Energy, have expensive equipment, but the main advantage is a quick payback. One type of such alternative is a heat pump for heating. Prices and descriptions of the types of such systems are clarified in this article.

Alternative to a gas boiler

Read in the article

History of the origin of heat pumps

The first signs of the heat pump concept appeared in 1852. William Thomson pioneered this development, and it was picked up and improved by Robert Weber in 1940, who often experimented with and accidentally discovered that heat was generated from the freezer unit. First, the scientist taught the system, and eventually the entire home. A great triumph was Weber's placement of copper pipes in the ground that collected natural heat and converted it into thermal energy.

The principle of operation of a heat pump for heating a house

The heat pump is designed in such a way that its internal units can process heat from the natural environment (water, earth and air) into heat for.

How the pump works from the inside

Regardless of the method of generating heat, all pumps contain the following elements:

• Expansion valve;
• High pressure evaporator;
• Compressor;
• Capacitor;

Conversion process

A geothermal heat pump at a good price works on the conventional principle, which, during the process of boiling the refrigerant, removes all the heat accumulated inside the unit to its rear wall. Only in the case, the extracted energy is released indoors.

Stages of creating thermal energy:

1. Depending on the type of natural element used, the pump removes heat in the range from 1 to 7 degrees.
2. The evaporator, which is located inside the device, contains refrigerant. This liquid can boil at zero temperature.
3. With the help of the resulting natural heat, the refrigerant boils and becomes gaseous.
4. The gas enters the compressor, which increases its pressure and as a result the temperature increases.
5. The maximally heated refrigerant in the form of gas passes into the condenser, where it gives off its heat. After cooling, the substance returns to a liquid state.
6. The expansion valve then allows fluid to pass through, reducing its pressure to its original level.
7. And again the refrigerant ends up in the evaporator, receives a portion of heat and the process repeats.

Therefore, the refrigerant is the main working element of the heat pump. The heat that it receives from nature is converted into 35-65 degrees of useful thermal resource.

Note! Although the heating temperature of the coolant is not so high, due to the increase in battery sections, complete and uniform heating of the premises is achieved. You can connect a heated floor to the system, it will heat up smoothly and not aggressively.

Main types of heat pumps

Heaters differ in the way they produce heat. They are divided into such types as: “water-water”, “air-air”, “ground-water”, “air-water”.

Water-water

The essence of the system is to extract heat from a reservoir or. Equipment of this type differs from others in its greater heat transfer efficiency. This is explained by the fact that water is less sensitive to temperature changes, especially in the ground.

Air-to-air

How to navigate when choosing a heat pump

To choose a specific type of heat with a good price, you need to decide on the following parameters:

• The amount you are willing to part with to purchase equipment;
• The type of area where the home you intend to provide with an alternative heating method is located. The type of installation depends on the location of the stakes or groundwater;
• You need to decide whether you have the opportunity to drill for a heat pump;
• The main nuance is the exact calculation of the required power for full heating of the house;

How to calculate the power of the required equipment

To more accurately determine the required power, you need to calculate the temperature difference between the street and the microclimate in the middle of the building: T = Tinside - Toutside = required degree Celsius.

The final formula includes taking into account all the above parameters: Q = V x T, kW.

Important! To avoid a lack of power for heating, it is necessary to add 10 percent of the nominal value to the resulting calculations in order to balance out all the shortcomings.

Review of manufacturers

In order to buy a heat pump, the price must be correlated with the reputation of the manufacturer and the range of functions.

Note! There is a wide choice of foreign manufacturers, the quality of their equipment is very high, but domestic firms do not give up and are able to outshine many European competitors. The price from Russian manufacturers is much more pleasant.

Heat pump for heating a house. Prices for different types

Each system, which differs from each other in type, has its own volumes of necessary structural elements. This fact affects the pricing policy of the finished product.

Prices of air-to-air heat pumps and other types

The power range of water systems reaches up to 18 kW. Additional modules can expand the functionality of the system to full automation. The price of such devices varies from 100 to 500 thousand rubles.

As for earthen devices, the power reaches up to 500 kW, and the cost reaches 3.5 million rubles.

Turnkey heat pump price range table.

Image	Manufacturer	power, kWt	Type	price, rub.
	Gree Versati GRS-CQ	5,5	Water water	300 000
	Altal 12	12	earth water	350 000
	Cooper/Hunter GRS-Cm	18	Air water	240 000
	PEA	6	Air water	400 000
	Mammoth j142	48	Water water	650 000
	DHL-L Varius	5,33	Air air	750 000

DIY heat pump

To create a heat pump with your own hands from a refrigerator you need to have a certain skill. But it is quite possible to bring the unit to working condition.

• First of all, you need to buy a compressor from a refrigerator or.
• Now you need to assemble a capacitor, the design of which begins with a coil. It is usually made from a copper tube with a thickness of 1 mm, and placed in a metal case. To place the coil inside the tank, it is first sawed in half, and after placing all the parts and threaded connections back. To make the coil turns even and with the same distance between the rings, you can wind the tube on a blank, and the distance is fixed with an aluminum angle with ribs.
• Complete assembly, soldering of tubes and pumping of refrigerant is carried out only by a professional refrigeration technician. Otherwise, an emergency may occur.
• That's it, the structure is ready to connect to.

Additional features of heat pumps

Thanks to the unique designs, Russian-made heat pumps make it possible to create additional processes, such as cooling and boiler heating of water. The cooling effect is achieved through the reverse process of constriction of the refrigerant. That is, the same manipulations occur in the compressor as during heating, only in the reverse order.

The water is heated indirectly. Inside the boiler there is a coil through which hot water passes, and the heat from the coil heats the water in the boiler.

Warranty and service

Due to the fact that the system is very complex, it is unacceptable to carry out diagnostic and repair work on the units yourself. For these purposes, when purchasing a pump, the manufacturer is obliged to enter into an agreement with you, which specifies the period of time during which the inspection will be carried out by a specialist.

1. The warranty implies a certain period of free service, which includes repair work on all components and assemblies.
2. Maintenance is an integral addition to the system itself. The schedule according to which the inspection is done can be monthly, quarterly, semi-annual and annual.

conclusions

If you are positive about buying a heat pump to heat your home, the prices should not scare you. After all, the main priority of such heating is that the efficiency is multiplied by 4 times compared to other types of heating. This means that the whole system will pay for itself very quickly. Warm winter evenings to you.

Heat pump- a mechanical device that allows for heat transfer from a resource with low potential thermal energy (low temperature) to a heating system (coolant) with an elevated temperature. Let's try to explain this in more understandable language.

Gone are the days when people heated their homes by burning wood in fireplaces or stoves. They are being replaced by multifunctional long-burning boilers. In regions where main gas is available, efficient gas equipment is used for heating. In places inaccessible to gas mains, it is increasingly used.

Humanity understands that burning non-renewable energy sources is not a promising business; resources are gradually depleted. Scientists don't stop searching new ways of producing thermal energyand develop modern mechanisms to implement the assigned tasks.

In one such project, a heat pump was designed. Indeed, just like to the majority heat-generating units, the operation of a heat pump is not possible without electrical energy. A serious difference is that electricity is not involved in heating, for example, a heating element, as in an oil radiator, and does not close the spiral in a heat gun. A heat pump does not have heating elements, it does not create thermal energy, the heat pump only serves as a carrier of it from the environment to the consumer (coolant).

The electricity consumed by the heat pump is spent only on compressing the refrigerant and pumping it around to circulate it. The refrigerant acts as a necessary working environment, it is he who moves heat from the environment to the heating system and hot water supply system. This review will help us how to choose a heat pump, the principle of its operation, and also learn about the pros and cons of such equipment.

Heat pump for heating

Traditional heating of a private home is still preferable if inexpensive resources are abundant. The question is, what to do when the availability of cheap sources is limited? An alternative solution is a heat pump - more than 40 years of operating experience in the European Union tells us that this can be very effective.

In the Russian Federation, the heat pump has not received proper distribution. The reason for this is two factors. Firstly, there is an abundance of oil, gas, and wood. Secondly, it is stopped by the high price and lack of popularization. Information about heat pumps is very scarce, the principle of their operation is not clear, and there is not enough information about the benefits.

In the European Union, fuel prices are so high that geothermal heating systems show benefits in operation. For example, up to 95% of households in Sweden and Norway they useheat pumps as the main source of heating. The International Energy Agency predicts that heat pumps will begin to provide 10% of energy demand for heating in Organization for Economic Cooperation and Development countries by 2020, and by 2050 this figure will reach 30%.

Heat pump for heating - operating principle

From a school physics course, recalling the second law of thermodynamics, it is known for certain that heat from a hot body is transferred to a cold one without any mechanisms. The trick is how to transfer heat in the opposite direction? To do this, we will need a series of actions that ensure results.

These are the actions that a heat pump will help us perform. The energy costs for operating a heat pump depend proportionally on the temperature difference between the media involved in this process.

Have you ever touched the black grille of a refrigerator at the back? Anyone can verify that the back wall is very hot. Pointing a laser pyrometer at the black grating, you can see that its surface temperature is about 40°C. In this way, refrigeration equipment engineers recover unnecessary heat from inside the freezer.

It is known that in the late forties of the last century, inventor Robert Weber drew attention to the useless heating of air with a refrigerator radiator. The inventor thought about it and connected an indirect heating boiler to it. As a result, Robert supplied the household with hot water in the required volume. It was then that the enthusiast began to think about how to “turn” the refrigerator inside out and transform the cooling device into a heating device. I must admit, he succeeded.

How does a heat pump work?

The principle of operation of a heat pump is based on the fact that underground at any time of the year, falling below the freezing level, we will encounter temperatures above zero. It turns out that the frost-free soil layer is right under our feet. What if you use it as the back wall of the freezer?

Applying the operating principle of refrigeration equipment, To transfer heat from the underground to the home space, a system of pipes is used through which refrigerant circulates. Freon refrigerants are heated by underground heat and begin to evaporate. Cold air from outside cools it, causing the freon to condense.

By heating the heat by alternating cycles of evaporation and heating, the heat pump forces the refrigerant to circulate. The compressor creates pressure, forcing freon to move through the tubes of two heat exchangers.

In the first heat exchanger, freon evaporates at low pressure, during which heat is absorbed from the immediate surrounding atmosphere. The same refrigerant is then compressed by a compressor under high pressure and moved to a second coil where it is condensed. It then releases the heat it absorbed earlier in the cycle.

The booster compressor plays the main role in the process. By increasing the pressure, the freon condenses and produces more heat than it received from the warm earth. Thus, ground positive values ​​​​of + 7 ° C andtransforms into comfortable home conditions + 24°C.

By using a heat pump for heating, we achieve high efficiency.

I would like to note that the entire structure does not require a specially dedicated electrical wiring line. Power consumption is comparable to the energy consumption of a household electric kettle. The trick is that the heat pump “produces” thermal energy four times more than it consumes electricity. To heat a cottage of 300 m2, in severe frosts of 30°C, no more than 3 kW will be spent.

However, the owner of a geothermal pump will have to fork out a lot at the beginning. The cost of equipment and materials for connection is at least $4,500. Let's add installation work and drilling, and the same amount, it turns out that the simplest system will cost 10 thousand dollars.

It is clear that it will cost an order of magnitude cheaper. But pay monthly based on 1 kW per 10 m2will have to anyway. So it turns out that for 300 sq. meters at home it will take 30 kW - 10 times more than will be spent on a heat pump.

Calculations for heating with gas using a gas boiler give approximately the same figures - 2000 rubles per month, which is comparable to the operation of a heat pump. Unfortunately, not everyone lives in a gasified area.

The heat pump has an undeniable advantage. In the summer, such a “reverse freezer” can be “turned inside out” and with a slight movement of the hand, the heat pump turns into an air conditioner. On hot days it’s +30°C outside, but in the dungeon it’s cool. Using tubes filled with coolant, the pump will transfer the cold of the underground into the home. Next, the fan is turned on, so we get an economical cooling system.

Operating practice indicates payback periods from 3 to 7 years. The Scandinavian countries have long calculated their profits and heat themselves using this method. A striking example is the giant heat pump in Stockholm, geothermal equipment. The source of thermal energy in winter and coolness in summer is the waters of the Baltic Sea. The slogan fully applies to the heat pump: pay now - save later! Savings are becoming greater due to the fact that energy resources are becoming more expensive.

Heat pump. The truth about its effectiveness.

Unfortunately, not everything is so rosy with efficiency today. One of the main questions tormenting the consumer remains: to buy or not to buy a heat pump. Our advice is to carefully weigh the pros and cons; most likely, the option of buying a conventional one will cost less after use, and installation will be easier.

If we consider a heat pump as a concept of the future, as a new idea for generating heat, the engineering idea definitely deserves respect. Geothermal equipment works, you can touch it with your hands, and every year it becomes more and more efficient. However, if we calculate how much money we will spend on its operation, add the initial costs of purchase and installation, we will most likely get an amount showing that we will spend much more money on it than on any other type of heat generating device.

Considering a heat pump as an economic system, when you spend 100 rubles on its operation and receive 300 rubles worth of thermal energy, do not forget that you paid a lot of money for the right to receive an excess profit of 200 rubles. By the way, in the European Union, sales of heat pumps are supported by government programs.

So in Finland, more than 60 thousand heat pumps are sold annually and the number of sales is growing at a 5% rate. But firstly, the economic effect of using such equipment there is higher due to expensive electricity. The cost of electricity in Finland is 35 euro cents, compared to Russia – 7 euro cents. Secondly, the subsidy program provides reimbursement for the purchase of a heat pump in the amount of 3,000 EURO.

As long as gas and electricity prices remain low, introducing a heat pump as a major competitor remains challenging. Mass consumption will become possible only in the event of a crisis with hydrocarbon production or a crisis with electricity generation.

How to choose the right heat pump

First stage.

Calculation of the required heat for heating a house. To select a heat pump (HP) that is included in the heating system of a house, it is important to calculate the heat demand. An accurate calculation will help you avoid unnecessary cost overruns, as this leads to unnecessary expenses.

Second phase.

Which heat source to choose for your heat pump. This decision depends on many components, the main ones:

• Financial component. This includes the direct cost of the equipment itself, as well as the work of installing a geothermal probe or laying an underground thermal circuit. This depends on the location of the site itself, as well as on the immediate surroundings (reservoirs, buildings, communications) and geology.

• Operational component. The main cost is the operation of the heat pump. This figure depends on the heating mode of your building and the selected heat source.

Third stage.

Analysis of initial data for selecting a heat pump:

1. Budget for the proposed system.
2. Heating system: radiators, air heating, heated floor.
3. The area of ​​the site that can be allocated for laying a thermal collector.
4. Is it possible to drill on the site?
5. Geology of the site to determine the depth of the geothermal probe if such a decision is made.
6. Is air conditioning required in summer?
7. Is air heating available or planned in the future?
8. Capital cost of purchase and installation of the HP with all work (approximate initial estimate).

Let's sort it all out in order

Budget for the proposed system

When creating a heating system using a heat pump, it is possible to install an air-water circuit. Capital investments will be minimal, since no expensive excavation work is required. But there will be high costs during the operation phase of this heating system due to low operating efficiency.

If you want to significantly reduce operating costs, then installing a geothermal pump is suitable for you. True, it will be necessary to carry out excavation work to lay the thermal circuit. This system will also provide “passive” cold.

Heating system: radiators, air heating, heated floors

To increase the efficiency of the HP system, it is desirable to reduce the difference between the temperature of the heated medium and the temperature of the heat source.
If you have not yet chosen a heating system, it is recommended to choose heated floors, which allow you to use the heating system more efficiently.

Area of ​​land that can be allocated for laying a thermal collector

The area of ​​the site for installing the collector is critical if it is impossible to drill and install a geothermal probe. Then you will have to lay the collector horizontally, and this will require a space approximately 2 times larger than the area of ​​the heated house. It should be taken into account that this area cannot be used for development, but only in the form of a lawn or lawn, so as not to block the flow of sunlight.

Is it possible to drill on the site?

If it is possible to drill on the site (good geology, access, lack of underground communications), the best solution would be to install a geothermal probe. It provides a stable and long-term heat source.

Geology of the site to determine the depth of the geothermal probe, if such a decision is made

After calculating the total drilling depth, it is necessary to study the site plan and determine how to ensure the drilling depth. In practice, the depth of one well usually does not exceed 150 m.

Therefore, if, for example, the estimated drilling depth is 360 m, then, based on the characteristics of the site, it can be divided into 4 wells of 90 m each, or 3 of 120 m each, or 6 of 60 m each. But we must take into account that the distance between the nearest wells should not be less than 6 m.
The cost of drilling work is directly proportional to the drilling depth.

Is air conditioning required in summer?

If air conditioning is required in the summer, then the obvious choice is a heat pump of the “water-to-water” or “ground-to-water” type; other heat pumps are not ready to effectively and economically perform air conditioning functions.

Is air heating available or planned in the future?

It is possible to integrate the heat pump into a single air heating system. This solution will allow to unify engineering networks.

Capital cost of purchasing and installing a heat pump with all work

The initial estimated capital costs* for purchase and installation depend on the type of heat pump:

HP with underground collector:

Works - $2500
Operating costs - $350/year

VT with probe:
Equipment and materials - $4500
Works - $4500
Operating costs - $320/year

Air VT:
Equipment and materials - $6500
Work - $400
Operating costs - $480/year

TN “water-water”:
Equipment and materials - $4500
Works - $3500
Operating costs - $280/year

* – approximate, average market prices. The final cost depends on the selected equipment manufacturer, the region of work performed, the cost of drilling operations and site conditions, and so on. Estimating department note

Fourth stage. Types of work

Single. The heat pump is the only heat source, providing 100% of the heat demand. Works for operating temperatures not higher than 55 °C.
Paired. The HP and the boiler work together, which allows the boiler to achieve higher operating temperatures.

Monoenergetic. The HP and the electric boiler form a power system with only one external energy source. This allows you to smoothly regulate power consumption, but increases the load on the input machine.

Selecting a heat pump

After collecting all the initial data and working out the main technical solutions, it is possible to select the appropriate type of HP. The configuration and choice of equipment supplier will depend on your financial capabilities. The main thing is to approach the choice of system with a full understanding of what you want. We will help you choose and implement a comfortable heating system. It can take into account all the nuances: from the climate control function to the distribution of heat across zones of the house.

Conclusion

By choosing an ecological heating system with a heat pump, you can be confident in the future. You get complete independence from heat supply organizations, world oil prices and the political situation in the country. The only thing you need is electricity. But over time, the generation of electricity can be transferred to absolute autonomy with the help of a windmill.

1.
2.
3.
4.
5.
6.

A unit such as a heat pump has a similar operating principle to household appliances - a refrigerator and an air conditioner. It borrows approximately 80% of its power from the environment. The pump pumps heat from the street into the room. Its operation is similar to the principle of operation of a refrigerator, only the direction of transfer of thermal energy is different.

For example, to cool a bottle of water, people put it in the refrigerator, then the household appliance partially “takes” the heat from this object and now, according to the law of conservation of energy, must release it. But where? Everything is simple, for this purpose the refrigerator has a radiator, usually located on its back wall. In turn, the radiator, heating up, gives off heat to the room in which it stands. Thus, the refrigerator heats the room. The degree to which it warms up can be felt in small shops in the hot summer, when several refrigeration units are turned on.

And now a little imagination. Suppose that warm objects are constantly placed in the refrigerator, and it heats the room, or it is placed in a window opening, the freezer door is opened outward, and the radiator is in the room. During its operation, the household appliance, cooling the air outside, will simultaneously transfer the thermal energy that exists outside into the building. This is exactly the principle of operation of a heat pump.

Where does the pump get heat from?

• ambient air;
• bodies of water (rivers, lakes, seas);
• soil and ground artesian and thermal waters.

Heating system with heat pump

The coolant, which absorbs heat from the environment, circulates along the external circuit. It enters the pump evaporator and releases approximately 4 -7 °C to the refrigerant, despite the fact that its boiling point is -10 °C. As a result, the refrigerant boils and then goes into a gaseous state. The already cooled coolant in the external circuit is sent to the next turn to set the temperature.

The heat pump functional circuit consists of:

• evaporator;
• refrigerant;
• electric compressor;
• capacitor;
• capillary;
• thermostatic control device.

• After boiling, the refrigerant, moving through the pipeline, enters the compressor, which operates using electricity. This device compresses the gaseous refrigerant to high pressure, causing its temperature to rise;
• the hot gas enters another heat exchanger (condenser), in which the heat of the refrigerant is transferred to the coolant circulating through the internal circuit of the heating system, or to the air in the room;
• cooling, the refrigerant turns into a liquid state, after which it passes through the capillary pressure reducing valve, losing pressure, and then again ends up in the evaporator;
• thus, the cycle has ended and the process is ready to repeat.

Approximate calculation of heating output

Q = (T 1 - T 2) x V, where:
V – coolant flow per hour (m 3 /hour);
T 1 - T 2 - temperature difference between inlet and inlet (°C).

Types of heat pumps

• ground-water - for their operation in a water heating system, closed ground contours or geothermal probes located at depth are used (more details: " ");
• water-water - the principle of operation in this case is based on the use of open wells for collecting groundwater and discharging it (read: " "). In this case, the external circuit is not looped, and the heating system in the house is water;
• water-air - install external water circuits and use air-type heating structures;
• air-to-air - for their operation, they use the dissipated heat of external air masses plus the air heating system of the house.

Advantages of heat pumps

1. Cost-effective and efficient. The principle of operation of the heat pumps shown in the photo is based not on the production of thermal energy, but on its transfer. Thus, the efficiency of the heat pump must be greater than unity. But how is this possible? In relation to the operation of heat pumps, a value is used that is called the heat conversion coefficient, or abbreviated as CCT. The characteristics of units of this type are compared precisely according to this parameter.The physical meaning of the quantity is to determine the relationship between the amount of heat received and the energy expended to obtain it. For example, if the CPT coefficient is 4.8, this means that 1 kW of electricity expended by the pump produces 4.8 kW of heat, free of charge from nature.
2. Universal universal application. If there are no power lines accessible to consumers, the pump compressor is operated using a diesel drive. Since natural heat is everywhere, the operating principle of this device allows it to be used everywhere.
3. Environmental friendliness. The operating principle of the heat pump is based on low electricity consumption and the absence of combustion products. The refrigerant used by the unit does not contain chlorocarbons and is completely ozone-safe.
4. Bidirectional mode of operation. During the heating season, the heat pump is able to heat the building and cool it in the summer. The heat taken from the room can be used to provide the house with hot water supply, and, if there is a swimming pool, to heat the water in it.
5. Safe operation. There are no dangerous processes in the operation of heat pumps - there is no open fire, and substances harmful to human health are not released. The coolant does not have a high temperature, which makes the device safe and at the same time useful in everyday life.
6. Automatic control of the room heating process.

Some features of pump operation

• the room must be well insulated (heat loss cannot exceed 100 W/m²);
• It is advantageous to use a heat pump for low-temperature heating systems. The underfloor heating system meets this criterion, since its temperature is 35-40°C. The CPT largely depends on the relationship between the temperature of the input circuit and the output circuit.

The operating principle of heat pumps is to transfer heat, which allows you to obtain an energy conversion coefficient of 3 to 5. In other words, every 1 kW of electricity used brings 3-5 kW of heat into the house.

More and more Internet users are interested in alternative heating methods: heat pumps.

For most, this is a completely new and unknown technology, which is why questions arise like: “What is it?”, “What does a heat pump look like?”, “How does a heat pump work?” etc.

Here we will try to provide simple and accessible answers to all these and many other questions related to heat pumps.

What is a Heat Pump?

Heat pump- a device (in other words, a “thermal boiler”) that removes dissipated heat from the environment (soil, water or air) and transfers it to the heating circuit of your home.

Thanks to the sun's rays, which continuously enter the atmosphere and the surface of the earth, there is a constant release of heat. This is how the surface of the earth receives thermal energy all year round.

The air partially absorbs heat from the energy of the sun's rays. The remaining solar thermal energy is almost completely absorbed by the earth.

In addition, geothermal heat from the bowels of the earth constantly ensures the soil temperature of +8°C (starting from a depth of 1.5-2 meters and below). Even in cold winter, the temperature at the depths of reservoirs remains in the range of +4-6°C.

It is this low-grade heat of soil, water and air that the heat pump transfers from the environment to the heating circuit of a private house, having previously increased the temperature level of the coolant to the required +35-80°C.

VIDEO: How does a Ground-Water heat pump work?

What does a Heat Pump do?

Heat pumps- heat engines that are designed to produce heat using a reverse thermodynamic cycle. transfer thermal energy from a low temperature source to a higher temperature heating system. During the operation of a heat pump, energy costs occur that do not exceed the amount of energy produced.

The operation of a heat pump is based on a reverse thermodynamic cycle (reverse Carnot cycle), consisting of two isotherms and two adiabats, but unlike the direct thermodynamic cycle (direct Carnot cycle), the process proceeds in the opposite direction: counterclockwise.

In the reverse Carnot cycle, the environment acts as a cold heat source. When a heat pump operates, the heat from the external environment is transferred to the consumer due to the work performed, but at a higher temperature.

It is possible to transfer heat from a cold body (soil, water, air) only through the expenditure of work (in the case of a heat pump, the expenditure of electrical energy for the operation of a compressor, circulation pumps, etc.) or another compensation process.

A heat pump can also be called a “refrigerator in reverse”, since a heat pump is the same refrigeration machine, only unlike a refrigerator, a heat pump takes heat from outside and transfers it into the room, that is, it heats the room (a refrigerator cools by taking heat from the refrigeration chamber and throws it out through the capacitor).

How does a Heat Pump work?

Now talk about how a heat pump works. In order to understand the principle of operation of a heat pump, we need to understand several things.

1. The heat pump is capable of extracting heat even at subzero temperatures.

Most future homeowners cannot understand the principle of operation (in principle, of any air source heat pump), because they do not understand how heat can be extracted from the air at subzero temperatures in winter. Let's go back to the basics of thermodynamics and remember the definition of heat.

Heat- a form of movement of matter, which is a random movement of particles forming a body (atoms, molecules, electrons, etc.).

Even at 0˚C (zero degrees Celsius), when water freezes, there is still heat in the air. It is significantly less than, for example, at a temperature of +36˚С, but nevertheless, both at zero and at negative temperatures, the movement of atoms occurs, and therefore heat is released.

The movement of molecules and atoms completely stops at a temperature of -273˚C (minus two hundred seventy-three degrees Celsius), which corresponds to absolute zero temperature (zero degrees on the Kelvin scale). That is, even in winter, at sub-zero temperatures, there is low-grade heat in the air that can be extracted and transferred into the house.

2. The working fluid in heat pumps is refrigerant (freon).

What is a refrigerant? Refrigerant- a working substance in a heat pump that removes heat from the cooled object during evaporation and transfers heat to the working medium (for example, water or air) during condensation.

The peculiarity of refrigerants is that they are able to boil at both negative and relatively low temperatures. In addition, refrigerants can change from a liquid to a gaseous state and vice versa. It is during the transition from liquid to gaseous state (evaporation) that heat is absorbed, and during the transition from gaseous to liquid (condensation) heat transfer occurs (heat release).

3. The operation of a heat pump is made possible by its four key components.

In order to understand the principle of operation of a heat pump, its device can be divided into 4 main elements:

1. Compressor, which compresses the refrigerant to increase its pressure and temperature.
2. Expansion valve- a thermostatic valve that sharply reduces the refrigerant pressure.
3. Evaporator- a heat exchanger in which a low-temperature refrigerant absorbs heat from the environment.
4. Capacitor- a heat exchanger in which already hot refrigerant, after compression, transfers heat to the working environment of the heating circuit.

It is these four components that allow refrigeration machines to produce cold and heat pumps to produce heat. In order to understand how each component of a heat pump works and why it is needed, we suggest watching a video about the principle of operation of a ground source heat pump.

VIDEO: Operating principle of the Ground-Water heat pump

Working principle of a heat pump

Now we will try to describe in detail each stage of the heat pump operation. As mentioned earlier, the operation of heat pumps is based on the thermodynamic cycle. This means that the operation of a heat pump consists of several cycle stages that are repeated over and over again in a certain sequence.

The work cycle of a heat pump can be divided into the following four stages:

1. Absorption of heat from the environment (refrigerant boiling).

The evaporator (heat exchanger) receives refrigerant, which is in a liquid state and has low pressure. As we already know, at low temperatures the refrigerant can boil and evaporate. The process of evaporation is necessary for the substance to absorb heat.

According to the second law of thermodynamics, heat is transferred from a body with a high temperature to a body with a lower temperature. It is at this stage of the heat pump operation that a low-temperature refrigerant, passing through a heat exchanger, takes away heat from the coolant (brine), which previously rose from the wells, where it took away the low-grade heat of the soil (in the case of Ground-Water ground heat pumps).

The fact is that the temperature of the soil underground at any time of the year is + 7-8 ° C. When used, vertical probes are installed through which brine (coolant) circulates. The task of the coolant is to heat up to the maximum possible temperature while circulating through the deep probes.

When the coolant has taken heat from the ground, it enters the heat pump heat exchanger (evaporator) where it “meets” the refrigerant, which has a lower temperature. And according to the second law of thermodynamics, heat exchange occurs: heat from a more heated brine is transferred to a less heated refrigerant.

Here is a very important point: heat absorption is possible during the evaporation of a substance and vice versa, heat transfer occurs during condensation. When the refrigerant is heated from the coolant, it changes its phase state: the refrigerant passes from a liquid state to a gaseous state (the refrigerant boils and evaporates).

After passing through the evaporator the refrigerant is in the gaseous phase. This is no longer a liquid, but a gas that has taken heat from the coolant (brine).

2. Compression of the refrigerant by a compressor.

In the next step, the refrigerant enters the compressor in a gaseous state. Here the compressor compresses freon, which, due to a sharp increase in pressure, heats up to a certain temperature.

The compressor of a regular household refrigerator works in a similar way. The only significant difference between a refrigerator compressor and a heat pump compressor is significantly lower performance.

VIDEO: How a refrigerator with a compressor works

3. Heat transfer to the heating system (condensation).

After compression in the compressor, the refrigerant, which has a high temperature, enters the condenser. In this case, a condenser is also a heat exchanger in which, during condensation, heat is transferred from the refrigerant to the working medium of the heating circuit (for example, water in a heated floor system or heating radiators).

In the condenser, the refrigerant changes from the gas phase to the liquid phase again. This process is accompanied by the release of heat, which is used for the heating system in the house and hot water supply (DHW).

4. Reducing the refrigerant pressure (expansion).

Now the liquid refrigerant must be prepared to repeat the operating cycle. To do this, the refrigerant passes through the narrow opening of the expansion valve (expansion valve). After “pushing” through the narrow opening of the throttle, the refrigerant expands, as a result of which its temperature and pressure drop.

This process is comparable to spraying an aerosol from a spray can. After spraying, the can becomes colder for a short time. That is, there was a sharp drop in aerosol pressure due to pressing outward, and the temperature also drops accordingly.

Now the refrigerant is again under such pressure that it is able to boil and evaporate, which is necessary for us to absorb heat from the coolant.

The task of the expansion valve (thermostatic expansion valve) is to reduce the freon pressure by expanding it at the exit from a narrow hole. Now the freon is ready to boil again and absorb heat.

The cycle is repeated again until the heating and domestic hot water system receives the required amount of heat from the heat pump.

Paying for electricity and heating becomes more difficult every year. When building or purchasing a new home, the problem of economical energy supply becomes especially acute. Due to periodically recurring energy crises, it is more profitable to increase the initial costs of high-tech equipment in order to then receive heat at a minimal cost for decades.

The most cost-effective option in some cases is a heat pump for heating a home; the operating principle of this device is quite simple. It is impossible to pump heat in the literal sense of the word. But the law of conservation of energy allows technical devices to lower the temperature of a substance in one volume, while simultaneously heating something else.

What is a heat pump (HP)

Let's take an ordinary household refrigerator as an example. Inside the freezer, water quickly turns to ice. On the outside there is a radiator grille that is hot to the touch. From it, the heat collected inside the freezer is transferred to the room air.

The TN does the same thing, but in reverse order. The radiator grille, located on the outside of the building, is much larger in order to collect enough heat from the environment to heat the home. The coolant inside the radiator or manifold tubes transfers energy to the heating system inside the house and is then heated again outside the house.

Device

Providing heat to a home is a more complex technical task than cooling a small volume of a refrigerator where a compressor with freezing and radiator circuits is installed. The design of an air heat pump is almost as simple, it receives heat from the atmosphere and heats the internal air. Only fans are added to blow the circuits.

It is difficult to obtain a large economic effect from installing an air-to-air system due to the low specific gravity of atmospheric gases. One cubic meter of air weighs only 1.2 kg. Water is about 800 times heavier, so the calorific value also has a multiple difference. From 1 kW of electrical energy spent by an air-to-air device, only 2 kW of heat can be obtained, and a water-to-water heat pump provides 5–6 kW. TN can guarantee such a high coefficient of efficiency (efficiency).

Composition of pump components:

1. Home heating system, for which it is better to use heated floors.
2. Boiler for hot water supply.
3. A condenser that transfers energy collected externally to the indoor heating fluid.
4. An evaporator that takes energy from the coolant that circulates in the external circuit.
5. A compressor that pumps refrigerant from the evaporator, converting it from a gaseous to a liquid state, increasing the pressure and cooling it in the condenser.
6. An expansion valve is installed in front of the evaporator to regulate the refrigerant flow.
7. The outer contour is laid on the bottom of the reservoir, buried in trenches or lowered into wells. For air-to-air heat pumps, the circuit is an external radiator grille, blown by a fan.
8. Pumps pump coolant through pipes outside and inside the house.
9. Automation for control according to a given room heating program, which depends on changes in outside air temperature.

Inside the evaporator, the coolant of the external pipe register is cooled, giving off heat to the refrigerant of the compressor circuit, and then is pumped through the pipes at the bottom of the reservoir. There it heats up and the cycle repeats again. The condenser transfers heat to the cottage heating system.

Prices for different heat pump models

Heat pump

Principle of operation

The thermodynamic principle of heat transfer, discovered at the beginning of the 19th century by the French scientist Carnot, was later detailed by Lord Kelvin. But the practical benefits of their works devoted to solving the problem of heating housing from alternative sources have appeared only in the last fifty years.

In the early seventies of the last century, the first global energy crisis occurred. The search for economical heating methods has led to the creation of devices capable of collecting energy from the environment, concentrating it and directing it to heat the house.

As a result, a HP design was developed with several thermodynamic processes interacting with each other:

1. When the refrigerant from the compressor circuit enters the evaporator, the pressure and temperature of the freon drops almost instantly. The resulting temperature difference contributes to the extraction of thermal energy from the coolant of the external collector. This phase is called isothermal expansion.
2. Then adiabatic compression occurs - the compressor increases the pressure of the refrigerant. At the same time, its temperature rises to +70 °C.
3. Passing the condenser, freon becomes a liquid, since at increased pressure it gives off heat to the in-house heating circuit. This phase is called isothermal compression.
4. When the freon passes through the choke, the pressure and temperature drop sharply. Adiabatic expansion occurs.

Heating the internal volume of a room according to the HP principle is possible only with the use of high-tech equipment equipped with automation to control all of the above processes. In addition, programmable controllers regulate the intensity of heat generation according to fluctuations in outside air temperature.

Alternative fuel for pumps

There is no need to use carbon fuel in the form of firewood, coal, or gas to operate the HP. The source of energy is the heat of the planet scattered in the surrounding space, inside of which there is a constantly operating nuclear reactor.

The solid shell of continental plates floats on the surface of liquid hot magma. Sometimes it breaks out during volcanic eruptions. Near the volcanoes there are geothermal springs, where you can swim and sunbathe even in winter. A heat pump can collect energy almost anywhere.

To work with various sources of dissipated heat, there are several types of heat pumps:

1. "Air-to-air." Extracts energy from the atmosphere and heats the air masses indoors.
2. "Water-air". Heat is collected by an external circuit from the bottom of the reservoir for subsequent use in ventilation systems.
3. "Ground-water". Heat collection pipes are located horizontally underground below the freezing level, so that even in the most severe frost they can receive energy to heat the coolant in the heating system of the building.
4. "Water-water." The collector is laid out along the bottom of the reservoir at a depth of three meters, the collected heat heats the water circulating in the heated floors inside the house.

There is an option with an open external collector, when you can get by with two wells: one for collecting groundwater, and the second for draining back into the aquifer. This option is only possible if the quality of the liquid is good, because the filters quickly become clogged if the coolant contains too many hardness salts or suspended microparticles. Before installation, it is necessary to do a water analysis.

If a drilled well quickly silts up or the water contains a lot of hardness salts, then stable operation of the HP is ensured by drilling more holes in the ground. The loops of the sealed outer contour are lowered into them. Then the wells are plugged using plugging made from a mixture of clay and sand.

Using dredge pumps

You can extract additional benefit from areas occupied by lawns or flower beds using ground-to-water HP. To do this, you need to lay pipes in trenches to a depth below the freezing level to collect underground heat. The distance between parallel trenches is at least 1.5 m.

In the south of Russia, even in extremely cold winters, the ground freezes to a maximum of 0.5 m, so it is easier to completely remove the layer of earth at the installation site with a grader, lay the collector, and then fill the pit with an excavator. Shrubs and trees, whose roots can damage the external contour, should not be planted in this place.

The amount of heat received from each meter of pipe depends on the type of soil:

• dry sand, clay - 10–20 W/m;
• wet clay - 25 W/m;
• moistened sand and gravel - 35 W/m.

The area of ​​land adjacent to the house may not be sufficient to accommodate an external pipe register. Dry sandy soils do not provide sufficient heat flow. Then they use drilling wells up to 50 meters deep to reach the aquifer. U-shaped collector loops are lowered into the wells.

The greater the depth, the higher the thermal efficiency of the probes inside the wells increases. The temperature of the earth's interior increases by 3 degrees every 100 m. The efficiency of energy removal from a well collector can reach 50 W/m.

Installation and commissioning of HP systems is a technologically complex set of works that can only be performed by experienced specialists. The total cost of equipment and component materials is significantly higher when compared with conventional gas heating equipment. Therefore, the payback period for initial costs extends over years. But a house is built to last for decades, and geothermal heat pumps are the most profitable heating method for country cottages.

Annual savings compared to:

• gas boiler - 70%;
• electric heating - 350%;
• solid fuel boiler - 50%.

When calculating the payback period of a HP, it is worth taking into account the operating costs for the entire service life of the equipment - at least 30 years, then the savings will many times exceed the initial costs.

Water-to-water pumps

Almost anyone can place polyethylene collector pipes at the bottom of a nearby reservoir. This does not require much professional knowledge, skills, or tools. It is enough to evenly distribute the coils of the coil over the surface of the water. There must be a distance between the turns of at least 30 cm, and a flooding depth of at least 3 m. Then you need to tie the weights to the pipes so that they go to the bottom. Substandard brick or natural stone are quite suitable here.

Installing a water-to-water HP collector will require significantly less time and money than digging trenches or drilling wells. The cost of purchasing pipes will also be minimal, since heat removal during convective heat exchange in an aquatic environment reaches 80 W/m. The obvious benefit of using HP is that there is no need to burn carbon fuel to produce heat.

An alternative method of heating a home is becoming increasingly popular, as it has several more advantages:

1. Environmentally friendly.
2. Uses a renewable energy source.
3. After commissioning is completed, there are no regular costs of consumables.
4. Automatically adjusts the heating inside the house based on the outside temperature.
5. The payback period for initial costs is 5–10 years.
6. You can connect a boiler for hot water supply to the cottage.
7. In summer it works like an air conditioner, cooling the supply air.
8. The service life of the equipment is more than 30 years.
9. Minimum energy consumption - generates up to 6 kW of heat using 1 kW of electricity.
10. Complete independence of heating and air conditioning of the cottage in the presence of an electric generator of any type.
11. Adaptation to the “smart home” system for remote control and additional energy savings is possible.

To operate a water-to-water HP, three independent systems are required: external, internal and compressor circuits. They are combined into one circuit by heat exchangers in which various coolants circulate.

When designing a power supply system, it should be taken into account that pumping coolant through the external circuit consumes electricity. The longer the length of the pipes, bends, and turns, the less profitable the VT. The optimal distance from the house to the shore is 100 m. It can be extended by 25% by increasing the diameter of the collector pipes from 32 to 40 mm.

Air - split and mono

It is more profitable to use air HP in the southern regions, where the temperature rarely drops below 0 °C, but modern equipment can operate at -25 °C. Most often, split systems are installed, consisting of indoor and outdoor units. The external set consists of a fan blowing through the radiator grille, the internal set consists of a condenser heat exchanger and a compressor.

The design of split systems provides for reversible switching of operating modes using a valve. In winter, the external unit is a heat generator, and in summer, on the contrary, it releases it to the outside air, working like an air conditioner. Air heat pumps are characterized by extremely simple installation of the external unit.

Other benefits:

1. The high efficiency of the outdoor unit is ensured by the large heat exchange area of ​​the evaporator radiator grille.
2. Uninterrupted operation is possible at outdoor temperatures down to -25 °C.
3. The fan is located outside the room, so the noise level is within acceptable limits.
4. In summer, the split system works like an air conditioner.
5. The set temperature inside the room is automatically maintained.

When designing the heating of buildings located in regions with long and frosty winters, it is necessary to take into account the low efficiency of air heaters at subzero temperatures. For 1 kW of consumed electricity there is 1.5–2 kW of heat. Therefore, it is necessary to provide additional sources of heat supply.

The simplest installation of VT is possible when using monoblock systems. Only the coolant pipes go inside the room, and all other mechanisms are located outside in one housing. This design significantly increases the reliability of the equipment and also reduces noise to less than 35 dB - this is at the level of a normal conversation between two people.

When installing a pump is not cost-effective

It is almost impossible to find free plots of land in the city for the location of the external contour of a ground-to-water HP. It is easier to install an air source heat pump on the external wall of the building, which is especially beneficial in the southern regions. For colder areas with prolonged frosts, there is a possibility of icing of the external radiator grille of the split system.

High efficiency of HP is ensured if the following conditions are met:

1. The heated room must have insulated external enclosing structures. The maximum amount of heat loss cannot exceed 100 W/m2.
2. TN is able to work effectively only with an inertial low-temperature “warm floor” system.
3. In the northern regions, HP should be used in conjunction with additional heat sources.

When the outside air temperature drops sharply, the inertial circuit of the “warm floor” simply does not have time to warm up the room. This happens often in winter. During the day the sun was warm, the thermometer showed -5 °C. At night, the temperature can quickly drop to -15 ° C, and if a strong wind blows, the frost will be even stronger.

Then you need to install regular batteries under the windows and along the outer walls. But the temperature of the coolant in them should be twice as high as in the “warm floor” circuit. A fireplace with a water circuit can provide additional energy in a country cottage, and an electric boiler can provide additional energy in a city apartment.

It remains only to determine whether the HP will be the main or supplementary heat source. In the first case, it must compensate for 70% of the total heat loss of the room, and in the second - 30%.

Video

The video provides a visual comparison of the advantages and disadvantages of various types of heat pumps and explains in detail the structure of the air-water system.

Evgeniy AfanasyevChief Editor