Do-it-yourself geothermal heat pump for home heating: device, design, self-assembly

Advantages of heat pumps

The advantages of heating systems with heat pumps include the following:

1. Economic efficiency. With the cost of 1 kW of electrical energy, you can get 3-4 kW of heat. These are average indicators, because. the heat conversion coefficient depends on the type of equipment and design features.
2. Environmental Safety.During the operation of the thermal installation, combustion products or other potentially hazardous substances do not enter the environment. The equipment is ozone safe. Its use allows you to get heat without the slightest harm to the environment.
3. Versatility of application. When installing heating systems powered by traditional energy sources, the owner of the house becomes dependent on monopolists. Solar panels and wind turbines are not always cost-effective. But heat pumps can be installed anywhere. The main thing is to choose the right type of system.
4. Multifunctionality. In the cold season, the installations heat the house, and in the summer heat they are able to work in air conditioning mode. The equipment is used in hot water systems, connected to the contours of underfloor heating.
5. Operational safety. Heat pumps do not require fuel, they do not emit toxic substances during their operation, and the maximum temperature of equipment units does not exceed 90 degrees. These heating systems are no more dangerous than refrigerators.

There are no ideal devices. Heat pumps are reliable, durable and safe, but their cost directly depends on the power.

High-quality equipment for full-fledged heating and hot water supply of a house of 80 sq.m. will cost about 8000-10000 euros. Homemade products are low-power, they can be used to heat individual rooms or utility rooms.

The efficiency of the installation depends on the heat loss of the house. It makes sense to install the equipment only in those buildings where a high level of insulation is provided, and heat loss rates are not higher than 100 W / m2.

Equipment is reliable and rarely breaks down

If it is homemade, then it is important to choose a high-quality compressor, best of all - from a refrigerator or air conditioner of a proven brand

Scheme of execution of hydrothermal heating

To date, the most widespread are three fundamentally different schemes for arranging underground heating. To ensure maximum efficiency of heating the house, the total area of ​​​​the external underground circuit should be 2.5 times the heated area of ​​\u200b\u200bthe residential building.

The following types of geothermal heating are used in autonomous heating:

1. Underwater option.
2. Horizontal bookmark.
3. Well construction.

In each case, the choice of one or another type of geothermal heating will depend on the area of ​​\u200b\u200bthe house, the financial capabilities of the homeowner, and the characteristics of the area. The underwater option can be used in cases where there are deep water bodies nearby that do not freeze to the bottom in the winter season.

There are several types of laying such heating

Horizontal bookmark

This option of hydrothermal heating involves the execution of a foundation pit near the house, the depth of which will be 2 meters deeper than the freezing point of the soil. Accordingly, to heat a private house with an area of ​​100 square meters, it will be necessary to dig a pit with a depth of more than 3 meters and a total area of ​​250 square meters.

If the available area of ​​​​the site allows such a foundation pit to be made, then the horizontal laying will be the best option for geothermal heating of a private house. Inside the pit, a system of pipes is laid through which a non-freezing coolant circulates. The external heating circuit is led into the house and connected to the heat exchanger.

Of the advantages of this scheme for the implementation of geothermal heating, it is customary to single out its efficiency, ease of arrangement, and reduction in the cost of installing an external circuit. At the same time, it is necessary to take into account the mandatory requirements for the correct calculation of the volume of the pit, which is not always possible to place on a small plot of land.

Geothermal home heating:

Underwater option

Owners of private houses who live near lakes and rivers often choose the option of hydrothermal heating using an underwater option. It is only necessary to think over the location of the outer contour, which is placed at a depth of more than 4 meters, which excludes the possibility of freezing of the lake or river to the bottom. The underground and above-ground part of the circuit, which goes directly from the shore of the lake to the heated private house, is necessarily insulated, and pipes are laid underground at a depth below the freezing point of the soil.

The use of the underwater option makes it possible to simplify the arrangement of the heating system of a private house, since it is not required to carry out expensive and complex earthworks. The external circuit will be heated by the heat of the water, after which the heated coolant is supplied to the system, ensuring the operability of the equipment.

Execution of hydrothermal wells

The implementation of geothermal wells for the organization of autonomous heating is the best option, which can significantly reduce the costs of the homeowner. The well is drilled to a depth of 30-50 meters, which increases the heating efficiency, since at great depths the temperature of the earth will be higher than at the surface itself.

Drilling a well is one of the most effective methods for installing such heating.

Today, many homeowners, equipping an autonomous geothermal heating system for a private house, choose the option of drilling wells, which greatly simplifies the laying of the circuit. In this case, the maximum efficiency of the equipment used is ensured, allowing you to use all the possibilities of such modern technologies even in the presence of a small area.

The implementation of heating a private house with the laying of an external circuit in deep wells allows to reduce the total cost of arranging autonomous heating in a house by 20-30%. Due to the high heating temperature of the coolant in the deep circuit, it is possible to use heating installations of small capacity, which simplifies the installation of equipment, reduces its cost, while providing maximum convenience for living in a private house.

1 How it works

A heat pump is a set of equipment whose task is to collect thermal energy and deliver it to the consumer. The source of heat energy can be any medium or body with a temperature above 1 degree. To better understand the principle of operation of these devices, you should get acquainted with their functional features:

• The unit does not produce heat energy on its own.
• The heat pump requires electricity to operate.
• The principle of operation of the device is based on the Carnot cycle, which is used in all refrigeration units.

Recently, the technology of manufacturing heat pumps has improved significantly. Modern units are able to take thermal energy from the air with a temperature of up to -30 degrees, as well as water and soil - up to 2 degrees.Freon is the working fluid in the Carnot cycle. This gaseous substance begins to boil at sub-zero temperatures. The refrigerant sequentially evaporates and condenses in two heat exchange chambers, while absorbing energy from the environment. Then he transports it to the consumer.

The scheme of a heat pump is similar to the principle of operation of an air conditioner working for heating:

• While freon is in a liquid state, the refrigerant circulates through the pipes of the heat exchanger. Taking heat energy from the environment, freon boils and begins to evaporate.
• Then the gas enters the compressor, which increases the pressure to the desired value. As a result, the boiling point of the refrigerant rises and the substance condenses at a higher temperature.
• Passing through the internal heat exchange chamber, freon gives off the accumulated energy to the coolant and again goes into a liquid state.
• After that, the gas enters the receiver and throttle. When the pressure of the substance is reduced, the working cycle is repeated.

Do-it-yourself geothermal heating at home

It is quite possible to mount and put into operation geothermal heating on your own. However, difficulties may arise in the course of work. First of all, this concerns the installation of an external circuit in the ground. Therefore, in the absence of the necessary skills, it is recommended to entrust the adjustment of the system to professionals who will make a competent calculation and mount the entire geothermal heating system.

Preliminary calculations

In order for geothermal heating to bring the planned effect, it is necessary to make calculations. They will help you choose the power of pumping equipment.Approximate figures for buildings with different levels of thermal insulation are different. So, to heat one square meter you will need:

• without thermal insulation - 120 W;

• with conventional thermal insulation - 80 W;

• with energy-saving insulation - 40 watts.

For calculations, you will also need numbers that determine the heat loss in the house. For example, if for a residential building with an area of ​​180 sq. meters with high-quality thermal insulation, heat loss is 9 kW / day, then the equipment must provide a power of 216 kWh (9 kW x 24 hours). Taking into account the fact that heat losses may differ at different times, an allowance of 10-20% is made. Thus, the final pump output of the geothermal heating system should be 10.8 kW.

When calculating, it is important to take into account some points. These include the temperature of the soil at the level of the well

In central Russia, it keeps within + 8 ... + 10 degrees (at a depth of 15-20 meters). With a horizontal arrangement of the external circuit of the heating system, a power of 50 kW per meter is taken into account. The exact figures depend on geological conditions (humidity, presence of groundwater). Different soils give different indicators:

• Dry soil - 25 W / m;

• Wet substrate - 45-55 W / m;

• Hard rocks - 85 W / m;

• The presence of groundwater - 110 W / m.

How is the installation of the heating system

Water systems are a rarity, geothermal heating through the ground is most in demand. Therefore, the first stage of work is associated with drilling wells or digging a pit. Recesses are made to a depth of 20 to 100 meters, using special equipment. The bottom of the pit is covered with sand.Further, plastic pipes are laid in the finished recesses or trenches, which are able to withstand a pressure of about 6 bar. These pipes will act as probes.

During installation, pipe piping of three or four lines is used, while the edge sections are connected in the form of the letter "U". The outer contour can be purchased ready-made or assembled independently.

When the most difficult part of the work on the installation of a geothermal heating system is completed, they begin to connect the pump. The wiring with this method is similar to the wiring of a traditional heating system.

The principle of operation of the device

Those who come into contact with the issues of cost-effective heating, the name "heat pump" is well known. Especially in combination with terms like “land-water”, “water-water”, “water-air”, etc. Such heat pump with Frenett device has practically nothing in common, except perhaps the name and the end result in the form of thermal energy, which is ultimately used for heating.

Heat pumps operating on the Carnot principle are very popular both as a cost-effective way to organize heating and as an environmentally friendly system. The operation of such a complex of devices is associated with the accumulation of low-potential energy contained in natural resources (earth, water, air) and its conversion into thermal energy with a high potential. The invention of Eugene Frenette is arranged and works in a completely different way.

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The heat generating system developed by E. Frenett cannot be unconditionally attributed to the class of heat pumps. According to the design and technological features, this is a heater

The unit does not use geo- or solar energy sources in its work.The oil coolant inside it is heated by the friction force created by rotating metal disks.

The working body of the pump is an oil-filled cylinder, inside of which the axis of rotation is located. This is a steel rod equipped with parallel discs set approximately 6 cm apart.

Centrifugal force pushes the heated coolant into the coil connected to the device. The heated oil exits the instrument at the top connection point. The cooled coolant is returned back from below

Appearance Frenette heat pump

Warming up the device during operation

Main structural components

The actual dimensions of one of the models

The principle of operation of this device is based on the use of thermal energy, which is released during friction. The design is based on metal surfaces located not close to each other, but at some distance. The space between them is filled with liquid. Parts of the device rotate relative to each other with the help of an electric motor, the liquid inside the case and in contact with the rotating elements is heated.

The resulting heat can be used to heat the coolant. Some sources recommend using this fluid directly for the heating system. Most often, a regular radiator is attached to a homemade Frenett pump. As a heating fluid, experts strongly recommend using oil, not water.

During the operation of the pump, this coolant tends to heat up very strongly. Water in such conditions can simply boil. Hot steam in a confined space creates excess pressure, and this usually leads to rupture of pipes or a casing.It is much safer to use oil in such a situation, since its boiling point is much higher.

To make a Frenette heat pump, you will need an engine, a radiator, several pipes, a steel butterfly valve, steel discs, a metal or plastic rod, a metal cylinder and a nut kit (+)

There is an opinion that the efficiency of such a heat generator exceeds 100% and can even be 1000%. From the point of view of physics and mathematics, this is not a completely correct statement. Efficiency reflects the energy losses spent not on heating, but on the actual operation of the device. Rather, the phenomenal claims about the incredibly high efficiency of the Frenette pump reflect its efficiency, which is really impressive.

The cost of electricity for the operation of the device is negligible, but the amount of heat received as a result is very noticeable. Heating the coolant to the same temperatures with the help of a heating element, for example, would require a much larger amount of electricity, perhaps ten times more. A household heater with such a consumption of electricity would not even heat up.

Why are not all residential and industrial premises equipped with such devices? The reasons may be different. Still, water is a simpler and more convenient coolant than oil. It does not heat up to such high temperatures, and it is easier to clean up the consequences of water leaks than to clean up spilled oil.

Another reason may be that by the time the Frenette pump was invented, a centralized heating system already existed and functioned successfully. Its dismantling for replacement with heat generators would be too expensive and would bring a lot of inconvenience, so no one even seriously considered this option.As they say, the best is the enemy of the good.

The principle of operation of heat pumps

The principle of operation of a device for heating a house is based on the fact that a substance (refrigerant) can give off thermal energy or take it away in the process of changing the state. This idea is the basis for the functioning of the refrigerator (because of this, the back wall of the appliance is hot).

The thermopump for heating functions as follows:

1. The incoming agent is cooled by 5 degrees in the evaporation section based on the energy from the heat carrier.
2. The cooled agent enters the compressor, which, as a result of work, compresses and heats it.
3. Already hot gas enters the heat exchange compartment, where it gives off its own heat to the heating system.
4. The condensed refrigerant is returned to the start of the cycle.

Device

A heat pump for heating a house consists of several main contour elements:

• a circuit with a coolant that moves energy from a heat source;
• a circuit with freon, which periodically evaporates, taking thermal energy from the first circuit, and again settles with condensate, transferring heat to the third;
• a circuit where a liquid circulates, which is a heat carrier for heating.

The operation of a thermal pump for heating a house is financially beneficial. The reason for this is that the device does not require high power (accordingly, the consumption of electricity is no more than that of a standard household appliance), but it produces 4 times more heat compared to the electricity consumed.

It is also not necessary to create a separate wiring line for connecting the pump.

Pros and cons

Before deciding whether to use a heat pump or not, you should familiarize yourself with the advantages and disadvantages of its operation. The main advantages of a heat pump include:

• low electricity consumption for heating the house;
• no need for regular inspection and maintenance, which makes the cost of operating a heat pump for heating minimal;
• installation in any area is allowed. The pump can work with heat energy sources such as air, soil and water. Therefore, it becomes possible to install it in almost any place where it is planned to build a house. And in conditions of remoteness from the gas main, the device is the most suitable method of heating. Even if there is no electricity, the operation of the compressor can be ensured by a drive based on gasoline or diesel;
• heating of the house is carried out automatically. It is not required to add fuel or carry out other manipulations, as, for example, in the case of boiler equipment;
• absence of environmental pollution by harmful gases and substances. All refrigerants used are completely safe and environmentally friendly;
• fire safety. Residents of the house will never be in danger of explosion or damage due to overheating of the heat pump;
• the possibility of operation even under cold winter conditions (up to -15 degrees);
• a high-quality heat pump for heating a house can last up to 50 years. The compressor needs to be replaced only once every 20 years.

Watch the video pros and cons

Like any device, heat pumps have certain disadvantages:

1. If the ambient temperature drops below 15 degrees, the pump will not be able to work.In this case, you will need to install a second heat source. At very low temperatures, the boiler, generator or electric heater is turned on;
2. High cost of equipment. It will cost approximately 350,000-700,000 rubles, and the same amount will have to be spent on creating a geothermal station and installing the device. Additional installation work is not required only for a heat pump using air as a heat source;
3. It is best to install a heat pump in combination with underfloor heating or fan convectors, however older buildings will require redevelopment and possibly even major refurbishment, which will incur additional time and cost. If a private house is being built from scratch, there is no such problem;
4. During the operation of the heat pump, the temperature of the soil located around the pipeline with the heat carrier decreases. This causes the death of some microorganisms involved in the functioning of the environment. Thus, some damage to the environment is still inflicted, but it is significantly less than the damage from gas or oil production.

Benefits of a geothermal heating system

Geothermal heating systems have several advantages:

• The release of thermal energy is several times greater than the consumption of electricity that the pump requires.
• Environmental safety is greater than that of other heating systems, since geothermal heating systems do not produce any harmful emissions.
• In order for the geothermal system to function, no fuel or additional chemicals are required. Therefore, it is safe for owners and for the environment.
• In the operation of such heating there is no risk of explosion or fire.
• If the heating system is properly installed, it will last at least 30 years without technical support.

Construction of geothermal systems

Construction of geothermal systems

Even from the name it is clear that the essence of this type of heating is to use the energy of the earth. According to the principle of operation, it remotely resembles air conditioners or refrigerators.

The main element is a heat pump connected to two circuits.

1. The internal circuit means the heating system familiar to us, it consists of radiators and pipelines.
2. External - this is a very dimensional heat exchanger installed underground or in a reservoir. In it, the coolant (and it can be plain water or antifreeze), having taken the ambient temperature, is supplied to the heat pump, from where the accumulated heat enters the internal circuit. This is how the heaters in the house heat up.

The main element of the system is precisely the heat pump - a device that takes up no more space than a gas stove. The performance of the heat pump is quite high: for every kilowatt of energy used, it produces up to five kilowatts of heat.

Heat pump operation diagram

Of course, geothermal heating is by far the most time-consuming and costly. Most of the money will have to be spent on earthworks and related equipment, including a heat pump. And many are wondering if it is possible to save on this and build, say, a home-made heat pump. To find out, you need to understand the types and features of the equipment.

We install geothermal heating ourselves

Immediately, we note such a feature: those who decide to equip heating with the heat of the earth will need to invest a huge amount in this once. Of course, over time, this cost will pay off, since we do not build housing for ourselves for a year or two. Also, gas and electricity prices go up every year, and with a geothermal system, you don't know what those price hikes are.

However, in this system, most of it will be hidden underground. Heating with earth energy is the presence of a well and a heat exchanger. In the dwelling, you only need to put a device that will generate heat - usually it does not take up much space.

How a heat pump works

On such a device, the user will be able to control the temperature and supply thermal energy. The installation of the heating system itself in housing is done as usual - with a branching of the pipeline and radiators. If you have a private house, or the building itself is small, then in this case the generator of the system is displayed in a separate room or in the basement.

The principle of operation of heat pumps

It should be noted that almost any medium has thermal energy. Why not use the available heat to heat your home? A heat pump will help with this.

The principle of operation of a heat pump is as follows: heat is transferred to the coolant from an energy source with low potential. In practice, everything happens as follows.

The coolant passes through pipes that are buried, for example, in the ground. Then the coolant enters the heat exchanger, where the collected thermal energy is transferred to the second circuit. The refrigerant, which is located in the external circuit, heats up and turns into a gas.After that, the gaseous refrigerant passes into the compressor, where it is compressed. This causes the refrigerant to heat up even more. Hot gas goes to the condenser, and there the heat passes to the coolant, which already heats the house itself.

Geothermal heating at home: how it works

Refrigeration systems are arranged according to the same principle. This means that refrigeration units can be used to cool indoor air.

Types of heat pumps

There are several types of heat pumps. But most often, devices are classified by the nature of the coolant on the external circuit.

Devices can draw energy from

• water,
• soil,
• air.

The resulting energy in the house can be used for space heating, for heating water. Therefore, there are several types of heat pumps.

Heat pumps: ground - water

The best option for alternative heating is to obtain thermal energy from the ground. So, already at a depth of six meters, the earth has a constant and unchanging temperature. A special liquid is used as a heat carrier in the pipes. The outer contour of the system is made of plastic pipes. Pipes in the ground can be placed vertically or horizontally. If the pipes are placed horizontally, then a large area must be allocated. Where pipes are installed horizontally, it is impossible to use the land for agricultural purposes. You can only arrange lawns or plant annuals.

To arrange pipes vertically in the ground, it is necessary to make several wells up to 150 meters deep.This will be an efficient geothermal pump, since the temperature is high at a great depth near the earth. Deep probes are used for heat transfer.

Type of water-to-water pump

In addition, heat can be obtained from water, which is located deep underground. Ponds, groundwater or wastewater can be used.

It should be noted that there are no fundamental differences between the two systems. The smallest costs are required when a system for obtaining heat from a reservoir is created. Pipes must be filled with coolant and immersed in water. A more complex design is needed in order to create a system for generating heat from groundwater.

Air-to-water pumps

It is possible to collect heat from the air, but in regions with very cold winters, such a system is not effective. At the same time, the installation of the system is very simple. You only need to select and install the desired device.

A little more about the principle of operation of geothermal pumps

For heating it is very advantageous to use heat pumps. Houses with an area of ​​​​more than 400 square meters pay off the costs of the system very quickly. But if your house is not very large, then you can make a heating system with your own hands.

First you need to buy a compressor. A device that is equipped with a conventional air conditioner is suitable. We mount it on the wall. You can make your own capacitor. It is necessary to make a coil from copper pipes. It is placed in a plastic case. The evaporator is also wall mounted. Soldering, refilling with freon and similar work should only be carried out by a professional. Inept actions will not lead to a good result. Moreover, you can get injured.

Before putting the heat pump into operation, it is necessary to check the condition of the electrification of the house.The power of the meter should be rated at 40 amperes.

Homemade geothermal heat pump

Note that a heat pump created by oneself does not always live up to expectations. The reason for this is the lack of correct thermal calculations. The system is underpowered and maintenance costs are rising

Therefore, it is important to carry out all calculations accurately.

Options for arranging geothermal heating

Methods for arranging the external contour

In order for the energy of the earth to heat the house to be used as much as possible, you need to choose the right circuit for the external circuit. In fact, any medium can be a source of thermal energy - underground, water or air.

But it is important to take into account seasonal changes in weather conditions, as discussed above.

Currently, two types of systems are common that are effectively used to heat a house due to the heat of the earth - horizontal and vertical. The key selection factor is the area of ​​the land. The layout of the pipes for heating the house with the energy of the earth depends on this.

In addition to it, the following factors are taken into account:

• Soil composition. In rocky and loamy areas, it is difficult to make vertical shafts for laying highways;
• soil freezing level. He will determine the optimal depth of the pipes;
• Location of groundwater. The higher they are, the better for geothermal heating. In this case, the temperature will increase with depth, which is the optimal condition for heating from the energy of the earth.

You also need to know about the possibility of reverse energy transfer in the summer. Then the heating of a private house from the ground will not function, and the excess heat will pass from the house into the soil.All refrigeration systems work on the same principle. But for this you need to install additional equipment.

Horizontal geothermal heating scheme

Horizontal arrangement of outer pipes

The most common way to install outdoor highways. It is convenient for ease of installation and the ability to relatively quickly replace faulty sections of the pipeline.

For installation according to this scheme, a collector system is used. For this, several contours are made, located at a minimum distance of 0.3 m from each other. They are connected using a collector, which supplies the coolant further to the heat pump. This will ensure the maximum supply of energy for heating from the heat of the earth.

However, there are some important things to keep in mind:

• Large yard area. For a house of about 150 m², it must be at least 300 m²;
• Pipes must be fixed to a depth below the freezing level of the soil;
• With the possible movement of the soil during spring floods, the likelihood of displacement of highways increases.

The defining advantage of heating from the heat of the earth of a horizontal type is the possibility of self-arrangement. In most cases, this will not require the involvement of special equipment.

Vertical diagram of geothermal heating

Vertical geothermal system

This is a more time-consuming way of organizing heating of a private house from the ground. Pipelines are located vertically, in special wells

It is important to know that such a scheme is much more efficient than a vertical one.

Its main advantage is to increase the degree of water heating in the external circuit. Those.the deeper the pipes are located, the more the amount of earth's heat for heating the house will enter the system. Another factor is the small area of ​​land. In some cases, the arrangement of the external geothermal heating circuit is carried out even before the construction of the house in the immediate vicinity of the foundation.

What difficulties can be encountered in obtaining earth energy for heating a house according to this scheme?

• Quantitative to quality. For a vertical arrangement, the length of the highways is much higher. It is compensated by higher soil temperature. To do this, you need to make wells up to 50 m deep, which is laborious work;
• Soil composition. For rocky soil, it is necessary to use special drilling machines. In loam, to prevent shedding of the well, a protective shell made of reinforced concrete or thick-walled plastic is mounted;
• In the event of malfunctions or loss of tightness, the repair process becomes more complicated. In this case, long-term failures in the operation of heating the house for the thermal energy of the earth are possible.

But despite the high initial costs and the complexity of installation, the vertical arrangement of the highways is optimal. Experts advise using just such an installation scheme.