Admission fresh air in the cold period of time leads to the need to heat it to ensure the correct microclimate of the premises. To minimize energy costs, supply and exhaust ventilation with heat recovery can be used.

Understanding the principles of its operation will allow you to most effectively reduce heat loss while maintaining a sufficient volume of replaced air. Let's try to understand this issue.

In the autumn-spring period, when ventilating rooms, a serious problem is the large temperature difference between the incoming air and the air inside. The cold flow rushes down and creates an unfavorable microclimate in residential buildings, offices and factories or an unacceptable vertical temperature gradient in a warehouse.

A common solution to the problem is integration into supply ventilation, with the help of which the flow is heated. Such a system requires energy consumption, while a significant volume of warm air escaping outside leads to significant heat loss.

The exit of air to the outside with intense steam serves as an indicator of significant heat loss, which can be used to heat the incoming flow

If the air inlet and outlet channels are located nearby, then it is possible to partially transfer the heat of the outgoing flow to the incoming one. This will reduce the energy consumption of the heater or eliminate it altogether. A device for ensuring heat exchange between gas flows of different temperatures is called a recuperator.

In the warm season, when the outside air temperature is significantly higher than room temperature, a recuperator can be used to cool the incoming flow.

Design of a unit with a recuperator

The internal structure of supply and exhaust ventilation systems is quite simple, so it is possible to independently purchase and install them element by element. If assembly or self-installation is difficult, you can purchase ready-made solutions in the form of standard monoblock or individual prefabricated structures to order.

An elementary device for collecting and discharging condensate is a tray located under the heat exchanger with a slope towards the drain hole

Moisture is removed into a closed container. It is placed only indoors to avoid freezing of the outflow channels at sub-zero temperatures. There is no algorithm for reliable calculation of the volume of water received when using systems with a recuperator, so it is determined experimentally.

Reusing condensate for air humidification is undesirable, since water absorbs many pollutants such as human sweat, odors, etc.

You can significantly reduce the volume of condensate and avoid problems associated with its occurrence by organizing a separate exhaust system from the bathroom and kitchen. It is in these rooms that the air has the highest humidity. If there are several exhaust systems, the air exchange between the technical and residential areas must be limited by installing check valves.

If the exhaust air flow is cooled to negative temperatures inside the recuperator, condensate turns into ice, which causes a reduction in the open cross-section of the flow and, as a consequence, a decrease in volume or a complete cessation of ventilation.

For periodic or one-time defrosting of the recuperator, a bypass is installed - a bypass channel for movement supply air. When a flow bypasses the device, heat transfer stops, the heat exchanger heats up and the ice passes into a liquid state. The water flows into the condensate collection tank or evaporates outside.

The principle of the bypass device is simple, therefore, if there is a risk of ice formation, it is advisable to provide such a solution, since heating the recuperator by other means is complex and time-consuming

When the flow passes through the bypass, there is no heating of the supply air through the recuperator. Therefore, when activating this mode, it is necessary automatic switching on heater.

Features of various types of recuperators

There are several structurally different options for implementing heat exchange between cold and heated air flows. Each of them has its own distinctive features, which determine the main purpose for each type of recuperator.

The design of the plate recuperator is based on thin-walled panels, connected alternately in such a way as to alternate the passage of flows of different temperatures between them at an angle of 90 degrees. One of the modifications of this model is a device with finned channels for air passage. It has a higher heat transfer coefficient.

Alternate passage of warm and cold air flow through the plates is realized by bending the edges of the plates and sealing the joints with polyester resin

Heat exchange panels can be made of various materials:

• copper, brass and aluminum-based alloys have good thermal conductivity and are not susceptible to rust;
• plastic made from a hydrophobic polymer material with a high thermal conductivity coefficient and low weight;
• hygroscopic cellulose allows condensation to penetrate through the plate and back into the room.

The disadvantage is the possibility of condensation forming when low temperatures. Due to the small distance between the plates, moisture or ice significantly increases aerodynamic drag. In case of freezing, it is necessary to block the incoming air flow to warm the plates.

The advantages of plate recuperators are as follows:

• low cost;
• long service life;
• long period between preventive maintenance and ease of its implementation;
• small dimensions and weight.

This type of recuperator is most common for residential and office premises. It is also used in some technological processes, for example, to optimize fuel combustion during furnace operation.

Drum or rotary type

The operating principle of a rotary recuperator is based on the rotation of a heat exchanger, inside of which there are layers of corrugated metal with high heat capacity. As a result of interaction with the outgoing flow, the drum sector is heated, which subsequently gives off heat to the incoming air.

The fine-mesh heat exchanger of a rotary recuperator is susceptible to clogging, so you need to pay special attention to the quality operation of fine filters

The advantages of rotary recuperators are as follows:

• quite high efficiency compared to competing types;
• return of a large amount of moisture, which remains in the form of condensation on the drum and evaporates upon contact with incoming dry air.

This type of recuperator is less often used for residential buildings for apartment or cottage ventilation. It is often used in large boiler houses to return heat to furnaces or for large industrial or commercial premises.

However, this type of device has significant disadvantages:

• a relatively complex design with moving parts, including an electric motor, drum and belt drive, which requires constant maintenance;
• increased noise level.

Sometimes for devices of this type you can come across the term “regenerative heat exchanger”, which is more correct than “recuperator”. The fact is that a small part of the exhaust air gets back due to the loose fit of the drum to the body of the structure.

This imposes additional restrictions on the ability to use devices of this type. For example, polluted air from heating stoves cannot be used as a coolant.

Tube and casing system

A tubular type recuperator consists of a system of thin-walled tubes of small diameter located in an insulated casing, through which there is an influx of outside air. The casing removes warm air from the room, which heats the incoming flow.

Warm air must be discharged through the casing, and not through a system of tubes, since it is impossible to remove condensate from them

The main advantages of tubular recuperators are as follows:

• high efficiency due to the countercurrent principle of movement of the coolant and incoming air;
• simplicity of design and absence of moving parts ensures low level noise and infrequent need for maintenance;
• long service life;
• the smallest cross-section among all types of recovery devices.

Tubes for this type of device use either light-alloy metal or, less commonly, polymer. These materials are not hygroscopic, therefore, with a significant difference in flow temperatures, intense condensation may form in the casing, which requires a constructive solution for its removal. Another disadvantage is that the metal filling has significant weight, despite its small dimensions.

The simplicity of the tubular recuperator design makes this type of device popular for self-made. Typically used as an outer casing plastic pipes for air ducts, insulated with polyurethane foam shell.

Device with intermediate coolant

Sometimes the supply and exhaust air ducts are located at some distance from each other. This situation may arise due to technological features buildings or sanitary requirements for reliable separation of air flows.

In this case, an intermediate coolant is used, circulating between the air ducts through an insulated pipeline. Water or a water-glycol solution is used as a medium for transferring thermal energy, the circulation of which is ensured by operation.

A recuperator with an intermediate coolant is a voluminous and expensive device, the use of which is economically justified for premises with large areas

If it is possible to use another type of recuperator, then it is better not to use a system with an intermediate coolant, since it has the following significant disadvantages:

• low efficiency compared to other types of devices, therefore such devices are not used for small rooms with low air flow;
• significant volume and weight of the entire system;
• the need for an additional electric pump to circulate the liquid;
• increased noise from the pump.

There is a modification of this system when, instead of forced circulation of the heat exchange fluid, a medium with a low boiling point, such as freon, is used. In this case, movement along the contour is possible naturally, but only if the supply air duct is located above the exhaust air duct.

Such a system does not require additional energy costs, but only works for heating when there is a significant temperature difference. In addition, it is necessary to fine-tune the point of change in the state of aggregation of the heat exchange fluid, which can be realized by creating required pressure or a certain chemical composition.

Main technical parameters

Knowing the required performance of the ventilation system and the heat exchange efficiency of the recuperator, it is easy to calculate savings on air heating for a room under specific climatic conditions. By comparing the potential benefits with the costs of purchasing and maintaining the system, you can reasonably make a choice in favor of a recuperator or a standard air heater.

Equipment manufacturers often offer a model line in which ventilation units with similar functionality differ in the volume of air exchange. For residential premises, this parameter must be calculated according to Table 9.1. SP 54.13330.2016

Efficiency

The efficiency of a recuperator is understood as the efficiency of heat transfer, which is calculated using the following formula:

K = (T p – T n) / (T v – T n)

Wherein:

• T p – temperature of the air entering the room;
• Tn – outside air temperature;
• T in – room air temperature.

The maximum efficiency value at standard and certain temperature conditions is indicated in the technical documentation of the device. Its actual figure will be slightly less.

In the case of self-manufacturing of a plate or tubular recuperator, in order to achieve maximum heat transfer efficiency, you must adhere to the following rules:

• The best heat transfer is provided by counter-flow devices, then cross-flow devices, and the least by unidirectional movement of both flows.
• The intensity of heat transfer depends on the material and thickness of the walls separating the flows, as well as on the duration of the air inside the device.

E (W) = 0.36 x P x K x (T in - T n)

where P (m 3 / hour) – air flow.

Calculation of the efficiency of the recuperator in monetary terms and comparison with the costs of its acquisition and installation for two-story cottage with a total area of ​​270 m2 shows the feasibility of installing such a system

The cost of recuperators with high efficiency is quite high; they have a complex design and significant dimensions. Sometimes you can get around these problems by installing a few more simple devices so that the incoming air passes through them successively.

Ventilation system performance

The volume of air passed through is determined by static pressure, which depends on the power of the fan and the main components that create aerodynamic resistance. As a rule, its exact calculation is impossible due to the complexity of the mathematical model; therefore, for typical monoblock structures, experimental studies, and for individual devices, components are selected.

The fan power must be selected taking into account the throughput of installed heat exchangers of any type, which is indicated in the technical documentation as the recommended flow rate or volume of air passed by the device per unit of time. As a rule, the permissible air speed inside the device does not exceed 2 m/s.

Otherwise, at high speeds, a sharp increase in aerodynamic resistance occurs in the narrow elements of the recuperator. This leads to unnecessary energy costs, ineffective heating of the outside air and reduced fan life.

The graph of pressure loss versus air flow rate for several models of high-performance recuperators shows a nonlinear increase in resistance, so it is necessary to adhere to the requirements for the recommended air exchange volume specified in the technical documentation of the device

Changing the direction of air flow creates additional aerodynamic drag. Therefore, when modeling the geometry of an indoor air duct, it is desirable to minimize the number of pipe turns by 90 degrees. Air diffusers also increase resistance, so it is advisable not to use elements with complex patterns.

Dirty filters and grilles create significant interference with flow, so they must be periodically cleaned or replaced. One of effective ways clogging assessment is the installation of sensors that monitor the pressure drop in areas before and after the filter.

Conclusions and useful video on the topic

Operating principle of rotary and plate recuperator:

Measuring the efficiency of a plate-type recuperator:

Household and industrial systems ventilation systems with an integrated recuperator have proven their energy efficiency in retaining heat indoors. Now there are many offers for the sale and installation of such devices, both in the form of ready-made and tested models, and individual order. You can calculate the necessary parameters and perform installation yourself.

If you have any questions while reading the information or find any inaccuracies in our material, please leave your comments in the block below.

The idea is not new, but quite often I return to it and think about implementing it in my home. Therefore, I stole a detailed article mainly for myself, but perhaps it will be useful to someone else.

I would like to note that such a system will not only cool the house in the summer, but also heat it in the winter. You can't live without ventilation. And if in winter you draw air already heated by an earthen heat exchanger into the house, then heating costs will also decrease. This is especially true if you have stove heating or any open flame boiler. It is better to take the air for combustion from the street and preheat it. Efficiency will increase significantly. The only thing the authors did not notice was a solution to the condensate issue. And it may be in the heat exchanger pipes buried in the ground. And it is advisable to provide for the possibility of removing it by gravity with drainage into the soil. As an option, make part of the pipe at the lowest point from a drainage pipe with perforation. Well, lay the pipe above the water main so that it doesn’t get flooded.

Natural recuperator or free air conditioner for a country house

Cooling the air in the summer is one of the primary tasks of the homeowner. This article will tell you how to use the energy around us for this purpose and make air conditioning practically free.

The importance of ventilation cannot be overestimated. We will not repeat what has been described many times and will focus on our own task - to cool and refresh the air in the house. Traditional ventilation systems can be quite expensive to install due to the cost of components and assemblies, as well as the cost of qualified installation work.

During operation, they consume a significant amount of electricity, especially for cooling the air mass, emit a lot of heat and create noise. The system described in this article is easy to install, energy efficient, does not require special skills and is intuitive. It’s worth noting right away that due to its simplicity, it has limited functions, but it provides for modernization in any area at any convenient time.

In our case, the term “recovery” is a synonym for the word “heat exchange”, therefore the concepts “recuperator” and “heat exchanger” are interchangeable. At the physical level, the process consists of cooling/heating air, changing its temperature due to the consumption of thermal energy, and then mixing. How and why this happens, we will look further.

Stable Energy Source

Pursuing the goal of lowering the indoor temperature in the summer, it is reasonable to ask the question: “Where should the energy of the heated atmospheric air be given? How to cool it? Here the forces of nature come to our aid. The fact that at a certain depth the soil temperature is constant will be our main argument when justifying the energy efficiency of the system.
The soil is capable of endlessly exchanging energy - cooling and heating any medium (air, water), but only to its own temperature at a given depth, which remains constant due to the relative stability of the earth's core.

International practice

Of course, we are far from the first who decided to use the endless and free energy of the Earth. IN European countries, which are usually called developed (Germany, Sweden, Belgium, etc.) have been using this energy since the beginning of the last century. The successes achieved in this field are impressive.

Heat exchange systems for water below ground level are called “heat pumps.” These underground and underwater devices heat and cool the entire home. Standard projects have been developed for any building and it is possible to convert the house from a traditional (gas, electric) air conditioning system to heat pumps. In a similar, but more primitive way, this energy is used in our country by arranging underground food storage facilities (cellars).

What is good about a natural heat exchanger?

The operation of our recuperator is based on the same physical process as in heat pumps. Focusing on savings, we use this principle, adapting it to our own needs and local realities.

Problems that an adapted autonomous recuperator can solve:

Constant natural ventilation with doors and windows closed.
Quickly replace indoor air with fresh air.
Cooling the air in the room.
Preparing the air mixture for subsequent actions.
Advantages:

Absolutely environmentally friendly. They are not used during installation and operation of the base system. toxic materials and there is no thermal release into the atmosphere.
Safety. The recuperator does not use electric motors (with a power of more than 100 W), chemical agents, or high voltage.
Simplicity and cheapness. For forced ventilation, only low-power 100 W fans are used. Ventilation occurs naturally.
Oxygen is not burned during operation.
Low noise level.
Flaws:

the basic system does not provide for filtration, humidity control, heating or other processing of the air mixture (but allows for the possibility of installing appropriate equipment later).
Simple and clear system

An autonomous heat exchanger for a country house is a system of ventilation ducts, partially laid underground, included in the supply and exhaust ventilation circuit. In order to create such an “air conditioner”, it is not necessary to understand the intricacies physical phenomena. Just knowing that it works is enough. You can verify this by going down into any basement, well or subway in the heat.

The operating principle is as follows:

Atmospheric air passes through pipes laid in the ground at a constant temperature (usually from +4 to +10 ° C).
In the underground part, cool soil absorbs thermal energy heated air.
Cooled air is delivered through ventilation ducts to the premises of the house.
Simultaneously exhaust fan removes saturated and heated air mixture (“old air”) from the room.
According to the principle of construction, such systems are divided into two main types: pipe and bunker.

Pipe - consists entirely of pipes. The design can be varied depending on the conditions of the site. Suitable for reconstructing a house without a spacious basement, but it will require a lot of work earthworks.Bunker or stone - the heat exchanger is a bunker filled with large stones. Occupies less area than a pipe one (you can arrange it in the basement of the house). Requires a basement or underground space. The best option for new construction.

We create internal system house ventilation ducts

In both cases, the ventilation ducts inside the house will be located approximately the same. Let's start with them.

A primitive supply and exhaust ventilation system consists of external and internal ventilation ducts connected into one network. Air outlets are located in the upper diagonally opposite corners of the rooms. In one there is an inflow, in the other there is an exhaust. In a one-story building, the main air ducts may be located in the attic. In a two-story building, the supply and exhaust air ducts of the first floor will pass in boxes inscribed in interior decoration, second floor - in the attic. The location of the main air ducts should be determined for each house individually, taking into account the layout (location of walls and partitions). Tip. Rooms in which supply and exhaust ventilation is recommended: living room, bedroom, children's room, kitchen, dining room, offices, pantry, recreation rooms, gym. In bathrooms and toilets there is only an exhaust fan. Not needed at all in corridors, vestibules, halls and loggias.

Rules for calculating the internal ventilation duct system:

Pipe sewer diameter 250 mm for supply distribution and combined outlet channels. Approximate consumption - two lengths of the house + height of the upper ceiling + 20%.
Sewer pipe (gray) with a diameter of 150 mm. Approximate consumption is three times the length of the house + 20%. For two-story house with equal floor area + 50%.
Pipe fasteners (based on the wall material) at the rate of 1 pc. by 70 cm.
Insulation (roll mineral wool) - 1 roll.
Foam, sealant, decorative grilles.
Elbows, revisions, couplings (1 piece per 70 cm).
Attention! Do not use 90° elbows, this will impede the passage of air and create noise. Combine 45° elbows (following the sewer example).

If you plan to install a pipe heat exchanger in a one-story building, supply channel will come out of the ground into a heat-insulated box outside the building and into the attic. In a two-story building, it is better to bring it into the building at the bottom of the first floor and install an internal vertical (distribution) channel, which will then be led into the attic space. When installing a bunker option in the basement of a building, the vertical distribution channel will exit the bunker directly into the room. It can also be mounted outside.

An example of calculating the consumption of materials for installing internal channels at home

Let's take as an example cottage with a calculated ventilated area of ​​60 m2, which will have approximately 100 m2 of total area and approximate dimensions of 8x12 m:

Pipe 250 mm: 2 x 12 + 3 + 20% = 32 m.
Pipe 150 mm: 3 x 12 + 20% = 43 m.
Fasteners: 32 + 43 / 0.7 = 107 pcs.
Elbows, revisions, couplings - take as 1 piece per 3 m: 32 + 43 / 3 = 55/3 = 20 pieces.
Grids: 8 pcs. (2 for each room).
Switches: 4 pcs.
Foam, sealant. Tube heat exchanger

In order not to complicate the calculations with mathematical calculations, we will provide data from tests already carried out in average form, or rather their results.

The basic principle that must be observed when creating a pipe system is that there must be at least one underground channel pipe per room. This will facilitate the operation of the fans due to atmospheric pressure. Now all that remains is to place required amount pipes in the underground part of the site. They can be laid separately or combined into a common channel (250 mm).

In this description, we propose not to take into account maximum load, when all rooms are forcedly ventilated at the same time, and the average, which will be supplied with regular periodic ventilation different rooms(as happens in real life). This means that there is no need to output a separate channel for each room. It is enough to connect 150 mm air ducts from each room to one common 250 mm channel. The number of common channels is taken at the rate of one channel per 60 m2.

Creating a recuperation field

Recommended layout of the underground part of the pipe heat exchanger: First you need to select the location of the pipes (recovery field). The greater the length of the laid pipes, the more effective the air cooling will be. It should be noted that after the work is completed, this area can be used for planting, landscape design or a children's playground. Under no circumstances should you plant trees on the recuperation field:

We excavate the soil to a freezing depth of plus 0.4 m.
We lay 250 mm pipes with a pitch of at least 700 mm along the axis.
We bring the air intakes to a height of 1 m. It is advisable that they be located in a shaded but well-ventilated place.
Using elbows and adapters, we combine them into a common 250 mm channel, which connects to the house ventilation system (see above).
Attention! In the underground part, use special soil sewer pipes with a thick wall. They do not need to be thermally insulated, but simply covered with soil and spilled with water. Only concreting is allowed if necessary.

Calculation of the amount of work and material consumption:

For a recuperation field we take an area measuring 15x6 m with an area of ​​90 m2.
The volume of soil in the pit at a freezing depth of 0.8 m will be: Vcat = (0.8 + 0.4) x 60 = 72 m3.
Volume of a trench 40 cm wide (10 m from the house): Vtr = 1.2 x 0.4 x 10 = 4.8 m3.
Total volume of excavation work: Vtotal = Vcat + Vtr = 72 + 4.8 = 77 m3.
Sections of 15 m: Notr = a / 0.7 = 6 / 0.7 = 9 pcs., where a is the width of the field.
Total pipe length: L = Notr x 15 + 10 = 9 x 15 + 10 = 145 linear. m.
The consumption of elbows, couplings, adapters is accepted as 2 pcs. x 15 m = 30 pcs.
Advice. The deeper the heat exchanger is installed, the more efficient its operation will be. More than one tier is allowed.

At a certain place, a pit measuring approximately 2x3x3 m is dug. A trench is made from the exit point of the common channel of the house ventilation system to the pit of the future tank, and a 250 mm pipe is laid into it to a depth of 140 cm, through which cooled air will be discharged from the bunker. Along the wall to which the trench approached, a vertical groove is laid to the bottom for a pipe with a diameter of 250 mm. Then the bottom is laid out with bricks or concreted. The bottom of the air tank must be at least 1 meter deeper than the soil freezing level.

Attention! After installing the bottom of the bunker, a 250 mm outlet pipe should be laid.

The beginning of the outlet pipe protrudes from the wall 1/3 of the distance to the opposite wall and is lined with brick protection. A protective grill is installed on the inlet opening.

Filling the tank

It is better to lay the walls out of brick or cast them from concrete (without slag!), since these materials conduct temperature better than others. Cinder block is not suitable due to its thermal insulation properties. The walls and bottom must be carefully waterproofed (roofing felt) on the outside and plastered on the inside to prevent the penetration of organic matter or moisture. The height of the walls is up to ground level minus 20 cm. An inlet hole is made at the top of any wall and air intake pipes are installed. To facilitate the operation of fans, we recommend installing 3 pcs.

After the solution has hardened, the bunker must be filled with large pebbles. Sizes from 200 to 450 mm in diameter. The stone must be clean of organic matter and washed.

The tank is covered with a “lid” made of solid plank flooring on wooden beams, covered with waterproofing materials. Turf is laid on top. Then the outlet pipe is connected to the house ventilation system (to the common ventilation duct) and backfilling is performed.

Calculation of the volume of work and consumption of materials:

With an air tank size of 2x3 m and a depth of 3 m, the volume of soil (excavation and stone for filling) will be: V = 2x3x3 = 18 m3 + Vtr = 22.8 m3.
Volume brickwork: Vclad = Swall + Sbottom x 0.125 = ((2x3) x 2 + (3x3) x 2 + 2x3) x 0.065 = 36 x 0.065 = 2.34 m3.
Total pipe length (10 m from the house): L = (10 + 3) + 10% = 15 m.
Number of elbows - 6 pcs. Bunker heat exchanger

If there are unoccupied basements, they can also be used to construct a hopper (air or heat exchange tank) for a stone heat exchanger. Its action is based on the energy intensity of the stone - it gradually gains temperature environment and balances the flow of passing air. If there is no free space in the basement, the bunker can be arranged in an area outside the house.

The cost of stone for filling a tank may vary depending on the region of construction.

As can be seen from the calculations, the final cost of air conditioning 1 m2 differs for both options. The main selection factor is the level of occurrence groundwater. If it is high, less than 3 m, then it will not be possible to build a bunker heat exchanger. The pipe one is suitable even with a groundwater level of 1.5 meters.

Installation of fans

The system presented here provides for the synchronous operation of two duct fans - supply and exhaust - installed in each air outlet of the room. This makes it possible to quickly deliver cool fresh air into the room and remove heated air. For effective ventilation, a fan power of 100 W each is sufficient. When choosing a fan, pay attention to the noise level when it operates.

Approximate cost of operation

If you ventilate each room three times during the day for 20 minutes, then we get 1 hour of operation of 8 0.1 kW fans. This is less than 1 kW/hour per day. Per month - 30 kW. At a price of 5 rubles/kW this will be 150 rubles/month.

The service life of recuperators and ventilation ducts at home is limited by the service life of the material. For underground elements - from 50 years, for internal ones - unlimited.

The system does not require maintenance (except for fans - once every 5 years).

Prospects

The described circuit can become the basis for a more complex air conditioning system. It can be gradually included additional elements- filters, heating and cooling elements, more powerful fans, automatic control units and others. The air mixture prepared underground has a stable temperature not only in summer, but also in winter, so it can also be used for heating.

05.05.2016 11:46

Nowadays, many people install air conditioners in their homes. In recent years, having an air conditioner at home has become an indicator of quality of life: after all, summer time without it, most apartments are hot, stuffy and want to go to the sea :-). Our goal is not to denigrate air conditioners. This useful devices, which cope perfectly with the main task assigned to them - cooling the air in the room. IN summer period The benefits of air conditioning are difficult to overestimate; it really makes life easier for many people.

The reaction of some of our friends and relatives to whom we told about ventilators was the question “why do we need a ventilator if we already have an air conditioner installed?” Let's look at the most common misconceptions regarding air conditioners and ventilators.

Myth No. 1. The air conditioner supplies fresh air to the room

Like most devices that combine several functions, supply air conditioners are rather weak in the “additional” functionality, which for them is the supply of fresh air. Observe: when they write about air conditioners, as a rule, they always describe in detail about filters, innovations and other “bells and whistles”. But as soon as it comes to the influx function, there is silence. Specific numbers are meant, because without numbers it is reminiscent of Ostap’s statement “Whoever says that this is a girl, let him be the first to throw a stone at me” (c). That is, the function itself is there, you can’t find fault with it. And who said that it would be a) effective and b) comfortable? Nobody wants to indicate in the description of the supply air conditioner that even at the lowest speed it makes a lot of noise (after all, no one has repealed the laws of physics, and in order to supply the same volume through a narrower channel, the supply speed must be higher, which inevitably means follows: EITHER the fan performance should be higher, and this automatically means more noise, OR the supply volume should be LESS). Now to the numbers:

The diameter of the hole when installing an air duct for an air conditioner with a supply function is 4 cm, which gives a cross-sectional area of ​​​​about 13 cm 2. The diameter of the hole when installing the air duct for the ventilator is from 8 to 12.5 cm, this gives a cross-sectional area of ​​50-123 cm 2. The calculations used the formula for the area of ​​a circle Pi-Er-square: S = π*R*R, π=3.14159...

Thus, the cross-sectional area of ​​the ventilator duct is 4-10 times larger. It follows that:

with the same fan performance and other equal conditions, the ventilator will supply 4-10 times more fresh air to the room.

The question arises: maybe so much air is not needed? Let's turn to building codes: the standard for providing one person with fresh air in a room is 30 m 3 per hour. The maximum productivity of modern ventilators is from 100 to 180 m 3 per hour, which is equivalent to sufficient supply of fresh supply air for 3 to 6 people constantly present in the room.

Let's take into account the fact that this is the maximum performance of household air handling units available on the market and therefore the noisiest operating mode. In practice, a performance level that is 2-3 times less than the maximum value turns out to be comfortable in terms of noise. As a result, we get a range of 33-90 m 3 per hour. That is, 1-3 people can sleep comfortably in the same room with a working ventilator, while having sufficient air exchange.

Now let's apply our theory to air conditioners with a fresh air supply function. According to our conclusion, it should turn out that the volume of inflow with a comfortable noise level of the air conditioner should be 4-10 times less than that of the ventilator, that is, from 3.3 to 22.5 cubic meters at one o'clock.

Let's compare these conclusions with technical characteristics air conditioners with supply function.

For example, let’s take the popular Hitachi RAS-10JH4 model worth about 50 thousand rubles. and another Japanese novelty with a unique humidity control function, Daikin Ururu Sarara, costing about 130 thousand rubles.

The maximum inflow volume is:

For Hitachi - there is no exact information, according to the seller - about 20 m 3 / hour

For Daikin - 32 m 3 / hour.

The point is that the inflow function in the air conditioner is indicated mainly for show, but in fact this inflow is only 20 “cubes” per hour - it’s somehow undignified to write about this.

In addition, in such air conditioner models restrictions are applied related to air temperature - for example, the air flow function operates at an outside air temperature of at least +3 degrees, or when there is a difference between outside and internal air no more than 7 degrees. We can conclude that during the cool season, supply air conditioners stand idle, just like standard recirculation air conditioners. Of course, there are expensive models in which these disadvantages are minimized. But the cost of such models is several times higher than the cost of a ventilator and a standard air conditioner combined (for example, Daikin air conditioners cost around 100-250 thousand rubles).

As for the inexpensive ones, like the Hitachi model, supply air conditioners, then here are excerpts from reviews about them (taken from Yandex.Market, spelling and punctuation of the authors are preserved) regarding the supply ventilation mode:

• “The supply/exhaust is noisy (the pump motor hums, the air hisses in the corrugation), does not distract from work at minimum and medium speed, but I would never put such an air conditioner in the bedroom.”
• “The manufacturer does not write anywhere how many cubic meters. m. per hour pumps in/out the inflow and outflow of this air conditioner. such a marketing intrigue. It’s understandable why, through an inch tube these values ​​will be “shameful” and will not reach the standards for submarines and places of detention.”
• “Basically, I was warned that the inflow would be weak, but I didn’t expect it to be this bad. In addition, you won’t be able to use it in winter - there are restrictions, the automation is watching. It is possible only in summer and autumn - the temperature difference between outside and inside is no more than 7 degrees. In principle, it is needed mainly in the summer, but these are not all its disadvantages. It is quite noisy, including the weakest mode, in which it barely blows at all, but you can fall asleep. :) It is much noisier than the main fan, and the flow is worse. Its management is inconvenient.”
• “The blow-in mode is not used - it’s too noisy and weak. »
• “The fresh air ventilation function does not work if the window outside is more than +30 degrees. »
• “The supply ventilation, for which we bought it, is, by and large, nonsense. This function exists separately from the air conditioner itself, pumped by a separate fan through a separate air duct. Even on maximum speed With this fan, the flow of incoming air is very modest, but it buzzes loudly. Plus there are a lot of conditions under which the air supply will not work.”

Myth No. 2. Air conditioner purifies the air

In fact. The air conditioner undoubtedly cleans the air, but standard models are equipped only with coarse air filters, which, if you look closely, are most often metal mesh, trapping large and medium-sized dust of indoor origin. Such a filter cannot effectively prevent the neutralization of microorganisms, pollen, small dust particles, bacteria and allergens that have entered the room.

Of course, expensive (more than 40-50 thousand) air conditioner models are equipped with fine air filters and a function for deactivating microorganisms and bacteria. But even inexpensive ventilator models, costing up to 30,000 rubles, are equipped with fine air filters that prevent small particles of dust, allergens, odors, impurities, and the smallest contaminants from entering the ventilated room ( dust mite, mold, mildew, bacteria and viruses, etc.). After all, it is easier (and usually cheaper) to prevent a problem than to eliminate its consequences. In addition, due to moisture condensation, pathogenic microorganisms, carcinogenic substances and spores of pathogenic fungi accumulate on the filters and in the drainage system of the indoor unit of the air conditioner (and often, if maintenance is not done in a timely manner, multiply) and infect residents. Since the ventilator has no contact with water, its filters do not pose such a danger. Of course, as in the case of an air conditioner, the condition of observing timely (recommended by the manufacturer) cleaning and replacement of filters is the main guarantee of healthy air and trouble-free operation of the equipment - any equipment must be monitored. The only difference is that the ventilator is a household appliance and it is quite easy to service it yourself, while cleaning the air conditioner, as a rule, requires the visit of a qualified service representative and specialized equipment (especially cleaning and diagnostics of the outdoor unit of the air conditioner, which is strictly not recommended and even prohibited to perform without appropriate qualifications).

Myth No. 3. Air conditioners and ventilators are installed in the same way

In fact. A household air conditioner has both outdoor and indoor unit(or several blocks). Installing an air conditioner on external wall building is not always possible: this is interpreted as redevelopment, which requires approval - that is, bureaucratic red tape with an unpredictable result.

Many residents install air conditioners without permission, without going through the redevelopment approval procedure. However, this is fraught with problems: such residents can be sued by both neighbors and Management Company or city authorities. With a high probability, the claim will be satisfied - there are already such precedents - and the air conditioner will have to be dismantled.

As for the ventilator, its installation indoors does not affect the appearance of the building, is not considered a redevelopment, and therefore is not subject to approval. From the outside of the building, the hole is closed with a grill. There are no special regulations regulating this aspect, so installing gratings without approval is legal.

Since the ventilator does not have an external unit, its installation does not require special climbing equipment, which reduces the cost of installation. Installation is carried out from inside the room: first, a hole is cut using diamond drilling equipment, then outside installed with a solution (possibly with a canopy against precipitation), and with inside– the device itself. Diamond drilling so neat that the effect of a “torn-out wall” is impossible, thanks to which the ventilator can be installed in a room under renovation. As for the air conditioner, a hammer drill is most often used to install it, which, if not used very skillfully or in the case of a problem wall (hitting the fittings), can greatly “damage” it.

Installation of the ventilator does not involve laying long air ducts - in 90% of cases the length of the air duct is equal to the thickness of the wall (with the exception of the case of laying the air duct through a balcony or loggia). The air coming from the ventilator spreads throughout the room without the help of pipes.

Myth No. 4. The air conditioner heats the air

In fact. This is partly true - an air conditioner made in the form of a split system can heat the air. However, there are a number of limitations, the main one of which is the impossibility of heating in winter. You can turn on the split system for heating only when the outside temperature is positive (more expensive models - up to -10C). When you try to heat a room with an air conditioner in cold weather, the compressor in an inexpensive air conditioner may break down, and in an expensive one the electronics will not allow you to turn on the heating. In autumn and spring, at above-zero temperatures, turning on the air conditioner in heating mode should be done with caution, since the radiator of the external unit is cooled and a large amount of condensation forms on it, and to prevent damage to the air conditioner it is necessary to remove it regularly.

In the descriptions of some air conditioners you can see the “winter kit” function. Some consumers, without understanding, believe that this air conditioner function will provide optimal temperature indoor air in winter. In fact, this function implies cooling in winter period rooms with intense heat generation (for example, rooms where a large amount of equipment is located). This has nothing to do with air heating, which is relevant for most consumers.

Now about the ventilators. Their modification, called a “breather”, which has a climate control function, heats the air in the room to a user-specified temperature, regardless of the temperature outside the window. The greater the temperature difference, the more efficient the heating. Most ventilators without a climate control function also heat the air, but without the ability to set a specific degree - the device has several heating powers, and the higher this power, the warmer the temperature of the fresh air in the room. Recuperators heat the air by transferring heat to the supply air from the exhaust air. If you have a ventilator that heats the air, you don’t need to spend money on a heater. In the case of a recuperator, heating does not even require additional energy costs.

Summary

Thus, we can conclude that a household air conditioner and a household ventilator are different devices, designed to solve different problems, and ideally complement each other. If there is a ventilator in the room, a simple, inexpensive air conditioner is sufficient to cool the air in the summer (when calculating the power of the air conditioner in tandem with the ventilator, it is necessary to install an air conditioner more powerful than if it were installed without a ventilator, since in the summer, ventilation with warm air will require from an additional power air conditioner) since the functions of supplying fresh air, filtering it from all kinds of impurities and, if necessary, heating are decided by the ventilator.

(c) Fresh Air. Copy with URL only

In this article we will not go into definitions and deep technical data. Let's talk in simple language.

In short, the difference is as follows. The air conditioner circulates the air that fills the room, and the recuperator replaces the entire volume of air several times per hour.

And now more details.

Air conditioner– this is a device that heats (cools) the air to a predetermined comfortable temperature in the room. It can be equipped with additional functions such as ionization, dehumidification (humidification), adding air from outside. Unscrupulous sellers often write that the air conditioner has a built-in ventilation function. This is a deception, because ventilation is the removal of air from inside a room and replacing it with outside air. Only industrial precision models have this function, and not ordinary household ones.

Recuperator(in its simplest design) is a supply and exhaust ventilation unit, which returns most of the heat back into the room. Heat recovery is performed by a heat exchanger, which has an efficiency of up to 90% and does not consume electricity at all. There are also models equipped with a climate control function, that is, they heat or cool the air to desired temperature, like the air conditioner. Due to the fact that the recuperator constantly supplies air from outside, there is no need to use a humidifier, dehumidifier, ionizer and other devices to control these parameters.

The most important difference between an air conditioner and a recuperator lies in the fact that the air conditioner pumps through itself only the air that is in the room, and the recuperator pumps out the air from the inside and supplies a fresh stream, thus completely renewing it 2 times an hour. Those who are familiar with ducted air conditioners may be indignant and say that this type of air conditioner also supplies fresh air. However, the whole point is that the duct delivers no more than 15% of fresh air (which the sellers, of course, do not talk about), and this cannot be compared with a 100% recuperator.

For clarity, the table below presents data with numbers.

Comparative characteristics of the recuperator and air conditioner.

	Characteristic	Recuperator	Air conditioner
	Energy consumption without heating (cooling), W
	Number of blocks, pcs.
	Installation method	In-wall / utility room	Indoor and outdoor
	Heating/cooling	(depending on model)
		(soft heating)	(dries out the air)
		(depending on model)
	Removing air	from 2 times per hour,
	Air supply from outside	from 2 times per hour,	(only in channels)
	Operation at external temperatures is permitted
	Heat exchanger
	The need for ventilation		3 times a day
	Mold growth	eliminates completely	promotes
	Allergic reactions in humans		increases
	Heart rate, blood pressure	is stabilizing	violated
	Need for filter cleaning	1-2 times a year	monthly

It is up to you to decide which equipment to choose: recuperator or air conditioner. But if someone in your family suffers from allergic reactions respiratory system, I advise you to refuse to buy an air conditioner, because the bacteria that inevitably accumulate in it will cause even greater stress on the immune system.

FAQMarley

In this section you will find answers to the most frequently asked questions related to Marley ventilation systems. If you have not found the answer to a question you are interested in or would like to clarify something, do not hesitate to contact our store managers - they will be happy to tell you everything!

What should be the wall thickness for recuperators?Marley?

Standard recuperators are suitable for walls with a thickness of 25 to 50 centimeters. If you require the installation of a wider channel, you can purchase an additional kit for walls with a thickness of 17 to 150 centimeters. With such a kit, the recuperator will have virtually no loss in performance, and noise and thermal insulation will remain at the same level.

If your walls are too thin, then in this case a special decorative blend is provided, which allows for easy and quick installation. Hood sold separately.

Is it true that according to building codes a recuperator must be installed in a house?

Legislation recommends the use of recuperators, but does not require it. According to clause 11.5 of SNiP ( Building Codes and Rules) 01/31/2003 SP 54.13330.2011 “Residential multi-apartment buildings” “In order to achieve optimal technical and economic characteristics of the building and further reduce specific energy consumption for heating, it is recommended to provide for ... recovery of waste air heat and Wastewater, use of renewable energy sources" (recuperators).

What is better – a recuperator or an air conditioner?

The main task of an air conditioner is to create the most comfortable temperature conditions. At the same time, the air conditioner does not improve the supply ventilation in any way or improves it only slightly (if the corresponding function is available). The recuperator creates a sufficient flow of fresh air so that you can breathe freely and do not experience increased fatigue. In addition, the recuperator retains heat in winter and coolness in summer, without using electricity and, as a result, reducing the electricity costs of the air conditioner. In other words, if in winter the temperature outside is approximately -30 degrees, and indoors +20, then, due to the accumulation of heat from the exhaust air, the temperature of the supply air will be +14. In summer when outside temperature at +30 and internal +20 the supply air will be cooled to +22. That is collaboration air conditioner and recuperator will be very effective.

Another advantage of the recuperator over a conventional air conditioner with the function of mixing fresh air is the filtration of the air flow. Dust, dirt, microorganisms are retained and do not enter the room, while in air conditioners, filtration, most often, occurs only with the air that is already in the room.

Simultaneous use of a recuperator and an air conditioner will help you not only create comfortable temperature at home or in the office, but also to receive sufficient quantity fresh and clean air and also save significant energy!

Is it possible to deliver recuperators?Marley on the territory of the Russian Federation?

Yes, for delivery we use the services “Business Lines”, PEC and PonyExpress (delivery is paid separately according to the tariffs).

Will a recuperator help?Marley get rid of condensation that occurs on plastic windows?

Window fogging is a common problem that often occurs after replacement. wooden windows and doors to plastic ones. The root cause of condensation is poor ventilation and high humidity. It’s as if the room stops “breathing” and the moisture doesn’t go anywhere. Over time, the problem can develop into a more serious one: the appearance of mold or “soaking” of building structures. In order for moisture to leave, the room must be regularly ventilated. In the cold season, when ventilating through the window, cold can enter the room, and in the warm season, heat can enter. With the help of a recuperator you will not only get rid of high humidity, creating optimal ventilation, but also maintain a comfortable temperature in winter and summer.

What is the operating temperature range of the recuperator?Marley?

Marley recuperators operate effectively at outside temperatures from –35°C. The maximum temperature of the supplied air is +40-45 degrees. Ventilation ducts and grilles are made of polyvinyl chloride and are suitable for use at temperatures up to +60°C.

Why is there a check valve in fans?Marley doesn't open right away?

If the valve opens immediately, cold, unheated air can enter the room. To prevent this from happening, the valve is equipped with a thermal switch that is activated when the set temperature is reached.

Can the fan power be adjusted separately?

This is theoretically possible, but we are not responsible for the use of elements from other manufacturers in the system. Most often, a fan speed controller or inductive loads (sold in electrical goods stores) are used for these purposes. ATTENTION! Lighting dimmers must not be used to adjust the fan power!

What is the maximum area of ​​the room in which the recuperator can be used?MarleyMenV 180?

The recuperator of this model was developed for small residential and office premises. It is perfect for rooms with an area from 20m2 to 40m2, but the volume should not exceed 100m3. If you need to increase the efficiency of ventilation, we recommend installing several devices at once, which will operate synchronously. For an accurate calculation of productivity, contact our store managers.

Can I useMarley as heating devices?

The supplied air is heated due to the temperature difference between inside and outside. By extracting warm air from the room, the ceramic element inside the recuperator is heated. This heat is then transferred to the air supplied inside (in the warm season it is used reverse principle). Thus, you will not be able to heat a room using a Marley recuperator, but the space will cool down much more slowly than with conventional ventilation or another type of ventilation.

Is it possible to cool the air in a room using recuperators?Marley?

When exhausting, Marley systems “collect” heat or cold in a special ceramic element, and then cool or heat the air flow depending on the time of year. In summer, when it’s hot, the temperature of the supply air will be lower than outside, but warmer than at home. For example, if it is +30 degrees outside and +20 degrees inside, then the temperature of the supplied air will be approximately 22 degrees Celsius.

That is, you cannot significantly cool the room, but you can reduce the load on the air conditioner and maintain a comfortable climate much longer than when ventilating through a window or using other types of ventilation.

Is it possible not to install another supply and exhaust ventilation system if recuperators are used in the house?Marley?

Can. But only on condition that installed recuperators provide sufficient fresh air in each room. We recommend installing one recuperator for approximately 100 m 3 (room area from 20 m 2 to 40 m 2).

What happens if the temperature “overboard” drops below -30 degrees?

If the outside temperature is above -30 degrees, the supplied air will be heated to approximately +15. If it is colder outside the window than -30, then warming up the air flow will be more difficult. In any case, its temperature will not drop below +10. You can also turn off the ventilation, and the check valve will not allow outside air and cold into the house.

How and how much can you save using a recuperator?

Marley recuperators increase the efficiency of air conditioning and heating appliances. When drawing ceramic element“collects” heat or cold, which are later transferred air flow. Thus, the load on the air conditioner or radiator is significantly reduced. According to the manufacturer, such a system can save from 100 euros per year.

If I install two recuperatorsMarley is not in one room, but in two different ones, will their work be in sync?

The operation of recuperators can be synchronized if they are separated from each other by no less than 1 m and no more than 10 m, and the thickness of the partitions between them does not exceed 15 cm. In this case, both devices will operate from the same remote control, alternately alternately removing and supplying air (the duration of each phase is 70 seconds). However, if the recuperators are located in different rooms, then there is no particular need for their synchronization.

If the apartment has two heat exchangers installed Marley, is it possible, without synchronizing the devices, to make one of them constantly work for exhaust, and the other for air supply?

Yes, you can do this, just turn on each device in the ventilation mode (one for exhaust, the other for supply). In this case, no cooling or heating of the air will occur. We do not recommend using this mode if the temperature outside the window drops below +5 degrees.

Do I need to connect devices?Marley to the mains?

Recuperators operate from a 220V network. At the same time, electricity consumption remains minimal - only 7 watts.

Is it difficult to install a recuperator?MarleyMenV 180?

The most difficult part of installation is drilling stone walls. If you have wooden walls or a channel for installing a recuperator is already ready, then you can easily install the device yourself without the help of specialists, just strictly follow the attached instructions. If you need professional help, you can contact the specialists of our store.

What happens to the condensation that forms inside the device?

Due to the constant movement of air and constant above-zero temperature, condensation does not form inside.

How is the recuperator maintained?Marley? How often do you need to change the filter and wash the heat exchanger?

The attached instructions describe the maintenance procedure in detail. Caring for the recuperator does not require special skills and you can easily do it yourself. For convenience, the device is equipped with a light indicator that will tell you when it is time to clean the filter. We recommend replacing the filter with a new one approximately once a year, or more often if you live in an environmentally unfavorable area.

We for free We provide our customers with replacement filters for three years after purchase.

Do I need to turn off the supply and exhaust ventilation?Marley, if you plan to be away for a long time?

If you plan to go on vacation or business for a long time, you can unplug the device from the mains, but leave the valve open so that natural ventilation premises. However, in winter it is better to close the valve.

At what height should the recuperator be installed?

The best position for Marley systems is at the top of the room, about 30 centimeters from the ceiling. Since warm air rises, the most effective recovery will occur there. But if you wish, you can place the device where it is convenient for you, for example, below the floor or in the middle.

How often should I turn on my Marley ventilation system?

Marley heat exchangers are designed for continuous use, meaning you can leave them on 24 hours a day. Thanks to high efficiency and economy, energy consumption remains minimal.

Temperature is calculated using the formula t3=0.79*(t2-t1)+t1, where t1 – outside temperature, t2 is the temperature of the house, t3 is the temperature of the supply air, and 0.79 is the efficiency value (can range from 0.79 to 0.85). Thus, if it is -15 outside and +23 at home, then the temperature of the supplied air will be approximately +15 degrees.

Is it possible to install a recuperatorMarley in a ready-made, renovated room without spoiling the interior?

Yes, you can. Our specialists will drill a hole in the wall and install the device without damaging the finish, and dust collectors will eliminate the occurrence of large amounts of dirt and construction dust.

If I install the recuperator myself, will the warranty still apply?

Yes, the warranty remains valid.