Heat pump working principle cooling. Heating system with heat pump

Any owner of a private house seeks to minimize the cost of heating the home. In this regard, heat pumps are significantly more profitable than other heating options, they provide 2.5-4.5 kW of heat per kilowatt of electricity consumed. back side medals: to obtain cheap energy, you will have to invest a lot of money in equipment, the most modest heating installation with a capacity of 10 kW will cost 3500 USD. e. (starting price).

The only way to reduce costs by 2-3 times is to make a heat pump with your own hands (abbreviated as TN). Consider several real working options, collected and tested by enthusiastic craftsmen in practice. Since the manufacture of a complex unit requires basic knowledge of refrigeration machines, let's start with theory.

Features and principle of operation of HP

How does a heat pump differ from other installations for heating private houses:

unlike boilers and heaters, the unit does not produce heat on its own, but, like an air conditioner, moves it inside the building;
HP is called a pump, because it “pumps out” energy from sources of low-grade heat - ambient air, water or soil;
the unit is powered exclusively by electricity consumed by the compressor, fans, circulation pumps and control board;
the operation of the unit is based on the Carnot cycle used in all refrigeration machines, such as air conditioners and split systems.

In heating mode, a traditional split system normally operates at temperatures above minus 5 degrees, at severe frost efficiency drops sharply

Reference. Heat is contained in any substance whose temperature is above absolute zero (minus 273 degrees). Modern technologies make it possible to take the specified energy from air with a temperature of up to -30 ° C, earth and water - up to +2 ° C.

The Carnot heat exchange cycle involves the working fluid - freon gas, boiling at sub-zero temperatures. Alternately evaporating and condensing in two heat exchangers, the refrigerant absorbs the energy of the environment and transfers it inside the building. In general, the principle of operation of a heat pump repeats that included in heating:

Being in the liquid phase, freon moves through the tubes of the external evaporator heat exchanger, as shown in the diagram. Receiving the heat of air or water through the metal walls, the refrigerant heats up, boils and evaporates.
Then the gas enters the compressor, which pressurizes to the calculated value. Its task is to raise the boiling point of the substance so that the freon condenses at a higher temperature.
Passing through the internal heat exchanger-condenser, the gas again turns into a liquid and gives the accumulated energy to the heat carrier (water) or room air directly.
At the last stage, liquid freon enters the receiver-moisture separator, then into the throttling device. The pressure of the substance drops again, freon is ready to go through a second cycle.

The scheme of operation of a heat pump is similar to the principle of operation of a split system

Note. Conventional split systems and factory heat pumps have common feature– ability to transfer energy in both directions and function in 2 modes – heating/cooling. Switching is implemented using a four-way reversing valve that changes the direction of gas flow along the circuit.

AT domestic air conditioners and HP, various types of thermostatic fittings are used to reduce the pressure of the refrigerant before the evaporator. In household split systems, a simple capillary device plays the role of a regulator; an expensive thermostatic expansion valve (TRV) is installed in pumps.

Note that the above cycle occurs in all types of heat pumps. The difference lies in the methods of heat supply / removal, which we will list below.

Types of throttle fittings: capillary tube (photo on the left) and thermostatic expansion valve (TRV)

Varieties of installations

According to the generally accepted classification, HPs are divided into types according to the source of energy received and the type of coolant to which it is transferred:

Reference. Varieties of heat pumps are listed in order of increasing cost of equipment along with installation. Air installations are the cheapest, geothermal installations are expensive.

The main parameter that characterizes a heat pump for heating a house is the efficiency coefficient COP, equal to the ratio between the energy received and the energy consumed. For example, relatively inexpensive air heaters cannot boast of high COP - 2.5 ... 3.5. We explain: having spent 1 kW of electricity, the installation supplies 2.5-3.5 kW of heat to the dwelling.

Methods for extracting heat from water sources: from a pond (left) and through wells (right)

Water and soil systems are more efficient, their real coefficient lies in the range of 3…4.5. Performance is a variable value that depends on many factors: the design of the heat exchange circuit, immersion depth, temperature and water flow.

An important point. Hot water heat pumps are not able to heat the coolant up to 60-90 °C without additional circuits. The normal water temperature from the HP is 35 ... 40 degrees, the boilers clearly win here. Hence the recommendation of the manufacturers: connect the equipment to low-temperature heating - water.

Which TN is better to collect

We formulate the problem: you need to build a home-made heat pump at the lowest cost. A number of logical conclusions follow from this:

The installation will have to use a minimum of expensive parts, so it will not be possible to achieve a high COP value. In terms of performance, our device will lose to factory models.
Accordingly, it is pointless to make a pure air HP, it is easier to use it in heating mode.
To get real benefits, you need to make an air-to-water, water-to-water heat pump or build a geothermal installation. In the first case, you can achieve a COP of about 2-2.2, in the rest - reach an indicator of 3-3.5.
It will not be possible to do without floor heating circuits. A coolant heated to 30-35 degrees is incompatible with a radiator network, except in the southern regions.

Laying the external contour of the HP to the reservoir

Comment. Manufacturers claim: the inverter split system operates when outdoor temperature minus 15-30 °С. In reality, the heating efficiency is significantly reduced. According to homeowners, on frosty days, the indoor unit delivers a barely warm air flow.

To implement the water version of the HP, certain conditions are required (optional):

a reservoir 25-50 m from the dwelling, at a greater distance, electricity consumption will increase dramatically due to a powerful circulation pump;
a well or well with a sufficient supply (debit) of water and a place for draining (pit, second well, gutter, sewerage);
prefabricated sewer (if you are allowed to crash into it).

Groundwater flow is easy to calculate. In the process of taking heat, a home-made HP will lower their temperature by 4-5 ° C, from here the volume of the flow is determined through the heat capacity of water. To obtain 1 kW of heat (we take a delta of water temperatures of 5 degrees), you need to drive about 170 liters through a heat pump for an hour.

Heating a house with an area of 100 m² will require a power of 10 kW and a water consumption of 1.7 tons per hour - an impressive volume. Such a thermal water pump is suitable for a small country house of 30-40 m², preferably insulated.

Methods of heat extraction by geothermal heat pumps

The assembly of a geothermal system is more realistic, although the process is quite laborious. The option of laying the pipe horizontally over an area at a depth of 1.5 m is immediately dismissed - you will have to shovel the entire area or pay money for the services of earthmoving equipment. The method of drilling wells is much easier and cheaper to implement, with virtually no disturbance to the landscape.

The simplest heat pump from a window air conditioner

As you might guess, for the manufacture of a water-to-air heat pump, a window cooler in working condition is required. It is highly desirable to buy a model equipped with a reversing valve and able to work for heating, otherwise you will have to redo the freon circuit.

Advice. When buying a used air conditioner, pay attention to the nameplate, which displays the technical characteristics of the household appliance. The parameter you are interested in is (indicated in kilowatts or British thermal units - BTU).

The heating capacity of the device is greater than the refrigeration one and is equal to the sum of two parameters - the performance plus the heat generated by the compressor

With some luck, you don't even have to release freon and re-solder the tubes. How to convert an air conditioner into a heat pump:

Recommendation. If the heat exchanger cannot be placed in the tank without breaking the freon lines, try to evacuate the gas and cut the pipes at the right points (away from the evaporator). After assembling the water heat exchange unit, the circuit will have to be soldered and filled with freon. The amount of refrigerant is also indicated on the label.

Now it remains to start a home-made HP and adjust the water flow, achieving maximum efficiency. Please note: the improvised heater uses a completely factory "stuffing", you just moved the radiator from the air to the liquid. How the system works live, look at the video of the craftsman:

Making a geothermal installation

If the previous option allows you to achieve approximately double savings, then even a home-made earth circuit will give a COP in the region of 3 (three kilowatts of heat per 1 kW of electricity consumed). True, financial and labor costs will also increase significantly.

Although a lot of examples of assembling such devices have been published on the Internet, there is no universal instruction with drawings. We will offer a working version, assembled and tested by a real home master, although many things will have to be thought out and completed on our own - it is difficult to put all the information about heat pumps in one publication.

Calculation of the ground circuit and pump heat exchangers

Following our own recommendations, we proceed to the calculations of a geothermal pump with vertical U-shaped probes placed in wells. It is necessary to find out the total length of the outer contour, and then - the depth and number of vertical shafts.

Initial data for the example: you need to heat a private insulated house with an area of 80 m² and a ceiling height of 2.8 m, located in middle lane. we will not produce for heating, we will determine the need for heat by area, taking into account thermal insulation - 7 kW.

Optionally, you can equip a horizontal collector, but then you will have to allocate a large area for excavation

An important clarification. Engineering calculations of heat pumps are quite complex and require high qualifications of the performer; entire books are devoted to this topic. The article provides simplified calculations taken from the practical experience of builders and craftsmen - lovers of homemade products.

The intensity of heat exchange between the ground and the non-freezing liquid circulating along the contour depends on the type of soil:

1 running meter of a vertical probe immersed in groundwater will receive about 80 W of heat;
in stony soils, heat removal will be about 70 W / m;
clay soils saturated with moisture will give off about 50 W per 1 m of collector;
dry rocks - 20 W / m.

Reference. The vertical probe consists of 2 loops of pipes lowered to the bottom of the well and filled with concrete.

An example of calculating the length of a pipe. To extract the required 7 kW of thermal energy from the raw clay rock, you need to divide 7000 W by 50 W / m, we get a total probe depth of 140 m. Now the pipeline is distributed over wells 20 m deep, which you can drill with your own hands. A total of 7 drillings of 2 heat exchange loops, the total length of the pipe is 7 x 20 x 4 = 560 m.

The next step is to calculate the heat exchange area of the evaporator and condenser. Various Internet resources and forums offer some calculation formulas, in most cases they are incorrect. We will not take the liberty of recommending such methods and misleading you, but we will offer some tricky option:

Contact any well-known manufacturer of plate heat exchangers, such as Alfa Laval, Kaori, Anvitek, and so on. You can go to the official website of the brand.
Fill out the heat exchanger selection form or call the manager and order the selection of the unit, listing the parameters of the media (antifreeze, freon) - inlet and outlet temperature, heat load.
The company's specialist will make the necessary calculations and offer a suitable model of the heat exchanger. Among its characteristics you will find the main one - the exchange surface area.

Plate units are very efficient, but expensive (200-500 euros). It is cheaper to assemble a shell-and-tube heat exchanger from a copper tube with an outer diameter of 9.5 or 12.7 mm. Multiply the figure issued by the manufacturer by a safety factor of 1.1 and divide by the circumference of the pipe, get the footage.

Stainless steel plate heat exchanger perfect option evaporator, it is efficient and takes up little space. The problem is the high price of the product

Example. The heat exchange area of the proposed unit was 0.9 m². Choosing a copper tube ½ "with a diameter of 12.7 mm, we calculate the circumference in meters: 12.7 x 3.14 / 1000 ≈ 0.04 m. Determine the total footage: 0.9 x 1.1 / 0.04 ≈ 25 m.

Equipment and materials

The future heat pump is proposed to be built on the basis of an outdoor unit of a split system of suitable capacity (indicated on the plate). Why is it better to use a used air conditioner:

the device is already equipped with all components - a compressor, a throttle, a receiver and a starting electrician;
homemade heat exchangers can be placed in the housing refrigeration machine;
there are convenient service ports for refueling freon.

Note. Users versed in the topic select equipment separately - compressor, expansion valve, controller, and so on. If you have experience and knowledge, such an approach is only welcome.

It is not advisable to assemble a heat pump on the basis of an old refrigerator - the power of the unit is too low. In the best case, it will be possible to “squeeze out” up to 1 kW of heat, which is enough to heat one small room.

In addition to the external "split" block, you will need the following materials:

HDPE pipe Ø20 mm - to the earth circuit;
polyethylene fittings for assembly of collectors and connection to heat exchangers;
circulation pumps - 2 pcs.;
manometers, thermometers;
high-quality water hose or HDPE pipe with a diameter of 25-32 mm for the shell of the evaporator and condenser;
copper tube Ø9.5-12.7 mm with a wall thickness of at least 1 mm;
insulation for pipelines and freon lines;
kit for sealing heating cables laid inside the water supply system (needed to seal the ends of copper pipes).

Bushing kit for sealed entry of copper tube

As an external coolant, a saline solution of water or antifreeze for heating - ethylene glycol is used. You will also need a supply of freon, whose brand is indicated on the nameplate of the split system.

Assembly of the heat exchanger

Before starting installation work, the outdoor module must be disassembled - remove all covers, remove the fan and a large regular radiator. Disable the solenoid that controls the reversing valve if you do not plan to use the pump as a coolant. Temperature and pressure sensors must be retained.

Assembly order of the main HP unit:

Fabricate the condenser and evaporator by inserting a copper tube inside the estimated length of the hose. At the ends, install tees for connecting the ground and heating circuits, protruding copper tubes seal with a special heating cable kit.
Using a piece of plastic pipe Ø150-250 mm as a core, wind home-made two-pipe circuits and bring the ends in the right direction, as is done in the video below.
Place and fix both shell-and-tube heat exchangers in place of the standard radiator, solder the copper tubes to the corresponding terminals. A "hot" heat exchanger-condenser is best connected to the service ports.
Install factory sensors that measure the temperature of the refrigerant. Insulate the bare sections of the tubes and the heat exchangers themselves.
Install thermometers and pressure gauges on water lines.

Advice. If you plan to install the main unit outdoors, you need to take measures to prevent the oil in the compressor from freezing. Purchase and install a winter kit for electric oil sump heating.

On thematic forums, there is another way to make an evaporator - a copper tube is wound in a spiral, then inserted into a closed container (tank or barrel). The option is quite reasonable in large numbers turns, when the calculated heat exchanger simply does not fit in the air conditioner housing.

Ground loop device

At this stage, simple but time-consuming earthworks and the placement of probes in wells are carried out. The latter can be done manually or invite a drilling machine. The distance between adjacent wells is at least 5 m. Further work procedure:

Dig a shallow trench between the holes for laying the supply pipes.
Lower 2 loops of polyethylene pipes into each hole and fill the pits with concrete.
Bring the lines to the connection point and mount the common manifold using HDPE fittings.
Insulate pipelines laid in the ground and cover with soil.

On the left in the photo - lowering the probe into the casing plastic pipe, on the right - laying eyeliners in the trench

An important point. Before concreting and backfilling, be sure to check the tightness of the circuit. For example, connect an air compressor to the manifold, pressurize 3-4 bar and leave for several hours.

When connecting the highways, be guided by the diagram below. Branches with taps will be needed when filling the system with brine or ethylene glycol. Lead the two main pipes from the collector to the heat pump and connect to the “cold” evaporator heat exchanger.

At the highest points of both water circuits, air vents must be installed; they are not conventionally shown in the diagram

Do not forget to install the pumping unit responsible for the circulation of the liquid, the direction of flow is towards the freon in the evaporator. The media passing through the condenser and evaporator must move towards each other. How to properly fill the lines of the "cold" side, see the video:

Similarly, the condenser is connected to the house floor heating system. It is not necessary to install a mixing unit with a three-way valve due to the low flow temperature. If it is necessary to combine the HP with other heat sources (solar collectors, boilers), use multiple outputs.

Filling and starting the system

After installation and connection of the unit to the mains, milestone– filling the system with refrigerant. A pitfall awaits here: you don’t know how much freon needs to be charged, because the volume of the main circuit has grown significantly due to the installation of a home-made condenser with an evaporator.

The issue is solved by the method of refueling according to the pressure and temperature of freon overheating, measured at the compressor inlet (the freon is supplied there in a gaseous state). Detailed instructions for filling in the temperature measurement method are set out in.

The second part of the presented video tells how to fill the system with R22 brand freon according to the pressure and temperature of the refrigerant superheat:

After refueling, turn on both circulation pumps to the first speed and start the compressor. Control the temperature of the brine and the internal coolant using thermometers. During the warm-up phase, the refrigerant lines may freeze, and then the frost should melt.

Conclusion

Making and running a geothermal heat pump with your own hands is very difficult. Surely, repeated improvements, bug fixes, tweaks will be required. As a rule, most malfunctions in home-made HPs occur due to improper assembly or filling of the main heat exchange circuit. If the unit immediately failed (safety automatics worked) or the coolant does not heat up, it is worth calling the refrigeration technician - he will diagnose and point out the mistakes made.

Having refrigerators and air conditioners in their home, few people know that the principle of operation of a heat pump is implemented in them.

About 80% of the power supplied by a heat pump comes from ambient heat in the form of scattered solar radiation. It is his pump that simply “pumps” from the street into the house. The operation of a heat pump is similar to the principle of operation of a refrigerator, only the direction of heat transfer is different.

Simply put…

To chill the bottle mineral water You put it in the refrigerator. The refrigerator must “take away” part of the thermal energy from the bottle and, according to the law of conservation of energy, move it somewhere, give it away. The refrigerator transfers heat to a radiator, usually located on its back wall. At the same time, the radiator heats up, giving off its heat to the room. In fact, it heats the room. This is especially noticeable in small mini-markets in the summer, with several refrigerators in the room.

We invite you to imagine. Suppose that we will constantly put warm objects in the refrigerator, and it will, by cooling them, heat the air in the room. Let's go to the "extremes" ... Let's place the refrigerator in the window opening with the open door of the "freezer" out. The refrigerator radiator will be in the room. During operation, the refrigerator will cool the air outside, transferring the "taken" heat into the room. This is how a heat pump works, taking dispersed heat from the environment and transferring it to the room.

Where does the pump get the heat?

The principle of operation of a heat pump is based on the "exploitation" of natural low-grade heat sources from the environment.

They may be:

just outside air;
heat of reservoirs (lakes, seas, rivers);
heat of the soil, groundwater (thermal and artesian).

How is a heat pump and a heating system with it arranged?

The heat pump is integrated into the heating system, which consists of 2 circuits + the third circuit - the system of the pump itself. A non-freezing coolant circulates along the external circuit, which takes heat from the surrounding space.

When it enters the heat pump, or rather its evaporator, the coolant gives off an average of 4 to 7 °C to the heat pump refrigerant. And its boiling point is -10 °C. As a result, the refrigerant boils, followed by a transition to a gaseous state. The coolant of the external circuit, already cooled, goes to the next “coil” through the system to set the temperature.

As part of the functional circuit of the heat pump "listed":

evaporator;
compressor (electric);
capillary;
capacitor;
coolant;
thermostatic control device.

The process looks like this!

The refrigerant "boiled" in the evaporator through the pipeline enters the compressor, powered by electricity. This "hard worker" compresses the gaseous refrigerant to high pressure, which, accordingly, leads to an increase in its temperature.

The now hot gas then enters another heat exchanger, which is called a condenser. Here, the heat of the refrigerant is transferred to the room air or heat carrier, which circulates through the internal circuit of the heating system.

The refrigerant cools down, at the same time turning into a liquid state. It then passes through a capillary pressure reducing valve, where it “loses” pressure and re-enters the evaporator.

The cycle is closed and ready to repeat!

Approximate calculation of the heating output of the installation

Within an hour, up to 2.5-3 m 3 of coolant flows through the external collector through the pump, which the earth is able to heat by ∆t = 5-7 °C.

To calculate the thermal power of such a circuit, use the formula:

Q \u003d (T_1 - T_2) * V_warm

V_heat - volumetric flow rate of the heat carrier per hour (m ^ 3 / h);

T_1 - T_2 - inlet and outlet temperature difference (°C) .

Varieties of heat pumps

According to the type of dissipated heat used, heat pumps are distinguished:

ground-water (use closed ground contours or deep geothermal probes and a water heating system for a room);
water-water (open wells are used for the intake and discharge of groundwater - the external circuit is not looped, internal system heating - water);
water-air (use of external water circuits and air-type heating systems);
(using the dissipated heat of external air masses, complete with the air heating system of the house).

Advantages and benefits of heat pumps

Economic efficiency. The principle of operation of a heat pump is based not on production, but on the transfer (transportation) of thermal energy, it can be argued that its efficiency is greater than one. What nonsense? - you will say. In the topic of heat pumps, the value appears - the coefficient of conversion (transformation) of heat (KPT). It is by this parameter that units of this type are compared with each other. His physical meaning- show the ratio of the amount of heat received to the amount of energy expended for this. For example, at KPT = 4.8, the electricity consumed by the pump in 1 kW will allow you to get 4.8 kW of heat with it free of charge, that is, a gift from nature.

Universal ubiquity of application. Even in the absence of available power lines, the heat pump compressor can be powered by a diesel drive. And there is "natural" heat in any corner of the planet - the heat pump will not remain "hungry".

Ecological purity of use. There are no combustion products in the heat pump, and its low energy consumption “exploits” power plants less, indirectly reducing harmful emissions from them. The refrigerant used in heat pumps is ozone-friendly and does not contain chlorocarbons.

Bidirectional mode of operation. The heat pump can winter time heat the room, and in the summer - cool. The “heat” taken from the premises can be used efficiently, for example, to heat water in a pool or in a hot water supply system.

Operational safety. In the principle of operation of a heat pump, you will not consider dangerous processes. The absence of open fire and harmful emissions dangerous for humans, the low temperature of the heat carriers make the heat pump a “harmless”, but useful household appliance.

Some nuances of operation

Efficient use of the principle of operation of a heat pump requires compliance with several conditions:

the room that is heated must be well insulated (heat loss up to 100 W / m 2) - otherwise, taking heat from the street, you will heat the street for your own money;
heat pumps are useful for low temperature systems heating. Under such criteria, underfloor heating systems (35-40 ° C) are excellent. The heat conversion coefficient significantly depends on the ratio of the temperatures of the inlet and outlet circuits.

Let's sum it up!

The essence of the principle of operation of a heat pump is not in production, but in the transfer of heat. This allows you to get a high coefficient (from 3 to 5) of thermal energy conversion. Simply put, each 1 kW of electricity used will “transfer” 3-5 kW of heat to the house. Is there anything else that needs to be said?

This autumn, there is an aggravation in the network about heat pumps and their use for heating country houses and dachas. In a country house that I built with my own hands, such a heat pump has been installed since 2013. This is a semi-industrial air conditioner that can effectively work for heating at outdoor temperatures down to -25 degrees Celsius. It is the main and only heating device in a one-story country house with a total area of 72 square meters.

2. Briefly recall the background. Four years ago, a plot of 6 acres was bought in a garden partnership, on which, with my own hands, without involving hired labor, I built a modern energy-efficient country house. The purpose of the house is the second apartment, located in nature. Year-round, but not permanent operation. Required maximum autonomy in conjunction with simple engineering. In the area where the SNT is located, there is no main gas and you should not count on it. There remains imported solid or liquid fuel, but all these systems require complex infrastructure, the cost of construction and maintenance of which is comparable to direct heating with electricity. Thus, the choice was already partly predetermined - electric heating. But here a second, no less important point arises: the limitation of electrical capacities in the garden partnership, as well as rather high electricity tariffs (at that time - not a "rural" tariff). In fact, 5 kW of electric power has been allocated to the site. The only way out in this situation is to use a heat pump, which will save on heating by about 2.5-3 times, compared with the direct conversion of electrical energy into heat.

So let's move on to heat pumps. They differ in where they take heat from and where they give it away. An important point, known from the laws of thermodynamics (8th grade of high school) - a heat pump does not produce heat, it transfers it. That is why its COP (energy conversion factor) is always greater than 1 (that is, the heat pump always gives off more heat than it consumes from the network).

The classification of heat pumps is as follows: "water - water", "water - air", "air - air", "air - water". Under the "water" indicated in the formula on the left is meant the removal of heat from the liquid circulating coolant passing through pipes located in the ground or a reservoir. The efficiency of such systems practically does not depend on the season and ambient temperature, but they require expensive and time-consuming earthworks, as well as the availability of sufficient free space for laying a soil heat exchanger (on which, subsequently, anything will grow poorly in summer, due to freezing of the soil) . The "water" indicated in the formula on the right refers to the heating circuit located inside the building. It can be either a system of radiators or liquid underfloor heating. Such a system will also require complex engineering work inside the building, but it also has its advantages - with the help of such a heat pump, you can also get hot water in the house.

But the category of air-to-air heat pumps looks the most interesting. In fact, these are the most common air conditioners. While working for heating, they take heat from the outdoor air and transfer it to the air heat exchanger located inside the house. Despite some drawbacks (serial models cannot operate at ambient temperatures below -30 degrees Celsius), they have a huge advantage: such a heat pump is very easy to install and its cost is comparable to conventional electric heating using convectors or an electric boiler.

3. Based on these considerations, Mitsubishi Heavy duct semi-industrial air conditioner, model FDUM71VNX, was chosen. As of autumn 2013, a set consisting of two blocks (external and internal) cost 120 thousand rubles.

4. The outdoor unit is installed on the facade on the north side of the house, where there is the least wind (this is important).

5. The indoor unit is installed in the hall under the ceiling, from which, with the help of flexible soundproof air ducts, hot air is supplied to all living spaces inside the house.

6. Because the air supply is located under the ceiling (it is absolutely impossible to organize the supply of hot air near the floor in a stone house), it is obvious that you need to take the air on the floor. To do this, with the help of a special box, the air intake was lowered to the floor in the corridor (in all interior doors, overflow grilles were also installed in the lower part). Operating mode - 900 cubic meters of air per hour, due to constant and stable circulation, there is absolutely no difference in air temperature between the floor and ceiling in any part of the house. To be precise, the difference is 1 degree Celsius, which is even less than when using wall-mounted convectors under windows (with them, the temperature difference between floor and ceiling can reach 5 degrees).

7. In addition to the fact that the indoor unit of the air conditioner, due to the powerful impeller, is able to drive large volumes of air around the house in recirculation mode, one should not forget that people need fresh air in the house. Therefore, the heating system also acts as a ventilation system. Through a separate air duct from the street, fresh air is supplied to the house, which, if necessary, is heated (during the cold season) using automation and a channel heating element.

8. Distribution of hot air is carried out through these grilles located in the living rooms. It is also worth paying attention to the fact that there is not a single incandescent lamp in the house and only LEDs are used (remember this point, this is important).

9. Waste "dirty" air is removed from the house through the hood in the bathroom and in the kitchen. Hot water is prepared in a conventional storage water heater. In general, this is a fairly large expense item, because. well water very cold (from +4 to +10 degrees Celsius depending on the time of year) and one might reasonably notice that solar collectors can be used to heat water. Yes, you can, but the cost of investing in infrastructure is such that for this money you can heat water directly with electricity for 10 years.

10. And this is "TsUP". Air source heat pump master and main controller. It has various timers and the simplest automation, but we use only two modes: ventilation (in warm time year) and heating (in the cold season). The built house turned out to be so energy efficient that the air conditioner in it was never used for intended purpose- to cool the house in the heat. LED lighting played a big role in this (heat transfer from which tends to zero) and very high-quality insulation (it's no joke, after arranging the lawn on the roof, we even had to use a heat pump this summer to heat the house - on days when the average daily temperature dropped below + 17 degrees Celsius). The temperature in the house is maintained year-round at least +16 degrees Celsius, regardless of the presence of people in it (when there are people in the house, the temperature is set to +22 degrees Celsius) and never turns off forced ventilation(because lazy).

11. The meter for technical electricity metering was installed in the fall of 2013. That is exactly 3 years ago. It is easy to calculate that the average annual consumption of electrical energy is 7000 kWh (in fact, this figure is slightly lower now, because in the first year the consumption was high due to the use of dehumidifiers during finishing work).

12. In the factory configuration, the air conditioner is capable of heating at an ambient temperature of at least -20 degrees Celsius. To work at lower temperatures, refinement is required (in fact, it is relevant during operation even at a temperature of -10, if outdoors high humidity) - installation of the heating cable in the drainage pan. This is necessary so that after the defrost cycle of the outdoor unit, the water in liquid state managed to leave the drain pan. If she does not have time to do this, then ice will freeze in the pan, which will subsequently squeeze out the frame with the fan, which will probably lead to the breaking of the blades on it (you can see photos of the broken blades on the Internet, I almost encountered this myself because . did not put down the heating cable immediately).

13. As I mentioned above, LED lighting is used everywhere in the house. This is important when it comes to air conditioning a room. Let's take a standard room in which there are 2 lamps, 4 lamps in each. If these are 50 watt incandescent lamps, then in total they consume 400 watts, while LED lamp will consume less than 40 watts. And all energy, as we know from the physics course, eventually turns into heat anyway. That is, incandescent lighting is such a good medium-power heater.

14. Now let's talk about how a heat pump works. All it does is transfer heat energy from one place to another. This is how refrigerators work. They transfer heat from the refrigerator to the room.

There is such good riddle: How will the temperature in the room change if you leave the fridge plugged in with the door open? The correct answer is that the temperature in the room will rise. For a simple understanding, this can be explained as follows: the room is a closed circuit, electricity flows into it through the wires. As we know, energy eventually turns into heat. That is why the temperature in the room will rise, because electricity enters the closed circuit from the outside and remains in it.

A bit of theory. Heat is a form of energy that is transferred between two systems due to temperature differences. Wherein thermal energy moving from a place of high temperature to a place of lower temperature. This is a natural process. Heat transfer can be carried out by conduction, thermal radiation or by convection.

There are three classical aggregate states of matter, the transformation between which is carried out as a result of a change in temperature or pressure: solid, liquid, gaseous.

To change the state of aggregation, the body must either receive or give off thermal energy.

During melting (transition from a solid to a liquid state), thermal energy is absorbed.
During evaporation (transition from a liquid to a gaseous state), thermal energy is absorbed.
During condensation (transition from a gaseous state to a liquid state), thermal energy is released.
During crystallization (transition from a liquid to a solid state), thermal energy is released.

The heat pump uses two transient modes in its operation: evaporation and condensation, that is, it operates with a substance that is either in a liquid or in a gaseous state.

15. The refrigerant R410a is used as the working fluid in the heat pump circuit. It is a fluorocarbon that boils (changes from liquid to gas) at very low temperatures. Namely, at a temperature of - 48.5 degrees Celsius. That is, if ordinary water boils at a temperature of +100 degrees Celsius at normal atmospheric pressure, then R410a freon boils at a temperature almost 150 degrees lower. Moreover, at a very negative temperature.

It is this property of the refrigerant that is used in the heat pump. By targeted measurement of pressure and temperature, it can be given the desired properties. Either it will be evaporation at ambient temperature with the absorption of heat, or condensation at ambient temperature with the release of heat.

16. This is what the heat pump circuit looks like. Its main components are compressor, evaporator, expansion valve and condenser. The refrigerant circulates in a closed circuit of the heat pump and alternately changes its state of aggregation from liquid to gaseous and vice versa. It is the refrigerant that transfers and transfers heat. The pressure in the circuit is always excessive compared to atmospheric pressure.

How it works?
Compressor draws in cold gaseous refrigerant low pressure coming from the evaporator. The compressor compresses it under high pressure. The temperature rises (the heat from the compressor is also added to the refrigerant). At this stage, we obtain a gaseous refrigerant of high pressure and high temperature.
In this form, it enters the condenser, blown with colder air. The superheated refrigerant gives up its heat to the air and condenses. At this stage, the refrigerant is in a liquid state, under high pressure and average temperature.
The refrigerant then enters the expansion valve. There is a sharp decrease in pressure in it, due to the expansion of the volume that the refrigerant occupies. The decrease in pressure leads to partial evaporation of the refrigerant, which in turn reduces the temperature of the refrigerant below ambient temperature.
In the evaporator, the pressure of the refrigerant continues to decrease, it evaporates even more, and the heat necessary for this process is taken from the warmer outside air, which is then cooled.
The fully gaseous refrigerant enters the compressor again and the cycle is completed.

17. I'll try to explain again in a simpler way. The refrigerant boils already at a temperature of -48.5 degrees Celsius. That is, relatively speaking, at any higher ambient temperature, it will have excess pressure and, in the process of evaporation, will take heat from the environment (that is, street air). There are refrigerants used in low-temperature refrigerators, their boiling point is even lower, down to -100 degrees Celsius, but it cannot be used to operate a heat pump to cool a room in the heat due to very high pressure at high ambient temperatures. R410a refrigerant is a kind of balance between the ability of the air conditioner to work both for heating and cooling.

Here, by the way, is a good documentary film shot in the USSR and telling about how a heat pump works. I recommend.

18. Can any air conditioner be used for heating? No, not any. Although almost all modern air conditioners work on R410a freon, other characteristics are no less important. Firstly, the air conditioner must have a four-way valve that allows you to switch to “reverse”, so to speak, namely, to swap the condenser and evaporator. Secondly, please note that the compressor (it is located on the lower right) is located in a thermally insulated casing and has an electric crankcase heater. This is necessary in order to always maintain a positive oil temperature in the compressor. In fact, at an ambient temperature below +5 degrees Celsius, even in the off state, the air conditioner consumes 70 watts of electrical energy. The second, most important point - the air conditioner must be inverter. That is, both the compressor and the impeller electric motor must be able to change performance during operation. This is what allows the heat pump to work efficiently for heating at outdoor temperatures below -5 degrees Celsius.

19. As we know, on the heat exchanger of the outdoor unit, which is the evaporator during heating operation, intensive evaporation of the refrigerant occurs with the absorption of heat from the environment. But in the street air there are water vapors in a gaseous state, which condense, or even crystallize on the evaporator due to a sharp drop in temperature (the street air gives up its heat to the refrigerant). And intensive freezing of the heat exchanger will lead to a decrease in the efficiency of heat removal. That is, as the ambient temperature decreases, it is necessary to “slow down” both the compressor and the impeller in order to ensure the most efficient heat removal on the evaporator surface.

An ideal heat pump for heating only should have a surface area of the external heat exchanger (evaporator) several times the surface area of the internal heat exchanger (condenser). In practice, we return to the very balance that the heat pump must be able to work both for heating and cooling.

20. On the left, you can see the external heat exchanger almost completely covered with frost, except for two sections. In the upper, not frozen, section, freon still has a sufficiently high pressure, which does not allow it to effectively evaporate with the absorption of heat from the environment, while in the lower section it is already overheated and can no longer take heat from the outside. And the photo on the right gives an answer to the question why the external unit of the air conditioner was installed on the facade, and not hidden from view on flat roof. It is because of the water that needs to be diverted from the drainage pan in the cold season. It would be much more difficult to drain this water from the roof than from the blind area.

As I already wrote, during heating operation at a negative temperature outside, the evaporator on the outdoor unit freezes over, water from the outdoor air crystallizes on it. The efficiency of a frozen evaporator is noticeably reduced, but the air conditioner electronics automatically controls the heat removal efficiency and periodically switches the heat pump to the defrost mode. In fact, the defrost mode is a direct conditioning mode. That is, heat is taken from the room and transferred to an external, frozen heat exchanger in order to melt the ice on it. At this time, the fan of the indoor unit runs at minimum speed, and cool air comes out of the air ducts inside the house. The defrost cycle usually lasts 5 minutes and occurs every 45-50 minutes. Due to the high thermal inertia of the house, no discomfort is felt during defrosting.

21. Here is a table of heat output for this heat pump model. Let me remind you that the nominal energy consumption is just over 2 kW (current 10A), and the heat transfer ranges from 4 kW at -20 degrees outside, up to 8 kW at a street temperature of +7 degrees. That is, the conversion factor is from 2 to 4. It is how many times the heat pump saves energy compared to the direct conversion of electrical energy into heat.

By the way, there is another interesting point. The resource of the air conditioner when working for heating is several times higher than when working for cooling.

22. Last fall, I installed the Smappee electric energy meter, which allows you to keep statistics on energy consumption on a monthly basis and provides a more or less convenient visualization of the measurements taken.

23. Smappee was installed exactly one year ago, in the last days of September 2015. It also attempts to show the cost of electricity, but does so based on manually set rates. And there is an important point with them - as you know, we raise electricity prices 2 times a year. That is, for the presented measurement period, tariffs changed 3 times. Therefore, we will not pay attention to the cost, but calculate the amount of energy consumed.

In fact, Smappee has problems with the visualization of consumption graphs. For example, the shortest column on the left is the consumption for September 2015 (117 kWh). something went wrong with the developers and for some reason there are 11, not 12 columns on the screen for a year. But the total consumption figures are calculated accurately.

Namely, 1957 kWh for 4 months (including September) at the end of 2015 and 4623 kWh for the whole of 2016 from January to September inclusive. That is, a total of 6580 kWh was spent on ALL the life support of a country house, which was heated all year round, regardless of the presence of people in it. Let me remind you that in the summer of this year for the first time I had to use a heat pump for heating, and for cooling in the summer it did not work even once in all 3 years of operation (except for automatic defrost cycles, of course). In rubles, at current tariffs in the Moscow region, this is less than 20 thousand rubles a year, or about 1,700 rubles a month. Let me remind you that this amount includes: heating, ventilation, water heating, stove, refrigerator, lighting, electronics and appliances. That is, it is actually 2 times cheaper than the monthly payment for an apartment in Moscow of the same area (of course, excluding maintenance fees, as well as fees for major repairs).

24. And now let's calculate how much money the heat pump saved in my case. We will compare with electric heating, using the example of an electric boiler and radiators. I will count at pre-crisis prices, which were at the time of the installation of the heat pump in the fall of 2013. Now heat pumps have risen in price due to the collapse of the ruble, and the equipment is all imported (the leaders in the production of heat pumps are the Japanese).

Electric heating:
Electric boiler - 50 thousand rubles
Pipes, radiators, fittings, etc. - another 30 thousand rubles. Total materials for 80 thousand rubles.

Heat pump:
Channel air conditioner MHI FDUM71VNXVF (outdoor and indoor unit) - 120 thousand rubles.
Air ducts, adapters, thermal insulation, etc. - another 30 thousand rubles. Total materials for 150 thousand rubles.

Do-it-yourself installation, but in both cases it is about the same in time. Total "overpayment" for a heat pump compared to an electric boiler: 70 thousand rubles.

But that's not all. Air heating using a heat pump is at the same time air conditioning in the warm season (that is, air conditioning still needs to be installed, right? So we add at least another 40 thousand rubles) and ventilation (mandatory in modern sealed houses, at least another 20 thousand rubles).

What do we have? "Overpayment" in the complex is only 10 thousand rubles. It is still at the stage of putting the heating system into operation.

And then the operation begins. As I wrote above, in the coldest winter months the conversion factor is 2.5, and in the off-season and summer it can be taken equal to 3.5-4. Let's take the average annual COP equal to 3. Let me remind you that 6,500 kWh of electrical energy is consumed in a house per year. This is the total consumption of all electrical appliances. Let's take for simplicity of calculations at a minimum that the heat pump consumes only half of this amount. That is 3000 kWh. At the same time, on average, for the year he gave 9000 kWh of thermal energy (6000 kWh "dragged" from the street).

Let's translate the transferred energy into rubles, assuming that 1 kWh of electrical energy costs 4.5 rubles (average day/night tariff in the Moscow region). We get 27,000 rubles of savings, compared with electric heating only for the first year of operation. Recall that the difference at the stage of putting the system into operation was only 10 thousand rubles. That is, already for the first year of operation, the heat pump SAVED me 17 thousand rubles. That is, it paid off in the first year of operation. Let me remind you that this is not permanent residence, at which the savings would be even greater!

But do not forget about the air conditioner, which specifically in my case was not required due to the fact that the house I built turned out to be over-insulated (although a single-layer aerated concrete wall is used without additional insulation) and it simply does not heat up in the summer in the sun. That is, we will throw off 40 thousand rubles from the estimate. What do we have? In this case, I began to SAVE on the heat pump not from the first year of operation, but from the second. It's not a big difference.

But if we take a water-to-water heat pump or even an air-to-water heat pump, then the figures in the estimate will be completely different. That is why an air-to-air heat pump offers the best price/performance ratio on the market.

25. And finally, a few words about electric heaters. I was tormented by questions about all sorts of infrared heaters and nano-technologies that do not burn oxygen. I will answer briefly and to the point. Any electric heater has an efficiency of 100%, that is, all electrical energy is converted into heat. In fact, this applies to any electrical appliances, even an electric light bulb gives off heat exactly in the amount in which it received it from the outlet. If we talk about infrared heaters, then their advantage lies in the fact that they heat objects, not air. Therefore, the most reasonable application for them is heating on open verandas cafes and bus stops. Where there is a need to transfer heat directly to objects / people, bypassing air heating. A similar story about the burning of oxygen. If somewhere in the brochure you see this phrase, you should know that the manufacturer is holding the buyer for a sucker. Combustion is an oxidation reaction, and oxygen is an oxidizing agent, that is, it cannot burn itself. That is, this is all the nonsense of amateurs who skipped physics lessons at school.

26. Another option for saving energy when electric heating(it does not matter, direct conversion or with the help of a heat pump) is the use of the heat capacity of the building envelope (or a special heat accumulator) to accumulate heat when using a cheap night electric tariff. That's what I'll be experimenting with this winter. According to my preliminary calculations (taking into account the fact that next month I will pay the village electricity tariff, because the building is already registered as a residential building), even despite the increase in electricity tariffs, next year I will pay for the maintenance of the house less than 20 thousand rubles (for all consumed electrical energy for heating, water heating, ventilation and equipment, taking into account the fact that the house is maintained at a temperature of about 18-20 degrees Celsius all year round, regardless of whether there are people in it).

What is the result? A heat pump in the form of a low-temperature air-to-air conditioner is the easiest and most affordable way to save on heating, which can be doubly important when there is a limit on electrical power. I am completely satisfied with the installed heating system and do not experience any discomfort from its operation. In the conditions of the Moscow region, the use of an air source heat pump fully justifies itself and allows you to recoup the investment no later than in 2-3 years.

By the way, do not forget that I also have Instagram, where I publish the progress of work almost in real time -

Economical home heating systems are replacing traditional types of heating using gas, solid fuels and electricity. An air source heat pump is one of the most popular alternative solutions.

Among the advantages, we can note the low cost compared to geothermal installations, the possibility of using it when creating new heating systems and reconstructing old ones. The heat pump is especially in demand in "passive house" systems - living quarters designed according to the principle minimal cost heat and the introduction of energy-saving technologies.

What is an air heat pump

The simplest heat pump was designed back in 1852 and was called the "heat multiplier". Lord Kelvin discovered the fundamental principles of action that formed the basis of all modern heating equipment.

According to the laws of physics, heat is transferred from a heated body to something that has a lower temperature. But, the reverse process is possible, provided that additional energy is used for this.

A little later, the principle of the reverse Carnot cycle was discovered. The substance absorbs heat when evaporating, and after condensing on the surface, it releases it. It is this law that underlies refrigerators and air conditioners. The low-temperature air heat pump works like these household appliances, only in the "backward direction".

Some manufacturers of air conditioners use this principle, offering the consumer air conditioners that can work to heat a room. But air conditioning systems have low efficiency at negative temperatures, since the main purpose of the equipment is cooling, not heating.

Low temperature air source heat pumps for home heating work using this physical law. How is heating carried out in practice?

Any, even a cooled body, has a high or low potential energy. Even at negative temperatures, the air contains a certain amount of heat. At -15°C, warmer than at -25°C. At -5°C, even more heat is in the air. The principle of operation of an air source heat pump allows you to extract the small amount of heat energy that remains in the winter season and transfer it to the room.
An evaporator coil is located in the outdoor unit installed outdoors. Freon circulates inside the circuit - a liquid that freely passes into a gaseous state and vice versa. Freon evaporates, while absorbing the heat that remains even at low temperatures.
The gas enters the compressor. The compressor creates high pressure and conditions for converting freon back into liquid.
Under pressure, freon is heated and enters the condenser. In the block, the gas finally becomes a liquid, giving off all the heat that it received in the outdoor unit installed on the street.
Freon, in a closed circuit, returns to the evaporator.

There is a dependence of the heat output of an air-to-water heat pump on the outdoor temperature. For this reason, manufacturers provide for the connection of additional heating equipment to the heat pump, which compensates for the lack of thermal energy when the outside temperature drops below -15°C. Work in cold conditions continues, although with less efficiency.

There are several types of air source heat pumps, differing in the principle used for space heating.

Thermal air/water pumps

Household heat supply systems and hot water supply, based on air heat pumps, are very effective for use in the temperate latitudes of the Russian Federation. The average COP (conversion ratio) is 3. It turns out that for every 1 kW spent, there are 3 kW of thermal energy produced.

The principle of operation is the same as in pumps of other modifications, but with certain differences:

The condenser is placed inside the storage boiler connected to the heating and hot water system.
The heat released during freon condensation is used to indirectly heat the coolant.
With the help, the heated coolant enters the DHW system and heating.

The heat carrier heating intensity varies from +30°С to +60°С. At temperatures below -15°C, combined heat supply with an air heat pump is switched on, which is indispensable in cold climates. The lack of heat compensates for any boiler (electricity, gas, wood).

Since the installation of the outdoor unit is carried out on the street, an additional advantage will be the presence of an anti-freeze or defrosting function.

Air heating heat pumps

Air heating heat pumps are used to heat individual rooms. The principle of operation is in many ways similar to that used by a fan heater, only the capacitor plays the function of a heating coil.

The body of the indoor unit of the heat pump is similar to an air conditioner and can also work for air heating and cooling.

The consumer is offered various solutions to the issue of heating:

Installation of separate independent heaters.
Installation of several heat pumps, united in a single network.

Heat pumps that heat a room with warm air have the following advantages:

Maximum efficiency- the absence of the need for pre-heating of the coolant leads to a more economical consumption of electricity. The air is heated only to a temperature of 20-40 ° C, and this, in turn, provides a higher COP coefficient of 4.
Rapid heating of the building – warm air begins to enter the room a few seconds after switching on.
Versatility– the equipment can be used as an air conditioner in summer. In the basic configuration, the function of cooling the room is provided.

When a negative temperature, critical for operation, is reached, automatic switch on backup heat source when using air HP. Thus, it is possible to compensate for the lack of thermal energy.

What is the difference between an air conditioner and an air heat pump

Indeed, the heat supply of premises with air source heat pumps in cold climates is in many ways similar to heating with conventional air conditioners. Used internal and outdoor units, similar structure. Even in the internal structure there are many similarities. The difference is that indoor air HPs are more efficient at heating than at cooling, while air conditioners are the opposite.

You can feel the difference by comparing some of the characteristics of the equipment. The air conditioner stops working for heating already at a temperature of about -5 ° C. The operating mode of heat pumps is from -25°С to +45°С.

Since there is a tendency to improve air heat pumps for "passive" houses, soon, for a wide range of consumers, equipment models capable of maintaining performance when the temperature drops to -32 ° C will become available.

The difference between an air heat pump and an air conditioner lies in different technical characteristics, although there are many similarities between them.

How to choose an air heat pump

The choice of air HP is not as difficult as it might seem at first glance. When choosing a suitable model, you should focus on the following parameters:

heating type.
Heated area.
Manufacturer.

Additionally, determine which type of boiler will be used as a backup heat source. As practice shows, air heating with the connection of an electric boiler remains the most popular, which allows you to completely do without gas.

Which brand to choose an air type heat pump

If you analyze reviews of air source heat pumps, it is quite easy to identify equipment manufacturers using most in demand at the domestic consumer:

Stiebel Eltron is a German company that started its journey with the invention of the boiler. Over time, the range of products has been constantly expanding. Today, Stiebel Eltron is a leader in the production of water heating and heating equipment. The company offers two types of heat pumps: geothermal and air, working to heat the coolant and air.
is another German manufacturer with over 30 years of experience in the production of air pumps. Viessmann stations connected to the water heating circuit deserve the greatest praise. As advantages - the presence of weather-dependent control sensors and many additional functions available in the basic configuration.
Mitsubishi is a Japanese corporation that pioneered Zubadan technology. The solution made it possible to increase the COP (which is the highest among similar equipment) and expand the scope of applications. Mitsubishi was one of the first to offer the consumer air conditioners that work on heating and air source heat pumps. New technologies are constantly being introduced to increase the scope of products.
– the company has developed a whole series of economical equipment geoTHERM. The range includes equipment that extracts heat from the earth, water, air and sunlight. Vaillant products are maximally adapted for use in the Russian Federation.

The cost of air HP with installation

The most expensive are heat pumps that heat the room with a coolant. The equipment will cost approximately 80 thousand rubles. (capacity 4.5 kW), up to 800 thousand rubles. (18.5 kW). Air heating heat pumps will cost from 50 thousand rubles. (per 4 kW) up to 120 thousand rubles. (at 8 kW).

The cost of installing an air heat pump is calculated individually, based on the technical parameters of the room and other factors.

The service life of the equipment is at least 20 years. The installed equipment pays for itself in 3-5 heating seasons, depending on the intensity of use.

Pros and cons of using air source heat pumps

Literally 5 years ago, the domestic consumer had practically no experience of heating buildings in winter using air source heat pumps. I had to be content with statements and extremely positive comments posted on the websites of various manufacturers of equipment, which did not give a clear idea of the capabilities of the equipment. Since then, a certain experience of use has appeared, which made it possible to identify not only the advantages, but also the disadvantages of air HPs.

Advantages

The advantages of operating air-to-water heat pumps - the main advantage is complete independence from gas heating. In some regions of the Russian Federation, only bringing the pipeline to the house is more expensive than buying and installing a heat pump. No commissioning permits required.
The systems are designed for installation in a passive house. Therefore, they were originally designed for economical heating of the house and heating of hot water. For 1 kW of electricity consumed, heat generation is 3-5 kW. A simple calculation of costs when using a heat pump will show that within 3-5 years the full payback of the equipment is achieved.
The operation of the pump does not adversely affect human health. To ensure hygienic conditions, in systems using the principle of air heating, it is enough to clean the filters from time to time.

Flaws

The high cost of equipment - a system with enough power to heat a residential building will cost 800-1200 thousand rubles, which is an unaffordable amount for most buyers.
Dependence on ambient temperature. Peculiarities autonomous heating houses with an air source heat pump are directly related to the total amount of heat energy received. The lower the temperature outside, the worse the pump works. Starting from -15°C, you will have to connect a backup heat source.
If we take into account that in most territories of the Russian Federation the average temperature regime is higher, then the expediency of this installation becomes clear. The optimal climatic zones for the use of air source heat pumps are parts of Russia with a temperate climate and an average temperature in winter of at least -15°C.

If we compare air heat pumps and gas heating, especially considering that the latest models pumping equipment able to maintain performance at -32 ° C, the advantage of the former becomes obvious. Heat pumps are economical, do not require a permit for operation, are installed within 1 day and have a higher efficiency than gas equipment.

AT recent times, manufacturers have somewhat reduced the cost of thermal installations, which allowed even more buyers to appreciate the dignity of the stations. If the trend continues, we can expect increased demand for heat pumps.