Rotary recuperator: design and principle of operation of the heat exchanger, known models, pros and cons of the unit

Providing warmth to your home during the winter months is a necessary and mandatory task. This is achieved by heating. Heating is usually carried out through metal pipes using hot water. In most residential buildings, apartment heating is regulated only by the services that supply heat. This is not very convenient and expensive. Having the ability to control the temperature immediately relieves the consumer of excessive heat energy consumption and allows him to control the desired temperature in the room.

We mentioned the winter period. However, during the summer months, maintaining a cool indoor temperature is also important. In hot weather, open windows are ineffective. During the day, the walls heat up to such an extent that they do not have time to cool down during the night, and, consequently, the stuffiness in the room remains. In this case, fans and air conditioners are used. However, there are other means, which we will talk about in the article.

Peculiarities

The rotary recuperator has a heat exchanger rotating at a given speed.

It contains two channels - exhaust and supply. They allow for high-quality ventilation.

The advantages of rotary recuperator models include the following points:

• very high efficiency (efficiency 70-90%), especially in winter;
• reducing the operating time of the air conditioner in the summer due to effective cooling of the room;
• the recovery process is fully automated;
• There is no need to worry about condensation as there are no defrost cycles.

However, like any technical devices, rotary-type recuperators also have their disadvantages, among them:

• high cost compared to other models;
• there is some noise during operation;
• mixing of cold and hot air may occur;
• some models have very large dimensions, which makes them impossible to use in small rooms;
• the device requires frequent maintenance, as it consists of many moving elements that can sometimes fail.

There are several types of rotary recuperators.

• Sorptive. These models use silica gel as a sorbent. Thanks to this material, the drum of the rotary heat exchanger perfectly absorbs moisture, preventing condensation from forming and disrupting the operation of the device.

• Epoxy. This type of coating of the inside of the recuperator allows you to protect the aluminum drum from the aggressive effects of certain chemical compounds in the air. The epoxy-coated recuperator perfectly resists the influence of sea salt, chlorine and chemical reagents in large-scale production.

• Enthalpy. In this type of device, the inner drum is covered with a material that absorbs not only moisture, thereby preventing condensation from forming, but also thermal energy.

• Condensation. On such models there is no special coating on the drum. They are not able to drain condensate, hence their name.

• Antibacterial. In this case, a special impregnation with an antimicrobial effect is applied to the inner surface of the recuperator. Such a device can purify and protect indoor air from 600 types of known pathogens.

In normal (non-production) conditions, the most budget-friendly condensing recuperators are most often used.

If there are high humidity levels in the room, then it is justified to install hygroscopic rotor models. Other types are intended to a greater extent to ensure effective ventilation of premises in hazardous industries.

Main components of the recovery system

The recovery system includes, in addition to the main unit with plates, a fan. In addition, recuperators are equipped with:

A system for removing condensate that inevitably forms on the plates in order to avoid water getting into the air channel or the formation of ice in it. Such a condensate collector must be equipped with a water seal that blocks the operation of the fan in the event of excess moisture. A special bypass valve is used as a device for regulating the intensity of air flows

An important design feature of such a valve and plate recuperator is the complete absence of moving parts.

As mentioned above, plate recuperator heat exchangers can be made of various materials. Each of them has its own properties, advantages and disadvantages.

Let's try to compare them with each other:

1. Aluminum plates or galvanized steel heat exchangers. Such systems are quite popular due to their relatively low cost. However, such a plate recuperator has a relatively low efficiency, since it regularly requires the use of a defrosting mode.
2. Plastic heat exchangers have higher efficiency and efficiency, but are also much more expensive.
3. Plates made of special paper are also highly efficient, but such heat exchangers cannot be used in rooms with high levels of humidity (swimming pools, car washes, some industrial premises), since condensate quite easily overcomes the walls of the cassette.
4. Recuperators with double paper cassettes are also used. Their efficiency is significantly higher due to additional heating of the air, but, nevertheless, they are also afraid of high levels of air humidity.

Principle of operation

The rotary recuperator operates on a heat transfer scheme from exhaust flows to supply flows. Fresh air entering the rotor is heated by the action of the plates and penetrates into the room. The device operates from the mains, and the settings allow you to select the optimal rotor speed. The two air flows do not mix with each other, but interact and it is due to the temperature difference that heat exchange occurs. Hot air in the recuperator is cooled, and cold air is heated.

Air recovery principle

To understand the advantages and benefits of using recuperative heat exchangers, you first need to understand the very essence of their work. Literally translated from Latin, recovery is called “return of used, spent.”

It is the energy return effect that is used in climate control devices of this design. Air flows passing through the unit exchange thermal energy with each other, allowing the air conditioner to subsequently maintain a comfortable temperature, using less energy. On particularly cold days, this allows you to significantly save on heating the room.

Example: the air temperature outside has reached minus 20°C. For residents to feel comfortable, the air conditioner must create a room temperature of at least + 25 C. The temperature difference is easy to calculate - 45 degrees Celsius. Of course, some part of the air will heat up due to the heat capacity of the walls, furniture, and heat exchange between the incoming and outgoing flows. But the air conditioner will still require a significant amount of energy to maintain comfort.

Plate and any other recuperator of the chosen design allows you to move the point of contact of cold and warm air outside the room. The device conducts active heat exchange between them, allowing the incoming flow of fresh air to reach a more comfortable temperature value than the original one.

How is it different from lamellar?

Plate recuperators are clearly inferior to rotary models, mainly due to their lack of an electric drive. In plate devices, you can only change the direction of the plates and limit or increase the throughput. In rotary devices everything is arranged better. It is more flexible in settings, does not freeze in winter and shows better energy saving results compared to plate models. As a result, the latter are much cheaper than rotary models.

How does a rotary recuperator work?

This device is cylindrical in shape and consists of a main element - an aluminum rotor, made up of smooth and corrugated plates. The aluminum rotor is covered by a housing made of galvanized steel.

Rotary air recuperator

In addition, the device includes a drive mechanism that has a belt for rotation, as well as axial bearings, a sensor for controlling the rotation of the rotor itself, and a sealing tape. The latter is designed to isolate air masses.

Principle of operation

The principle of operation of the device is quite simple. The device is put into operation by engaging a V-belt drive. If the product is operated at high temperatures, the electric motor is mounted outside the body of the heat exchanger. Also in this case, a chain is used instead of a belt.

Inside the rotary heat exchanger, heat is transferred from heated gas to cold gas. A rotating cylinder rotor, which is made of small metal plates, is responsible for this. Subsequently, the hot gas heats up these plates, and then the plates go into the flow of cooled gas, after which they transfer thermal energy to it.

Operating principle of a rotary recuperator (video)

Types of rotary drum coating

There is a classification of recuperators according to the type of coating of the rotary drum. There are currently five types of products:

• condensation type - in this case, the rotor is an aluminum drum, which has no coating and can only remove the thermal energy of air masses, but it is not capable of moving the heat of moisture from air masses;
• hygroscopic type - in this case, the drum is covered with a special hygroscopic coating, which has sorbing properties - the drum collects moisture during operation, and then transfers it from stream to stream, during which both moisture and latent heat of air masses are removed;
• sorption type - in this case we are talking about a modification of the hygroscopic type using a coating in the form of silica gel - this sorbent has a huge surface area, approximately 800 m2/g, which makes it an extremely powerful means for absorbing moisture;
• epoxy type - this coating is used in cases where it is necessary to additionally protect the aluminum drum from the possible destructive effects of chemical compounds present in the treated air (for example, if the air in the room contains chlorine or various vapors, such as ammonia);
• antibacterial type - in this case, the drum is protected with an antibacterial coating that can withstand about six hundred types of pathogenic and non-pathogenic microorganisms (usually such a coating is required for enthalpy rotors).

Types by area of ​​application

Now there are three main types of air mass recuperators, differing in the scope of operation and additional “filling”.

Product types:

1. Standard view. In this case, the regenerator is divided into several sector parts (from 4 to 12). This type of device is used to remove excess heat from exhaust air. Also, such a device transfers moisture when working out air flows below the “dew point” temperature.
2. High temperature type. This type of device is used to remove heated air currents, the initial temperature of which reaches approximately +250 degrees.
3. Enthalpy view. This device is used to remove total thermal energy, but in addition to this, the device also transfers moisture.

Operating principle of the air recuperator

Recuperators are also divided according to their design. In this regard, there are two types of products: horizontal and, accordingly, vertical rotor.

Model rating

When choosing a heated supply and exhaust system, many people rightly pay attention to Mmotors eco-freshness 01 standard. The standard channel for air passage here is 100 mm

The manufacturer guarantees normal installation in walls with a thickness of 0.27 m or more. An optimal microclimate in the house is maintained, since the supply air remains fresh even after passing through the filter. Energy consumption is relatively low, and there is also a wired control panel.

It is worth noting:

• the presence of a carbon filter that suppresses burning odors;
• carbon dioxide concentration determinant;
• suitability for individual premises, including medical institutions;
• two-stage speed adjustment;
• sensor for measuring humidity;
• low-noise electric motor on very advanced radial bearings.

The total power of the electric drive is only 18 W. In an hour, air renewal is ensured over an area of ​​up to 100 square meters. m. If desired, a control panel operating on infrared rays is added. But, of course, the market is far from limited to this model. And many experts believe that a high-end wall-mounted heat exchanger may be the best choice.

You just need to carefully select the linear size to ensure compatibility. For the manufacture of Shuft heat exchangers, high-quality galvanized steel with a thickness of at least 0.7 mm is used. The drainage pan is also made of galvanized steel and can be removed if necessary.

Important Features:

• suitability for residential, administrative and main production facilities;
• unsuitable for aspiration systems;
• unsuitability for air containing toxic and caustic impurities, flour, glue fumes;
• condensate drain pipe with a diameter of ½ inch;
• aluminum heat exchange cassette.

The Korf/PR 40-20 heat exchanger is equipped with a fitting for the condensate drainage channel. The manufacturer claims that heat transfer efficiency can reach 70%. The plate device, like previous models, is designed for channels measuring 0.2x0.4 m. Aluminum plates, the maximum thickness of which is no more than 0.2 mm, help increase efficiency. Accurate calculation allows you to achieve an optimal balance between performance and mechanical strength.

For 150 sq. m., even 200 sq. m. the Dantex DV-200HRE model is confidently calculated. This recuperator perfectly maintains the microclimate in the house at temperatures from -20 to 40 degrees. The use of 146 mm channels is envisaged. The sound volume when working in various conditions is stated to be from 32 to 39 dB. The manufacturer promises that it will be possible to clearly regulate the level of humidity in the house.

Other parameters:

• external atmospheric pressure in static conditions up to 60 Pa;
• efficiency at enthalpy 49/51%;
• own weight of the device is 18 kg;
• power supply from the mains voltage 220-240 V;
• time programming option;
• possibility of connecting an additional electric heater (inside or outside the heat exchanger).

RCS 350 has a wider temperature range. This device will help out both at -28 and at +50 degrees. Its total productivity is even higher than that of the previous model - in an hour you can refresh the air on an area of ​​330 sq. m. This is already quite worthy even for a large private cottage.

Electrolux STAR EPVS-1100 cannot boast of a wide temperature range, which ranges only from - 15 to + 40 degrees. But the productivity is record high - up to 1100 sq. m. in 1 hour. The “star” will drive air through a channel with a diameter of 250 mm, creating noise up to 41 dB. Which, however, still won’t drown out even a conversation in a normal voice. The highest static pressure will be 350 Pa, and the total mass of the unit is 66.5 kg.

Types of recuperators

When making a device with your own hands, you should decide on its type. There are several types of recuperators:

• rotary;
• lamellar;
• recirculating water;
• chamber;
• freon

Rotary

The rotary recuperator consists of corrugated steel plates. Externally, the design is a cylindrical container. A rotating drum alternately passes warm and cold flows. During operation, the rotor heats up, which transfers heat to the cold air. The rotary apparatus is highly economical. You can set the required number of rotor revolutions and adjust the power. The advantage is that this type can be used throughout the year, since an ice crust does not form on it.

The disadvantages include the size of the structure. It requires a large ventilation chamber.

Lamellar

The plate recuperator consists of aluminum, plastic and special paper plates. In some models, air flows move perpendicular to each other, in others they move in opposite directions.

If aluminum plates are used in the design, the system is characterized by a low efficiency. This is due to the fact that the device often freezes and needs regular thawing. The advantage is its low cost. In addition to aluminum plates, galvanized steel can be used. Heat exchangers made of plastic have greater efficiency, but are also more expensive.

If the material is special paper, then the output of such equipment is high. However, there is a significant drawback: the device cannot be used in a damp room. The resulting condensate impregnates the paper layers.

Recirculating water

A distinctive feature of this type is the separation of supply and exhaust heat exchangers. With the help of antifreeze or water, thermal energy is transferred from the exhaust part to the supply part.

The system has its advantages:

• no possibility of mixing flows;
• separated heat exchangers facilitate work at the design stage;
• the ability to combine several supply or exhaust flows into a single one.

Flaws:

• the need for a water pump;
• Recuperators are only capable of heat exchange, and moisture exchange is impossible.

Chamber

Both flows are directed into a single chamber. It is divided by a partition. After heating one part, the partition is rotated. The heated part, which heats the room, begins to accept supply air. The disadvantage is the high probability of mixing air flows, which leads to contamination.

Freon

Based on the physical characteristics of freon, which is located in hermetically sealed tubes. At the beginning of the pipe, air is heated along with freon, which boils and evaporates. The heat moves on. Freon vapors come into contact with cold streams and condense. Then the cycle repeats.

Energy efficient system that conserves heat

In addition to the material from which the heat exchanger elements are made, recuperators also differ in the direction of air flow. In the most common cross-flow type of recuperator, the flow of supply and exhaust air flows perpendicular to each other, and in the counter-flow type - in opposite directions. This is due to the fact that for effective heat exchange, the flows, ideally, should not come into contact with each other and mix.

Using this principle of operation, a plate heat exchanger ensures uninterrupted heating of incoming air during the cold season and reduces to a practical minimum that common effect of ventilation and heating systems, which is commonly called “street heating”. Which is the main feature of the so-called energy efficient systems.

Recuperators, unlike conventional air ventilation systems, are capable of not only successfully performing heat exchange functions, but also combating unpleasant odors, and certain types can cope with high room humidity. If you are not ready to purchase a plate recuperator, you can try to make it yourself using these instructions.

Rivals of the rotary recuperator

There are other types of recuperative heat exchangers, which often become elements of supply and exhaust systems.

Lamellar

These devices are the most popular because they are relatively simple, they do not require electricity and serious maintenance. Low cost is another big advantage. Such devices are heat exchangers consisting of a large number of plates, between which minimal distances are left. The materials for their manufacture vary greatly: it can be metal, plastic or cellulose. Recuperation in devices occurs in different planes, so the flows of warm and cold air do not mix.

There is a downside - the accumulation of condensation, freezing in extreme cold, so the devices require regular thawing in winter. For this reason, in cold weather, the ventilation unit is turned off, or an additional element is installed - a supply air flow heater.

Mermen

If they are called correctly, they are glycol or alcohol, since ordinary liquid will quickly freeze in winter. This equipment consists of two heat exchangers that are connected by a liquid circuit. Such elements are installed at a distance from each other, so the air flows also do not mix.

Another advantage of the device is minimal fat deposition, which means less fire hazard. For this reason, they are often installed in cafes and restaurants, even in hot shops. The device does have some disadvantages: it is large in size, not very impressive efficiency, barely exceeding 50%, and high price due to the need for additional equipment - a heat pump.

Other types - chamber, tubular recuperators - are not used for ventilation in private homes, so there is little point in describing them. If we consider this “trio” of candidates as models for self-assembly, then there is only one leader - a simple plate device.

Kinds

Lamellar

This type of heat exchanger is the cheapest. However, this does not prevent engineers from achieving exceptional practicality. The most profitable designs of plate-type recuperators are made of aluminum. But plastic products, despite their slightly higher price, allow for more efficient ventilation. Potentially, cellulose recuperators would be the most effective, but their poor resistance to moisture spoils everything.

Rotary

Any plate heat exchanger, even the best one, can freeze in winter. And nothing can be done about it - this is the basic principle of work. But in a rotor system there are plates inside that move with the air flow. By influencing the rate of movement of the rotor, overall performance can be increased. The problem is that you will have to periodically change the filters, and this increases the cost of ownership several times compared to other types.

Roof

Such devices are best suited for utility rooms. They can often be seen in garages, hangars, and warehouses.

However, its cost will also be high, which greatly darkens the prospects for home use.

Glycolic

This recovery option allows you to combine the exhaust and suction circuits

What is important is that you can connect different channels even at a certain distance from each other. Thermal energy is transferred using a special coolant (glycol fluid)

Pure glycol is rarely used; commercial models usually contain a water-glycol mixture. Heat exchangers must be installed in a countercurrent flow relative to the air stream.

Direct connection is practiced only by amateurs. This immediately reduces the efficiency of the entire system. To drain condensate during the cold season, special containers are used. They are complemented by so-called drip eliminators. A coarse air filter will help to avoid clogging of air coming almost directly from outside.

How to increase efficiency

Careful assembly and attention to detail when creating a homemade heat exchanger will allow you to achieve good efficiency indicators. However, the assembled air recuperator with your own hands can be significantly improved and its efficiency increased. To do this, when calculating the design and its implementation, it is necessary to provide for the following nuances:

1. Maximum sealing of the device;
2. Use of high-quality heat-insulating materials;
3. Increase the size of the recuperator and the area of ​​the heat exchange surface. This will reduce the speed of air passing through the device, and accordingly allow it to warm up or cool down better;
4. The use of corrugated plates or plates with stampings, which will significantly increase the heat transfer surface area while maintaining the total volume of the device;
5. Increasing the exhaust volume compared to the inflow. Thus, a larger volume of outgoing air will better transfer heat to a smaller volume of incoming air.

A do-it-yourself air recuperator is a simple, affordable, cheap and effective way to save expensive thermal energy and effectively use irreplaceable natural resources.

Recuperator efficiency

The most important characteristic of a recuperator is its efficiency. It shows how much the recuperator was able to heat the supply air relative to the ideal option. The ideal option is taken to be the case when the supply air is heated to the temperature of the exhaust air. In practice, this option is unattainable, and heating occurs to a certain intermediate temperature Tp. The efficiency formula is as follows: K= (T_P-T_N)/(T_B-T_N), where:

• TP – supply air temperature after the recuperator, °C,
• ТН – outside air temperature (supply air to the recuperator), °С,
• TV – temperature of the exhaust air to the recuperator, °C.

This formula takes into account the change in sensible heat in air flows. However, the relative humidity of the flows may also change, and then it is better to resort to calculating the efficiency of the recuperator based on the total heat. The formula is similar in appearance to the previous one, but is based on the enthalpies of air flows: K = (I_П-I_Н)/(I_В-I_Н), where:

• IP – enthalpy of supply air after the recuperator, °C,
• IN – enthalpy of outside air (supply air to the recuperator), °C,
• IB – enthalpy of exhaust air to the recuperator, °C.

The first formula allows you to quickly assess the efficiency of recovery. For more accurate results, use the second formula.

Advantages and disadvantages of different types of recuperators

The advantage of recuperators is obvious - they allow you to significantly save on heating the supply air in winter and cooling the supply air in the summer. Among the disadvantages of recuperators are the following:

• They create additional aerodynamic resistance in the network. Indeed, like any other element in the ventilation network, recuperators have some resistance, which should be taken into account when choosing a fan. However, this resistance is not high (usually no more than 100 Pa), and does not lead to a significant increase in fan power.
• Recuperators increase both the cost of the ventilation unit and the cost of its maintenance. Like any other solution aimed at increasing the energy efficiency of the system, recuperators cost some money and require regular maintenance. However, experience has repeatedly proven that the costs of heat recovery are much lower than the benefits obtained.
• Rotary, chamber and, to a much lesser extent, plate heat exchangers have one drawback, which can be critical at some facilities - leakage of air flows is possible in them. In this case, the danger is the flow of exhaust air into the supply air. Such leaks are undesirable in clean room ventilation systems and are not acceptable, for example, in infectious diseases departments of hospitals and operating rooms. The reason is the danger of viruses that have entered the hood from any room flowing into the supply air flow with subsequent spread throughout all rooms of the facility. As a result, recuperators with intermediate coolant or freon recuperators are used at such facilities.
• Recuperators increase the dimensions of the ventilation unit. This primarily applies to plate recuperators, since they are air-to-air heat exchangers and are quite large in size. In addition, this applies to recuperators with intermediate coolant due to the presence of two separate heat exchangers, two pipeline lines and piping units near each of the heat exchangers

Methods for organizing recuperative ventilation

Recovery is arranged in one of the following ways: centralized and decentralized. In the first case, ventilation flows from the entire room pass through the heat exchanger, in the second - from one room.

Centralized complex – air handling unit

A centralized system is installed at the stage of construction or major modernization of the ventilation system.

A forced supply and exhaust unit (PVU) with a built-in recuperator is selected. The main selection criterion is the overall performance of the complex based on the entire volume of air in the structure (+)

A PVU with a recuperator ensures sufficient air exchange even in houses with sealed windows. At the same time, air flows are distributed evenly without creating drafts.

Complex supply and exhaust units of monoblock type are equipped with:

• fans – round-the-clock supply of clean air and emission of jets saturated with carbon dioxide;
• heaters – preheating of inflow;
• filters – retain dust and microparticles;
• recuperator – different types of installations can be used.

The functionality of some PVUs is expanded with a delay timer, power regulator, humidity level sensors, etc.

The body of monoblock models is covered with noise-absorbing material, making the operation of the PVU very quiet. Vertical, horizontal and suspended versions of ventilation units are possible

Recuperative monoblock PVUs produced by: Vents (Ukraine), Dantherm (Denmark), Daikin (Japan), Dantex (England) have proven themselves well.

Local units - an addition to the existing ventilation system

To restore the circulation of air masses in the room being used, decentralized air inlets with heat recovery are suitable.

They cut into the façade of a building or are mounted through a window. Their main task is to improve the supply ventilation in the house.

Local recuperators are equipped with a fan and a plate heat exchanger. The inlet “sleeve” is insulated with sound-absorbing material. The control unit of compact ventilation units is located on the internal wall

Features of decentralized ventilation systems with recovery:

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

Popular manufacturers of local recuperators: Prana (Ukraine), O.Erre (Italy), Blizzard (Germany), Vents (Ukraine), Aerovital (Germany).

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

Handmade production

A do-it-yourself recuperator is not at all a difficult task for craftsmen. However, an ordinary person should understand some rules before making:

• The first is to accurately calculate the parameters of the required ventilation device.
• Secondly, get all the necessary materials and tools.
• Third, think through possible ways to mount the recuperator and purchase or manufacture the required number of fasteners.

It is best to use steel sheets for the manufacture of the housing, and aluminum sheets for the rotating rotor. It is important to remember that automating the recovery process requires installing a motor. To start the rotor, a V-belt drive is installed. It is also recommended to think about proper sound insulation of the device, for which mineral wool, fiberglass, or silicone sealant can be used.

The manufacture of a rotary recuperator in itself is not at all complicated, but it requires accurate calculations. Therefore, if you are not very well versed in this issue, it is better to consult with professionals.

Recuperator control

The rotor mechanism is rarely controlled separately from the main supply and ventilation system. The latest designs use the ability to electronically control the device via a controller panel. In automatic mode, the owner can set parameters such as rotation speed, percentage ratio between air intake and exhaust volumes, degree of purification, time operating intervals, etc. The operating parameters of the mechanism are monitored using sensors, which, in particular, record the throughput of the equipment . Also, an air supply unit with a rotary heat exchanger can be configured for special operating modes. One of the modern modes of this type is operation in conditions of maintaining constant air pressure. This program eliminates the risk of overloading the electric drive with subsequent overheating.

Device maintenance

The surfaces of the rotor and the housing itself require regular cleaning. The plates are cleaned and, if necessary, additionally treated with anti-corrosion compounds. You should also regularly check the direction of rotation of the rotor, and in the drive system, the quality of the belt tension. Since the recuperator works in close conjunction with other functional ventilation components, it is important to check their condition too. In particular, the filter, air ducts, dust collectors, valves with sensors, etc. are subject to revision. If possible, it would be a good idea to remove the rotary heat exchanger from the installation site and completely check for leaks. The fact is that in the presence of even minor gaps, the quality of the incoming air sharply deteriorates.

Additional components in the “inflow” scheme

Having decided on the selection of the main components of the apartment supply system - a fan and a heater, you should consider options for providing other accessories. In particular, equipping the air handling unit with a coarse air filter. That is, we are talking about creating equipment in a complex.

The rules for the installation of fresh air ventilation necessarily require the introduction of an air filter of cleaning class “EU3”, no less, which must be placed in front of the electric (water) heater. One of the main functions of the filter is to separate small dust particles from the incoming air.

Apartment supply ventilation with the function of heating the air flow (classic scheme): 1 – outside air inlet; 2 – output of treated air; 3 – filter class “EU3”; 4 – channel axial fan; 5 – heating module with round pipes

If there is no filter, the electric heating element or water heater quickly becomes dirty, which is fraught with a serious loss of heating power, and for the electrical structure there is also a risk of fire.

The filter installed in the system must be periodically replaced with a new one as it becomes dirty. Accordingly, a do-it-yourself home structure should provide for the ability to quickly and easily change the filter element.

It is worth noting that industrial air supply structures are usually equipped with differential air pressure sensors. In turn, the sensors are connected to automatic control, which signals the user that the filter is dirty.

In fact, it is also advisable to supplement a serious home air supply system, made by yourself, with a filter condition monitoring function.

Instructions on how to make a recuperator with your own hands

Creating an air recuperator with your own hands is a completely feasible task for a person who knows how to use them correctly. Experts call the plate recuperator the most suitable for this purpose. This type of recycler is the most common, especially homemade models. The disadvantages of the design, which include freezing of the heat exchanger at low air temperatures outside and intersection of air duct pipes, are compensated by the low cost and simplicity of the design.

To make an air recuperator with your own hands, the following materials are important:

1. metal sheet (galvanized sheet, roofing sheet, galvanized iron or any other sheet metal) with an area of ​​3–4 m2;
2. cork, wooden strip or textolite;
3. metal sheet or similar material to create the body;
4. plastic flanges with tips corresponding to the diameter of the ventilation pipes;
5. sealant;
6. insulation;
7. silicone

Creating an air recuperator with your own hands takes several steps:

1. Sheets of metal are cut into plates measuring 20 x 30 cm. It is recommended to use at least 3–4 m2 of metal. Particular attention is paid to cutting. The plates must be cut almost perfectly evenly, which cannot be achieved with metal scissors. Engineers recommend using a hacksaw or grinder. Place the plates one on top of the other, ensuring a gap of at least 4 mm. To do this, glue frames made of thermal insulation material (cork, wooden strip, textolite) along the contour of the plates, providing holes for air flow in the appropriate direction, alternating cross flows. Upon completion of laying the plates, go through all the cracks with a neutral composition sealant.
2. The body is made of tin or other sheet metal. It is a box of a suitable size to tightly fit the resulting block of plates. Cut holes in the walls of the box into which to insert pre-prepared plastic flanges corresponding to the diameter of the air duct pipes. The cracks must be carefully sealed to prevent loss of device efficiency.
3. After the sealant has dried, place the resulting block of plates in the housing.

1. It is recommended to lay thermal insulation (foam plastic, glass wool) on top of the resulting body with a laid block of plates. The entire resulting structure can be additionally packed in a wooden box.

The recommended air flow speed is 1 m/s.

According to expert calculations, with a total heat-transfer surface area of ​​3–4 m2 and a productivity of 150 m3/h, the efficiency of such a recuperator should be from 50 to 60%.

In winter, at sub-zero temperatures outside, there is a possibility of frostbite in the plate unit of the heat exchanger. To avoid blocking the operation of the recuperator for a long period, it is recommended to provide a bypass. Then, by switching the incoming air flow to it, the system will quickly thaw due to the temperature of the warm air blown out.

To make it easier to detect frostbite in the system, a pressure change sensor can be provided. However, periodic prevention by shutting off cold air and warming up the plate system will also help.

Due to the fact that condensation settles in the recuperator, it is recommended to equip the structure with a hose for draining water.

Process description

In order for the design to be correct and reliable, it is necessary to adhere to a certain algorithm of actions. You don’t need any special knowledge, but you will have to show ingenuity and intelligence:

1. The material is laid on a flat surface, divided by a cutting tool into square plates with sides of 20-30 cm. Several dozen such blanks will be needed. Ideally even plates are obtained when using a jigsaw.
2. Then wooden slats and cork material are prepared. Their parameters must exactly match the sides of the pre-cut squares. They are glued to opposite sides of the blanks, the latter remains empty. The process is suspended until the glue dries completely.

When assembling the recuperator yourself, it is important to perform the steps sequentially

At the next stage, the squares are assembled into a single cassette. Each sheet is carefully laid at an angle of 90° relative to the previous one. The final element of the recuperator is an uncoated plate. The prepared functional installation is fixed in the frame using a construction angle. Existing holes and cracks are treated with a sealant that prevents corrosion processes. Fasteners must be made to secure the flanges on the sides of the cassette with plates. The lower part is equipped with a drainage hole through which a tube with condensate is discharged. The cabinet walls are equipped with guides, which are made of durable corners. After this, the prepared work part is placed in a box that meets the parameters. Do not forget about the insulating material laid in the recuperator. It is firmly attached to the inside of the body walls of the structure. Ice accumulation in winter is prevented by installing a pressure sensor. It is usually mounted in an area through which warm air flows. The final stage is the installation of a ready-to-use recuperator into the general ventilation system.

There is a huge selection of cooling systems installed in residential and industrial facilities. But for your own needs, it is quite possible to manufacture a recuperator for a heat exchanger yourself, while saving money.