Heat recovery refers to the return of part of the heat energy, and its reuse in the heating system of the house.

The ventilation process of residential premises is similar to the ventilation process: fresh air is supplied to the room from the outside, and waste air masses with a low oxygen content are removed and thrown into the surrounding space. Together with the exhaust air, it is removed from the room thermal energy... The task of heat recovery during ventilation is to cool warm air before it is discharged outside and to use the heat generated to heat the air masses coming from outside. The issue of heat recovery in ventilation systems is especially acute in winter time of the year.

It is solved depending on the method of ventilation of the house.

Two ways of ventilation - two approaches to recuperation

In modern residential buildings two types of ventilation are widely used: natural and forced.

Natural ventilation is effective in homes with high thermal inertia. These are houses built of stone, brick, concrete and reinforced concrete. As a rule, heavy, solid pillow foundations are used for their construction.

In houses with high inertia, heat accumulates in the mass of the house and its supply may be sufficient to maintain comfortable conditions in the room when the heating is turned off for several hours, or even several days.

Ventilation ducts for removing exhaust air in inertial houses are located in an array of walls, making them vertical with an exit to attic... Entering the ventilation duct, warm air moves upward, while heating the walls of the canal, and hence the walls of the house, while giving up its own thermal energy. Then the air enters the under-roof space, warming it up with the remaining heat.

Saved in the walls ventilation duct the heat is then used to maintain the temperature of the walls and heat the house.

In houses with natural ventilation, heat recovery is also natural and does not need additional regulation.

Ventilation in low-inertia houses

The need to manage heat recovery arises in houses equipped with forced ventilation systems. As a rule, we are talking about low-inertia structures, the design of which contains modern heat-insulating materials.

These can be frame houses with walls made of sandwich panels, houses made of foam blocks or gas silicate blocks, as well as panel buildings with an inner layer of modern highly efficient thermal insulation material... Low-inertia houses are lightweight compared to traditional buildings made of brick or concrete; for their construction, they usually use lightweight foundation options, giving preference to a strip or pile foundation.

There are practically no heat losses by thermal conductivity through the surface of the walls in low-inertia houses, however, the walls in them do not accumulate heat, and the systems natural ventilation not effective. For heating a low-inertia structure, it is enough to heat the air in the room. It is for this reason that one of the most demanded and economical heating methods in such a house is air system heating, in which warm air is supplied to the room through the supply openings, and the cooled air masses are taken in and, after heating, are again fed into the supply channels.

Air exchange in the room directly depends on the efficiency of work ventilation system and its design features. Natural ventilation in low-inertia houses is ineffective. For better air exchange, it is necessary to use systems forced ventilation providing fresh air supply and removal of waste air masses.

A constant supply of fresh (cold) air and the removal of waste (heated) air masses leads to an increase in heating costs. We can safely say that in low-inertia houses with ventilation, all the money spent on heating the home can fly into the chimney, unless, of course, the thermal energy recovery system is used.

When heat is recovered in the ventilation system, the task is to warm up the air entering the room due to the thermal energy of the outgoing air masses. Heating can be

• central, designed for the entire building at once and installed on the central ventilation system
• local, providing only one separate room and installed on the local ventilation system

For this, the ventilation system is supplemented with a heat engineering unit designed for heat exchange between cold and warm air. Heat exchangers can have various device and technical characteristics.

Plate recuperators

The simplest air recuperator is plate heat exchanger, which is a chamber with parallel air ducts separated by a metal partition that plays the role of a heat-conducting plate. The heated air, when it comes into contact with the partition on one side, heats it, and the cold air moving from the opposite side takes heat.

Despite the primitive design, the plate recuperators have a high efficiency, the value of which can be up to 90%. Another advantage of the plate recuperator is the absence of moving parts.

The plate recuperator also has a significant drawback: when the air is cooled, condensation forms on the plate, which when negative temperature outside air can lead to icing of the heat exchanger.

A rotary recuperator is deprived of this drawback, which is a rotating plate installed between the supply and exhaust air ducts. One half of the plate is in the heating zone and is in contact with warm air, and the other half of the plate, on the contrary, is in the supply air duct and contacts with cold air, then it turns 180 degrees and the position changes, the heated plate enters the cold air duct, and the cooled plate enters the heating zone. The intensity of heat exchange depends on the rotor speed and the temperature difference between cold and heated air. The efficiency of a rotary recuperator can be 75-85%.

Rotation of the rotary recuperator is accompanied by noise, which is its disadvantage. In addition, the device is in constant need of maintenance.

Recuperators with an intermediate heat carrier can have a different device, but they have in common the use of a heat carrier (freon, water) to transfer heat from one air stream to another air stream. So, for example, heat pipes are widely used in the device of air recuperators.

Let's summarize

The heat recuperator is an optional part of the supply and exhaust ventilation system, the use of which significantly reduces heating costs and allows you to maintain comfortable conditions in a house with lower costs.

It is well known that there are several types of room ventilation systems. Natural ventilation is most widespread, when the inflow and outflow of air is carried out through ventilation shafts, open vents and windows, as well as through cracks and leaks in structures.

Of course, natural ventilation is needed, but its operation is associated with a lot of inconveniences, moreover, it is almost impossible to achieve savings with its device. Yes, and it is a stretch to call ventilation the movement of air through ajar windows and doors - most likely, it will be ordinary ventilation. To achieve the required intensity of circulation of air masses, the windows must be open around the clock, which is unattainable in the cold season.

That is why a forced or mechanical ventilation device is considered a more correct and rational approach. Sometimes it is simply impossible to do without forced ventilation, most often they resort to its device in industrial premises with worsened working conditions. Let's leave aside industrialists and production workers and turn our attention to residential buildings and apartments.

Often, in pursuit of savings, cottage owners, country houses or apartments invest a lot of money in the insulation and sealing of housing and only then realize that due to the lack of oxygen it is difficult to be in the room.

The solution to the problem is obvious - you need to arrange ventilation. The subconscious mind suggests that the best option would be an energy-saving ventilation device. Lack of properly designed ventilation can turn your home into a real gas chamber. This can be prevented by choosing the most rational decision- device of forced-exhaust ventilation with heat and moisture recovery.

Recovery is understood as its preservation. The outgoing air flow changes the temperature (heats, cools) the air supplied by the air handling unit.

The design assumes separation of air streams to prevent mixing. However, using a rotary heat exchanger does not exclude the possibility of the exhaust air flow entering the incoming one.

The "Air Recuperator" itself is a device that provides heat recovery from exhaust gases. Heat exchange is carried out through the dividing wall between the coolants, while the direction of movement of the air masses remains unchanged.

The most important characteristic of a recuperator is determined by the recuperation efficiency or efficiency. Its calculation is determined from the ratio of the maximum possible obtaining heat and actually received heat behind the heat exchanger.

Coefficient useful action recuperators can vary over a wide range - from 36 to 95%. This indicator is determined by the type of recuperator used, the speed of the air flow through the heat exchanger and the difference in temperatures between the outgoing and incoming air.

Types of recuperators and their advantages and disadvantages

There are 5 main types of air recuperators:

• Lamellar;
• Rotary;
• With intermediate heat carrier;
• Chamber;
• Heat pipes.

Lamellar

Plate recuperator characterized by the presence of plastic or metal plates. The outflow and incoming streams pass on opposite sides of the heat-conducting plates, without contacting each other.

On average, the efficiency of such devices is 55-75%. The absence of moving parts can be considered a positive characteristic. The disadvantages include the formation of condensation, which often leads to freezing of the recuperative device.

There are plate recuperators with moisture-permeable plates, ensuring the absence of condensation. The efficiency and principle of operation remain unchanged, the possibility of freezing of the heat exchanger has been eliminated, however, at the same time, the possibility of using the device to reduce the humidity level in the room is also excluded.

Rotary

In a rotary recuperator, heat transfer is carried out using a rotor that rotates between the supply and exhaust ducts. This device is characterized by a high level of efficiency (70-85%) and reduced power consumption.

The disadvantages include a slight mixing of streams and, as a result, the spread of odors, a large number of complex mechanics, which complicates the maintenance process. Rotary recuperators are effectively used for dehumidification of premises, therefore they are ideal option for installation in swimming pools.

Recuperators with intermediate heat carrier

In recuperators with an intermediate heat carrier, water or a water-glycol solution is responsible for heat transfer.

The exhaust air provides heating of the coolant, which, in turn, transfers heat to the incoming air stream. Air flows do not mix, the device is characterized by a relatively low efficiency (40-55%), usually used in industrial premises with a large area.

Chamber recuperators

A distinctive feature of chamber recuperators is the presence of a damper that divides the chamber into two parts. High efficiency (70-80%) is achieved due to the possibility of changing the direction of the air flow by moving the damper.

Disadvantages include slight mixing of streams, transfer of odors and the presence of moving parts.
Heat pipes are a whole system of tubes filled with freon, which evaporates when the temperature rises. In another part of the tubes, freon is cooled to form condensate.

The advantages include the elimination of mixing flows and the absence of moving parts. The efficiency reaches 65-70%.

It should be noted that earlier recuperative plants, due to their significant dimensions, were used exclusively in production, now at construction market recuperators are presented with small dimensions, which can be successfully used even in small houses and apartments.

The main advantage of recuperators is that there is no need for air ducts. However, this factor can also be considered as a disadvantage, since for effective operation, sufficient clearance is required between the exhaust and supply air, in otherwise fresh air is immediately drawn out of the room. The minimum allowable distance between opposite air flows should be at least 1.5-1.7 m.

What is moisture recovery for?

Moisture recovery is necessary to achieve a comfortable ratio of humidity and room temperature. A person feels best at a humidity level of 50-65%.

During the heating period, the already dry winter air loses even more moisture due to contact with a hot coolant, often the humidity level drops to 25-30%. With this indicator, a person not only feels discomfort, but also causes significant harm to his health.

In addition to the fact that dry air has Negative influence on the well-being and health of a person, it also causes irreparable damage to furniture and joinery from natural wood as well as paintings and musical instruments... Someone might say that dry air helps get rid of dampness and mold, but this is far from the case. Such disadvantages can be dealt with by insulating the walls and installing high-quality supply and exhaust ventilation while maintaining a comfortable level of humidity.

A recuperator (lat. Receiving back, returning) is a special supply and exhaust device that removes exhaust air from the room and supplies fresh air from the street. One of the key structural elements is a heat exchanger. Its functional purpose is to extract heat, and in some systems and moisture, from the removed air and its transfer to the incoming fresh air... All recuperators are characterized by low power consumption.

What material are heat exchangers made of in recuperators?

The heat exchanger material is one of important factors, which must be taken into account when choosing a ventilation system. Here are taken into account individual characteristics the place of operation of the system so that the unit will serve as long as possible. At the moment, in the manufacture of the heat exchanger, the following are used: aluminum, copper, ceramics, plastic, stainless steel and paper.

What are the advantages of a household recuperator?

Ventilation with recuperation has many advantages, among the most significant it is worth noting the ability to provide both inflow and exhaust with one device, as well as saving costs for heating / cooling the room up to 50%, normalizing humidity and reducing the level harmful substances in the air of the room. The device is able to provide a favorable microclimate, regardless of the season and weather outside.

How much heat does recovery save?

Any device provides a recovery level of 70-90%. The indicator depends on external conditions and operating mode. With the organization of all ventilation in the room on recuperators, it is possible to achieve savings in heating / cooling costs of the room up to 60%

For example, for the climatic zone of Siberia, the use of a recuperator allows you to save on electricity (when using a heater) up to 50-55%.

Is there a risk of drafts when the recuperator is operating?

The performance of the recuperators does not allow for a draft in the literal sense of the word, however, when choosing an installation site, it is better to minimize possible future discomfort on frosty days and not place the devices directly above work and sleeping places.

Can a recuperator be installed in a city apartment?

It is possible, but with a few caveats. The recuperators are not recommended to be installed in rooms with a well-functioning general hood. But if the window openings are closed with sealed double-glazed windows, and the general exhaust system does not work well. Exactly supply and exhaust system with recuperation is an effective tool to combat stuffiness, high humidity, mold and unpleasant odors.

How noisy do household recuperators work?

For each specific installation, this indicator is different - it depends on the power and mode of operation. But in general, the noise level at first speeds is so insignificant that most people do not notice it. And at the last speeds, any device is noisy.

Is it true that recuperators effectively solve the problem of indoor humidity?

If excessive moisture appears in rooms due to low-efficiency ventilation or its complete absence, then the installation of any recuperator will radically change the situation for the better. The equipment will ensure normal air exchange in the room, which means that moisture is removed naturally.

What is the energy consumption of household recuperators?

Any ventilation system with recuperation belongs to economical climatic equipment. Requires 2 to 45 W / h to work electrical energy... What makes up monetary equivalent from about 100 to 1500 rubles per year.

What is the thickness of the wall for mounting a wall-mounted recuperator?

If the thickness wall structure 250 mm or more, then there will be no problems with the installation of a household ventilation system with recuperation - everything is done according to the standard algorithm. If this parameter is below the given indicator, then the specialists apply individual solutions. For example, Wakio has a model for thin walls Wakio Lumi, and for the Marley MEnV 180 a special wall extension hood. There are also systems that are not demanding on wall thickness, for example Mitsubishi Lossnay Vl-100.

How many ventilation units will be optimal for one apartment?

Normal air exchange is considered when the air in the room is completely renewed in one hour. With an average room area of ​​18 meters and a ceiling height of 2.5 m, it turns out that about 45 cubic meters per hour must be fed and removed. Almost any household recuperator can cope with this task. However, there is another way to calculate the required air volume - by the number of people in the room. In this case, according to the law of the city of Moscow, it is required to supply and remove 60 cubic meters per hour per person. In this case, household recuperators are installed in pairs and this method is considered the most optimal.

Are there any types of buildings where you cannot use a household recuperator?

There are no direct prohibitions on the installation of household recuperators, however, holes in the wall cannot be made in buildings protected by the state, in all other buildings, the organization of holes with a diameter of up to 200 mm is not prohibited by law. High floors with strong winds and premises with a very strong general hood, here the installation of recuperators is not recommended.

Is it allowed to install ventilation systems in already operated buildings where people live?

Where does the condensate go?

The high level of heat recovery creates the conditions for condensation to occur - this is a natural process. In installations with heat recovery, due to part of this moisture, the incoming air stream is humidified, that is, comfortable climatic conditions are created in the room. And the surplus is discharged through a special top cover so that it does not settle on the facade. Whatever the weather outside, the changeable cycle of the system prevents the appearance of the dew point. This means that the equipment does not freeze. It is also worth noting that the amount of condensate produced is not at all great.

What is the peculiarity of the ventilation unit functioning in summer?

There are no differences in the operation of the equipment in the winter and summer time no. Always respected main principle- heat remains in the environment where it was originally located. Thus, temperature regime does not change at any time of the year when heat recovery is on. And if it is necessary to cool the air, the function is disabled - by means of the controllers of the unit, the "ventilation" mode is set.

Are there any special features for bathroom ventilation based on household recuperators?

It is impossible to overestimate the relevance of the installation in the bathroom - excess moisture is removed from the room, and the temperature regime remains comfortable. In bathrooms, it is recommended to install recuperators with a humidity sensor, so ventilation will work in automatic mode and only when needed.

Can germs grow in household recuperators?

First of all, we note that the problem of microbes is relevant for places where moisture accumulates for a long time. And since the heat exchanger of the device is completely dried in any conditions, no microorganisms can multiply in it. For complete confidence, we recommend that you carry out preventive cleaning of the heat exchanger 2 times a year - just wash it under running water or in dishwasher... The element can also be cleaned with steam.

What is the frequency of cleaning ventilation devices?

There is no definite answer here. A number of factors are taken into account - the intensity of the operation of the premises, its purpose, climatic zone... We recommend that you visually check the degree of contamination of filters and heat exchangers and clean them as necessary.

Will the hole in the wall for the recuperator become a source of cold penetration into the room?

As long as the system is operating in recuperation mode, the risk of a cold bridge is zero. When the system is off, the heat in the heat exchanger clogs the hole and does not escape. True, it is important correct location heat exchanger - it must be pulled out far enough, and an air shut-off valve must be located on the side of the room.

Who should I contact regarding the choice of the location of the ventilation units?

The choice of the optimal location for ventilation units with recuperation is a free service for our company's customers. We are ready to provide it at a convenient time for you with a visit to the facility.

Can I install a household recuperator myself?

Theoretically, in houses made of SIP panels, wood and frame houses, the recuperator can be installed independently, however, the device loses the warranty for installation, and often the warranty for the device itself. V stone houses it is not possible to install the recuperator on your own, as this requires an expensive professional equipment not used in everyday life, as well as a specialist in diamond drilling.

A special variety forced system ventilation is supply ventilation with heating and heat recirculation, which provides partial heating of the inlet air flow due to the warm air removed from the room using a special device - a recuperator. In this case, the main heating of the outside air is carried out by a conventional air heater.

Heat recovery in supply and exhaust ventilation- the phenomenon is not new, but so far it is not widespread in our country. From a technical point of view, recuperation is the most common heat exchange process. The word “recuperation” itself has a Latin origin and means “return of what was spent”. Ventilation heat recuperators return some of it back to the room by means of heat exchange between the incoming and outgoing flow. The reverse process occurs in hot weather, when the outgoing cold conditioned air cools the oncoming warm stream. In this case, this should be called cold recovery.

What is recuperation for? Obviously, in the first place to save energy resources. A recuperator is a device in which heat exchange of incoming and outgoing air masses takes place. With the usual ventilation, the temperature difference between incoming and outgoing air in cold and hot seasons is significant. If, for example, it is -20 ° С outside, and + 24 ° С indoors, then the difference is more than 40 ° С. This difference will need to be bridged by the heating system. In summer, the difference is smaller, but it will also add load to the air conditioner. The recuperator allows you to reduce this difference to a minimum. Correctly selected equipment provides at 0 ° С outside air and + 20 ° С indoors, the difference between the incoming and outgoing air flow is within 4 ° С, i.e. cut it down by a factor of five. The recuperation efficiency drops as the outside temperature drops, but the savings are still significant. Moreover, when there is a significant difference between indoor and outdoor temperatures, recuperation is especially useful.

Many modern construction technologies assume airtight and vapor-tight enclosing structures. For effective ventilation and removal of water vapor from rooms with sealed walls and double-glazed windows, a forced supply and exhaust ventilation... Heat recovery in this case is the key to comfortable air exchange with minimal heat loss.

In the USA and Canada, long before the appearance of recuperation equipment, in order to get not too cold air into the room in winter and too warm in summer, they came up with the idea of ​​using a ground heat exchanger, which was later called the "Canadian well". His idea

consists in the fact that the outside air, before entering the premises, passes through the supply air ducts buried in the ground, acquiring a temperature value close to + 10 ° C - a constant ground temperature at a depth of 2 m or more. A Canadian well, in fact, is not a recuperator, but it reduces energy costs for heating and air conditioning. Ventilation of premises in traditional pattern with a Canadian well, it is natural, but it can also be forced.

Recuperators as an element of ventilation equipment are actively used in European countries. The reason for their popularity is in the economic benefits that the return of heat provides. There are two types of recuperators: plate and rotary. Rotary ones are more efficient, but also more expensive. They are capable of returning 70-90% of the heat. Lamellar ones are cheaper, but save less, in the range of 50-80%.

One of the factors influencing the efficiency of heat recovery is the type of room. If the temperature in it is maintained above 23 ° C, then the recuperator will definitely pay for itself. And the more expensive the cost of energy resources, the shorter the payback period. The service life of recuperators is quite long, and with timely maintenance and replacement of inexpensive consumables, it is theoretically unlimited... The recuperators can be supplied as a monoblock or several separate modules.

The recuperator is a special type of heat exchanger to which the inputs and outputs of the supply and exhaust ducts of the ventilation system are connected. The polluted air removed from the room, passing through the recuperator, gives off its heat to the incoming outside air, without directly mixing with it. Such additional heating supply ventilation allows you to significantly reduce energy consumption for heating the inlet air, especially in winter.

Plate recuperators

Plate recuperators are arranged in such a way that the air flows in them do not mix, but contact each other through the walls of the heat exchange cassette. This cassette consists of a plurality of plates that separate cold air currents from warm air currents. Most often, plates are made from aluminum foil, which has excellent heat transfer properties. The plates can also be made of special plastic. These are more expensive than aluminum ones, but they increase the efficiency of the equipment.

Plate heat exchangers have a significant disadvantage: as a result of the temperature difference, condensate precipitates on cold surfaces, which turns into ice. An icy recuperator stops working efficiently. To defrost it, the incoming flow is automatically bypassed by the heat exchanger and heated by a heater. The escaping warm air, meanwhile, melts the ice on the plates. In this mode, of course, there is no energy saving, and the defrosting period can take from 5 to 25 minutes per hour. To heat the incoming air during the defrosting phase, heaters with a capacity of 1-5 kW are used.

Some plate heat exchangers preheat the incoming air to a temperature that prevents the formation of ice. This reduces the efficiency of the recuperator by about 20%.

Another solution to the problem of icing is hygroscopic cellulose cassettes. This material absorbs moisture from the exhaust air stream and transfers it to the incoming air stream, thereby returning moisture back as well. Such recuperators are justified only in buildings where there is no problem of waterlogging. The undoubted advantage of hygrocellulose recuperators is that they do not need electric heating of the air, which means that they are more economical. Recuperators with a double plate heat exchanger have an efficiency of up to 90%. Frost does not form in them due to the transfer of heat through the intermediate zone.

Well-known manufacturers of plate heat exchangers:

• SCHRAG (Germany),
• MITSUBISHI (Japan),
• ELECTROLUX,
• SYSTEMAIR (Sweden),
• SHUFT (Denmark),
• REMAK, 2W (Czech Republic),
• MIDEA (China).

Rotary recuperators

Unlike lamellar ones, they partially mix the incoming and outgoing air. Their main element- a rotor mounted in the housing, which is a cylinder filled with layers profiled metal (aluminum, steel). Heat transfer occurs during the rotation of the rotor, the blades of which are heated by the outgoing flow and give off heat to the incoming one, moving in a circle. The heat exchange efficiency depends on the rotor speed and is adjustable.

In a rotary recuperator, it is technically impossible to completely eliminate the mixing of incoming and outgoing air. Besides, given type equipment, due to the presence of moving parts, requires more frequent and more serious maintenance. Nevertheless rotary models are very popular thanks to high rates heat recovery (up to 90%).

Rotary recuperator manufacturers:

• DAIKIN (Japan),
• KLINGENBURG (Germany),
• SHUFT (Denmark),
• SYSTEMAIR (Sweden),
• REMAK (Czech Republic),
• GENERAL CLIMATE (Russia-Great Britain).

From an economic point of view, heat recuperators will certainly justify themselves sooner or later, but much depends on how efficiently the recuperation itself is organized. The equipment is highly reliable and the consumer can count on a long service life. Many companies produce a wide range of supply air heat exchangers designed specifically for apartments. So Supply unit heat recovery for a 2-3-room apartment can cost about 17,000 rubles. The ventilation system capacity in apartments is within the range of 100-800 m³ / h. For country cottages this figure is about 1000-2000 m³ / h.

Recuperators with intermediate heat carrier

This heat exchanger consists of two parts. One part is located in the exhaust duct, the other in the supply duct. Water or water-glycol solution circulates between them. The removed air heats the coolant, which, in turn, transfers heat to the supply air. In this recuperator, there is no risk of transfer of contaminants from the extract air to the supply air. Changing the circulation rate of the heating medium can regulate the transfer of heat. These recuperators have no moving parts, but they have low efficiency (45-60%). They are mainly used for industrial facilities.

Chamber recuperators

The damper divides the chamber into two parts with a damper. One part is heated by the evacuated air, then the damper changes the direction of the air flow. Due to this, the supply air is heated from the warm walls of the chamber. Dirt and odors can be transferred from the extract air to the supply air. The damper is the only moving part of this heat exchanger. Its efficiency is quite high (70-80%).

Heat pipes

This recuperator consists of a sealed tube system. They are filled freon or other easily evaporating component. These substances evaporate when heated by the removed air. Vapors condense in another part of the tube and again pass into liquid state... In this heat exchanger, the transfer of contaminants is excluded, there are no moving parts, the efficiency is quite low (50-70%).

Many believe that HEATERS are expensive, bulky, difficult to integrate into technological processes devices with a short service life, and their repair stops production for a long period, making the use of a recuperator ineffective. The listed disadvantages allow skeptics to put up with colossal losses of thermal energy and environmental problems. As a result, recuperators are not installed at all enterprises where it is advisable.

The solution can be the installation of Finned Plate Heat Exchangers (recuperators of the OPT ™ type)

Technical features of recuperators of the OPT type

• due to the return of thermal energy, reduce the cost of purchasing it by up to 40%;
• reduce fuel consumption by increasing the combustion temperature of exhaust gases (heating scheme for boiler houses, furnaces, etc.);
• improve the quality characteristics of fuel combustion through the use of previously heated air, reduce mechanical underburning of fuel in the furnace heating cycle in boiler houses and other facilities;
• cool flue gases to comply with environmental and sanitary requirements;
• use the heat of exhaust gases for heating premises, heating the outside air;
• for technological processes requiring low temperatures, to cool off flue gases;
• reduce temperatures flue gas thereby reducing the cost of gas cleaning;
• replace recuperators requiring complex repairs with more reliable ones;
• successfully comply with the requirements of Law No. 261 FZ "On Energy Saving";

Advantages of Finned Plate Heat Exchangers over traditional plate, rotary and shell-and-tube models

• the ability to use in aggressive and abrasive environments, in environments with strong gas content and dust;
• increased operating temperature limits - up to 1250 C, while the service life of analog recuperators is reduced already at 800 C;
• optimized dimensions and weight - 4-8 times lighter than analog recuperators;
• much lower cost;
• shorter payback periods;
• low resistance indicators during the passage of air flows along the paths;
• an improved design that prevents the accumulation of slags;
• increased service life;
• extended working period before preventive measures;
• improved weight and size characteristics that facilitate installation and transportation of recuperators

Why is this type of recuperator the right choice?

• increase in the area of ​​the heat transfer surface per unit volume and mass;
• high reliability of the used recuperator;
• significant reduction in the possibility of failure of the recuperator due to abrasive wear and thermal deformation;
• simplification of the processes of repair and maintenance of recuperators;
• possibility of modular design and assembly of recuperators
• The most common applications of the recuperator.

Gas-gas heat exchangers are used in many areas, which can be roughly divided into the following categories:

Processes with a low level of coolant temperature:

Interval 20 to 60 ° C

• for small volumes of gases, for example, as a waste heat exchanger for gas boilers in a small room, where a heat exchanger is used in the ventilation system.
• with large volumes of gases, for example, in the ventilation system of workshops, concert halls, indoor stadiums and other large rooms.

Range 60 to 200 ° C

• for small volumes of gases, for example, for the output of the flue product of fuel combustion, which is released in the form of gas in a variety of technological processes.
• with large volumes of gases, for example, the use of a gas heat exchanger is possible in the ventilation system of drying and paint shops.

Processes with an average temperature of the coolant.

The interval is from 200 to 600 ° C, an example can be the utilization of flue gas heat during the operation of boiler houses, and it is also possible to save coal by redirecting excess heat to warm up the air supplied to the furnace.

Processes having high level coolant temperature.

• The interval is from 600 to 800 ° C, for example, in the production of plastics, a heat exchanger can be useful for cooling the gas or for recovering heat, the carrier of which is flue gases.
• The interval up to 1000 ° C and higher, which are observed in the production of glass, in metallurgy, oil and gas processing and other areas of production, where the heat exchanger will become the basis for solving such a problem as saving coal, or will act as a utilizer of the resulting flue gases.

It should be noted that the use of a gas-to-gas heat exchanger at an exhaust gas temperature of 45-50 ° C requires a separate calculation of the efficiency.

conclusions

Heat recovery units reduce energy consumption for space heating by half. Installing them often pays off the very first heating season... Installation of recuperators during construction and reconstruction allows partially reducing the load on the heating system of the entire building and eliminating a significant part of the traditional heating equipment... The cost of installing recuperators is an investment not only in reducing heating costs, but also in ensuring optimal climatic conditions indoors and ultimately in human health.

Devices that can save heat and other types of energy are becoming more and more important, as energy prices are constantly rising. Also, we have long had no doubts about the need to breathe fresh clean air indoors. The installation of popular plastic windows and sealed doors. They disrupt air exchange and lead to undesirable consequences. Against the background of all these factors, heat recovery ventilation systems come to our aid. They not only save our money, but also protect our health.

In the process of ventilation, not only the exhaust air is utilized from the room, but also part of the thermal energy. In winter, this leads to an increase in energy bills.

Reducing unjustified costs, without compromising air exchange, will allow heat recovery in centralized and local ventilation systems. For the recovery of thermal energy are used different types heat exchangers - recuperators.

The article describes in detail the models of aggregates, their design features, principles of work, advantages and disadvantages. The information provided will help in choosing the best option for arranging the ventilation system.

In Latin, recuperation means refund or return. With regard to heat exchange reactions, recuperation is characterized as a partial return of the energy spent on carrying out a technological action for the purpose of using it in the same process.

The local recuperators have a fan and a plate heat exchanger. The "sleeve" of the inlet is insulated with sound-absorbing material. The control unit for compact ventilation units is located on the inner wall

Features of decentralized ventilation systems with recuperation:

• Efficiency – 60-96%;
• low productivity- the devices are designed to ensure air exchange in rooms up to 20-35 sq.m .;
• affordable cost and wide choose units ranging from conventional wall valves to automated models with a multi-stage filtration system and the ability to regulate humidity;
• ease of installation- no duct laying is required for commissioning, you can do it yourself.

  Important criteria for choosing a wall inlet: permissible wall thickness, performance, heat exchanger efficiency, air duct diameter and temperature of the pumped medium

  Conclusions and useful video on the topic

  Comparison of the operation of natural ventilation and a forced system with recuperation:

  The principle of functioning of a centralized recuperator, calculation of efficiency:

  Design and operation of a decentralized heat exchanger using the example of the Prana wall valve:

  About 25-35% of the heat leaves the room through the ventilation system. To reduce losses and efficient heat recovery, recuperators are used. Climatic equipment allows you to use the energy of the waste masses to heat the incoming air.

  Do you have anything to add, or do you have questions about the operation of different ventilation recuperators? Please leave comments on the publication, share your experience in operating such installations. The contact form is in the lower block.