How to make a heat pump. How to make a heat pump for home heating with your own hands: the principle of operation and assembly diagrams Do-it-yourself heat pump from the refrigerator

There is a certain amount of heat in any environment that surrounds us, but on condition that its temperature is above zero degrees Celsius. The question arises: why not use this heat to heat your own home? This is quite feasible, but it requires a heat pump.

Types of heat pumps

The principle of operation of the pump is as follows: a heat source, the energy potential of which is quite low, transfers its heat to a carrier with a higher temperature. How it works in practice can be seen in the figure. By the way, refrigeration devices work on the same principle, so in summer a heat pump can successfully function as an air conditioner.

There can be several classifications of pumps, but it would be correct to divide them according to the type of coolant, which can be:

• Water;
• Priming;
• Air.

The energy obtained using such a system can be used for various purposes: space heating, air conditioning, water heating. The combination of types of coolants and the functions performed can also be different. Based on this, the pumps are divided into three groups.

1. Water-to-water equipment. It is a very effective way of generating heat, because at a considerable depth, water can remain in a permanent state for a long time, maintaining the required temperature. In this case, the source of thermal energy is open reservoirs, underground or waste water, and the heat carrier is a special ecological substance.

   It is worth noting that it will be easier to build a pump for use in lakes and rivers (open-type reservoirs), while underground ones will require additional work and costs. The design of the device will be complicated, a special reservoir will be required to concentrate moisture from the heat exchanger. For the circuit, plastic pipes are used, which can be installed both vertically and horizontally underground. A vertical collector is more efficient, since wells are drilled for it 100-150 meters deep, and there the temperature can last longer.

   

   Important! Horizontal collectors must not be used for household purposes, only for planting plants and lawns. For one kilowatt of device power, approximately 20-50 square meters may be required.

2. Ground-water class equipment are the most convenient, because already at a depth of 5 m you can observe a constant soil temperature, and weather changes practically do not affect it. The design of these pumps is almost the same as in the previous version.

   

3. class "water-air" less effective because in winter their power drops significantly. But there are no difficulties during installation - neither deep wells nor earthworks are required. All you need to do is install the equipment in a suitable place. It could be, for example, the roof of a house. The advantage of such a system is that the used thermal energy can be reused, leaving the building as gas, smoke, air or even water. But it cannot provide full-fledged heating of the house due to low power, so for winter time you need to take care of alternative heating.

   

Principle of operation - generalized scheme

To understand the principle of operation of a heat pump, let's first get acquainted with a generalized scheme of its device. Thanks to this, we will be able to move from simple to complex.

You should start with a closed loop. In this circuit, gas moves, which circulates thanks to the compressor. Agree, now this design has practically no functions, but if you equip it with some components, you can get a functioning heat pump.

First of all, we add an expansion valve to our circuit.

Now in our circuit there are two areas - high and low pressure. At the same time, we can observe an important physical effect: the compressing gas heats up, and during pressure reduction, on the contrary, its temperature decreases.

The maximum temperature in this case is observed at the point where the gas leaves the compressor.

The lowest temperature is observed at the outlet of the expansion valve.

The gas, which has a high temperature, when passing through the heat exchanger, will give off most of the heat to the external consumer. At the same time, the gas, the temperature of which is low, when passing through the heat exchanger, on the contrary, will absorb heat energy from an external source.

The design that we have turned out has all the functions that a heat pump should have. But in order for it to be complete, it is necessary to equip it with a source of low-temperature heat, as well as connect it to the heating system.

The most optimal option for our region is the use of geothermal probes, which will serve as sources of the above-mentioned low-temperature heat.

As for heating devices, batteries, warm floors / walls can be used as such.

Costs and required power

A heat pump is expensive, on average 4000-6500 euros, depending on the quality of the product. But practice shows that such significant expenses will pay off in about one and a half to two years, and if you do it yourself, as planned, then even faster.

You may be interested in information about what you need

Regarding the power of the device, it may be different. For buildings with poor thermal insulation, the power should be about 75 watts per square meter, but if the house is more modern and good quality materials were used for insulation, then 50 watts is enough. And when using special insulating technologies, you can get by with 30 watts. It is desirable that the heat pump become part of the project of the house even at the construction stage.

We make a heat pump with our own hands

Yes, heat pumps are really expensive, even if they are their own, so not everyone can afford such a purchase. But you can make it yourself, using used parts or those that are on the farm.

If you plan to install in an old building, then first you need to check the condition of the meter and wiring. The order of work is the following.

You may be interested in information about what is

Step 1. The first thing you need to do is buy a compressor. A cheaper option is to find a compressor from an old air conditioner. It is ideal for making a pump. Fasten the part to the wall surface using fasteners-brackets (model L 300).

Step 2. Then it is necessary to make a capacitor, which will require a steel tank V = 100 liters. It must be cut in half, and a copper coil of suitable diameter with a wall thickness of more than one millimeter should be placed inside.

Coil manufacturing

Step 3. When you fix the coil, the halves of the container must be welded back.

Step 4. Next, make an evaporator. For it, you will need another plastic container, 70 liters. A coil is also mounted in it, only the diameter of the pipe should be smaller. Attach the evaporator to the wall using the same “L” type brackets of the required size.

Step 5. The next step is to hire a specialist. The fact is that it is not easy to weld pipes and pump freon on your own, especially in the absence of the necessary knowledge. A refrigerator repair expert will do a great job of this.

Step 6 So, the "core" of the system is already ready, it remains to connect it to the distributor and the heat intake. And if there are no problems with the distributor, then a lot of time and effort will have to be spent on the intake. Of course, it is better to turn to a specialist again, but let's try to figure out how to do everything yourself.

Features of the installation are different for each type of thermal units.

In this case, waste is inevitable, since it is necessary to drill a well, and it is impossible to do this without a drilling rig. The depth of the well should be a minimum of 50 and a maximum of 150 meters. A geothermal probe is lowered into the finished well, which is subsequently connected to the pump.

For horizontal systems, a collector made of pipes is required. Such a collector should be placed below the freezing level of the soil, which depends on the climatic features of the area, but often does not exceed 1.5 meters.

To install the collector, remove the top layer of soil. You can use special equipment for this or do everything with a shovel, which is much cheaper. After laying the pipes, backfill the earth.

There is another technology for laying pipes - to dig a separate ditch for each. There should be several such ditches and all of them should be placed below the freezing level of the soil. We put pipes in them, we fall asleep.

Connect the collector on land using HDPE pipes. After that, fill the coolant into the system and move it to the water. It is desirable to immerse the collector in the central part of the reservoir or simply to the desired depth.

As mentioned above, for this kind of pumps, no large-scale work is required, because the heat is extracted from the air. You just need to choose a place - the roof of a building, for example - and install a collector. Further, the latter is connected to the heating system.

This completes the manufacture and installation of the heat pump. We hope that the article was really useful for you!

Prices for a heat pump for water supply

air-to-water heat pump

Video - Homemade water-to-water heat pump

The owners of country houses have always been sensitive to the issue of hot water supply and heating.

Installing a gas, electric or diesel boiler makes it possible to heat a country house and supply it with hot water and heat, but now there are alternatives to our usual heating.

One of these alternatives is . This is quite an expensive pleasure, but you can make it yourself. We will talk about how to do this in this article.

The principle of operation of the heat pump

The peculiarity of heat pumps is that they operate from natural energy sources. The pump does not need diesel fuel, electricity or solid fuel to release heat energy.

Water, atmosphere and soil are used as an energy source. Pumps do not generate heat, but simply transfer it into the building. It uses a small amount of electricity.

In order to provide the house with heat, it is necessary to have only a heat pump and a heat source. The principle of operation of the system resembles the operation of a conventional refrigerator, only in reverse. In this case, the heat is taken from outside and transported into the house.

Important point: the main element in the alternative heating system is the heat pump, so its construction must be approached very carefully.

The pump consists of the following elements:

• compressor, which is an intermediate element of the system;
• evaporator. In it there is a transfer of low-potential energy;
• throttle valve through which the refrigerant (freon) returns to the evaporator;
• condenser, where freon is cooled and thermal energy is released.

The pump works according to a certain principle. It looks something like this:

The principle of operation of the heat pump. (Click to enlarge)

1. Low-grade heat, which is released from external energy sources, is transferred through pipes to the evaporator - to the first element in the pump design. Heat is transferred by coolants that are able to withstand low temperatures and not freeze at the same time.
2. Here, the heat is transferred to the refrigerant, which circulates in a closed circuit of the system. Freon is often used as a refrigerant.
3. In the compressor, high pressure acts on freon, which significantly increases its temperature.
4. At the next stage, the refrigerant enters the condenser, where heat is transferred to the heating circuit. As a result, heat goes into the room, and freon, cooling, returns to a liquid state.
5. Through the reducing valve, freon enters the evaporator, where the process is repeated.

Based on the principle of operation of the pump, electricity is spent only on the operation of the compressor. As a result, this makes the heat pump the most economical way to transfer heat.

Using an old refrigerator

Refrigerator heat pump device

So, to assemble a heating system in a country house, you must have a heat pump.

Today, such units are not cheap, this is due to high technical characteristics and painstaking work on their assembly. But, if you wish, you can assemble the heat pump with your own hands.

You can build a simple heat pump from a household refrigerator. The peculiarity of the technique lies in the fact that it has two main components of a heat pump - a condenser and a compressor. This will significantly speed up the assembly of the heat pump with your own hands.

So, the assembly of the pump from the old refrigerator is carried out as follows:

1. Capacitor assembly. The element is made in the form of a coil. In refrigerators, it is most often installed at the back. This well-known lattice is a condenser, with the help of which heat is transferred by the refrigerant.
2. The capacitor is installed in a container that is highly durable and able to withstand high temperatures. In order not to damage the coil during installation, experts recommend cutting the container and installing a capacitor in it. After that, the container is welded.
3. Next, a compressor is attached to the container. It is almost impossible to make a unit at home. Therefore, it is better to take it from an old refrigerator. At the same time, it is worth paying attention to the fact that it is in good condition.
4. As an evaporator, you can use a regular plastic barrel.
5. After all the elements of the system are ready, they are interconnected. Plastic pipes are used to connect the unit to the heating system.

Thus, it is possible to build a heat pump from an old household refrigerator. If you need to pump freon into the system, then for this you need to call the wizard. This work can only be done with special equipment.

Take note: Refrigerated heat pumps are often used to heat small spaces and domestic buildings. It could be a garage or a small shed.

The refrigerator can also be used as a heat source. That is, it will play the role of a radiator for the heating system. You just need to mount two air ducts, through which the equipment will receive and exhaust air.

The first channel will let air into the freezer, and the second will let it out. In this case, physical processes occur that cause the capacitor to heat up.

Air Conditioner Application

Scheme of the heat pump from the air conditioner

It lies in the fact that according to the principle of operation, it resembles a heat pump.

But, there are some differences. First of all, it is worth noting the temperature regime of the climate technology. Split systems are not desirable for use at low temperatures.

To make a heat pump from an air conditioner, it is necessary to carry out a number of modifications and redevelopments:

1. The first way to assemble the pump is to remake the air conditioner. In this case, the outdoor and indoor units are reversed. In the indoor unit there is an evaporator, which is needed to transfer low-grade heat. A capacitor is installed in the external unit, which transfers thermal energy. Both air and water can be used as the heat carrier of the heating system. In the second case, the condenser is mounted in a special tank where heat transfer will take place.
2. The second way is to install a four-way switching valve in the system. Only professionals can do this job. This is especially true for the installation of a thermal probe.
3. The third option is to completely disassemble the climate control equipment. The parts are used to assemble the heat pump in the usual way: evaporator - compressor - condenser.

The assembly of a heat pump based on an air conditioner should be approached very carefully and it is better to involve a professional. The productivity of the unit will depend on the correct assembly.

Before proceeding with the assembly of the heat pump, it is worth considering the insulation of the house. If the building has low thermal insulation properties, then the efficiency of using the pump and other heat sources will be significantly reduced.

Such pumps are best used in low-temperature heating systems. In this case, the best option would be a warm floor. Given all the features of the assembly, it is quite possible to build a heat pump with your own hands.

Watch the video in which an experienced user explains in detail the scheme for using a heat pump made from an air conditioner with your own hands:

Heat pump completely by yourself (photo story)
(moderators, if necessary, please correct, otherwise it was not possible to fill in the post correctly)

Good afternoon, forum users!

I will tell my story in which I tried to solve the problem of heating my house.

Background:

There was only a built house on 2.5 floors. Square:

1st floor 64 m2,
2nd floor 94 m2,
2.5 floor 55 m2,
garage 30 m2.

From the very beginning, a used gas-fired wood-fired boiler with a capacity of 40 kW was purchased. But as the time for the installation approached, I completely ceased to please the prospect of harvesting firewood, the eternal struggle with garbage, and by nature I am more of a dervish, I can easily not appear at home for a couple of days.

And then I leaned towards liquefied gas. I note that a low-pressure natural gas pipe runs 1.5 km from the house. But our population density is low, and pulling a pipe for me alone + project + installation just plunges me into horror.

I also can’t put a barrel on several cubes on the site. I don't want to ruin the look. I decided to install a couple of cabinets with a battery of 80-liter propane tanks of 6 pieces each.

The gas operator assured that they themselves come, change themselves, you just call us. The inconvenience included only a headache once every three weeks, as well as the possibility of an unauthorized entry of a gas car into my future cobblestone-passenger parking lot, rolling and dragging cylinders along it. In general, the human factor. But the case solved the problem:

Heat pump idea:

I've had the idea of ​​a heat pump for a long time. But the stumbling block was single-phase electricity and an antediluvian meter for 20 amperes of maximum load. It is not yet possible to change the eclectic power supply to a three-phase one or add power in our area. But unexpectedly, they planned to change the meter to a new one, 40 amperes.

Having estimated, I decided that this would be enough for partial heating (I did not plan to use the 2.5th floor in winter), I undertook to probe the heat pump market. The prices requested in one company (single-phase HP for 12 kilowatts) made us think:

Thermia Diplomat TWS 12 k. h. 6797 euros
Thermia Duo 12 k.v. h. 5974 euros

It required at least 45 amps for starting current.
In addition, since it was planned to take heat removal from well water, there was no confidence in the debit of my well. In order not to risk such an amount, I decided to assemble the TN myself, since some skills were from life. He worked when he was a manager for the distribution of ventilation and air conditioning equipment.

Concept:

I decided to make a HP from two single-phase compressors of 24,000 BTU each (7 sq. H. Cold). Thus, a cascade with a total thermal power of 16-18 kilowatts was obtained with electricity consumption at COP3 of about 4-4.5 kilowatts / hour. The choice of two compressors was due to lower starting currents, since it was thought not to synchronize their starts. As well as the phased commissioning. So far, only the second floor has been inhabited and one compressor will suffice. Yes, and having experimented on one, then it will be bolder to complete the second section.

Refused to use plate heat exchangers. Firstly, for reasons of economy, I did not want to pay 389 euros apiece for Danfos. And secondly, to combine the heat exchanger with the capacity of the heat accumulator, that is, by increasing the inertia of the system, thereby killing two birds with one stone. And I didn’t want to do water treatment for delicate plate heat exchangers, thereby reducing efficiency. And my water is bad, with iron.

The first floor is already equipped with a heated floor piping with an approximate step of 15 cm.

The second floor has radiators (thank God, it was enough stinginess to put them with 1.5 thermal reserves earlier). Coolant intake from the well (12.5 m. Installed on the first layer of dolomite. +5.9 measured on 03.2008). Disposal of waste water into the general sewerage system (two-chamber sump + infiltration soil absorber). Forced circulation in heat removal circuits.

Here is the schematic:

1. Compressor (so far one).
2. Capacitor.
3. Evaporator.
4. Thermal expansion valve (TRV)

It was decided to abandon other safety devices (filter-drier, viewing window, pressure switch, receiver). But if anyone sees the point of using them, I will be glad to hear advice!

To calculate the system, I downloaded the CoolPack 1.46 calculation program from the Internet.

And a good program for the selection of Copeland compressors.

Compressor:

I managed to buy from an old friend of the refrigeration, a little used compressor from a 7 kilowatt split system of some kind of Korean air conditioner. I got it almost for nothing, and I didn’t lie, the oil turned out to be completely transparent inside, it worked for only a season and was dismantled due to a change in the concept of the premises by the customer.

The compressor turned out to have a capacity of 25,500 Btu, which is about 7.5 kW. in cold and about 9-9.5 in heat. What made me happy, in the Korean split there was a solid compressor of the American company Tecumset. Here is his data:

Those. characteristics.

The compressor is on R22 freon, which means a slightly higher efficiency. Boiling point -10c, condensation +55c.

Lapsus number 1: From old memory, I thought that only scroll type compressors (scroll) are installed on household split systems. Mine turned out to be a piston one ... (It looks a little oval and the engine winding dangles inside). Bad, but not fatal. To its minuses, a quarter less resource, a quarter lower efficiency, a quarter more noisy. But nothing, experience is the son of difficult mistakes.

Important: Freon R22 under the Montreal Protocol will be completely decommissioned by 2030. Since 2001, the commissioning of new installations has been prohibited (but I am not introducing a new one, but have modernized the old one). Since 2010, the use of R22 freon is only used. BUT at any time you can transfer the system from R22 to its replacement R422. And no more trouble.

I fixed the compressor on the wall with L-300mm brackets. If I later mount the second one, I lengthen the existing ones using the U-profile.

2. Capacitor:

I successfully purchased a stainless steel tank of about 120 liters from a welder friend.
(By the way, all welded manipulations with the tank were performed by a respected welder free of charge. But he asked to mention his modest role for history!)

It was decided to cut it into two parts, insert a coil from a copper pipe of a freon guide, and weld it back. At the same time, weld in several technical inch-threaded connections.

The formula for calculating the surface area of ​​a copper coil pipe:

M2 = kW/0.8 x ∆t

M2 is the area of ​​the coil pipe in square meters.
kW - Heat dissipation power of the system (with compressor) in kilowatts.
0.8 - coefficient of thermal conductivity of copper / water under the condition of counterflow of media.
∆t is the difference between the water temperature at the inlet and outlet of the system (see diagram). For me it is 35s-30s = +5 degrees Celsius.

So it turns out about 2 square meters of the heat exchange area of ​​the coil. I slightly reduced it, since the temperature at the freon inlet is about + 82 ° C, this can save a little. But as I wrote earlier Santa Claus, not more than 25% of the size of the evaporator!

The simulated system in CoolPack showed a Cop of 2.44 on stock heat exchanger tube diameters. And Cop 2.99 with a diameter one step higher. And this is to my advantage, since in the future I expect to attach a second compressor to this branch. I decided to use a ½ inch (or 12.7 mm outer diameter) copper pipe, refrigeration. But, I think, you can use the usual plumbing, it’s not like that there and there will be a lot of dirt inside.

Lapsus number 2: I used a pipe with a wall of 0.8 mm. In fact, she turned out to be very gentle, a little crushed and she already hesitates. It is difficult to work, especially without special skills. Therefore, I recommend taking a 1mm or 1.2mm wall pipe. So the durability will be longer.

Important: The freon conductor of the coil enters the condenser from above, exits from below. So condensing liquid freon will accumulate at the bottom and leave without bubbles.

Thus, having taken 35 meters of the pipe, he turned it into a coil, winding it around a convenient cylindrical object (cylinder).

At the edges, I fixed the turns with two aluminum slats for strength and equal spacing of the loops.

The ends were brought out with the help of plumbing transitions to a copper tube for twisting. He slightly drills them from a diameter of 12 to 12.7 mm, and instead of a compression ring, after assembly, he wound flax on a sealant and clamped it with a lock nut.

3. Evaporator:

The evaporator did not require high temperature, and I opted for a 127 liter wide-mouthed plastic container.

Important: A 65 liter barrel would be ideal. But I was afraid, the ¾ pipe bends very badly, so I took a larger size. If anyone has other sizes or has a good pipe bender and work skills, then you can take a chance on this size. With a 127 liter drum, my HP increased the expected dimensions by 15 cm up, 5 cm deep and 10 cm wide.

I calculated and manufactured the evaporator according to the same principle as that of the condenser. It took 25 meters of pipe ¾ 'inch (19.2mm outer) with a wall of 1.2mm. As stiffening ribs, I used segments of the UD profile for the installation of gypsum plaster. Twisted with ordinary copper electrical wire without insulation.

Important: Flooded type evaporator. That is, the liquid phase of freon enters the cooled water from below, evaporates and in the gaseous state rises up to the compressor. This is better for heat transfer.

Transitions can be taken from plastic drinking pipes PE 20 * 3/4 ​​'with an external thread, unscrewed from the barrel with lock nuts and a seal made of flax and sealant. The supply and drainage of water was made from ordinary sewer pipes and rubber sealing cuffs inserted by surprise.

The evaporator was also mounted on L-400mm brackets.

4. TRV:

Acquired TRV from Honeywell (former FLICA). For my power, it took a 3mm nozzle to it. And a pressure equalizer.

Important: TRV during soldering cannot be overheated above +100c! Therefore, I wrapped it with a cloth soaked in water to cool it. Please do not be horrified, after the raid I cleaned it with fine sandpaper.

I soldered the equalization line tube as it should be in the installation instructions for the expansion valve.

Assembly:

Bought a kit for hard soldering Rotenberg. And electrodes 3 pieces with 0% silver content and 1 piece with 40% silver content for soldering in the compressor side (vibration resistant). With their help, I assembled the entire system.

Important: Take the Maxigaz 400 bottle (yellow bottle) right away! It is not much more expensive than Multigas 300 (red), but the manufacturer promises up to +2200c flame. But this is not enough for ¾ 'pipe. Soldered badly. I had to contrive, use a heat shield, etc. Ideally, of course, have an oxygen burner.

Yes, and you need to solder a filling pipe with a nipple to connect the hose to the system. I don't remember its exact name off the top of my head.

It was soldered at the compressor inlet. Nearby, the inlet pipe of the equalizer of the expansion valve is also visible. It is soldered after the evaporator, thermostatic expansion valve, but before the compressor.

Important: We solder the filling pipsik by first unscrewing the nipple from it. Neither from the heat, the nipple seal will definitely fail.

I did not use reducing tees, as I was afraid of a decrease in reliability from additional solder joints near the compressor. Yes, and the pressure in this place is not great.

Freon charging:

collected, but not filled The system must be evacuated with water. It is better to use a vacuum pump, if not, then the craftsmen adapt a conventional compressor from an old refrigerator. You can simply blow through the system with freon by squeezing out the air, but I didn’t tell you this, because you can’t do that!

Freon cylinder of the smallest capacity. The system will not need more than 2 kg at all. freon. But how rich.

I also bought a pressure gauge. But not a special freon one for $10. e., and the usual one for a pumping station for 3.5 c.u. e. I was guided by it when filling out.

I filled the system as much as possible with the help of the internal pressure of freon in the cylinder. I let it stand for a couple of days, the pressure did not drop. So there is no leak. Additionally, I missed all the connections with soapy foam, it did not bubble.

Important: Since in my case the filling nipple is soldered immediately in front of the compressor (in the future, the pressure in this place will be measured when setting up), in no case should the system be filled with liquid freon with the compressor running. The compressor will probably fail. Only in the gaseous phase - balloon up!

Automation:

You need a single-phase starting relay, and at the same time, for a very decent starting current of about 40 A! Automatic fuse From the group to 16A. Electrical panel with DIN rail.

I also installed two temperature switches with copelar thermal sensors. One put on the water at the outlet of the condenser. I set it to about 40 degrees to turn off the system when the water reaches this temperature. And to the outlet of water from the evaporator to 0 degrees, so that it emergency shuts down the system and does not unfreeze it by chance.

In the future, I'm thinking of purchasing a simple controller that takes these two temperatures into account. But besides the appearance and clarity of use, it also has a drawback - the programmed values ​​​​go astray even with a short power outage. While thinking.

Run (trial):

Before starting, I pumped about 6 bar of pressure from the cylinder into the system. More did not work, and there is no need. I threw a temporary wire, connected the starting capacitor. I filled the containers with water first. They stood for a day, filled, and therefore, at the time of launch, they had a room temperature of about + 15C.

Solemnly turned on the machine. He was knocked out immediately. Still, the same. During this short interval, you can hear the engine buzzing, but not starting. I moved the terminals on the capacitor (for some reason there are three of them). Turned the machine back on. The pleasant rumble of a running compressor caressed my ears!

The suction pressure immediately dropped to 2 bar. Opened the freon bottle to fill the system. According to the plate, I calculated the required boiling pressure of freon.

For my required +6 inlet and +1 outlet water, a boiling point of -4c is required. Freon boils at this temperature at a pressure of 4.3 kg. see (bar) (atmospheres). The table can also be found online.

No matter how I tried to set the exact pressure, nothing worked. The system has not yet been brought to operating temperature. Therefore, premature adjustments are only approximate.

Five minutes later, the feed reached about +80 degrees. While the uninsulated evaporation pipe was covered with light frost. The water in the condenser after ten minutes to the touch has already warmed up to +30 - +35. The water in the evaporator is close to 0c. In order not to unfreeze something, I turned off the system.

Summary: Trial run showed full working capacity systems. Anomalies were not observed. Further adjustments of the expansion valve and freon pressure will be required after connecting the heating circuit and cooling with well water. That's why continuation of the photo essay and report in about two to three weeks when I figure out this part of the work.

By that time, I think:

1. Connect the space heating circuit and the well water heat exchange circuit.
2. Carry out a full cycle of commissioning.
3. Make some kind of case.
4. Draw conclusions and give a short summary.

Important: TN turned out not so small in size. By using plate heat exchangers instead of capacitive heat exchangers, you can save a lot of space.

The cost of manufacturing a heat pump with an approximate capacity of 9 kilowatt hours in terms of heat:

Capacitor:

Tank stainless steel 100 liters - 25 c.u. e.
Stainless steel electrodes - 6 c.u. e.
Stainless steel couplings - 5 c.u. e.
Services of a welder (lunch) - 5 c.u. e.
Copper pipe 12.7 (1/2”)*0.8mm. 35 meters - 105 c.u. e.
Copper pipe 10*1 mm. 1 meter - 3 c.u. e.

Air blower Du 15 - 5 c.u. e.
Safety valve 2.5 bar - 4 c.u. e.
Drain valve Du 15 - 2 at. e.

Total: 163 c.u. e. (in comparison, plate heat exchanger Danfos 389 c.e.)

Evaporator:

Plasma barrel. 120 liters - 12 c.u. e.
Copper pipe 19.2 (3/4”)*1.2mm. 25 meters - 130 USD e.
Copper pipe 6*1mm. 1 meter - 2 c.u. e.
Thermoregulatory valve Honeywell (nozzle 3mm.) - 42 c.u. e.
Brackets L-400 2 pieces - 9 c.u. e.
Drain valve Du 15 - 2 at. e
Transitions to copper (set) - 3 c.u. e.
RVS pipe 50-1m. 2 pieces - 4 cu. e.
Rubber transitions 75 * 50 2 pieces - 2 cu. e.

Total: 206 c.u. e. (in comparison, plate heat exchanger Danfos 389 c.e.)

Compressor:

Compressor little used 7.2 k.v. (25500 btu) - 30 c.u. e.
Brackets L-300 2 pieces - 8 c.u. e.
Freon R22 2 kg. - 8 at. e.
Mounting kit - 4 cu. e.

Total: 50 c.u. e.

Mounting kit:

Blowtorch ROTENBERG (set) - 20 c.u. e.
Hard soldering electrodes (40% silver) 3 pieces - 3.5 cu e.
Hard soldering electrodes (0% silver) 3 pieces - 0.5 c.u. e.
Manometer for freon 7 bar - 4 c.u. e.
Filling hose - 7 at. e.

Total: 35 c.u. e.

Automation:

Starter relay single-phase 20 A - 10 cu. e.
Built-in electric shield - 8 c.u. e.
Single-phase fuse C16 A - 4 cu. e.

Total: 22 c.u. e.

Total in general 476 c.u. e.

Important: At the next stage, more circulation pumps Calpada 25 / 60-180 60 c.u. will be required. e. and Calpeda 32/60-180 78 c.u. e. Although they will be taken out of the chapels of my boiler, they usually refer to the boiler itself.

On the Internet in general, and on YouTube in particular, you can find a description of various types of homemade heat pumps. It cannot but rejoice that despite the availability of highly efficient industrial designs, people's interest in self-assembly of heat pumps does not fade away.

Perhaps the reason for this is the legacy from the time of the Soviet Union, brought up by such magazines as "Modelist-constructor", "Young Technician", etc. It is also possible that high prices for heat pumps, the lack of state subsidies and cost compensation for the introduction of environmentally friendly energy-saving solutions that are used to develop an alternative heating in Europe. Also, perhaps the reason for the desire to make a heat pump with your own hands is inaccurate calculations. Often, when a person is enthusiastically engaged in assembling a heat pump, and incurs small expenses in large quantities, he forgets to track the cost of assembling and connecting the heat pump as a whole on a turnkey basis. The reality is that with industrial assembly in the form that is intended to be realized in a homemade product, the cost will always be cheaper if you do not use free components that went into the bin, but they were given a second life. Whatever the motivation of a person (curiosity or material motivation), assembling a heat pump with his own hands, in any case, this is a good experience, which entails the development of the topic of heat pumps in Russia as a whole.

One of the most common ways is the use of low-grade heat in self-made heat pumps. These are various water flow plans. Water is taken from a well or reservoirs or other source of low-grade heat, and is downloaded or poured into another container, while using a heat exchanger installed along its path, in which freon boils, heat with a low temperature is taken for its subsequent conversion into high-temperature heating (using a reflux condenser i.e. a heat pump). This scheme has both its pros and cons. The advantage can be that if there is a good aquifer and well flow rate, there is no need to make a long geothermal heat collector circuit, but you can get by with only two wells, one of which in any case needs to be done for water supply at home. The second advantage of overflow schemes is that if there is a good water flow in the wells, the power of the heat pump installed according to this scheme is actually unlimited. Water is mixed in the aquifer underground and enters into heat exchange with a virtually unlimited volume of soil and water. Where it would be necessary to dig up many cubic meters of soil by placing horizontal heat collectors or to drill kilometer-long vertical geothermal probes, only 2 pipes are enough to take water from the drain, respectively. In general, this is where the main advantages of this scheme ends.

• The main disadvantage is reliability, which primarily depends on the quality and physical properties of water as a heat carrier. If plate heat exchangers are used in the scheme, then they will require mandatory maintenance. Contaminants can be deposited on the plates: limescale, which will block heat removal, increase thermal resistance, reduce the efficiency of the entire heat pump as a whole and lead to its breakdown. Shell-and-tube evaporators or self-made tube-in-tube heat exchangers are more unpretentious to pollution and can withstand even slight freezing. With comparable efficiency and power, they cost significantly more than plate heat exchangers.
• The second drawback of this system is the high energy consumption for pumping water. Certainly water is one of the most heat-consuming liquid on Earth. However, heat exchange with water at low temperatures is limited by the phase transition of water to a solid state. As well as an anomaly of water (when in the solid state water occupies a larger volume than in the liquid state), which is accompanied by rupture of pipes and damage to heat exchange equipment. To solve these problems, it is necessary to install additional flow sensors, as well as special protective automation. One cubic meter / hour of pumped water, cooled by 1 ° C, allows you to extract about 1.16 kW * hour of heat.
• 3rd, it is less environmentally friendly compared to other alternative sources of low-potential energy, this is primarily in comparison with a geothermal DH circuit or a glycol circuit with an intermediate heat carrier in various versions. This is due to the possible contamination of water when it comes into contact with air in open systems, after which the water drains underground without being filtered through a many-meter layer of sand and soil. Of course, you can make reliable equipment that excludes all possible contamination of the aquifer. However, there are risks still remain.

The self-made heat pump shown in the video takes low-grade heat from groundwater using a home-made "pipe in pipe" heat exchanger about 20 m long. The heat output is very high for the installation site. Therefore, it was not possible to check how this heat pump would work at 100% load capacity for 3 days or a week. The operation of this heat pump was tested at an outdoor temperature close to -30 ° C, but there was an additional heating source (gas boiler) in the house.

The water temperature in the well at such low temperatures outside was +8..+9°C. Circulation pumps (the second one was supplied just in case) of 50 W consumption each. Two wells in this case are communicating vessels. But the whole system with such a solution must be under vacuum. Otherwise, the water will "fall" into the well under its own weight, which is a disadvantage of this kind of solution, since when the vacuum is lost, the flow disappears and there is a risk of freezing and system failure. Moreover, under its own weight equal to about 10 meters of water column, the water boils and bursts, respectively, such a solution is applicable only in individual cases where water can be raised by surface water pumps.

A room of about 40 square meters in which the indoor unit is installed was heated to 30 degrees Celsius for 30 minutes. When the heat pump was running in air conditioning mode in the heat of July 2011 (about 30 degrees), the room cooled down to 20 degrees in less than 30 minutes ...

This autumn, there has been an aggravation in the network about heat pumps and their use for heating country houses and summer cottages. 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. the well water is very cold (between +4 and +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 simple automation, but we use only two modes: ventilation (during the warm season) and heating (during the cold season). The built house turned out to be so energy efficient that the air conditioner in it was never used for its 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 the supply ventilation never turns off (because laziness).

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 when operating even at a temperature of -10, if the humidity is high outside) - installing a heating cable in a drainage pan. This is necessary so that after the defrosting cycle of the outdoor unit, the liquid water has time 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 lamps 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 a good riddle: How will the temperature in the room change if you leave the refrigerator plugged into the outlet 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. In this case, thermal energy is transferred from a place with a high temperature to a place with a 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?
The compressor sucks in the low pressure cold refrigerant gas 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 at an 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 a 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’ll 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. At the same time, let me remind you that this is not a permanent residence, in 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 in cafes and at 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 with electric heating (whether by direct conversion or using a heat pump) is to use the heat capacity of building envelopes (or a special heat accumulator) to store heat 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 capacities. 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 -