Air recuperators. PVU for home. Supply and exhaust units with heat recovery Supply and exhaust ventilation of recuperative type

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

Of these installations will be put into operation at our construction site, which determined the topic of this article. Questions regarding varieties ventilation systems We will analyze the criteria by which recuperators should be selected with the help of manufacturers - engineers from the TURKOV company.

In this article:

• types of ventilation systems;
• what are the advantages of a recuperator;
• what parameters should you use to select a recuperator;
• basic and additional functions of the recuperator;
• sanitary standards for installation and connection of the recuperator.

So why was it chosen? supply and exhaust system? To fully understand the issue, let’s look at the types of modern supply and exhaust systems.

Natural ventilation

Natural impulse ventilation is a system that includes wall and window supply valves (providing access fresh air into the room), as well as a system of exhaust air ducts (removing waste air from toilets, bathrooms and kitchens). Possibility of air exchange if available natural ventilation is ensured by the difference in temperature 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 the summer, when the temperature of indoor and outdoor air equalizes, 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 flow. Its disadvantages:

1. The energy efficiency of the 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.
2. Low quality of air exchange in the house (the hood does not work all the time, but only when using bathrooms and kitchens). Even with constant operation of exhaust fans, air exchange in the room will not be able to reach the level required for 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 air exchange and functionality, the combined system falls far short of full-fledged supply and exhaust ventilation.

Classic coercive system

Classic forced ventilation ensures the circulation of air flows in specified 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 recuperator is the most advanced system capable of circulating air flows in specified modes and volumes. Its operation involves minimal energy consumption. After all, the flow from the street is first heated by the recuperator (due to the heat contained in the exhaust air), and then the air is additionally heated to a temperature comfortable for humans. In many developed countries such a technical solution has already become a construction standard, enshrined in legislation.

Taking into account the growing requirements for the comfort of residential premises, it is advisable to equip any new house not just with standard ventilation ducts, but with multifunctional and economical system forced ventilation. A recuperator-based system provides a supply of clean air at a comfortable temperature and simultaneously removes waste air masses outside the room. At the same time, heat (and sometimes moisture) is selected and transferred from the exhaust flow to the supply flow.

Why did you choose an enthalpy recuperator?

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

On hot days summer days heat exchange occurs in the opposite direction, which also allows you to save 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 a gaseous state to a liquid state (condensation). Condensation appears on the surface of the recuperator, and the lower the temperature outside, the greater the likelihood of condensation forming on the recuperator. Since the enthalpy recuperator allows moisture to be transferred from the exhaust air to the supply air, the “dew point” shifts to a zone of very low temperatures. The recuperator allows you to maintain a higher relative humidity supply air (compared to classical ventilation), and also significantly increases frost resistance and eliminates the need for condensate drainage.

The presence of the above functions fully explains the choice of such an air handling unit.

Introducing functional diagram installations.

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 parameters should you use 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 manufacturer or seller of the equipment. We often hear the following: “efficiency up to 99%”, “efficiency up to 100%”, “operation down to -50ºС” - all these phrases are nothing more than a manifestation of a marketing strategy with a simultaneous attempt to mislead the buyer. As experience in operating recuperators in the Russian climate has shown, metal recuperators operate stably when the temperature drops to -10ºС. Then the process of reducing efficiency begins due to freezing of the recuperator. To prevent this from happening, many manufacturers use additional heating sources (electrical preheating).

The second thing you need to pay attention to is the thickness of the equipment casing, the material from which the casing frame is made and the presence of cold bridges in the casing. Let's return to the experience of use again: let's look at the features of the 30mm thick case. This housing cannot withstand a drop in street temperature to -5ºС and must be additionally insulated. 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 large bridge of cold, “spreading” along the entire perimeter of the case.

Third: one of common mistakes when choosing a recuperator, 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 the buyer learns that the fan has a pressure of 0 Pa at 500 m³ only after finishing the house renovation, that is, during the operation of the already installed equipment.

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

As for performance: the main calculation parameter is the volume of air that should enter the room within one hour. In accordance with sanitary standards, this volume should be equal to 60 m³ per adult or one times per hour of the total cubic capacity of the premises served (living room, kitchen, bedrooms). When choosing a recuperator, 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 productivity to specialists. Indeed, in case of an error, replacing the recuperator will require significant financial costs.

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

Selecting a recuperator by design type

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

The design of the rotary heat exchanger allows partial mixing of the supply and exhaust flows, since the air flow insulator in it is a brush. Fine bristle brush, in itself, is a poor insulator between air flows, and a slight imbalance in the system leads to an even greater flow of exhaust air into the supply channel. Also, the weak link in a rotary recuperator is the engine and the belt that spins the rotor: additional moving parts reduce the overall reliability of the equipment and also 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 recuperators are shopping centers, hypermarkets and others public buildings With large area, where the flow of air is only for the benefit of the building owners.

We present a diagram of the operation of a rotary recuperator.

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

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

PeterPro FORUMHOUSE user

Used in plate heat exchangers different material. Plastic and metal heat exchangers freeze. 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, depending on the model.

Efficiency is one of the main characteristics of a recuperator, and special attention should be paid to its value before purchasing an installation.

It is important to choose a recuperator 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 supply and exhaust fans;
• air conditioning control;
• humidifier control;
• automation and dispatching.

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

• automatic fan power control system – VAV system (maintaining constant air flow);
• automatic air flow control system based on a CO2 sensor (adjusts the air flow pressure depending on the carbon dioxide content in the exhaust duct);
• timer with several events per day;
• water or electric air heaters;
• additional air dampers;

This also includes an improved filtration system.

When choosing equipment, you need to consider the air handling unit as climate complex, which 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 recuperator itself cannot maintain the required supply air temperature, then the device should be retrofitted with a heater of appropriate power. On average, if the calculated temperature in the channel does not fall below +14...+15°C, then the heater does not need to 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 above systems and devices make it possible to minimize human participation in system management and improve the quality of the microclimate in the house. A modern climate system is capable of constantly monitoring the performance of all components of optional equipment and, if necessary, warning the user about problems in the operation of the system and changes in the microclimate in the room. When using a VAV system, the operating costs of the installation are significantly reduced by temporarily and/or partially disconnecting individual rooms from the ventilation system.

Currently, there are models of recuperators that are capable of connecting 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 recuperator, it is important to pay attention to the noise level 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 can be suspended (mounted on the ceiling) or floor-mounted (installed on a flat horizontal surface or hung on a wall). Exits for ventilation ducts can be either on both sides (“through” layout) or on one side (“vertical” layout). Which recuperator you need depends on the specific parameters of your ventilation system and on where exactly the supply and exhaust equipment will be installed.

Installation recommendations mainly concern the premises in which the recuperator should be installed. First of all, boiler rooms are used for installation (if we are talking about private households). Recuperators are also installed in basements, attics and other technical rooms.

If this does not conflict with the requirements of the technical documentation, then the installation can be installed in any unheated room, while wiring 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 thermally insulate the passages of air ducts through external walls.

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

Regarding the placement of the recuperator in the apartment: best place there will be a balcony or some technical room for it.

If this is not possible, the installation of a recuperator can be allocated 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.

It is recommended to pay special attention to such an element as the crossbar. Already existing bolts can become big problem when laying a ventilation network. You can only get around this element through a technical room or a built-in closet, which is not always possible. Therefore, you should think about the ventilation design even when designing a house, having previously provided for the presence of passage windows in the crossbar. The same recommendation applies to roof penetrations.

Which rooms should be connected to the recuperator?

If a recuperator is built into the ventilation system, it is recommended to equip the rooms with exhaust ducts common use(corridors, hallways, etc.), as well as technical rooms. In this case, fresh air should be supplied to living rooms: bedrooms, offices, halls, etc.

However, there are situations in which connecting bathrooms to a ventilation system with a recuperator is permitted (please note that we are talking specifically about rooms, and not about hoods located in these rooms). But due to the cold Russian climate, such a connection requires observing quite a lot of nuances, which is not always possible. In any case, if you have any questions about the possibility of such a connection, you need to contact the relevant specialists. It is strongly not recommended to connect bathrooms to the recuperator yourself.

DiJo User FORUMHOUSE

The air intake should be done from the side where the wind blows less (so less dust will enter).

The supply air intake point should be located at a sufficient distance from exhaust openings, chimneys and other sources of pollution.

Installation and maintenance work on the recuperator should be carried out in accordance with the manufacturer's requirements. It is advisable to involve specialists who are familiar with all the nuances of operating such equipment when performing installation work.

general information

The service life of ventilation unit equipment manufactured by our company is established subject to compliance with operating rules and timely replacement of filters and parts with a limited resource. The list of such parts and their service life is indicated in the User's Guide for each specific model.

To avoid misunderstandings, we kindly ask you to carefully study the User Manual, pay attention to the conditions for the occurrence of warranty obligations, and check that the warranty card is filled out correctly. The warranty card is valid only if it is correctly and clearly indicated: model, serial number of the product, date of sale, clear seals of the seller company, installer company, and buyer’s signature. The model and serial number of the product must match those indicated in the warranty card.

Warranty Limitations

If these conditions are violated, as well as in the event that the data specified in the warranty card is changed, erased or rewritten, the warranty card is invalid.

In this case, we recommend that you contact the seller to obtain a new warranty card that meets the above conditions. If the date of sale cannot be determined, in accordance with consumer protection legislation, the warranty period is calculated from the date of manufacture of the product.

Warranty for recuperators is 7 years.

A 7-year warranty applies to equipment operated in accordance with all operating rules specified in the “ZENIT Equipment Operation Manual”. The warranty does not apply to equipment operated in rooms with high humidity (swimming pools, saunas, rooms with humidity more than 50% in winter), but the warranty can be maintained if the equipment is equipped with a duct dehumidifier.

Delivery in Moscow and the Moscow region up to 10 km from the Moscow Ring Road

Delivery times are indicated in the card of each product. Delivery costs are paid separately. Delivery is carried out by a transport company.

Delivery to regions

Delivery to the regions is made after 100% payment for services transport company. Delivery costs are not included in the order price.

general information

If you want to know about the terms of delivery and payment, but do not want to read about them, then contact a sales consultant in your city, who will definitely help you.

Prices on the website may differ from retail prices in different regions, this is due to logistics costs. The price for the ordered product is valid for 24 hours from the date of placing the Order.

Payment by credit card on the website

Payment by credit card on the website is made through the payment system. After placing and paying for your order, our sales consultant will contact you to confirm the Order and clarify the delivery time.

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

What material are heat exchangers in recuperators made of?

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

What are the advantages of a household recuperator?

There are many advantages of ventilation with recovery; among the most significant, it is worth noting the ability to provide both supply and exhaust with one device, as well as cost savings on heating/cooling of the room up to 50%, normalization of humidity and reduction of the level of harmful substances in the air of the room. The device is able to provide a favorable microclimate, regardless of the season and weather outside.

How much heat does recovery save?

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

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

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

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

Is it possible to install a recuperator in a city apartment?

It's possible, but with a few caveats. Recuperators are not recommended to be installed in rooms with a well-functioning communal exhaust hood. But if the window openings are closed with sealed double-glazed windows, and the general house exhaust system does not work well. It is the supply and exhaust system with recovery that is effective tool fight against stuffiness, high humidity, mold and unpleasant odors.

How noisy are domestic heat exchangers?

Each specific installation has its own indicator - it depends on the power and operating mode. But in general, the noise level at first speeds is so insignificant that most people do not notice it. And at the latest speeds, any device is noisy.

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

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

What is the level of energy consumption of household recuperators?

Any ventilation system with recovery belongs to economical climate control equipment. Requires from 2 to 45 W/h to operate electrical energy. Which is in monetary terms approximately from 100 to 1500 rubles per year.

What should be the thickness of the wall to install a wall-mounted heat exchanger?

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

What number of ventilation units will be optimal for one apartment?

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

Are there types of buildings where it is impossible to use a domestic recuperator?

There are no direct prohibitions on the installation of household recuperators, however, in state-protected architectural monuments, holes cannot be made in the wall; in all other buildings, the creation of holes with a diameter of up to 200 mm is not prohibited by law. A limitation can also be high floors with strong winds and rooms with very strong communal exhaust, here the installation of recuperators is not recommended.

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

Where does the condensate go?

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

What is special about the operation of a ventilation unit in summer?

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

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

It is impossible to overestimate the relevance of having an installation in the bathroom - excess moisture is removed from the room, and the temperature remains comfortable. In bathrooms, it is recommended to install heat exchangers with a humidity sensor, so the ventilation will work automatically and only when necessary.

Can microbes multiply in household recuperators?

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

What is the frequency of cleaning ventilation devices?

There is no clear answer here. A number of factors are taken into account - the intensity of use of the premises, its purpose, climate zone. We recommend visually monitoring the degree of contamination of filters and heat exchangers and cleaning them as necessary.

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

As long as the system operates in recovery mode, the risk of a cold bridge occurring is zero. When the system is turned off, the heat in the heat exchanger clogs the hole and does not evaporate. The truth is important correct location heat exchanger - it must be pushed out far enough, and an air shut-off valve must be located on the room side.

Who should I contact about choosing the location of ventilation units?

Choice optimal location placement of ventilation units with recovery is a free service for clients of our company. We are ready to provide it at a time convenient for you with an on-site visit.

Is it possible to install a household recuperator yourself?

Theoretically, in houses made of SIP panels, wood and frame houses, the recuperator can be installed independently, but this will void the installation warranty, and often the warranty on the device itself. It is not possible to install a recuperator in stone houses yourself, since this requires expensive professional equipment that is not used in everyday life, as well as a diamond drilling specialist.

Supply and exhaust ventilation with heat recovery is a system that allows you to establish a reliable change of exhaust air in the room. Installation of equipment allows you to heat the air entering the room using the temperature of the outlet flow. The costs of purchasing and installing the system quickly pay off.

It is important to know the main points when selecting and installing equipment.

What is heat recovery?

The air recuperator releases heat from exhaust gases. The two flows are separated by a wall through which heat exchange occurs between moving air flows in a constant direction. Important characteristic equipment is the level of efficiency of the recuperator. This is the value for different types equipment is in the range of 30-95%. This value is directly dependent on:

• designs and types of recuperator;
• the temperature difference between the heated exhaust air and the temperature of the carrier behind the heat exchanger device;
• accelerating the flow through the heat exchanger.

Advantages and disadvantages of a ventilation system with a heat exchanger

Such equipment allows:

• make a permanent shift air masses in rooms of different sizes;
• if the residents need it, a heated flow can be supplied;
• the incoming oxygen is constantly purified;
• if desired, it is possible to install equipment with the ability to humidify the air in the rooms; such systems have a channel for removing condensate;
• By recovering heat and selecting equipment with sufficient power, it is possible to significantly reduce the cost of paying for electricity.

Among the disadvantages of the system, several points can be highlighted:

• increased noise level during fan operation;
• when installing cheap equipment, there is no way to cool the incoming air during hot periods;
• it is necessary to constantly monitor and remove condensate.

The principle of operation of the ventilation system

Such ventilation with heat recovery allows reducing the load on the air conditioning system of buildings during the hot season. Conditioned air from the room, when passing through the heat exchanger, lowers the temperature of the atmospheric flow from the street. In winter, the outboard flow is heated according to this scheme.

Installation in buildings with a large area and common system conditioning. In such places, the level of air exchange can exceed 700-800 m 3 / h. Such installations have impressive dimensions, so you will need to prepare separate room in the basement, basement or attic. If installation is required in the attic, this will need to be done additional sound insulation and prevent heat loss and condensation in air ducts.

The ventilation system with recovery is manufactured in several types; we will analyze the advantages and disadvantages of each of them.

Types of air recovery devices

For better comparison Let's present the types of recuperators in a separate table.

A heat recovery unit with heat pipes is available for individual small rooms in a building. They do not require an air duct system. But in this case, if the distance between the flows is insufficient, incoming flows may be removed and there will be no circulation of air masses.

List of possible problems after installing the system

Critical problems do not arise if recuperative ventilation is installed in the building. The main malfunctions are eliminated by the system manufacturers under warranty, but several “troubles” can overshadow the joy of the owners of buildings and premises after installing the equipment for the supply and exhaust air ventilation system. These include:

1. Possibility of condensation formation. When passing air mass flows from high temperature heating and contacting them with cold atmospheric air, in a closed chamber, drops of water fall out on the walls of the chamber. At sub-zero temperatures outside, the heat exchanger fins freeze, and the movement of flows is disrupted, reducing the efficiency of the system. If the channels are completely frozen, the operation of the device may stop.
2. System energy efficiency level. Supply and exhaust systems equipped with an additional heat exchanger of various types require electricity to operate. Therefore, it is necessary to carry out accurate calculations equipment different types specifically for the premises that will be served by the system.

You should not save money when purchasing, and purchase a device in which the level of energy savings will exceed the cost of operating the equipment.

1. Full payback period for an air ventilation system. The period for a full refund of the funds spent on the purchase and installation of equipment directly depends on the previous point. It is important for the consumer that these costs are recouped within 10 summer period. Otherwise, equipping a room or building with an expensive ventilation system is not cost-effective.

During this period, it will be necessary to carry out repairs and possible replacement of system parts and additional costs for their purchase and payment for their replacement.

Ways to prevent recuperator freezing

Some types of devices are made to prevent severe freezing of the heat exchanger surfaces. At low temperatures outside, ice build-up can completely block the access of fresh air to the room. Some systems begin to become overgrown with a crust of ice when the outside temperature drops below 0 0 .

In this case, the flow leaving the room is cooled to a temperature below the dew point and the surfaces begin to freeze. To resume operation of the device, you will need to raise the temperature of the incoming flow to positive values. The ice crust will collapse, the equipment will be able to continue working.
To avoid such situations, inflow - exhaust systems with a built-in heat recuperator, you can protect against such damage using several methods:

• To protect the device, it may be necessary to additionally equip the installation with an electric air heater. It does not allow the outgoing air masses to cool below the dew point and prevents the appearance of water droplets and the formation of ice;
• most reliable method, eliminating the possibility of freezing of the recuperator fins is the equipment of the device with an electronic control system for defrosting circuit, the activation of which takes into account several parameters. This may require setting a go-live date. electric heaters incoming air, at the first sub-zero temperatures.
  You can install a sensor that reacts to cold air and turns on air heating elements in the ventilation system. In any case, the operation of air heating devices in ventilation is cyclical, only in the cold season. When turned on supply ventilation, the incoming flow and exhaust gases removed from the room are heated.

After a certain period of time, the supply fan turns off. At this time, in the recuperator, the incoming flow is heated by the temperature of the outlet air, which is displaced using an exhaust fan. This operating principle of the heating circuit operates automatically throughout the cold period of the year.

To prevent ice from forming on the device, we recommend purchasing a plate-type heat exchanger with plastic ribs.

A method for independently calculating the power of supply and exhaust ventilation

First of all, it is necessary to determine the volume of all air flows necessary to create comfortable conditions. This can be done in several ways:

1. You can make a calculation based on the total area of ​​the building, without taking into account the occupants. The following calculation scheme is used here - within an hour, for each m2 of total area, 3 m3 of air should be supplied.
2. Based on sanitary standards, for a comfortable stay, at least 60 m3 must be supplied per hour for each person living in the room; for arriving guests, another 20 m3 must be added.
3. Based building standards 08/2/01-89, standards for the frequency of air replacement in a room of a certain area per hour were developed. Here the calculation is made taking into account the purpose of the buildings. To do this, it is necessary to determine the product of the frequency of complete replacements of air masses and the volume of the entire room or building.

In conclusion, we note.

Regardless of the pronunciation of the word ventilation, in English or other languages, the main task a supply and exhaust system with a heat recuperator – creating comfortable conditions for people in the room. Therefore, having decided on the calculation of the required power and the type of heat exchanger, you can safely begin equipping your home with a reliable ventilation system.

To increase service life, air purification filters can be added to the circuit. But you should remember that it is easier to prevent breakdowns by carrying out timely maintenance and care than to spend money on repairs or purchasing new equipment.