat exchanger, you do not need to use a large area, but you will need to use specialized drilling rigs. Depending on the chosen technology, the depth of the finished well can reach up to 200 meters, the minimum value is 50 meters. The service life of the system is up to one hundred years. It is beneficial to install this type of geothermal heating if it is installed on an already developed area. The landscape of the area will remain virtually untouched.
- Horizontal heat exchanger: this type is used quite often. When installing a horizontal heat exchanger, the pipes are laid to a sufficiently large depth, which necessarily exceeds soil freezing level. The main disadvantage of using exactly this type of wiring is that it requires a large area to be used for installing the collector. It is difficult to install such a system on an already developed site.
- Water-based heat exchanger: this installation is the most cost-effective among all the variety of geothermal heating, as it works due to energy of water bodies. This system is relevant for those homeowners who have a body of water hundreds of meters away. Such a heat exchanger the most profitable which makes its installation the most appropriate among all types of similar heating.
Pros and cons of geothermal heating
Geothermal heating became relevant in America during the crisis in the 80s. Initially, installation of the units cost big money and such heating was used exclusively by wealthy people, but later geothermal heating became more accessible for mass use by the population.
Advantages of using geothermal heating in a private home:
- Geothermal energy can be obtained and subsequently used almost anywhere;
- the supply of this type of heat is unlimited;
- the use of such energy is considered the most sustainable;
- geothermal energy does not contain various types of harmful emissions from combustion carbon dioxide;
- heating based on a geothermal installation does not require constant maintenance of the house;
- heating is considered free for the home owner;
- installation pumps take a lot less space Compared to similar thermal installations, a geothermal pump requires approximately the same amount of space for installation as, for example, a refrigerator;
- geothermal energy helps both heat the room and, if necessary, cool it; the operating principle is similar to the operating algorithm of air conditioners;
- If desired, such heating can be installed together with other heat supply systems, for example, with gas system, diesel or powered by solar energy.
Despite a number of positive points use of this type of heating, geothermal installations also have their own flaws, the main ones are:
- high costs for installation of the entire system;
- long payback period.
Such shortcomings of the heating system pale in comparison with the current trends in global cost increases. various types fuel. Of course, the payback period is long, but in a hundred years a geothermal installation will show all its advantages and prove its efficiency on practice. This type of heating has already been appreciated in a number of European countries and America. For example, in Sweden, about 70% of private homeowners chose just such a system for heating.
Video
Sergey Elgazin found out everything about geothermal heating in one of the Finnish houses:
The limited reserves of natural energy resources force humanity to search for alternative sources energy. Geothermal home heating is a great alternative traditional ways heating. This can be confirmed by factual data on the widespread use of geothermal heating systems in Europe and America as the main sources of heat.
A little history! Geothermal heating systems “expanded” significantly in the late eighties of the last century, mainly in America. At the beginning, the substantial investment in installing such a unit allowed it to be used only by wealthy people, but a few years later this system became accessible to less wealthy Americans, raising the importance of geothermal heating systems in the heating equipment market.
In European countries, just two decades ago, the number of geothermal installations exceeded 12 million, but today one can only guess about the size of the “population” of geothermal installations in private homes.
Why is this happening?
Everything is very simple! The most accessible and convenient system gas heating reduces natural fuel reserves for money out of your pocket. And burning solid fuel(firewood, coal, peat) is not only inconvenient, but is also accompanied by the release of harmful carbon dioxide, loss of soot and tar. And it is also necessary additional room for storing fuel.
Operating principle of the system
Geothermal heating systems have a principle of operation similar to that of a refrigerator (air conditioner). Simply, the refrigerator refrigerator cools the air, and the geothermal heat pump heats the heating system coolant.
The heat (energy) of the Earth is used to heat the room. A heat pump located in the house takes energy from groundwater or the soil itself, converting it into heat. This “heat” is then used to heat the coolant in the home’s heating system itself.
Based on the operating principle heat pump lies the reverse Carnot cycle, developed back in the 19th century.
The “heart” of such a system is the compressor, which “compresses” and “transfers” heat. For this he needs external source energy - electrical network.
In a company with compressors, the internal circuit of the heat pump operates: a condenser, an evaporator and a throttle valve.
A heat pump works like this:
- The heat intake manifold is filled with a non-freezing liquid (glycol mixture, a mixture of water and alcohol, or salty water), which will transport "underground" or "underwater" heat to the pump.
- This thermal energy in the evaporator is transferred to the very low boiling point refrigerant, causing it to rapidly boil and evaporate (turn to steam).
- A running compressor increases the pressure of this steam, which accordingly leads to an increase in its temperature.
- In the condenser, the refrigerant is cooled, transferring heat to the heating circuit of the house, and condenses.
- Through the throttle valve, the refrigerant flows back into the compressor, and the cycle repeats again...
A heat pump can also be called, in other words, an “inside out” refrigerator. After all, in a refrigerator, the refrigerant is heated due to the heat of the products placed in it (the refrigerator), and through a system of tubes it is discharged to back wall, heating the air outside the refrigerator.
And in the case of a heat pump, this generated heat heats the coolant in the heating system of the house itself. “Warm floors” are most often and more efficiently used as heating devices in such heating systems.
Notice! If there is a high-quality and correctly calculated “heat intake” circuit, with a consumption of 1 kW of electricity, the heat pump is capable of delivering up to 5 kW of thermal energy to the system!
Types of heat exchangers for geothermal heating systems
Horizontal heat exchanger
Horizontal pipes are laid to a depth exceeding the thickness of the soil freezing layer.
This option thermal circuit optimal when available big square personal plot without garden plantings (trees). Laying the circuit pipe is not allowed at a distance of less than 1.5 m from the tree crown.
When heating a house of 250 m2, an area of 600 m2 will be needed to accommodate the heat exchange circuit. But such space is not always available. Especially in densely populated cottage towns.
This factor can be called a disadvantage of this type of heat exchanger.
Vertical heat exchanger
A vertical heat exchanger is a luxury that perhaps not every developer can afford. To “arrange” such a heat exchanger, you will need special drilling equipment.
The heat exchanger circuit is lowered into a well 50-200 m deep. To increase the thermal power, several such wells are used, the pipelines of which are connected through special collector units.
The advantage of organizing such a heat exchanger circuit system is the possibility of working in a developed area - this method will not damage the existing landscape.
Heat exchanger placed in water
This option is the most economical to install - there is no need to carry out excavation work, but it requires the presence of a reservoir with an area of at least 200 m2 at a distance of no more than 100 m from the house. The circuit pipes are laid to a depth greater than the freezing depth (at least 2-3 m) at the bottom.
Advantages and disadvantages of geothermal heating systems
We would like to highlight one of the most significant advantages of geothermal heating systems: environmental safety for your home. After all, the process normal operation heat pump is not accompanied by any harmful emissions into the atmosphere. And the absence of flammable substances in fuel pump if there is proper electrical wiring, it virtually eliminates the threat of fire.
The absence of fuel means the absence of costs for its delivery and storage.
Low electricity consumption with relatively high heat transfer (from 1 kW of electricity to 5 kW of thermal energy) is another important (or the most important) factor determining the choice of a geothermal heating system for a country house.
The autonomy of a geothermal heating system frees you from the need to monitor and maintain it.
Important functional advantage A geothermal heating system is its ability to work like an air conditioner in hot weather. In this mode, the opposite happens: heat from the room warms up the refrigerant, which transfers it to the external heat collector.
The disadvantage of such a system is the complexity of its installation and the correspondingly high cost, as installation work, and the equipment itself.
Geothermal heating system is the most expensive to install and purchase equipment.
In this case, you can save money on self-installation this system, but it is necessary to pay considerable attention to calculations and consultations with the “pros”.
Using a bivalent heating circuit
The bivalent system involves the parallel use of two heat sources during peak loads (at low temperatures environment).
In such a system, an additional boiler, for example an electric boiler, is connected in parallel to the heat pump. It is used when it is necessary to use intensive heating mode at low ambient temperatures.
If there are few “frosty” days a year in the region where you live, then the presence of such an “assistant” allows you to save on the power of the heat pump, which significantly affects its cost.
It must be admitted that the average person thinks little about the depletion of the earth's interior, the pollution of the atmosphere and the environment in general from the burning of hydrocarbons. And only now people have seriously begun to pay attention to environmentally friendly and renewable energy sources, as the cost of hydrocarbon fuels has begun to rise steadily. One way to use such inexhaustible sources is to heat a house with the heat of the earth. You will find information about how it works and how it is implemented in this article.
How it works?
It is a well-known fact that the soil temperature at a depth of about 1.5 m or more is constant throughout the year. Its value lies in the range of plus 5-7 ° C, and the temperature gradually increases with increasing depth. Thanks to this phenomenon, people store food and vegetables from their gardens in basements.
It turns out that the temperature there is always positive and it would be a sin not to use this heat from the ground to heat your home.
What attracts people most is the fact that the thermal energy of the soil is free. But extracting it and sending it into the house will cost a tidy sum, which we will talk about later.
It is absolutely pointless to move such weak heat as +7 °C into rooms. The problem is not like this: we need energy, not temperature. And a regular air conditioner can help with this, only turned upside down. After all, what is he doing? In summer it takes energy from inside the building and moves it outside, and in winter it moves it in the opposite direction. This occurs due to heat exchange processes inside refrigeration machine(Carnot cycle).
In short and in simple words, then the coolant liquid circulates inside the air conditioner between two heat exchangers. In the first, it evaporates, taking heat from the air in the room, and in the second, it condenses, releasing it into environment. Transfer of refrigerant from one state of aggregation the other is facilitated by 2 main units - a compressor and an expansion valve.
In the same way, the thermal energy of the earth is released. A coolant heated to a temperature of +7 °C moves along a contour of pipes placed deep in the soil. In the first heat exchanger, it meets the working fluid - freon, causing it to evaporate. In the second, freon condenses, transferring the resulting thermal energy to the heating system.
As a result of this movement, the earth cools by 2-3 °C, but the house warms up by 20-40 °C. You should not pay attention to the temperature discrepancy, because 10 times more liquid circulates in the earth circuit than in the heating circuit. Energy consumption is negligible; electricity is consumed to operate the compressor, pump and automation. In general, the ratio of energy consumption to energy extracted from the ground is approximately 1: 5-1: 7.
An installation that uses earth's energy for heating has its own name - a geothermal heat pump.
Types of installations for ground heat extraction
The internal structure of the heat pump, briefly described above, remains unchanged in any case. But the design of the external circuit, which extracts energy from the ground, comes in two types:
- horizontal: placed in a pit of the calculated size and depth of 1.5-2 m polymer pipe with a certain step;
- vertical: circuit pipes are lowered into deep wells. Their number is also determined by calculation.
It is convenient to dig a pit at the stage of construction of a private house; this is done exactly in the place where the building is planned to be erected. Also, a horizontal contour can be arranged if there is enough large plot land near the house. When there is no such area and there is very little space, the earth’s energy is collected by geothermal probes from deep wells. You will have to do several of them in different places.
The ends of the pipes from one or more external circuits are laid underground to the house and enter the basement of the building, where they are connected to the heat pump itself. The coolant flowing in underground coils is usually water or non-freezing liquid, depending on the region of construction.
In terms of the efficiency of obtaining energy from the earth, vertical contours are superior to horizontal ones, since they often pass through aquifers, and this improves the selection of heat. They also hold the lead in terms of installation cost, especially if wells are drilled in difficult conditions.
Advantages and disadvantages
Thermal energy extracted from the ground, as we have already found out, costs practically nothing and this is the main advantage. But there are others:
- the heat source is renewable, in other words, inexhaustible;
- the environmental friendliness and safety of the thermal installation are unparalleled;
- good energy output at low costs;
- no installation or connection permits are required;
- high degree of automation, and therefore comfort;
- infrequent maintenance;
- low degree of fire danger.
There is another important advantage of the geothermal system. Since the temperature of the soil at depth remains unchanged all year round, in the summer the pump ceases to be a heat pump, but becomes a cooling one. The installation switches to summer mode, the refrigerant moves in the other direction, and the heat exchangers functionally change places. If a private house equipped with units air heating– fan coils, then the system supplies them cold water, which cools the indoor air.
Solar systems have only one drawback, but it is so significant that it often cancels out all the advantages. As you might guess, this is the cost of equipment and installation work. Everyone will understand that digging pits and drilling wells will cost a pretty penny; you cannot do such work with your own hands. Pipes about a kilometer long, the installation itself, automation - all this will cost a tidy sum. That is why the use of earth's heat is still available to very few people.
Conclusion
It is absolutely clear that the use of thermal energy from the ground to heat a house has long-term prospects. It is in Europe that such systems have become commonplace; our citizens’ incomes have not yet reached the required level. But heat pumps are the future, there is no doubt about that either.
UPS - source uninterruptible power supply. This is a device that powers electrical appliances. during a power outage.
They are often used in conjunction with a computer or servers when it is necessary to keep things running 24 hours a day. UPS running geothermal based, do not allow the house with an electric boiler to cool down.
Features of geothermal heating at home
Geothermal heating is a type of heating system in which energy comes from the earth.
Such a system can be built with one’s own hands, for this reason they popular in Europe, and middle lane Russia. But some believe that this is a fashion that will soon pass.
Such equipment difficult to heat large rooms, because the soil temperature in the areas where the heat exchangers are located is usually 6—8 °C.
But especially expensive equipment designed for production scales is capable of producing large amount of energy. Only devices of this type have huge cost.
Principle of operation
Thermal energy is taken from the ground by special heat pumps. Pipes are lowered into the ground through which liquid circulates, which heats up and delivers heat to the house. When compressed and expanded, the temperature of the gas changes; this temperature is enough to heat a house.
Reference! The process is called Carnot cycle. The discovery happened in 1824 French physicist Sadi Carnot. Refrigerators work according to the same scheme, as well as heat engine, invented by Carnot himself.
The device consists of three circuits and a pump, supporting exchange between processes within the system, the number of which is equal to three.
Inner circuit
This circuit is filled with water or a specialized liquid called coolant. Comprises pipes and radiator.
Purpose internal contour- heating of the coolant, which circulates through the system and heats the whole house. It is worth adding that the internal circuit prevents the ground around the unit from freezing.
External
Inside the contour is antifreeze liquid, the circuit itself is deep underground, below freezing depth. Designed to collect thermal energy from the ground. Subsequently, the thermal energy is transferred to the freon circuit.
Freon circuit
The main circuit within which occurs freon boiling. Consequently, a large amount of gas is released, on which the principle of operation of the system is based.
Important! The boiling point of freon is very low.
How different types of geothermal systems work
Exists three types heat exchangers, each of them its advantages. The choice depends on the type of terrain, the size of the area where the equipment will be located, the area of the heated room, the presence of a reservoir, and other factors.
Each of the systems is not cheap, but is economical in terms of consumption, and the power of the unit depends on consumption. The main difference is type of heat exchanger.
Vertical heat exchanger
The main plus is space saving. Ideal for small areas. For example, such equipment can be kept not under the house, but under a hill, without disturbing the landscape, but for this you will have to use powerful drilling equipment, for greater depth.
Photo 1. Burying a vertical type geothermal heating shaft. Spiral-wrapped pipes descend deep into the ground.
Average depth 150 meters, and the diameter 15 cm.
Horizontal heat exchanger
Over such a system you won't be able to plant a garden. It is ideal for heating large rooms from 300 m 2. There is not just a well underground, but a whole system of pipes in special tunnels.
Photo 2. Geothermal heating with pipes laid horizontally: the depth of the pit is small, but the area is large.
Area ratio equipment to the area of the heated area 1 to 3. This is very big sizes.
Placed in water
Such a system, of all those proposed, the most economical. But there is one criterion without which work is impossible: presence of a body of water nearby. The body of water must be located at a distance up to 100 meters from the heated area.
Photo 3. Geothermal heating placed in water: pipes with coolant are immersed in the nearest body of water.
IN in this case thermal energy is not taken from the ground, but of water.
Advice. The area of the reservoir should be more than 200 m2.
Useful video
The video explains how geothermal heat pumps work.
Advantages and disadvantages of heating from the heat of the earth
After conducting a detailed analysis, we were able to identify positive and negative sides such systems.
There are a number of autonomous engineering systems, which are an integral part of any private country house. One of them is a heating system that provides comfortable temperature internal air houses for living at any time of the year, depending on weather conditions.
Geothermal heating is a promising heating option based on the use natural resources- the heat of the earth, which is an inexhaustible resource. The heat pump transfers heat from the ground or surface water coolant circulating through heating system inside the house.
The Gidroinzhstroy company will perform all the work necessary to organize geothermal heating: we will prepare a project, select and deliver equipment, carry out excavation, we will carry out installation and commissioning. Everything will be done within the stipulated time frame and with the maximum high quality. We provide a guarantee for the work performed.
Benefits of Geothermal Heating
Geothermal heating of the house: principle of operation
The home's geothermal heating system has three closed loops. A saline solution or antifreeze circulates through the external circuit pipes, located in the ground or water, to remove heat. Passing through the heat exchanger (evaporator) in the heat pump installation, it transfers heat to the refrigerant of the internal circuit. The heated refrigerant is pumped by the compressor, resulting in an increase in the temperature of the refrigerant. Through another heat exchange device (condenser), the refrigerant transfers its energy to heating circuit Houses.
The outer loop can be a horizontal manifold or a vertical probe.
Horizontal collector
1. The collector pipes are laid on the horizontal surface of the bottom of a trench dug to a depth of 1.5 meters - below the freezing level of the soil. A free area is required for laying pipes large area, on average - about 500 square meters.
2. The collector is placed at the bottom of the reservoir.
Vertical probe
If there is no river, pond, or lake nearby, and the area of the site is such that it is not possible to mount a horizontal heat collector, you can drill an artesian well and lower a vertical probe into it - a pair of u-shaped HDPE pipes through which brine will flow and collect soil heat. The number and depth of wells are calculated depending on the heated area of the house and the hydrogeological conditions of the site.
Disadvantages of Geothermal Heating
Cost of geothermal heating
Organizing heating based on a geothermal heat pump will require considerable financial costs. But in this case, high cost can only be considered a disadvantage as a stretch. Efficient, environmentally friendly and economical, the system is well worth the large initial outlay (which will pay for itself over time). The cost of the system depends on many factors: the area of the heated premises, the power of the heater, the option of installing the collector, etc. For example, the turnkey cost of a heat pump installation with a capacity of 11 kW (suitable for heating a house with an area of 150-170 sq. m) will range from 700 000 to 850,000 rubles.
Other heating system options
Today there are many different systems heating, but the heating system using liquid coolant has become the most widely used. Compared to other systems, it has the most high efficiency, practicality and safety. The principle of its operation is that the heat generator (boiler) heats water or non-freezing liquid (antifreeze), which enters the heating devices(radiators, convectors), heating them, which in turn heat the air in the room, and returns to the place of its heating.
Based on the type of energy carrier, heat generators are divided into 4 groups:
Gas.
The most common and relatively inexpensive option. Gas heating requires the presence of a main gas pipeline or the installation of gas tanks. Advantages: cost-effectiveness and high degree of automation.
Liquid fuel.
Liquid heating diesel fuel- a more expensive method.
Electrical.
It is convenient, but not cheap, to heat your home using an electric boiler.
Solid fuel.
There is a lot of hassle with a boiler that runs on wood or other solid combustible materials: you need to regularly load fuel and clean the combustion chamber from ash.
