The climatic features of our country, in the cold time, lead to the need for air heating. But consuming the heated air we produce a decay product, with the result that for normal life, it is necessary to change the heated air to fresh. Total, only the air heated - I drive it out into the street, the new air arrived, heated again. Recuperators serve to catch the warmth of the outgoing air and give it warmly incoming.
Cutting-exhaust ventilation with heat recovery is still little known to a simple man. About the recovery is known to mainly specialists.
But this equipment has a big prospect for all consumers who clarify their expenses.
In Europe, such devices received wide useAlthough it should be noted that the climatic conditions there is much softer.
And all this thanks to energy saving, which is spent on air treatment.
The use of a plate recovery leads to energy savings from 50 to 80%.
The use of a rotary recovery, saves from 70 to 90% of energy.
The percentage of savings directly depends on the difference in the temperatures of exhaust and supply air. The recovery installation brings significant savings of money, while the unit serves a long time (with proper maintenance) and over the years, financial savings are only increasing.
The heat recovery of the supply and exhaust installation partially takes the heat of the exhaust air and transmits it to the newly incoming air. This allows the warmth to return to the house, while there is a comfortable ventilating room.
Using the recuperator, we have fresh air temperature (between room and outdoor).
Thus, such an aircraft is safer and while the recuperator allows you to carry out an extermination.
The recuperator itself consumes the minimum amount of energy - the heating of the supply air comes through natural heat exchange.
Heat recuperators can be in the form of a special module of the supply and exhaust installation, and can be an individual autonomous device.
In everyday life, lamellar and rotary heat recoveors were widely used.
Plate regenerators consist of plates through which air flow and air inlet pass.
Air flows, in such recuperators, each other is not in contact and not mixed, i.e. Each stream is in its own way, and heat is transferred to the heat exchange cassette.
The heat exchange cassette consists of several thin plates having a large area.
Usually these plates are made of aluminum foil or plastic.
Aluminum foil cassettes are cheaper, but the efficiency of plastic cassettes is higher than aluminum foil cassettes.
The disadvantages of lamellar recoveors include the formation of condensate.
Condensate is formed by B. winter time Due to the difference in the temperature of the supply and exhaust air.
In winter, the condensate freezes and formed to go out.
To combat outland, use automation.
When the icing sensor is triggered, the trim air goes past the heat exchanger and heats up this air using a canopy.
And the exhaust warm air from the building passes through the heat exchanger and defrosts the cassette.
The defrost process takes from 5 to 25 minutes per hour.
Naturally, no energy saving is happening at this time.
In addition, the design should have a drainage bath and drainage water supply and condensate collection.
In cases of nondes, the heat recovery is able to save only 45% of energy.
To solve the condensation problem, cassettes are used from hygroscopic cellulose.
The whole chip is that the walls of this cassette can absorb moisture from the outgoing air and transmit this moisture to the incoming flow.
The use of hygroscopic cassettes allows recovery (return) not only heat, but also moisture from the air. After such procedures, fresh air complies with comfortable temperature and humidity.
Thus, the efficiency rises to 70%, and if the recuperator has a double plate heat exchanger From hygroscopic paper, this makes it possible to eliminate the formation of a land and raise the efficiency up to 90%.
Important! Cellulose cassettes do not apply in rooms with high humidity.
The recovers are mounted in the rotor housing, which is a rotating cylinder.
The cylinder throughout the volume is filled with layers with profiled metal, aluminum or steel.
When working, the rotor drum moves in a circle between the supply and exhaust air.
When passing through the exhaust flow - the plates are heated, when passing through the trimth flow - the plates give their heat.
The heat exchange directly depends on the rotor speed, which is adjusted.
The efficiency of the recovery reaches a maximum if the rotational speed is automatically adjusted in accordance with the testimony of the sensors of the outer and internal air temperature.
The disadvantages of rotary recuperators include partial mixing of exhaust and supply air.
Therefore, cleaning filters have to be installed at the input and output. The design of rotary recuperators is more complicated and therefore, maintenance Rotary recuperators produce more often than lamellar.
Nevertheless, despite these disadvantages, rotary models are reliable, have a greater efficiency of the return of thermal energy, up to 80%.
Choosing a recuperator, you need to know the required installation performance.
To do this, it is necessary to know the multiplicity of air exchange, namely: how many times within an hour, it produces a complete replacement of air indoors.
The multiplicity of air replacement for the apartment is 1, and for a country house from 0.5 to 1.
Normally, per person, the air replacement is required 36 m3 per hour.
Competent specialists, familiarized with the house plan, will pick you up the desired model.
It is necessary to take into account when choosing a recovery, the lower limit of the operating temperature.
And for Russia, the lower limit has a scatter from -5 * from to -40 * in winter.
Fundamental differences between the installation of conventional air conditioners and supply-extensive installations With heat recovery.
The only thing that air conditioning lies air to the room, and there will be two channels in the recovery system (influx and exhaust).
Mounting will cost a little more expensive, as it uses more air ducts, but it is not more difficult than the installation of ordinary supply ventilation.
To prevent the formation of condensate on the walls of the air duct, the air ducts must be thermally insulated.
When installing, you must pay attention to constructive features Some models, since individual models can only work in a certain position, i.e. plastics or vertically.
If the recovery model requires drainage, this device must stand in the warm room, and water under the tilt is derived to the nearest riser.
Lower an energy efficient house - the dream of each developer. Many believe that to achieve this goal, it is enough to warm the perimeter of the building and supply it modern windows. But is it just solved by this question? It turns out no. Only insulation of the enclosing structures and installation of hermetic window blocks it is impossible to provide comfortable accommodation and a full-fledged energy saving of the building. For some reason, many forget to take into account even the need to use ventilation - supply-exhaust installations (PDA).
To preserve the inner heat of the room need suppress and exhaust ventilation to equip heat exchanger — recessable airwhich will dispose of heat outgoing from the air flow premises by giving it to the supply. Such systems are widely used in Western Europe, providing building buildings with a heat loss level of 5-10 times less compared to a conventional residential foundation. Due to the recycling of exhaust air heat, save up to 70% of heating costs And thus pay off in the shortest possible time, as a rule, it is 3-5 years.
Small-sized suppress-exhaust systems with heat recovery type AVTU, which are designed specifically for use in residential and other small rooms. They are served in the building of fresh, heated, purified by outdoor dust air.
The energy of ventilation emissions in modern buildings reaches 50% of the overall level of heat loss, so energy-efficient is called a building in which in addition to the insulation of the enclosing structures and the installation of hermetic window groups, the energy returned to the room by recycling the heat of ventilation emissions is used.
The duration of the heating season in energy efficient buildings can be reduced by more than a month.
Is as follows. The heated air is closed by means of air intakes in the most wet rooms (kitchen, bathroom, toilet, economic room, etc.) and through the air ducts removed the outside of the building. However, before leaving the building, it passes through the heat exchanger of the heat exchanger, where it leaves a part of the heat. With this warmth, the cold air is heated outside (it also passes through the same heat-wedge, but in another direction) and is supplied inside (living room, bedrooms, cabinets, etc.). Thus, constant air circulation occurs inside the room.
Principle of operation of the supply and exhaust installation with heat recovery
Cutting-exhaust installation with a recuperator can be of different power and sizes - it depends on the volume of ventilated premises and their functional purpose. SAMI simple installation It is an isolated thermally and acoustically and enclosed in a steel housing a set of interconnected elements: a heat exchanger, two fans, filters, sometimes a heating element, a condensate removal system (automation unit, electrical stroke elements and air ducts in this context are not considered).
Organization of air exchange in residential cottage premises
Through the heat exchanger during the operation of the installation, two air flows pass - the internal and external, which are not mixed at the same time. Depending on the design of the heat exchanger, recuperators are several types.
The most far-sighted homeowners are designed in their buildings at once two ventilation systems: gravitational (natural) and mechanical with heat recovery (forced). System natural ventilation In this case, it is an emergency and serves as a challenge in the operation of the supply and exhaust installation and is mainly used in the unheated period. At the same time, it should be remembered that during operation of the mechanical ventilation system, the gravitational air ducts must be tightly closed. Otherwise effective forced ventilation will be lost.
Removed and dying air pass on both sides of a row of plates. At the same time, a certain amount of condensate can be formed in the plate recuperators on the plates. Therefore, they should be equipped with condensate discharges. Condensate collectors must have a water shutter that does not allow the fan to capture and supply water into the channel.
Principle of operation of the supply and exhaust installation with heat recovery
Due to condensate loss, there is a serious risk of ice formation, and therefore the defrosting system is necessary. Heat recovery can be adjusted by a bypass valve controlling the flow rate passing through the air recuperator. There are no moving parts in the recovery plate. It is characterized by high efficiency (50-90%).
Plate recovery
It has been well established to install this type from the manufacturer TM Naveka - Node1. They have an aluminum heat recovery, a drainage system for condensate drain and a recovery protection system. As well as the quietest in its class fans, an electric or water heater, built-in automation and remote control with the setting of modes and work schedules.
The heat is transmitted rotating between the removable and supply channels by the rotor. it open systemTherefore, there is a great risk that dirt and smells can move from the removed air in the dying, which can be avoided to some extent if the fans are properly placed correctly. The level of heat recovery can be adjusted by the rotor speed. In a rotary heat recovery, the risk of freezing is low. Rotary recuperators have moving parts. They are also characterized by high efficiency (75-85%).
Rotary recuperator
This solution is successfully implemented by the manufacturer TM Naveka in the Node3 series installations. Installations have a freezing system, built-in automation and remote control. Performance of Vertical - installations have heat-free insulation from mineral non-combustible wool 50 mm thick, and the possibility of outdoor (outdoor) installation and operation.
In this design, the coolant (water or water-glycolic solution) circulates between two heat exchangers, one of which is located in the exhaust channel, and the other is in the supply. The coolant is heated by removed air, and then transmits heat to the supply air. The coolant circulates in a closed system, and there is no risk of transmission of contaminants from the removed air to the trim. Heat transmission can be adjusted by changing the circulation rate of the coolant. These recoveors do not contain moving parts and have low efficiency (45-60%).
Recuperator with intermediate coolant
In such a recuperator, the camera is divided into two parts of the flap. The removed air heats one part of the chamber, then the flap changes the direction of the air flow in such a way that the trim air is heated from the heated walls of the chamber. In this case, pollution and odors can be transmitted from the removed air to the trim. The only movable part of the recovery is the damper. The unit is characterized by high efficiency (80-90%).
Chamber recuperator
This recuperator consists of a closed system of tubes filled with freon, which evaporates when heated by air removed. When the trim air passes along the tubes, steam condenses and turns into a liquid again. Transfer of contaminants in this design is excluded. The recuperator does not have mobile parts, but has relatively low efficiency (50-70%).
Channel Type Recuperator based on heat pipes
Plastic and rotary recoveors were most common in practice. Moreover, there are models of recuperators in which sequentially two plate heat exchanger can be installed. They are characterized by high efficiency.
Two-stage recovery by two rotors
The heat volume taken by means of a heat exchanger depends on a number of factors, in particular, the temperature of the internal and outer air, its humidity, the air flow rate. The more temperature difference inside and outside the room, the greater the humidity, the greater the effect of the recovery operation. By the way, most installations have the ability to mount on summer period instead of the usual heat exchanger of the so-called summer cassettethat allows you to provide air flow without recovery process. In addition, in some cases, you can change the direction of air flows inside the installation, so that they will bother the heat exchanger.
The main characteristics and features of the types of heat exchangers
Air movement provides fans - a trim and exhaust, although you can find systems with an integrated supply-exhaust fan that runs from one engine. IN simple models Fans have three levels of revolutions: Normal, lowered (used for work at night or in the absence of tenants, if it is a house or apartment) and maximum (used when you need the most high level Air exchange). Some modern models Fans have much more degrees of speed, which makes it possible to better meet the needs of the system users in different degrees of ventilation intensity.
The operation of the fans can be controlled automatically. The control panel is usually installed indoors in places, convenient to use them. Temporary programmers ensure the establishment of the mode of rotation of the fans during the day or week. In addition, some advanced models can be integrated into the smart home system and manage the central computer. The operation of the recuperator may also depend on the level of humidity in the premises (for this you need to install the appropriate sensors) and even the level of carbon dioxide.
Since the ventilation system should work around the clock, high quality fans is extremely an important feature Supply-exhaust installation.
The air, taking the outside, must be supplied to the room only passing through the filter. Usually, filters, delaying particles up to 0.5 microns, are installed in recuperators. Such a filter corresponds to the EU7 class by DIN or F7, according to Eurostandards. Thus, the filter delays dust, disputes of mushrooms, pollen of plants, soot.
This feature of the supply and exhaust installation should be appreciated by allergic. At the same time, the filter in front of the heat exchanger is also installed in the exhaust system. True, his class is somewhat lower - EU3 (G3). It protects the heat exchanger from pollution, which, along with air, removed from the premises. Filters are made from synthetic materials, they can be both single and reusable. The material of the latter should be easy in cleaning. Such filters can be shaken and washed. Some models of recovery installations have filter contamination sensors that at a certain point signals the need to replace or clean the filter.
Of course, the situation when the trim air is heated due to the removed heat, would be perfect. But in some cases it is impossible to achieve this. For example, if outside the window -25 ° C, then the temperature of the removed air, whatever the effectiveness of the heat exchanger, will not be enough to warm the trim air to a comfortable temperature. In this regard, recuperators are equipped with electrical system Additional heating of air supplied to air. As practice shows, heated supply air is needed in the event that the temperature is less -10s outside the temperature.
The heating element is also controlled automatically and is turned on depending on the program, if the selected heat is not enough to heal the supply air in accordance with the specified parameters. It is usually mounted along with the heat exchanger. Power and sizes of heating elements depend on the power of the entire installation.
It happens that with a large humidity of air and a strong frost on the heat exchanger, condensate is formed, which can freeze. To avoid this phenomenon, there are several technical solutions.
For example, a trim fan can work with breaks (turn on every half an hour for five minutes), and then running the exhaust fan, and warm air, passing through the heat exchanger, protects it from the formation of land.
The second, fairly common solution is to send part of the flow of cold air by the heat exchanger. There are a number of other methods, up to the use of an electric heater, which partially heels the air incoming outside the heat exchanger. The resulting condensate should not be assembled inside the unit, but to be removed through the system of pipelines or directly into the sewage system, or to another space provided by the project.
During the construction of individual houses, it is possible to apply the constructive scheme of the device of the forced ventilation system with a fence of air at a certain distance from home and delivery to a supply-exhaust unit by means of air ducts in the ground, below the level of primerization of the soil. During the passage of such a channel, the air temperature will increase, which reduces the risk of condensate formation and land on the heat exchanger and in general increases the efficiency of the recovery.
As we have noted, the installation of the supply and exhaust ventilation is much easier to perform in the building under construction than in the already exploited. Consequently, its design should be an element of the entire construction project. Typically, the installation is placed on unused attics (it is easier to provide a fence of cleaner air), in basements, boiler houses, economic and utility rooms. It is important that it was a dry room with positive temperatures. Air ducts B. unheated premises Must be thermally insulated. Inside the premises, they are usually mounted behind suspended ceilings.
Aluminum or plastic flexible air ducts
In practice are used different types Air ducts. Most convenient installation - Aluminum or plastic flexible ducts in the form of a pipereinforced with steel wire. Pipes can also be insulated mineral Vata.. A ducts are used rectangular or square cross section. Ventilation grilles are usually mounted in walls or ceilings. Specialists are recommended as the most convenient option to use anestat-adjustable anemostats for the influx of air, although regular lattices are still used for these purposes. The intake air fence should be made in places where it is least susceptible to pollution.
In conclusion, several videos on the use of supply-exhaust plants with heat recovery:
Device and principle of operation of a plate heat recovery.
The use of air recuperator, as a fixed assessment to combat mold and fungi in a residential room.
The recuperator often becomes part of the ventilation system. However, not many know what this device is and what features it has. Also, an important question becomes whether the acquisition of the recovery will be accumulated, as it will change the operation of the ventilation system, is it possible to create a similar item with your own hands. On this and many other questions give answers to the information below.
The unusual name was given the usual. The task of the device is to take part of the heat with already spent reserved air from the room. The selected heat is transmitted to the stream, which comes from the clean air supply system. The above information determines the fact that the purpose of using this system is to save on the heating of the house. It should be noted the following points:
Principle of operation of the system with heat recovery
The above information determines that heat recuperator is installed in many ventilation systems. It is not active, many versions do not consume energy, do not make noise, have an average efficiency. Heat exchangers were installed over the years, but recently many have a question if there are reasons for complicating the ventilation system by this device, which has quite a lot of problems due to work in a medium with different temperatures.
There are practically no potential problems associated with the use of similar equipment. Some are solved by the manufacturer, others become the buyer's headache. The main problems can be attributed:
The occurrence of condensate on VENT. System
The above problems should be considered when choosing a heat exchanger that there are several dozen species.
Box: Important: There are several options for the execution of the heat exchanger. Considering the principle of the device, it should be borne in mind that it depends on the type of device itself. The plate type of device is a device in which the trim and exhaust channel pass through a common case. Two channels are separated by partitions. The partition consists of a numerous amount of plates, which are often made of copper or aluminum. It is important to note that the copper composition has greater thermal conductivity than aluminum. However, aluminum is cheaper.
The following can be called the features of the device under consideration:
This class of devices can be attributed to the low price category. This is due to the fact that when creating a structure, a primitive method of heat transfer is used. The effectiveness of this method is lower. An important point It can be called that the cost of the device depends on its size and size of the inlet system itself. An example can be called a channel size of 400 per 200 millimeters and 600 per 300 millimeters. The price difference will be more than 10,000 rubles.
Recovery ventilation scheme
The design consists of the following items:
The dimensions of the heat exchanger depend on the power of the ventilation system and which dimensions of the air ducts.
The next type of design can be called a device with heat tubes. Its device is almost identical to the previous one. The difference lies only in the fact that the design does not have a huge number of plates that permeate the partition between the channels. For this, a heat tube is used - a special device that transfers heat. The advantage of the system can be called the fact that on a warmer end of hermetic copper tube Freon evaporates. Condensate accumulates at a colder end. The features of the design under consideration can be attributed:
The system of the system has the following features:
The design of hermetic and works with high efficiency. The advantage can be called that the design has smaller sizes and is more simple in operation.
Rotary type can be called modern option execution. On the border between the supply and exhaust channel is a device that has blades - they slowly rotate. The device is designed so that the plates are heated from one side and transmitted from the second when rotating. This is due to the fact that the blades are located at a certain angle to redirect heat. The features of the rotor system include the following:
However, you can also single out several flaws:
It is also important to understand that the chambers of the recuperators do not have a hermetic separation. This moment determines the transmission of the smell from one camera to another. In general, the rotary system resembles a kind of fan of quite large overall dimensions with bulky blades. To improve the efficiency of the system, the device must connect to the power source.
An intermediate type is a classic design that consists of water heating with convectors and pumps. The system is used extremely rare, due to the low efficiency and complexity of the design. However, it is practically no replace in the case when the trim and exhaust canal are at a great distance from each other. Heat is transferred through water, which is used for many years when creating such systems. To ensure water circulation regardless of the location of the devices, the pump is installed in the system. It is important to understand that design features in this case determine the low reliability of the system and the need for periodic inspections.
comparison table
In order to determine whether to install the heat redirection system, the effectiveness is carried out. An example of such a calculation we give on a relatively small frequent house. The features of counting include:
According to the calculation on the basis of the data entered, the payback period is approximately 114 years. Therefore, to acquire a plate heat exchanger does not make sense for a private house.
Significantly reduce costs independent manufacture Designs. The principle of its work is quite simple. Therefore, when using sweater materials, you can create. Recommendations for the creation of the design under consideration are as follows:
The principle of operation is as follows:
Similarly, it is created simple design To exchange heat between two systems.
In conclusion, we note that the above information allows you to calculate the profitability of the establishment of the heat exchange system. Almost all designs are highly reliable and do not fail. Also, their effectiveness is relatively small, the installation is appropriate only in large ventilation systems.
