Recovery system with cooling. Supply and exhaust ventilation with heat recovery: the principle of operation, an overview of the advantages and disadvantages. The principle of operation of the PVU

06.04.2020

Recuperators

Supply and exhaust ventilation is an integrated approach to the problem of ventilation.

Air handling units provide active air supply fresh air into the room and removal of exhaust air masses from the room. Recuperators are becoming increasingly popular, the advantage of which is the supply of fresh air heated to room temperature, with minimal annual energy consumption.

Recuperators return up to 95% of heat back to the room, practically without creating additional energy costs. Thus, recuperators are the most economical type of ventilation unit with the supply of warm air into the room. This is achieved by conserving heat from the waste room air on heat exchangers.

The latest models of recuperators combine the functions of supply and exhaust ventilation and fine air purification from allergens, equipped with carbon dioxide sensors, heat exchangers of a special design to maintain optimal humidity conditions, the ability to control from a smartphone.

Installing a heat exchanger effectively helps to cope with stuffiness, humidity control in rooms, mold and dampness in the house, and condensation on plastic windows.

We are official dealer leading manufacturers, and can provide a best price guarantee. You can choose and buy any model of the recuperator from us with delivery in Moscow and Russia.

Price: 25 500 RUB

Units with recuperation and plate heat exchanger, Mitsubishi LOSSNEY are designed for air exchange and maintenance of relative humidity in small rooms for various purposes. Made in Japan.

Air consumption - from 55 to 100 m3/hour.

Price: 62 600 RUB

Series of air handling units with heat recovery, Daikin ( VAM-150F,VAM-250F, VAM-350FB, VAM-500FB, VAM-650FB, VAM-800FB), designed for air exchange, energy saving and maintaining relative humidity in rooms for various purposes. They are suitable for country houses, cottages, apartments and commercial premises. The main distinguishing feature of DAIKIN plants is high efficiency and low power consumption. Data ventilation units can work both independently and as part of VRV air conditioning systems, as well as in conjunction with air humidifiers.

Air consumption - from 150 to 2000 m3/hour.

Price: 51 500 RUB

A series of air handling units with plate heat exchanger, Mitsubishi LOSSNEY ( LGH-15RX5ELGH-5E, LGH-25RX5ELGH-5E, LGH-35RX5ELGH-5E, LGH-50RX5ELGH-5E, LGH-65RX5ELGH-5E, LGH-80RX5ELGH-5E, LGH-100RX5ELGH-5E), designed for air exchange, energy saving and maintaining relative humidity in rooms for various purposes. They are perfect for country houses, cottages, apartments and commercial premises. The main distinguishing feature of LOSSNEY units is high efficiency and low power consumption. Made in Japan.

Air consumption - from 100 to 1000 m3/hour.

Price: 29 500 RUB

Series of installations inlet recuperative ventilation, Electrolux ( EPVS-200, EPVS-300, EPVS-450, EPVS-650, EPVS-1100, EPVS-1300), designed for air exchange, energy saving and maintaining relative humidity in rooms for various purposes. They are perfect for country houses, cottages, apartments and commercial premises. The main distinguishing feature of Electrolux STAR units is high efficiency up to 90% and low power consumption.

Air consumption - from 200 to 1300 m3/hour.

Price: 131 000 RUB

A series of air handling units with plate heat exchanger, TURKOV ZENIT ( 200 heco, 350 heco, 450 heco, 550 heco), designed for ventilation, energy saving and maintaining relative humidity in rooms for various purposes. They are perfect for country houses, cottages, apartments and commercial premises. TURKOV air handling units with heat recovery have the ability to connect an electric heater 1.5 kW, which allows you to control the temperature of the incoming air into the room.
Office for WIFI and MODBAS with smart home system.

Air consumption - from 200 to 550 m 3 /hour.

Price: 29 400 RUB

Series of supply and exhaust ventilation units with plate heat exchanger, Dantex DV ( DV-200HRE DV-250HRE DV-350HRE DV-400HRE DV-500E DV-600HRE DV-800HRE DV-1000HRE DV-1200HRE), designed for ventilation, energy saving and maintaining relative humidity in rooms for various purposes. They are perfect for country houses, cottages, apartments and commercial premises. Dantex air handling units with heat recovery have the ability to control the temperature of the incoming air into the room and low power consumption.

Air consumption - from 150 to 1200 m3/hour.

Price: 36 500 RUB

A series of air handling units with heat recovery, Royal Clima ( RCS 350, RCS 500, RCS 650, RCS 950, RCS 1350, RCS 1500), designed for air exchange, energy saving and maintaining relative humidity in rooms for various purposes. High efficiency and low power consumption.

Air consumption - from 330 to 1500 m3/hour.

Price: 87 900 RUB

With rotary heat exchanger, UNI ( Norway) are designed for ventilation and energy saving in the premises of country houses, cottages, apartments. The main distinguishing feature of the installations is built-in electric air heater allowing to regulate the temperature of the outgoing air into the room, low power consumption and a wide range of operating temperatures. Supply and exhaust UNI installations, can be connected to the system " Smart House" via the MODBUS protocol.

Air consumption - up to 720 m3/hour.

It is possible to create a comfortable microclimate in the premises of the house only with appropriate ventilation. Stale air can cause mold to grow on the walls, as well as physical discomfort. An open window or window cannot always qualitatively renew the air in the premises of a private house. To do this effectively, you need to install a supply and exhaust ventilation system.

The principle of operation and the need for supply and exhaust ventilation in a private house

This type of ventilation is also called "forced". Unlike the natural circulation option, it is equipped with electrical appliances that pump and promote air currents.

Designs with a forced air exchange system are equipped with fans of various capacities, electronics, silencers and heating elements. All these devices are designed to supply housing with environmentally friendly oxygen, creating internal comfort and a feeling of freshness.

The presence of these elements will create effective ventilation in the house

Unlike natural ventilation, the supply and exhaust type of air exchange is effective under the following conditions:

The minimum temperature difference between indoors and outdoors when rising warm air, cannot generate thrust.
With a difference in air pressure between the upper and lower levels of the building.

This type of ventilation should be used for residential premises or buildings with several rooms located at different levels, as well as in areas with a polluted atmosphere. The supply and exhaust ventilation method will not only change the air in the room, but also make it clean, thanks to special filters provided in the system.

The design can carry out not only the usual filtration through the foam layer, but also carry out this process using an ultraviolet lamp.

Efficient forced ventilation system

An important role in the supply and exhaust system is played by:

motor and fan power;
filter material class;
heating element size;
quality of material and type of air ducts.

Fans

The forced movement of air masses is provided by fans. Simple models are equipped with three levels of blade speed:

normal;
low (used for "quiet" work at night or during the absence of the owners);
high, (used to create powerful air currents).

Modern models of fans are made with a large number of speeds, which satisfies the needs of any owner. Fans are upgraded with automatic and electronic controllers. This makes it possible to program the device by setting the speeds of rotation of the blades. Electrical equipment allows you to synchronize ventilation with the "smart home" system.

Preference when choosing should be given to proven manufacturers

Since the operation of the ventilation system is designed for a continuously long period, the quality of the fans must be at the highest level.

Filters

Supply air masses must be cleaned with filters. Recuperators are equipped with filter layers that are capable of retaining particles less than 0.5 microns. This parameter corresponds to the European standard. A filter with such a capacity does not let fungal spores, plant pollen, dry soot and dust into the room.

The presence of this device is especially important for owners suffering from allergic diseases.

The design of ventilation ducts can be equipped with several filter barriers, mounting them in front of heat exchangers. However, such filters are designed to protect them from dirt carried by exhaust flows.

Made with multiple layers

Recovery systems are equipped with electronic sensors, which, having fixed the maximum degree of contamination of the filters, signal with a sound or light indicator.

heating elements

The supply and exhaust ventilation system requires the installation of heating elements, since the heat exchangers lose their effectiveness if the external air temperature is below -10°C. To do this, the supply channel is mounted electrical system heating of the incoming air.

Modern heating elements are programmed for a certain mode of operation. This makes it possible to control the temperature without outside interference. As a rule, computerized heating elements are installed and synchronized with the smart home system.

The size, power, shape and design of the heating elements are selected in compliance with the parameters of the entire ventilation system and the desire of the owner.

Makes the temperature comfortable

When choosing the power of the heater, one should take into account its operation at an external low temperature and high humidity. Such conditions will contribute to the fact that condensate may appear on the parts of the heat exchanger, which subsequently turns into ice. This problem can be solved in two ways:

Change the operation of the supply fan. It must be turned on every 20-30 minutes for 5-10 minutes. The heated air flow passing through the heat exchanger eliminates icing.
Change the direction of cold air flow. To do this, the supply air masses are separated, directing their flows past the heat exchanger.

air ducts

It is most convenient to mount ventilation in a building under construction - in basements, attics or behind suspended panels. It should be noted that the installation of this system must be carried out in a dry and insulated room with a positive temperature.

The most convenient and popular air ducts are flexible options made of aluminum or plastic. Pipes are made with a round, square or rectangular section. This material has a reinforcing frame made of steel wire, and can also be covered with a heat-insulating layer based on mineral fibers, for example - mineral wool.

Supply and exhaust ventilation with heat recovery

Such a system implies its operation in the cold months. In order for the incoming air flows not to cause cold in the house, the system must be upgraded with a heat exchanger - an air recuperator. The device gives off heat to cold air at the time of outgoing utilization.

Humid air concentrated in the kitchen, bathroom or utility room is directed outside with the help of air intakes. Before leaving the air ducts, it lingers in the heat exchanger, which takes part of the heat, giving it to the opposite (inflow air masses).

A good recovery option with partial moisture return is implemented in Naveka units, Node5 series: https://progress-nw.ru/shop?part=UstanovkiventilyatsionnyieNode5.

The principle of operation of the device

Systems equipped with recuperators have become very popular in countries Western Europe. Thanks to this equipment, buildings built in these regions lose 5-10 times less heat than those built without these systems. Utilization of heated exhaust streams reduced the cost of heat generation by 65–68%. This made it possible to recoup such a system in a period of 4–5 years. The energy efficiency of houses that are equipped with this system made it possible to reduce the duration of the heating period.

The dimensions and power of the supply and exhaust systems equipped with a heat exchanger depend on the area and location of the ventilated premises.

Enterprising homeowners install natural and forced (with heat recovery) in their homes. This is necessary in case of malfunction or repair of mechanical air exchange. Natural ventilation is convenient to use in an unheated period.

When using two ventilation systems in your home, you should follow the rule - natural ventilation ducts must be tightly closed during forced air exchange.

If this is neglected, then the quality of air renewal using the supply and exhaust system will significantly decrease.

In ventilation systems, the following types of recuperators are most often used:

lamellar;
rotary;
with an intermediate coolant;
chamber;
in the form of heat pipes.

Plate heat exchangers

In this device, warm and cold air flows from both sides of the plates. This contributes to the formation of condensation on them. In this regard, special outlets for accumulated water are installed on such structures. Moisture collection chambers must be equipped with closures to prevent liquid from entering the channel. Ice may form if water drops enter the system. Therefore, for the normal operation of the device, a defrost system is necessary.

The formation of ice can be avoided by controlling the operation of the bypass valve, which regulates the amount of air flowing through the device.

The design feature increases its efficiency

Rotary

Heat exchange in this device occurs through the removed and supply channels as a result of the rotation of the rotor discs. The elements of this system are not protected from dirt and odors, so their particles can move from one air stream to another.

The recovery of warm air flows can be controlled by changing the speed of rotation of the rotor discs.

This device, unlike the previous one, is less prone to freezing, since the working elements are dynamically movable. The efficiency of these devices reaches 75-85%.

Equipped with movable elements

Recuperators with intermediate heat carrier

The heat carrier in this heat exchanger design is water or a water-glycol solution. The peculiarity of this type is that the heat exchangers in different channels - one in the exhaust, the other in the supply. Water moves through the tubes between two heat exchangers. The design has a closed system. This prevents the ingress of contaminants from the exhaust air into the supply stream.

Heat transfer is controlled by changing the rate of movement of moisture in the coolant.

Such devices do not have moving elements, so their efficiency is lower, which is 45–60%.

Has no moving parts

Chamber

The exchange of heat in such a design occurs as a result of a change in the direction of the air flow. Chamber recuperators are devices, usually in the form of a rectangular parallelepiped, with a chamber, which are divided into two parts by a damper. During operation, it changes the direction of the air masses so that the temperature of the supply flow rises from the heated chamber body. The disadvantage of this heat exchanger is that dirty particles and odors can mix with the exhaust and supply air.

Flows inside the chamber can mix

heat pipes

Recuperators of this type have a sealed housing, inside which a system of tubes filled with freon is installed. Under the influence of high temperature (in the process of removing air), the substance turns into steam. At the moment of passage of the supply masses along the tubes, the steam collects into drops, forming a liquid. The design of such recuperators eliminates the transmission of odors and dirt. Since the body of this device has no moving parts, it has a low efficiency (45-65%).

The work is based on the temperature changes of freon

Due to their high efficiency, rotary and vane types have gained the most popularity. Recuperator designs can be upgraded, for example, by installing two plate-type heat exchangers in series. The efficiency of such ventilation increases.

PES design

When designing a ventilation system, it is necessary to determine the type of this device, since not every owner may be suitable for its power and the amount of electricity consumed. In this regard, if there is no need for forced ventilation, then it is better to install natural ventilation.

Each ventilation system has its own standard parameters for the volume of air passed in 1 hour:

for the natural option, this rate is 1 m³ / h;
for forced - in the range from 3 to 5 m³ / h.

When a ventilation system is designed for large rooms, it is advisable to install forced ventilation.

The design and installation of ventilation systems is technically complex process, which includes several stages:

The first stage consists of drawing up drawings and collecting data on the layout of the premises. Based established information the type of ventilation system is selected, and the power of the equipment is determined.
At the second stage, the necessary calculations are made for the volume of air exchange for each room in the house. This is a crucial moment in the design, since incorrect calculations, in the future, will cause stagnant air, the appearance of mold and fungi, and a feeling of stuffiness.
The third stage is to carry out calculations of sections for air ducts. This is also an important point, since incorrect calculations will cause the entire system to be inefficient, despite expensive equipment. Therefore, it is better to entrust the calculations to specialists than to do it yourself. For the correct calculation of the size of the ducts, the following basic rules are followed:

in a natural hood, the air flow rate should correspond to 1m / s;
in air ducts equipped with fans, this parameter is 5 m/s;
in the branches of the air ducts, the speed of air masses is 3 m / s.

At the fourth stage, a diagram of the ventilation system is drawn up, indicating the dividing valves. The purpose of this stage is to correctly distribute barriers that prevent the spread of smoke and fire in case of fire.
The fifth stage is to coordinate the selected system with the current regulatory documents and rules for installation and placement. The finished project of the ventilation system must be approved by the fire, sanitary and hygienic and architectural organizations. Obtaining permits from all these services and government agencies gives the right to install.

Pay attention to the material on the design and installation of ventilation in the cellar of a private house:.

Calculations

During the calculation of supply and exhaust ventilation systems, it is necessary to take into account the amount of air replaced in the room for a certain time. The unit of measure is cubic meter per hour (m³/h).

To apply this figure to the calculations, you need to calculate the passage of air flows and add 20% (resistance of the filter layers and gratings).

Air Volume Calculation

As an example, the air volume was calculated for a private house with a ceiling height of 2.5 m. The system will also serve 3 bedrooms (11 m² each), an entrance hall (15 m²), a toilet (7 m²) and a kitchen (9 m²). Substitute the values (3∙11+15+7+9) ∙2.5=160 m³.

When making calculations, it is necessary to round the received data upwards.

The installed heat exchanger must correspond to the power of all fans in the supply and exhaust system. To do this, it is necessary to subtract 25% from the sum of the fan performance (air flow resistance in the system). The inlet and outlet of the heat exchanger must be equipped with fans.

It should be noted that in each room of the house where the system is located, 1 supply and 1 exhaust fan must be installed. The required performance of each of them is calculated as follows:

Bedroom: 11∙2.5=27.5+20%=33 m³/h. Since the house has three bedrooms with the same area, this value must be multiplied by three: 33∙3=99 m³/h.
Hallway: 15∙2.5=37.5+20%=45 m³/h.
Toilet: 7∙2.5=17.5+20%=21 m³/h.
Kitchen: 9∙2.5=22.5+20%=27 m³/h.

Now we need to add these values to get the total fan capacity: 99+45+21+27=192 m³/h.

The load on the heat exchanger will be: 192–25%=144 m³/h.

Calculation of the diameter of the ventilation duct

To calculate the diameter of the ventilation duct, it is necessary to use the formula for calculating the cross-sectional area, which looks like this: F=L/(S∙3600), where L is the total amount of air mass passing in one hour, S is average speed air movement equal to 1 m/s. Let's substitute the values: 192/(1 m/s∙3600)=0.0533 m².

To calculate the pipe radius with round section you need to use the following formula: R=√(F:π), where R is the radius round pipe; F - section of the duct; π is a mathematical value equal to 3.14. On an example, it looks like this: √ (0.0533 ∙ 3.14) = 0.167 m².

Electricity calculation

Properly calculated power consumption will allow rational use of the ventilation system. This is especially important if the air duct structure is equipped with heating elements.

To calculate the amount of energy consumed, use the formula: M=(T1∙L∙C∙D∙16+T2∙L∙C∙N∙8)∙AD:1000, where M is the total price for the electricity used; T1 and T2 - temperature difference in the daytime and nighttime periods (the values differ depending on the month of the year); D, N - the cost of electricity in accordance with the time of day; A, D - the total number of calendar days in a month.

Air temperature readings are easy to read from local weather forecasts, so there is no need to purchase any guides. Tariffs are determined according to the region of residence. Using these sources, you can get accurate readings on the energy consumption during the operation of the ventilation system.

Equipment installation procedure

The installation of equipment elements for the supply and exhaust ventilation system of the premises is carried out after the walls are finished, before the installation of suspended ceiling panels. The equipment of the ventilation system is installed in a certain order:

The intake valve is installed first.
After it - the filter for cleaning the incoming air.
Then an electric heater.
Heat exchange device - recuperator.
Air duct cooling system.
If necessary, the system is equipped with a humidifier and a fan in the supply duct.
If the power is high, then a noise isolating device is installed.

Do-it-yourself installation of a supply and exhaust ventilation system

Installation of the ventilation system consists of several construction stages:

Using the values obtained earlier, calculate the optimal parameters for holes in the wall.
Make markings for the placement of the supply channel. To drill a hole in a concrete wall, it is necessary to use a drill rig to concrete surfaces. This device is fixed to the wall, so that the hole is even, in a precisely marked place. The point of contact between the core drill and concrete wall is insulated with a special cap, to which pipes with a jet of water and a powerful vacuum cleaner are attached.
Provide forced movement of air masses

Installation of air ducts

The installation of air ducts must be preceded by drawing up diagrams and drawings. And you should also take care of the presence of additional fasteners and clamps. Installation of air ducts is carried out in the following order:

How to operate and maintain a PES

High-quality operation of the supply and exhaust ventilation system depends not only on professional installation but also good service. The elements of the supply and exhaust device require:

periodic cleaning of filters;
their renewal, in case of contamination or expiration of their service life;
replacement of lubrication of moving parts and parts of fans;
if the system is equipped with heating elements, ionizers and noise isolators, regular checks of their serviceability are necessary.

Usually, all necessary actions for the care of this system are described in the operating rules and instructions.

Video: apartment ventilation in 2 levels with heat recovery

Having familiarized yourself with all the nuances of installing and equipping the ventilation system, you can create a healthy and comfortable atmosphere in your home, providing yourself and your loved ones with fresh air.

According to what parameters to choose a heat exchanger and where to install it, what rooms to connect to the heat exchanger - recommendations of experts.

As part of the project, we decided to answer the questions of portal users regarding the selection and installation of recuperators.

Of these installations, it will be put into operation at our construction site, which determined the subject of this article. Questions regarding the types of ventilation systems and the criteria by which recuperators should be selected will be discussed with the help of manufacturers - engineers from TURKOV.

In this article:

types of ventilation systems;
what are the advantages of the recuperator;
according to what parameters should a recuperator be chosen;
basic and additional functions of the recuperator;
sanitary standards for the installation and connection of the heat exchanger.

So why was chosen supply and exhaust system? To fully understand the issue, consider the varieties of modern supply and exhaust systems.

natural ventilation

Natural ventilation - a system that includes wall and window inlet valves (providing fresh air access to the room), as well as an exhaust duct system (removing exhaust air from toilets, bathrooms and kitchens). The possibility of air exchange in the presence of natural ventilation is provided by the difference in temperatures inside and outside the room.

The advantages of such a system are its simplicity and low cost, the disadvantages include low efficiency and insufficient quality of air exchange. Also, the disadvantages include a large load on the heating system and seasonal instability. For example, in summer, when the temperature of the indoor and outdoor air equalizes, the air exchange in the room practically stops. In winter, on the contrary, the system works more efficiently, but this requires additional costs for heating the air coming from the street.

Combined system

Combined ventilation - a system with forced exhaust and natural air supply. Its disadvantages:

The energy efficiency of a combined system is even lower than that of natural ventilation. The fact is that fans create a stable flow of exhaust air, and this significantly increases the load on the heating system.
Poor quality of air exchange in the house (the hood does not work constantly, but only in the process of using bathrooms and kitchens). Even with the constant operation of the exhaust fans, the air exchange in the room will not be able to reach the level that is necessary for a comfortable stay.

The advantages of the combined system are its relatively low cost and the absence of seasonal problems with draft in the exhaust duct. However, in terms of the level of air exchange and functionality, the combined system falls far short of a full-fledged supply and exhaust ventilation.

Classic forced system

Classical forced ventilation ensures the circulation of air flows in the given modes and volumes. This system is equipped with supply and exhaust air ducts, as well as specialized ventilation equipment capable of all year round maintain stable air exchange in the room. Such systems have one big disadvantage: they are very energy consuming when used in winter period. This is explained by the fact that the cold air flow from the street must be constantly heated to a comfortable room temperature.

Forced system with recuperator

Forced ventilation with a heat exchanger is the most advanced system capable of circulating air flows in specified modes and volumes. Its operation is associated with minimal energy consumption. After all, the flow from the street is first heated by a heat exchanger (due to the heat contained in the exhaust air), and then the air is additionally heated to a temperature comfortable for a person. In many developed countries, such a technical solution has already become a building standard, enshrined at the legislative level.

Given the growing demands for the comfort of living spaces, any new house it is advisable to equip not just standard ventilation ducts, but a multifunctional and economical forced ventilation system. The system based on the recuperator provides an inflow clean air with comfortable temperature and at the same time removes the exhaust air masses outside the premises. At the same time, heat (and sometimes moisture) is removed from the exhaust stream and transferred to the supply stream.

Why did you choose an enthalpy heat exchanger

Firstly, unlike classical ventilation, the heat exchanger allows you to significantly save on the operation of the equipment. Secondly, the cost of the heat exchanger is not much higher than the cost of classical ventilation equipment. Thirdly, during the operation of the heat exchanger, 80% of the heat of the exhaust air is returned back to the supply air, which significantly reduces the cost of heating it.

In hot summer days heat exchange occurs in the opposite direction, which also saves on air conditioning. Simultaneously with the transfer of heat in the heat exchanger, moisture is transferred from the exhaust air to the supply air. In physics there is such a thing as "dew point". This is the moment when the relative humidity of the air reaches 100% and the moisture changes from gas to liquid (condensate). Condensate appears on the surface of the heat exchanger, and the lower the outside temperature, the more likely it is that condensate will form on the heat exchanger. Since the enthalpy heat exchanger allows moisture to be transferred from the exhaust air to the supply air, the “dew point” shifts to a very low temperatures. The heat exchanger allows to maintain a higher relative humidity of the supply air (compared to classical ventilation), and also significantly increases frost resistance and eliminates the need for condensate removal.

The presence of the above functions fully explains the choice of such a supply and exhaust unit.

We present a functional diagram of the installation.

Where:
M1 and M2 - supply and exhaust fans;
D (1, 2, 3) – temperature sensors;
K (1, 2, 3) - heat exchangers;
F (1, 2) - air filters.

What are the parameters to choose a recuperator

The first thing you need to pay attention to when choosing a model of a supply and exhaust heat exchanger is the wording used by the equipment manufacturer or seller. Often we hear the following: “efficiency up to 99%”, “efficiency up to 100%”, “operation up to -50ºС” - all these phrases are nothing more than a manifestation marketing strategy while trying to mislead the buyer. As the experience of operating recuperators in the Russian climate has shown, metal recuperators work stably when the temperature drops to -10ºС. Then the process of reducing the efficiency begins due to freezing of the heat exchanger. To prevent this from happening, many manufacturers use additional heating sources (electric preheating).

The second thing you need to pay attention to is the thickness of the equipment case, the material from which the frame of the case is made and the presence of cold bridges in the case. Again we return to the experience of use: consider the features of the case with a thickness of 30mm. This case cannot withstand lowering outdoor temperature to -5ºС and it must be isolated additionally. If the case is made of an aluminum frame, then additional insulation will also become an integral part of it. After all, aluminum is one big bridge of cold, "spread out" around the entire perimeter of the case.

Third: one of common mistakes when choosing a heat exchanger, the buyer does not take into account the free pressure of the fans. He sees only the magic figure - 500 m³ and the price - 50 thousand rubles, and that the fan has a pressure of 0 Pa at 500 m³, the buyer learns only after the repair of the house is completed, that is, during the operation of already installed equipment.

The fourth selection criterion is the availability of automation and the ability to connect optional components to it. Automation can significantly reduce operating costs and achieve maximum comfort during operation of the equipment.

With regard to performance: the main design parameter is the volume of air that must enter the room within one hour. In accordance with sanitary standards, this volume should be equal to 60 m³ per adult or one hour per hour of the total cubic capacity of the premises served (living room, kitchen, bedrooms). When choosing a heat exchanger, you need to look not only at the performance of the installation, but also at the pressure of the fans that pump your ventilation network around the house.

It is better to entrust the calculation of the required performance to specialists. Indeed, in the event of an error, the replacement of the heat exchanger will require tangible financial costs.

When calculating and choosing an installation, in order to obtain more accurate information, you will have to read specialized literature and forums, call equipment manufacturers and suppliers (the topic is very extensive). It is always better to turn to specialists. And for those people whom this advice does not stop, it is still recommended to confirm the correctness of the choice with the equipment manufacturer or distributor.

The choice of heat exchanger according to the type of construction

It cannot be said that some recuperator is worse or better, each type of recuperator has its own strengths and areas of application. The efficiency of a rotary and plate heat exchanger is absolutely the same, since the efficiency depends on two parameters: the area of the heat exchange surface of the heat exchanger and the direction of the air flow in the heat exchanger.

The design of the rotary heat exchanger allows partial mixing of the supply and exhaust flows, since the brush is the insulator of the air flows in it. Fine bristle brush, in itself, is a poor insulator between air flows, and a small imbalance in the system leads to an even greater flow of exhaust air into the supply duct. Also, the weak link in the rotary heat exchanger is the engine and the belt that turns the rotor: additional moving parts reduce the overall reliability of the equipment, as well as increase energy costs for recuperation. The rotary heat exchanger can only be installed in one position, which also reduces the possibility of its use at home. The main objects for the use of rotary heat exchangers are shopping centers, hypermarkets and other public buildings with a large area, where air flow is only for the benefit of the building owners.

We present a diagram of the operation of a rotary heat exchanger.

Plate heat exchangers, unlike rotary devices, are not so massive, but at the same time they are easy to install and reliable in operation. Among plate heat exchangers, membrane-type equipment deserves special attention. A special polymer membrane built into the heat exchanger returns moisture from the exhaust air to the supply air. At the same time, it prevents the formation of condensate, as well as the formation of ice inside the device (during its operation at low temperatures).

On the basis of plate heat exchangers, it is possible to build a multi-stage recuperation, which avoids direct contact of the coldest air flow (coming from the street) with the warmest one (coming from the house). And in conjunction with an enthalpy heat exchanger, this technology allows you to avoid freezing of the heat exchanger. A smooth decrease in the temperature of the exhaust air and a gradual increase in the temperature of the supply air inside the heat exchanger make the device resistant even to the temperatures of the Far North. As practice shows, such equipment successfully works in the most severe climatic conditions, for example, in Yakutsk.

PiterPro FORUMHOUSE user

AT plate heat exchangers used different material. Plastic and metal heat exchangers freeze up. Membrane heat exchangers use a thin film that only allows moisture to pass through. There are two or three heat exchangers in such an installation at once, depending on the model.

Efficiency is one of the main characteristics of the heat exchanger, and special attention should be paid to its value before purchasing the unit.

It is important to choose a heat exchanger for your home that has sensitive and reliable automation. After all, there is nothing worse than equipment that is constantly involved in work and requires attention with enviable regularity. Modern automation of recuperators opens up additional opportunities for users:

separate adjustment of the supply and exhaust fan;
air conditioning control;
humidifier control;
automation and dispatching.

BUT design features allow you to equip the device with additional options and systems:

automatic fan power control system - VAV-system (maintaining a constant air flow);
system of automatic adjustment of air flow by CO2 sensor (regulates the pressure of the air flow depending on the content of carbon dioxide in the exhaust duct);
timer with multiple events per day;
water or electric air heaters;
additional air dampers;

This also includes an improved filtration system.

When choosing equipment, consider air handling unit, as a climatic complex that will maintain air flow, as well as temperature and humidity (if necessary) in a given mode. Installing additional heaters, coolers, VAV valves, humidifiers or dehumidifiers is already becoming a vital necessity today.

Shuvalov Dmitry

If the heat exchanger itself cannot maintain the desired supply air temperature, then the device should be retrofitted with a heater of the appropriate power. On average, if the design temperature in the duct does not fall below +14...+15°C, then the heater may not be installed. My opinion is this: it is better not to turn on the heater if it is not needed, than when it is needed - there will be nothing to turn on.

The systems and devices listed above make it possible to minimize human participation in system management and improve the quality of the microclimate in the house. Modern climate system is able to constantly monitor the performance of all units of optional equipment and, if necessary, warn the user about problems in the operation of the system and changes in the microclimate in the room. Using VAV systems the operating costs of the installation are significantly reduced by temporarily and / or partial disconnection of individual rooms from the ventilation system.

Currently, there are models of recuperators that are able to connect to individual systems“ ” using the ModBus or KNX protocols. Such devices are ideal for connoisseurs of advanced and modern functionality.

Additional selection criteria

When choosing a heat exchanger, it is important to pay attention to the noise level that it creates during operation. This indicator depends on the material from which the device case is made, on the thickness of the case, on the power of the fans, and on other parameters.

According to the type of installation, recuperators are suspended (mounted on the ceiling) and floor-mounted (installed on a flat horizontal surface or hung on a wall). Outlets for ventilation ducts can be either on two sides (“through” layout) or on one side (“vertical” layout). Which heat exchanger is right for you - it depends on the specific parameters of your ventilation system and on where exactly the supply and exhaust equipment will be installed.

Installation recommendations mainly refer to the rooms in which the heat exchanger should be installed. First of all, boiler rooms are used for installation (if we are talking about private households). Also, recuperators are mounted in basements, attics and other technical rooms.

If this does not differ from the requirements of the technical documentation, then the unit can be installed in any unheated room, while the wiring of ventilation ducts, if possible, should be installed in rooms with heating.

Ventilation ducts passing through unheated premises (as well as outdoors) should be made as insulated as possible. Air ducts running from the equipment to the street (supply and exhaust) are also necessarily insulated. It is also necessary to insulate the nodes of the passage of air ducts through the outer walls.

Considering the noise that the equipment can produce during operation, it is best to place it away from bedrooms and other living areas.

As for the placement of the recuperator in the apartment: the best place for him there will be a balcony or some Utility room.

In the absence of such a possibility, it is possible to allocate free space dressing room.

Be that as it may, the location of the installation largely depends on the layout of the apartment or house, on the layout and location of the ventilation network, and on the dimensions of the device.

Particular attention is recommended to be paid to such an element as a crossbar. Already existing crossbars can become a big problem when laying a ventilation network. You can get around this element only through a technical room or a built-in closet, which is far from always possible. Therefore, you should think about the ventilation project even when designing a house, having previously provided for the presence of walk-through windows in the crossbar. The same recommendation applies to the nodes of the passage through the roof.

Residential premises can be equipped with both exhaust and supply channels - at the same time, but in most cases, supply channels are sufficient. The hood in this case is made "central", as a rule, representing one or two exhaust points located in the corridors.

As for kitchens and bathrooms: these rooms should be equipped with separate exhaust hoods that dispose of the exhaust air into the general ventilation ducts (in apartments) or outside (in private houses).

However, there are situations in which connecting bathrooms to ventilation system with a heat exchanger is allowed (please note that we are talking about rooms, and not about hoods located in these rooms). But due to the cold Russian climate, with such a connection, a lot of nuances must be observed, which is far from always possible. In any case, with the question of the possibility of such a connection, you need to contact the relevant specialists. It is strongly not recommended to independently connect bathrooms to the heat exchanger.