The question of the quality of inhaled air has been and remains the most important for human life. Various parameters play a role. Temperature, cleanliness and freshness take the first place among them. Often there is not enough light ventilation with the help of a window. Too cold incoming air brings a certain discomfort. The appearance of a stuffy summer lazy breeze also does not bring pleasure.

What is it and how does it work

Ventilation-type heat-exchange structures (recuperators) help to change the situation. The name of the device comes from the English and Latin words for "return».

The principle of work fully corresponds to the etymological meaning. The air in the room sucked in by the ventilation system and forcibly thrown out into the street. At the same time, an external jet of freshness is sent into the room. Inside heat exchange takes place, thanks to which the air masses of the required temperature are returned to the room.

An important indicator of ventilation systems is the percentage of mixing of incoming and exhaust air. The operation of recuperators makes it possible to reduce this position to almost zero. This is achieved by the presence of a plastic, copper, aluminum or zinc separator. Heat exchange takes place by transferring the flow energy to the boundary. The jets themselves run either parallel or crosswise.

Grates of a special type at the inlet of the stream from the street allow you to trap dust, pollen, insects, and reduce the number of incoming bacteria. The air is purified and enters the room. At the same time, waste particles containing many harmful ingredients. In addition to the circulation of air flows, the supply jets are cleaned and warmed.

Most of the existing recuperators have gentle sound modes, which promote strong healthy sleep when installed in a nursery or bedroom.

Many designs of recent years are compact and easy to install, have a remote control, and have additional features.

The temperature standards in the apartment are studied in detail in this article:

Types of recuperators

Depending on the various parameters consider:

• Plate heat exchangers
• Rotary heat exchangers
• Chamber recuperators
• Recuperators with an additional built-in heat exchanger
• Composition of several heat pipes

Plate heat exchangers. The heat exchanger inside consists of one or more fixed plates made of copper, aluminum, plastic or extra strong, specially treated cellulose. Air passes through a series of cassettes. Due to the temperature difference between the incoming and outgoing streams, a slight condensate may occur. Possibly in cold weather some formation of ice. As a rule, to combat it, the device is equipped with additional elements, the functions of which are to remove the accumulation of condensate, to increase the heat supply to defrost the system.

If the recuperators are equipped with one air movement cassette, then when droplets form, the flow is redirected to bypass it, and the accumulated moisture is removed through a special drainage device. If the system involves several elements, then condensation is reduced to zero.

When ice appears, a special valve blocks the flow of incoming air, due to the heat on the plates, the internal components of the device are heated. Another way to solve the problem was creation of pulp cassettes. However, their use in rooms with a high degree of humidity increases the formation of condensate and makes the devices inapplicable.

Plate heat exchangers are designed in such a way that the mixing of incoming and outgoing jets is not possible, and the filtration system is additionally removes dust, pollen and bacteria. This makes it possible to use it in bedrooms, in a nursery, in hospitals. Creation of ribbed plates allows increase the efficiency of the structure, makes it more reliable and durable. Due to their compactness and low cost, such designs are more applicable both in hospitals, catering establishments, and at home.

Many craftsmen have learned to create designs on their own from some a set of copper or galvanized plates with the use of special sealant and material for additional gasket between the sheets.

Рhttp://site/eko/rekuperator-vozduha-svoimi-rukami.htmlmotor recuperators. Its features are the rotating blades of one or two rotors, due to which the air moves. Most often, these devices are cylindrical shape with densely installed plates inside and a drum, the rotation of which creates flows. First, an air jet leaving the room is passed, then the direction of rotation changes and street air enters.

The efficiency of rotary heat exchangers is higher than lamellar, but the devices themselves are more bulky. Their use is more suitable for industrial premises, trading floors. Since the probability of mixing air flows reaches, as a rule, 5-7 percent, the installation of rotary heat exchangers becomes impossible for hospitals, canteens, cafes and restaurants. More expensive equipment, bulkiness and complexity of installation made the use of such structures possible only in special industrial areas.

Chamber recuperators. The air from the room enters a special chamber, in which heat is transferred to the walls of its part, then it is thrown out into the street. Further, the outside air is sucked inward into another compartment, additionally warming up from the borders, and enters the room.

Recuperators with an additional built-in heat exchanger. It enhances the heat transfer edge. However, it is less efficient because it reduces efficiency and increases condensate.

Composition of several heat pipes. The air from the room is additionally heated, turning into steam, and then reverse condensation occurs. The advantages of such recuperators are in the complete anti-bacterial air protection in the design.

When choosing a device, the size of the room and the degree of its humidity, its purpose, the need for quiet operation, efficiency and the cost of the structure and its installation are taken into account.

You can read more about comfortable humidity in the apartment in this article:

The use of recuperators (video)

1. In rooms to create additional climatic comfort.
2. To save energy resources.
3. In hospitals, to increase the antibacterial zone, to create a comfortable environment, to maintain the thermal characteristics of the room.
4. In industrial premises, for ventilation of large spaces while maintaining a zone of constant temperatures, rotary heat exchangers are more often used that can withstand temperatures up to 650 degrees.
5. in automotive structures.

Electric motors are designed to drive various mechanisms, but after the movement is completed, the mechanism must be stopped. To do this, you can also use an electric machine and a recuperation method. What is energy recovery is described in this article.

What is recovery

The name of this process comes from the Latin word “recuperatio”, which translates as “back receiving”. This is the return of part of the energy or materials used for reuse.

This process is widely used in electric vehicles, especially those powered by batteries. When driving downhill and during braking, the recovery system returns the kinetic energy of movement back to the battery, recharging them. This allows you to drive a longer distance without recharging.

Regenerative braking

One type of braking is regenerative. In this case, the rotation speed of the electric motor is greater than that specified by the network parameters: the voltage at the armature and the excitation winding in DC motors or the frequency of the supply voltage in synchronous or asynchronous motors. In this case, the electric motor switches to the generator mode, and the generated energy is returned to the network.

The main advantage of the recuperator is energy saving. This is especially noticeable when driving around the city with a constantly changing speed, suburban electric transport and the subway with a large number of stops and braking in front of them.

In addition to the advantages, recovery has disadvantages:

• the impossibility of a complete stop of transport;
• slow stop at low speeds;
• lack of braking force in the parking lot.

To compensate for these shortcomings, an additional system of mechanical brakes is installed on vehicles.

How the recovery system works

To operate, this system must provide mains power to the motor and return energy during braking. This is most easily done in urban electric vehicles, as well as in older electric vehicles equipped with lead batteries, DC motors and contactors - when downshifting at high speed, the energy recovery mode is activated automatically.

In modern transport, a PWM controller is used instead of contactors. This device allows you to return energy to both DC and AC networks. During operation, it works as a rectifier, and during braking, it determines the frequency and phase of the network, creating a reverse current.

Interesting. During dynamic braking of DC motors, they also switch to generator mode, but the generated energy does not return to the network, but is dissipated by additional resistance.

Power descent

In addition to braking, the recuperator is used to reduce the speed when lowering loads by hoisting mechanisms and while driving down an inclined road of electric vehicles. This eliminates the need for a wearable mechanical brake.

Application of recuperation in transport

This braking method has been used for many years. Depending on the type of transport, its application has its own characteristics.

In electric vehicles and electric bicycles

When driving on the road, and even more so, off-road, the electric drive works almost all the time in traction mode, and before stopping or at an intersection - “coasting”. The stop is made using mechanical brakes due to the fact that the recovery at low speeds is inefficient.

In addition, the efficiency of batteries in the charge-discharge cycle is far from 100%. Therefore, although such systems are installed on electric vehicles, they do not provide large savings in charge.

On the railway

Recuperation in electric locomotives is carried out by traction motors. At the same time, they turn on in the generator mode, which converts the kinetic energy of the train into electricity. This energy is fed back into the network, unlike rheostat braking, which causes the rheostats to heat up.

Recuperation is also used during long downhill runs to maintain a constant speed. This method saves electricity, which is returned to the grid and used by other trains.

Previously, only DC locomotives were equipped with this system. In devices operating on AC power, there is a difficulty in synchronizing the frequency of the output energy with the mains frequency. Now this problem is solved with the help of thyristor converters.

In the underground

In the subway, during the movement of trains, there is a constant acceleration and deceleration of cars. Therefore, energy recovery gives a great economic effect. It reaches its maximum if it occurs simultaneously in different trains at the same station. This is taken into account when scheduling.

In city public transport

In urban electric transport, this system is installed in almost all models. It is used as the main one up to a speed of 1-2 km / h, after which it becomes ineffective, and the parking brake is activated instead.

In Formula 1

Starting from 2009, a recovery system has been installed in some machines. This year, such devices have not yet given tangible superiority.

In 2010, such systems were not used. Their installation, with a limitation on power and the amount of recovered energy, resumed in 2011.

Braking of asynchronous motors

Speed ​​reduction of asynchronous electric motors is carried out in three ways:

• recovery;
• opposition;
• dynamic.

Regenerative braking of asynchronous motor

Regeneration of asynchronous motors is possible in three cases:

• Changing the frequency of the supply voltage. Possible when the motor is powered by a frequency converter. To switch to the braking mode, the frequency is reduced so that the rotor speed is greater than synchronous;
• Switching windings and changing the number of poles. It is possible only in two, - and multi-speed electric motors, in which several speeds are provided constructively;
• Power descent. It is applied in load-lifting mechanisms. In these devices, electric motors with a phase rotor are installed, the speed control of which is carried out by changing the value of the resistance connected to the rotor windings.

In any case, when braking, the rotor begins to overtake the stator field, the slip becomes greater than 1, and the electric machine begins to work as a generator, transferring energy to the network.

Anti-inclusion

The opposition mode is carried out by switching the two phases that feed the electric machine between themselves and turning on the rotation of the apparatus in the opposite direction.

It is possible to switch on when additional resistances are turned on in the stator circuit or phase rotor windings. This reduces current and braking torque.

Important! In practice, this method is rarely used due to the excess currents 8-10 times higher than the nominal ones (with the exception of motors with a phase rotor). In addition, the device must be turned off in time, otherwise it will begin to rotate in the opposite direction.

Dynamic braking of asynchronous motor

This method is carried out by applying a constant voltage to the stator winding. To ensure trouble-free operation of the electric machine, the braking current should not exceed 4-5 no-load currents. This is achieved by including additional resistance in the stator circuit or by using a step-down transformer.

The direct current flowing in the stator windings creates a magnetic field. When crossing it, an EMF is induced in the rotor windings, and a current flows. The released power creates a braking torque, the strength of which is greater, the higher the speed of rotation of the electric machine.

In fact, an asynchronous electric motor in dynamic braking mode turns into a DC generator, the output terminals of which are shorted (in a machine with a squirrel-cage rotor) or connected to additional resistance (an electric machine with a phase rotor).

Recuperation in electric machines is a type of braking that saves energy and avoids wear on mechanical brakes.

Video

When building a house, it is necessary to select and install a system for heat recovery in ventilation systems. There are several modifications of ventilation equipment, which are chosen depending on its manufacturer. Natural impulse equipment includes wall and window vents to bring fresh air into the rooms. To remove odors from toilets and bathrooms, as well as from kitchens, exhaust ducts are installed.

Air exchange is obtained due to the temperature difference in the room and outside. During the summer, temperatures even out both inside and outside the rooms. That is, air exchange is suspended. In winter, the effect manifests itself more quickly, but it will require more energy to heat cold outdoor air.

Composite hood is a system with forced ventilation and natural air circulation. The disadvantages are:

The advantages include low price and the absence of external natural factors. But at the same time, in terms of quality and functionality, aeration cannot be considered a full-fledged ventilation.

To ensure comfortable conditions in new residential buildings, universal systems of forced aeration are installed. Systems with a heat exchanger ensure the supply of fresh air at a normal temperature with the simultaneous removal of exhaust air from the premises. Along with this, heat is removed from the discharge stream.

Saving heat energy using supply and exhaust ventilation with a heat exchanger // FORUMHOUSE

Depending on the types of recuperators and the size of the rooms in which ventilation is installed, the microclimate is improved more or less effectively. But even with installed recuperation with an efficiency of only 30%, energy savings will be significant, and the overall microclimate in the rooms will also improve. But heat exchangers also have disadvantages:

• increase in electricity consumption;
• condensate release, and icing occurs in winter, which can lead to damage to the heat exchanger;
• loud noise during operation, causing great inconvenience.

Heat exchangers or heat recovery units in ventilation systems with enhanced heat and noise insulation operate very quietly.

Recuperators of the directed movement of heat carriers assume ventilation and utilization of warm exhaust air. The device moves air in two directions at the same speed. With heat exchangers, the comfort of life in houses increases.

At the same time, heating and ventilation costs are significantly reduced, combining both serious processes into one. Such devices can be used both in residential and industrial premises. Thus, the savings in money will be approximately thirty to seventy percent. Heat exchangers can be divided into two groups: single-acting heat exchangers and heat pumps for increasing the reserve of utilized heat. Heat exchangers can only be used in cases where the resources of the sources are greater than the resources of the microclimate to which heat energy is transferred.

Apartment ventilation system with Ecoluxe EC-900H3 recuperator.

Devices that transfer heat from sources to consumers using intermediate working fluids, for example, liquids circulating in closed circuits, consisting of circulation pumps, pipelines and heat exchangers located in heated and cooled chambers, are called recuperators with intermediate heat carriers. Such equipment is widely used in various heat exchangers and circulation pumps at large distances between the heat source and consumer.

This principle is used in an extensive system of heat recovery and energy consumers with different characteristics. The operation of a heat exchanger with an intermediate heat carrier is that the process in it proceeds in the range of water vapor with a change in the state of aggregation at a constant temperature, pressure and volume. The operation of heat recovery units with heat pumps is different in that the movement of the working fluid in them is produced by a compressor.

Efficiency of the heat exchanger pipe in the pipe in the fall. +6g.C. outside.

Mixed action devices

For disposal and for heating supply air use exchangers of recuperative or contact type. Mixed-action devices can also be installed, that is, one - recuperative action, and the second - contact. It is desirable to install intermediate coolants that are harmless, inexpensive, non-corrosive in pipelines and heat exchangers. Until recently, only water or aqueous glycols acted as intermediate heat carriers.

At the moment, their functions are successfully performed by the refrigeration unit, which works as a heat pump in combination with a heat exchanger. Heat exchangers are located in the supply and exhaust air ducts, and with the help of a compressor, freon is circulated, the flows of which transfer heat from the exhaust air stream to the supply air and vice versa. It all depends on the time of year. Such a system consists of two or more, which are united by one refrigeration circuit, which ensures synchronous operation of the units in different modes.

Features of plate and rotor designs

The simplest design of the plate heat exchanger. The basis of such a heat exchanger is hermetic chamber with parallel air ducts. Its channels are separated by steel or aluminum heat-conducting plates. The disadvantage of this model is the formation of condensate in the exhaust ducts and the appearance of an ice crust in winter. When the equipment is defrosted, the incoming air goes to the heat exchanger, and the warm outgoing air masses contribute to the melting of ice on the plates. To prevent such situations, it is preferable to use plates made of aluminum foil, plastic or cellulose.

Rotary heat exchangers are the most highly efficient devices and are cylinders with corrugated metal layers. As the drum set rotates, a warm or cold air stream enters each section. Since the efficiency is determined by the rate of rotation of the rotor, it is possible to control such an apparatus.

The advantages include the return of heat of approximately 90%, the economical use of electricity, humidification of the air, the shortest payback period. To calculate the efficiency of the heat exchanger, it is necessary to measure the air temperature and calculate the enthalpy of the entire system using the formula: H = U + PV (U - internal energy; P - system pressure; V - system volume).

Heat recovery has become quite often used recently in ventilation systems. If we consider the process itself in more detail, then we first need to decide and understand what the term recovery itself means. Heat recovery in ventilation systems means that the passed air, which is removed by special installations, is passed through a filter system and fed back.

It is worth paying special attention to the fact that in ventilation systems with a share of exhaust air, part of the heat from the room is also drawn out. And it is precisely this thermal energy that is returned back.

These systems are effectively used in large industries and in large workshops, since in order to ensure the optimum temperature for such premises in winter, it is necessary to incur great costs. These installations can significantly compensate for such losses and reduce costs.

Even in a private house, ventilation units with heat recovery will be quite relevant today. Even in an individual house, ventilation is always carried out and when air circulates, heat also leaves any room. Agree that it is simply impossible to seal the building completely and thereby avoid any heat loss.

Today, these systems should be used even in a private house for the following reasons:

• For the rapid removal of air with a large admixture of carbon dioxide;
• For the influx of the required amount of fresh air into the living quarters;
• To eliminate high humidity in rooms, as well as eliminate unpleasant odors;
• To save heat;
• And also to remove dust and harmful microorganisms that may be contained in it.

Air supply systems with recuperation

The air handling unit with heat recovery is becoming increasingly popular among private homeowners. And its merits, especially in the cold season, are very high.

As you know, there are many ways to provide a living space with the necessary ventilation. This is the natural circulation of air, which is mainly carried out by ventilating the rooms. But you must admit that it is simply impossible to use this method in winter, since all the heat will quickly leave the living quarters.

If, however, in a house in which air circulation is carried out only naturally, there is no more efficient system, then it turns out that in cold weather the rooms do not receive the necessary volume of fresh air and oxygen, respectively, which further negatively affects the well-being of all family members.

Of course, recently, when almost all owners install plastic windows and doors, it turns out that arranging ventilation in a natural way is simply inefficient. Therefore, there is a need to install additional equipment that can provide good air circulation inside the premises. And, of course, every owner will agree that it would be desirable for any system to spend electricity economically.

And here the best option would be heat recovery in ventilation systems. Ideally, it is desirable to purchase a unit that could also provide moisture recovery.

What is moisture recovery?

In any room, a certain level of humidity should always be maintained, at which each person feels most comfortable. This norm has a value from 45 to 65%. In winter, most people experience excessively dry indoor air. Especially in apartments, when the heating is turned on to full and the air becomes very dry with a humidity of about 25%.

In addition, it often turns out that not only a person suffers with such changes in humidity. But also floors with furniture, as you know, wood has a high hygroscopicity. Very often, furniture and floors dry out from too dry air, and in the future it turns out that the floors begin to creak, and the furniture falls apart. These installations will primarily maintain the required level of humidity in any room, regardless of the time of year.

Types of recuperators

In individual residential buildings, ventilation systems with centralized heat exchangers are most often installed. In addition, today you can choose from several types of recuperative ventilation designs, but the following are in higher demand:

1. Lamellar.
2. Rotary.
3. Chamber.
4. Having an intermediate coolant.

Plate type heat exchangers

The simplest designs for ventilation systems. The heat exchanger is made in the form of a chamber divided into separate channels located parallel to each other. Between them there is a thin lamellar partition, which has high heat-conducting properties.

The principle of operation is based on the exchange of heat of air flows, that is, the exhaust air that is removed from the room and gives off its heat to the supply air, which enters the house already warm, thanks to such an exchange.

The advantages of this technology include:

• simple device setup;
• the complete absence of any moving parts;
• high efficiency.

Well, one of the most significant drawbacks in the operation of such a heat exchanger is the formation of condensate on the plate itself. Typically, such heat exchangers require additional installation with special drop eliminators. This is a necessary parameter, since in winter the condensate can freeze and stop the device. That is why some devices of this type have built-in defrost systems.

Rotary heat exchangers

Here the main part is taken over by the rotor, which is located between the air ducts and heats the air with the help of constant rotation. Rotary type heat recovery ventilation has a very high efficiency. This system allows you to return back to the room about 80% of the heat.

But a significant drawback is the inferiority of the system with respect to dirt, dust and odors. There is no density in the design between the rotor and the housing. Because of them, air flows can mix and therefore all pollution can again get back. And of course, the noise level here is an order of magnitude higher than that of a plate heat exchanger.

Chamber type heat exchangers

In this type of heat exchanger, the air flows are separated directly by the chamber itself. The exchange of heat occurs due to the damper, which periodically changes the direction of air flow. This system is highly efficient. And the disadvantages include only the presence of moving parts inside the device.

Heat exchangers with intermediate carrier

The principle of operation of this device is almost similar to the operation of a plate heat exchanger. Here the heat exchanger is a closed circuit of the tube. In it there is a constant circulation of water or a water-glycol solution. The efficiency of heat transfer processes directly depends on the circulation rate in a closed fluid circuit.

In such a device, mixing of air flows is completely excluded. The only downside is the lack of efficiency. Such a device is able to return approximately 50% of the heat taken from the room.

heat pipes

It is worth highlighting another type of recuperators. Heat recovery in the house using heat pipes is quite effective. Such devices are sealed tubes made of metal, which has high heat-conducting properties. Inside such a tube is a liquid that has a very low boiling point (usually freon is used here).

Such a heat exchanger is always installed in a vertical position, with one of its ends located in the exhaust duct and the other in the supply duct.

The principle of operation is simple. The warm air that is drawn out, washing the pipe, transfers heat to the freon, which, when boiling, moves upwards, with a large amount of heat. And the supply air washing the top of the tube takes this heat with it.

The advantages include high efficiency, quiet operation and high efficiency. So today you can significantly save on heating the house, partially returning it back.

Ecology of consumption. Manor: Heat loss is a serious problem that building science is struggling with. Effective insulation, sealed windows and doors solve it only partially. Heat leakage through walls, windows, roofs and floors can be significantly reduced. Despite this, the energy has one more wide way to "escape". This is ventilation, without which it is impossible to do in any building.

Heat loss is a serious problem that building science is struggling with. Effective insulation, sealed windows and doors solve it only partially. Heat leakage through walls, windows, roofs and floors can be significantly reduced. Despite this, the energy has one more wide way to "escape". This is ventilation, without which it is impossible to do in any building.

It turns out that in winter we spend precious fuel on heating the premises and at the same time continuously throw heat out into the street, letting in cold air.

The problem of energy saving can be solved with the help of a heat recuperator. In this device, warm room air heats the outdoor air. This achieves considerable savings in heating costs (up to 25% of the total cost).

In the summer, when it is hot outside, and the air conditioner is working in the house, the recuperator also benefits. It cools the hot inlet stream, reducing air conditioning costs.

Let's take a closer look at household recuperation units in order to have an idea about their design, advantages and features of choice.

Types, principle of operation and device of recuperators

The idea to use the heat of room air to heat the outside turned out to be very fruitful. It was the basis for the operation of all recuperators.

Today, three types of such devices are used:

• lamellar;
• rotary;
• recirculating water.

The most common and simple in design are plate heat exchangers. They are non-volatile, compact, reliable in operation and have a fairly high efficiency (40-65%).

The main working part of such a device is a cassette, inside which parallel plates are installed. The air leaving the room and entering it is cut by them into narrow streams, each of which goes through its own channel. Heat transfer occurs through the plates. Outdoor air is heated, while indoor air cools and is released into the atmosphere.

The principle of operation of a plate heat exchanger

The main disadvantage of lamellar installations is freezing in severe frosts. The condensate that settles in the recovery unit turns into ice and drastically reduces the performance of the device. Three methods have been found to combat this phenomenon.

The first is to install a bypass valve. Having received a signal from the sensor, it starts up a cold stream bypassing the block. Only warm air passes through the plates, defrosting the frost. After defrosting and removal of condensate, the valve restores the normal operation of the system.

The second option is to use hygroscopic cellulose plates. Water settling on the walls of the cassette is absorbed into them and penetrates into the channels through which the supply air moves. This solves two problems at once: the elimination of condensate and humidification.

The third way is to preheat the cold stream to a temperature that prevents water from freezing. To do this, a heating element is placed in the supply ventilation duct. The need for it arises when the outdoor air temperature is below -10C.

In recent years, plate reversing units have appeared on the market. Unlike direct-flow devices, they operate in two cycles: the first is the release of warm air to the street, the second is the suction of cold air through the heated block.

The principle of operation of the reversible installation

Another type of installation is rotary recuperators. The efficiency of such devices is significantly higher than that of lamellar ones (74-87%).

The principle of operation of the rotary unit is the rotation of the cassette with cells in the flow of incoming and outgoing air. Moving in a circle, the channels alternately pass warm internal and cold external flows. Moisture in this case does not freeze, but saturates the supply air.

It should be noted that the supply and exhaust unit with a rotary heat exchanger allows you to smoothly adjust the heat transfer. It is done by changing the speed of rotation of the cassette. The main disadvantage of rotary systems is the high cost of maintenance. In terms of reliability, they are also inferior to lamellar ones.

The next view is a recirculating water plant. It is the most complex in design. The heat transfer here is not carried out through the plates or the rotor, but with the help of antifreeze or water.

The first liquid-air heat exchanger is placed on the exhaust duct, and the second on the suction duct. The work goes on the principle of a heater: room air heats water, and it heats the street.

The efficiency of such a system does not exceed the performance of plate heat exchangers (50-65%). The high price that has to be paid for the complexity of the design is justified by the only advantage: the blocks of such an installation can be placed not in one building, but in areas of supply and exhaust ventilation that are remote from each other. For powerful industrial systems, this is of great importance. In small buildings, such devices are not installed.

Features of choosing a recuperator

Having got acquainted with the features of the operation of recuperator units, it's time to move on to the practical part - the selection criteria for performing specific tasks.

The first thing you need to pay attention to is the installation method. In the working position, domestic supply and exhaust ventilation with heat recovery can be installed in several ways:

• Inside the wall. The housing is mounted in a pre-drilled hole. A cap is placed on the outside, a grill and a control unit on the inside.

• Indoors. The unit is hung on the wall. A grille or cap is placed outside.

• Outdoor placement. The advantages of this solution are obvious: minimum noise and space saving. The channel device of the device allows you to place it on balconies and loggias, as well as just on the facade of the building.

Another parameter to consider when buying is the number of fans. Budget air recuperators for the home are equipped with one ventilation unit that works both for supply and exhaust.

More expensive devices have 2 fans. One of them pumps in, and the other throws out air. The performance of such devices is higher than single-fan.

When buying, you should also pay attention to the presence of an electric heater. With its help, freezing of the cassette is excluded and the lower temperature limit of the device operation is increased.

Climate control function. Allows you to precisely set the temperature to which the heat exchanger will heat the air.

Possibility of regulation of humidity. This parameter significantly affects the comfort of the microclimate. A standard heat exchanger dries the air by removing moisture from it.

The presence or absence of a filter. An additional option that positively affects the sanitary characteristics of the air mixture.

An important parameter that requires attention is the temperature of the pumped air. In different models, its value can differ significantly. The widest operating temperature range from -40 to +50C is rare for household appliances.

Therefore, in addition to taking into account the optimal performance in m3 / h, when buying, choose a device that can fully work in your climatic conditions.

Performance calculation

Detailed calculations of the operation of recuperators in the supply and exhaust ventilation system are quite complex. Many factors have to be taken into account here: the frequency of air exchange in the premises, the cross section of the channels, the speed of air movement, the need to install silencers, etc. Only experienced engineers can competently perform such a task.

An ordinary consumer can use a simplified methodology in order to correctly navigate when buying a device.

The performance of the heat exchanger directly depends on the sanitary norm of air consumption per 1 person. Its average value is 30 m3/hour. Therefore, if 4 people permanently live in an apartment or a private house, then the installation performance should be at least 4x30=120 m3/hour.

Own electric power of household recuperators is small (25-80 W). It is determined by the level of energy consumption of duct fans. In installations with electric heating of the incoming flow, heating elements with a total capacity of 0.8 to 2.0 kW are installed.

Popular brands and estimated prices

When choosing a household heat exchanger, you should focus on manufacturers and models that have earned high customer ratings. As an example, we can cite the products of foreign companies Electrolux (Electrolux), Mitsubishi (Mitsubishi), Marley (Marley).

Heat exchanger for small rooms Mitsubishi Electric VL-100EU5-E. Air consumption 105 m3/h. Price from 21,000 rubles.

A popular model from Electrolux. Estimated retail price from 42,000 rubles.

The 2017 price tags for household installations of these brands start at 22,000 rubles and end at 60,000 rubles.

MARLEY MENV-180. Air consumption 90 m3/hour. Cost from 27,500 rubles.

The equipment of Russian and Ukrainian companies Vents (Vents), Vakio (Vakio), Prana and Zilant has proven itself well. Not inferior to foreign counterparts in performance and reliability, they often turn out to be more affordable.

Installing Vakio. Capacity 60 m3/h in recuperation mode, up to 120 m3/h in supply ventilation mode. Price from 17,000 rubles.

The estimated cost of air recovery systems of these companies (capacity from 120 to 250 m3/hour) is from 17,000 to 55,000 rubles.

Prava 200g. Inflow - 135 m3/h, extract - 125 m3/h. The recommended area for system maintenance is up to 60 m2.

The nature of reviews about air recuperators is mostly positive. Many owners note that with their help, the problem of excessive humidity, which caused the appearance of mold and fungus in the premises, was solved.

In the calculations of the payback period for this equipment, figures from 3 to 7 years are given. We did not find data on instrumental measurements of real energy savings on forums dedicated to this topic.

Briefly about self-assembly

In most photo and video instructions for the independent manufacture of recuperators, plate models are considered. This is the easiest and most affordable option for a home master.

The main part of the design is the heat exchanger. It is made of galvanized steel, cut into plates 30x30 cm in size. To create channels at the edges and in the middle of each section, plastic strips 4 mm thick and 2-3 cm wide are glued with silicone.

The heat exchanger is assembled by laying and alternately turning the plates at an angle of 90 degrees relative to each other. So get isolated channels for the oncoming movement of cold and warm air.

After that, a housing made of metal, chipboard or plastic is made to fit the dimensions of the heat exchanger. It has four holes for air supply. Fans are installed in two of them. The heat exchanger is turned at an angle of 45 degrees and fixed in the housing.

Thorough sealing of all assembly joints with silicone completes the work.