Compact ventilation system with recuperator. Supply and exhaust ventilation with heat recovery: operating principle of the system and types of recuperators

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Ventilation with recovery is equipment designed to process air to such parameters that a person could feel comfortable and safe. Such parameters are regulated by standards and lie within the following limits: temperature 23÷26 C, humidity 30÷60%, air speed 0.1÷0.15 m/s.

There is another indicator that is directly related to the safety of a person’s presence in enclosed spaces - this is the presence of oxygen, or more precisely, the percentage carbon dioxide in the air. Carbon dioxide displaces oxygen and, at levels of 2 to 3% carbon dioxide in the air, can cause loss of consciousness or death.

It is to maintain these four parameters that the ventilation units with recovery. This is especially true for modern business centers, where there is no natural influx fresh air. Industrial, administrative, commercial, residential, and other premises cannot do without modern ventilation equipment. With today's air pollution, the issue of installing ventilation units with recovery is most relevant.

It is possible to install additional filters and other devices in ventilation with recovery that allow you to even better clean and process the air to the specified parameters.

All this can be done using Dantex ventilation units.

Operating principle of a supply and exhaust ventilation system with heat recovery

Thanks to supply and exhaust system ventilation is forced into the room fresh air, and the heated exhaust air is discharged outside. Passing through the heat exchanger, the heated air leaves part of the heat to the walls of the structure, as a result of which the cold air coming from the street is warmed up by the heat exchanger without spending additional energy on heating. This system is more efficient and less energy-consuming than a ventilation system without heat recovery.

The efficiency of the recuperator varies depending on the outside air temperature; it can be calculated using the general formula:

S = (T1 – T2) : (T3 – T2)
Where:

S– recovery efficiency;
T1– temperature of the air entering the room;
T2– air temperature outside;
T3– room air temperature.

Types of recuperators

Plate recuperators

This type of heat exchanger consists of a set of thin plates made of aluminum or any other material, preferably with good heat transfer characteristics). This is the cheapest and most popular type of device (recuperator). The efficiency of a plate recuperator can range from 50% to 90%, and the service life, due to the absence of moving parts, is very long.

The main disadvantage of such recuperators is the formation of ice due to temperature differences. There are three options for solving this problem:

Do not use recovery under extreme conditions low temperatures
Use models with an automated recovery process. IN in this case cold air bypasses the plates, and warm air warms the ice. But it is worth considering that the efficiency of such models in cold weather will decrease by 20%.

Rotary recuperators

The heat exchanger has a moving part - a cylindrical rotor (recuperator), which consists of profiled plates. Heat transfer occurs when the rotor rotates. Efficiency ranges from 75 to 90%. In this case, the rotation speed affects the level of recuperation. The speed can be adjusted independently.

Ice does not form on rotary heat exchangers, but they are more difficult to maintain, unlike plate heat exchangers.

With intermediate coolant

In the case of an intermediate coolant, as in plate recuperators, two channels are provided for clean and exhaust air, but heat exchange occurs through a water-glycol solution or water. The efficiency of such a device is below 50%.

Chamber recuperators

In this form, the air passes through a special chamber (recuperator), which has a movable damper. It is the damper that has the ability to redirect the flow of cold and hot air. Due to such periodic switching of air flows, recovery occurs. However, in such a system there is a partial mixing of outgoing and incoming air flows, which leads to the entry of foreign odors back into the room, but, in turn, this design has a high efficiency of 80%.

Heat pipes

This mechanism has many tubes, which are assembled into a single sealed block, and inside the tubes are filled with a special easily condensing and evaporating substance, most often freon. Warm air, passing through a certain part of the tubes, heats and evaporates it. It moves into the area of the tubes through which cold air passes and heats it with its heat, while the freon cools and this can lead to the formation of condensation. The advantage of this design is that polluted air does not enter the room. Optimal application heat pipes possible in small spaces V climatic zones with a small difference between internal and external temperatures.

Sometimes recovery is not enough to heat the room at low outside temperatures, so electric or water heaters are often used in addition to recovery. In some models, heaters perform the function of protecting the heat exchanger from icing.

Creating an energy efficient administrative building, which will be as close as possible to the “PASSIVE HOUSE” standard, is impossible without modern air handling unit(PVU) with heat recovery.

Under recovery means the process of recycling heat from internal exhaust air with temperature t in, emitted during the cold period with high temperature to the street, to heat the supply of outside air. The process of heat recovery occurs in special heat recuperators: plate recuperators, rotating regenerators, as well as in heat exchangers installed separately in air currents with different temperatures (in exhaust and supply units) and connected by an intermediate coolant (glycol, ethylene glycol).

The last option is most relevant in the case when the supply and exhaust are spaced along the height of the building, for example, Supply unit- in the basement, and the exhaust - in attic, however, the recovery efficiency of such systems will be significantly less (from 30 to 50% compared to PES in one building

Plate recuperators They are a cassette in which the supply and exhaust air channels are separated by aluminum sheets. Heat exchange occurs between the supply and exhaust air through aluminum sheets. The internal exhaust air through the recuperator plates heats the external supply air. In this case, the air mixing process does not occur.

IN rotary recuperators heat transfer from the exhaust air to the supply air is carried out through a rotating cylindrical rotor consisting of a package of thin metal plates. During operation of a rotary heat exchanger, the exhaust air heats the plates, and then these plates move into the flow of cold outside air and heat it. However, in the flow separation units, due to their leakage, the exhaust air flows into the supply air. The percentage of overflow can be from 5 to 20% depending on the quality of the equipment.

In order to achieve the set goal - to bring the building of the Federal State Institution "Research Institute CEPP" closer to passive, during long discussions and calculations, it was decided to install supply and exhaust ventilation units with a recuperator from a Russian manufacturer of energy-saving climate systems– companies TURKOV.

Company TURKOV produces PES for the following regions:

For the Central region (equipment with two-stage recovery ZENIT series, which works stably down to -25 O C, and is excellent for the climate of the Central region of Russia, efficiency 65-75%);
For Siberia (equipment with three-stage recovery Zenit HECO series works stably down to -35 O C, and is excellent for the climate of Siberia, but is often used in the central region, efficiency 80-85%);
For the Far North (equipment with four-stage recovery CrioVent series works stably down to -45 O C, excellent for extremely cold climates and used in the harshest regions of Russia, efficiency up to 90%).

Traditional teaching aids, based on the old school of engineering, criticize companies that claim high efficiency of plate recuperators. Justifying this by what to achieve given value Efficiency is only possible when using energy from absolutely dry air, and in real conditions with a relative humidity of the exhaust air = 20-40% (in winter period) the level of dry air energy use is limited.

However, the TURKOV PVU uses enthalpy plate recuperator, in which, along with the transfer of implicit heat from the exhaust air, moisture is also transferred to the supply air.
The working area of the enthalpy recuperator is made of a polymer membrane, which passes water vapor molecules from the exhaust (humidified) air and transfers them to the supply (dry) air. There is no mixing of the exhaust and supply flows in the recuperator, since moisture is passed through the membrane through diffusion due to the difference in vapor concentration on both sides of the membrane.

The dimensions of the membrane cells are such that only water vapor can pass through it; for dust, pollutants, water droplets, bacteria, viruses and odors, the membrane is an insurmountable barrier (due to the ratio of the sizes of the membrane “cells” and other substances).

Enthalpy recuperator essentially a plate recuperator, where aluminum is used instead polymer membrane. Since the thermal conductivity of the membrane plate is less than that of aluminum, the required area of the enthalpy recuperator is significantly larger than the area of a similar aluminum recuperator. On the one hand, this increases the dimensions of the equipment, on the other hand, it allows the transfer of a large volume of moisture, and it is thanks to this that it is possible to achieve high frost resistance of the recuperator and stable operation of the equipment at ultra-low temperatures.

IN winter time(outdoor temperature below -5C), if the humidity of the exhaust air exceeds 30% (at an exhaust air temperature of 22...24 o C), in the recuperator, along with the process of transferring moisture to the supply air, the process of moisture accumulation on the recuperator plate occurs. Therefore, it is necessary to periodically turn off supply fan and drying the hygroscopic layer of the recuperator with exhaust air. The duration, frequency and temperature below which the drying process is required depends on the staging of the recuperator, the temperature and humidity inside the room. The most commonly used recuperator drying settings are shown in Table 1.

Table 1. Most commonly used heat exchanger drying settings

Recuperator stages	Temperature/Humidity
	<20%	20%-30%	30%-35%	35%-45%
2 steps	not required	3/45 min	3/30 min	4/30 min
3 steps	not required	3/50 min	3/40 min	3/30 min
4 steps	not required		3/50 min	3/40 min

Note: Setting up the drying of the recuperator is carried out only in agreement with the technical staff of the manufacturer and after providing the internal air parameters.

Drying the recuperator is required only when installing air humidification systems, or when operating equipment with large, systematic moisture inflows.

With standard indoor air parameters, the drying mode is not required.

The recuperator material undergoes mandatory antibacterial treatment, so it does not accumulate contamination.

In this article, as an example of an administrative building, we consider a typical five-story building of the Federal State Institution “Research Institute of Central Electrical Equipment” after the planned reconstruction.
For this building, the flow of supply and exhaust air was determined in accordance with air exchange standards in administrative premises for each room of the building.
The total values of supply and exhaust air flow rates by building floors are given in Table 2.

Table 2. Estimated flow rates of supply/exhaust air by building floors

Floor	Supply air flow, m 3/h	Exhaust air flow, m 3/h	PVU TURKOV
Basement	1987	1987	Zenit 2400 HECO SW
1st floor	6517	6517	Zenit 1600 HECO SW Zenit 2400 HECO SW Zenit 3400 HECO SW
2nd floor	5010	5010	Zenit 5000 HECO SW
3rd floor	6208	6208	Zenit 6000 HECO SW Zenit 350 HECO MW - 2 pcs.
4th floor	6957	6957	Zenit 6000 HECO SW Zenit 350 HECO MW
5th floor	4274	4274	Zenit 6000 HECO SW Zenit 350 HECO MW

In laboratories, PVUs operate according to a special algorithm with compensation for the exhaust from fume hoods, i.e., when any fume hood is turned on, the AHU hood is automatically reduced by the amount of the cabinet hood. Based on the estimated costs, Turkov air handling units were selected. Each floor will be served by its own Zenit HECO SW and Zenit HECO MW PVU with three-stage recovery up to 85%.
Ventilation of the first floor is carried out by PVU, which are installed in the basement and on the second floor. Ventilation of the remaining floors (except for laboratories on the fourth and third floors) is provided by PVU installed on the technical floor.
The appearance of the Zenit Heco SW installation PES is shown in Figure 6. Table 3 shows the technical data for each installation PES.

Installation Zenit Heco SW includes:

Housing with heat and noise insulation;
Supply fan;
Exhaust fan;
Supply filter;
Exhaust filter;
3-stage recuperator;
Water heater;
Mixing unit;
Automation with a set of sensors;
Wired remote control.

An important advantage is the possibility of installing equipment both vertically and horizontally under the ceiling, which is used in the building in question. As well as the ability to place equipment in cold areas (attics, garages, technical rooms, etc.) and on the street, which is very important during restoration and reconstruction of buildings.

Zenit HECO MW PVU is a small PVU with heat and moisture recovery with a water heater and a mixing unit in a lightweight and versatile polypropylene foam housing, designed to maintain the climate in small rooms, apartments, and houses.

Company TURKOVhas independently developed and produces Monocontroller automation for ventilation equipment in Russia. This automation is used in the Zenit Heco SW PVU

The controller controls electronically commutated fans via MODBUS, which allows you to monitor the operation of each fan.
Controls water heaters and coolers to accurately maintain supply air temperature in both winter and summer.
For CO control 2 in the conference room and meeting rooms the automation is equipped with special CO sensors 2 . The equipment will monitor the CO concentration 2 and automatically change the air flow, adjusting to the number of people in the room, to maintain the required air quality, thereby reducing the heat consumption of the equipment.
A complete dispatch system allows you to organize a dispatch center as simply as possible. A remote monitoring system will allow you to monitor equipment from anywhere in the world.

Control panel capabilities:

Clock, date;
Three fan speeds;
Real-time filter status display;
Weekly timer;
Setting the supply air temperature;
Display of faults on the display.

Efficiency mark

To assess the efficiency of the installation of Zenit Heco SW air handling units with recuperation in the building under consideration, we will determine the calculated, average and annual loads on the ventilation system, as well as costs in rubles for the cold period, warm period and for the entire year for three PVU options:

PVU with recovery Zenit Heco SW (recuperator efficiency 85%);
Direct-flow PVU (i.e. without a recuperator);
PVU with heat recovery efficiency of 50%.

The load on the ventilation system is the load on the air heater, which heats (during the cold period) or cools (during the warm period) the supply air after the recuperator. In a direct-flow PVU, the air in the heater is heated from the initial parameters corresponding to the parameters of the outside air during the cold period, and is cooled during the warm period. The results of calculating the design load on the ventilation system in the cold period by floor of the building are shown in Table 3. The results of calculating the design load on the ventilation system in the warm period for the entire building are given in Table 4.

Table 3. Estimated load on the ventilation system during the cold period by floor, kW

Floor	PVU Zenit HECO SW/MW	Direct-flow PVU	PES with recovery 50%
Basement	3,5	28,9	14,0
1st floor	11,5	94,8	45,8
2nd floor	8,8	72,9	35,2
3rd floor	10,9	90,4	43,6
4th floor	12,2	101,3	48,9
5th floor	7,5	62,2	30,0
54,4	450,6	217,5

Table 4. Estimated load on the ventilation system during the warm period by floor, kW

Floor	PVU Zenit HECO SW/MW	Direct-flow PVU	PES with recovery 50%
20,2	33,1	31,1

Since the calculated outdoor air temperatures in the cold and warm periods are not constant during the heating and cooling periods, it is necessary to determine the average ventilation load at the average outdoor temperature:
The results of calculating the annual load on the ventilation system during the warm period and cold period for the entire building are shown in Tables 5 and 6.

Table 5. Annual load on the ventilation system during the cold period by floor, kW

Floor	PVU Zenit HECO SW/MW	Direct-flow PVU	PES with recovery 50%
66105	655733	264421
66,1	655,7	264,4

Table 6. Annual load on the ventilation system during the warm period by floor, kW

Floor	PVU Zenit HECO SW/MW	Direct-flow PVU	PES with recovery 50%
12362	20287	19019
12,4	20,3	19,0

Let us determine the costs in rubles per year for additional heating, cooling and fan operation.
The consumption in rubles for reheating is obtained by multiplying the annual values of ventilation loads (in Gcal) during the cold period by the cost of 1 Gcal/hour of thermal energy from the network and by the operating time of the PVU in heating mode. The cost of 1 Gcal/h of thermal energy from the network is taken to be 2169 rubles.
The costs in rubles for operating fans are obtained by multiplying their power, operating time and the cost of 1 kW of electricity. The cost of 1 kWh of electricity is taken to be 5.57 rubles.
The results of calculations of costs in rubles for the operation of the PES in the cold period are shown in Table 7, and in the warm period in Table 8. Table 9 shows a comparison of all options for the PES for the entire building of the Federal State Institution "Research Institute TsEPP".

Table 7. Expenses in rubles per year for the operation of the PES during the cold period

Floor	PVU Zenit HECO SW/MW		Direct-flow PVU		PES with recovery 50%
	For reheating	For fans	For reheating	For fans	For reheating	For fans
Total costs	*368 206*	337 568	3 652 433	337 568	1 472 827	337 568

Table 8. Expenses in rubles per year for the operation of the PES during the warm period

Floor	PVU Zenit HECO SW/MW		Direct-flow PVU		PES with recovery 50%
	For cooling	For fans	For cooling	For fans	For cooling	For fans
Total costs	*68 858*	141 968	112 998	141 968	105 936	141 968

Table 9. Comparison of all PES

Magnitude	PVU Zenit HECO SW/MW	Direct-flow PVU	PES with recovery 50%
, kW	54,4	450,6	217,5
20,2	33,1	31,1
25,7	255,3	103,0
11,4	18,8	17,6
66 105	655 733	264 421
12 362	20 287	19 019
	78 468	676 020	283 440
Reheating costs, rub	122 539	1 223 178	493 240
Cooling costs, rub	68 858	112 998	105 936
Costs of fans in winter, rub.	337 568
Costs of fans in summer, rub.	141 968
*Total annual costs, rub*	*670 933*	*1 815 712*	*1 078 712*

An analysis of Table 9 allows us to draw an unambiguous conclusion - the air handling units Zenit HECO SW and Zenit HECO MW with heat and moisture recovery from Turkov are very energy efficient.
The total annual ventilation load of the TURKOV PVU is less than the load in the PVU with an efficiency of 50% by 72%, and in comparison with the direct-flow PVU by 88%. Turkov PVU will allow you to save 1 million 145 thousand rubles - in comparison with direct-flow PVU or 408 thousand rubles - in comparison with PVU, the efficiency of which is 50%.

Where else are the savings...

The main reason for failures in the use of systems with recovery is the relatively high initial investment, however, with a more complete look at the costs of development, such systems not only quickly pay for themselves, but also make it possible to reduce the overall investment during development. As an example, let’s take the most widespread “standard” development with use of residential, office buildings and shops.
Average heat loss of finished buildings: 50 W/m2.

Included: Heat loss through walls, windows, roofing, foundation, etc.

The average value of general supply ventilation is 4.34 m 3 / m 2

Included:

Ventilation of apartments based on the purpose of the premises and multiplicity.
Ventilation of offices based on the number of people and CO2 compensation.
Ventilation of shops, corridors, warehouses, etc.
The ratio of areas was chosen based on several existing complexes

Average ventilation value to compensate for bathrooms, bathrooms, kitchens, etc. 0.36 m3/m2

Included:

Compensation for toilets, bathrooms, kitchens, etc. Since it is impossible to organize an intake from these rooms into the recovery system, an influx is organized into this room, and the exhaust goes through separate fans past the recuperator.

The average value of general exhaust ventilation is 3.98 m3/m2, respectively

The difference between the amount of supply air and the amount of compensation air.
It is this volume of exhaust air that transfers heat to the supply air.

So, it is necessary to develop the area with standard buildings with a total area of 40,000 m2 with the specified heat loss characteristics. Let's see what savings can be achieved by using ventilation systems with recovery.

Operating costs

The main purpose of choosing recuperation systems is to reduce the cost of operating equipment by significantly reducing the required thermal power to heat the supply air.
With the use of supply and exhaust ventilation units without recovery, we will obtain a heat consumption of the ventilation system of one building of 2410 kWh.

Let's take the cost of operating such a system as 100%. There are no savings at all - 0%.

Using stacked supply and exhaust ventilation units with heat recovery and an average efficiency of 50%, we will obtain a heat consumption of the ventilation system of one building of 1457 kWh.

Operating cost 60%. Saving with typesetting equipment 40%

Using monoblock highly efficient TURKOV supply and exhaust ventilation units with heat and moisture recovery and an average efficiency of 85%, we will obtain a heat consumption of the ventilation system of one building of 790 kWh.

Operating cost 33%. Savings with TURKOV equipment 67%

As you can see, ventilation systems with highly efficient equipment have lower heat consumption, which allows us to talk about the payback of the equipment within 3-7 years when using water heaters and 1-2 years when using electric heaters.

Construction costs

If construction is carried out in the city, it is necessary to extract a significant amount of thermal energy from the existing heating network, which always requires significant financial costs. The more heat required, the more expensive the supply cost will be.
Construction “in the field” often does not involve the supply of heat; gas is usually supplied and the construction of your own boiler house or thermal power plant is carried out. The cost of this structure is proportional to the required thermal power: the more, the more expensive.
As an example, assume that a boiler house with a capacity of 50 MW of thermal energy has been built.
In addition to ventilation, heating costs for a typical building with an area of 40,000 m2 and heat loss of 50 W/m2 will be about 2000 kWh.
Using supply and exhaust ventilation units without recovery, it will be possible to build 11 buildings.
With the use of stacked supply and exhaust ventilation units with heat recovery and an average efficiency of 50%, it will be possible to construct 14 buildings.
Using monoblock highly efficient TURKOV supply and exhaust ventilation units with heat and moisture recovery and an average efficiency of 85%, it will be possible to construct 18 buildings.
The final estimate for supplying more thermal energy or building a high-capacity boiler house is significantly more expensive than the cost of more energy-efficient ventilation equipment. With the use of additional means of reducing the heat loss of a building, it is possible to increase the building size without increasing the required heating output. For example, by reducing heat loss by only 20%, to 40 W/m2, you can build 21 buildings.

Features of equipment operation in northern latitudes

As a rule, equipment with recovery has restrictions on the minimum outdoor air temperature. This is due to the capabilities of the recuperator and the limit is -25...-30 o C. If the temperature drops, the condensate from the exhaust air will freeze on the recuperator, therefore at ultra-low temperatures an electric preheater or a water preheater with non-freezing liquid is used. For example, in Yakutia the estimated street air temperature is -48 o C. Then classical systems with recovery work as follows:

o With preheater heated to -25 o C (Thermal energy consumed).
C -25 o The air is heated in the recuperator to -2.5 o C (at 50% efficiency).
C -2.5 o The air is heated by the main heater to the required temperature (thermal energy is consumed).

When using a special series of equipment for the Far North with 4-stage recovery TURKOV CrioVent, preheating is not required, since 4 stages, a large recovery area and moisture return prevent the recuperator from freezing. The equipment operates in a graying manner:

Street air with a temperature of -48 o C heats up in the recuperator to 11.5 o C (efficiency 85%).
From 11.5 o The air is heated by the main heater to the required temperature. (Thermal energy is consumed).

The absence of preheating and high efficiency of the equipment will significantly reduce heat consumption and simplify the design of the equipment.
The use of highly efficient recovery systems in northern latitudes is most relevant, since low outside air temperatures make the use of classical recovery systems difficult, and equipment without recovery requires too much thermal energy. Turkov equipment successfully operates in cities with the most difficult climatic conditions, such as: Ulan-Ude, Irkutsk, Yeniseisk, Yakutsk, Anadyr, Murmansk, as well as in many other cities with a milder climate in comparison with these cities.

Conclusion

The use of ventilation systems with recovery allows not only to reduce operating costs, but in the case of large-scale reconstruction or capital development, to reduce the initial investment.
Maximum savings can be achieved in middle and northern latitudes, where equipment operates in difficult conditions with prolonged negative outdoor temperatures.
Using the example of the building of the Federal State Institution "Research Institute TsEPP", a ventilation system with a highly efficient recuperator will save 3 million 33 thousand rubles per year - in comparison with a direct-flow PVU and 1 million 40 thousand rubles per year - in comparison with a stacked PVU, the efficiency of which is 50%.

Modern technologies that have come to our country encourage the population to also use the latest developments. Solar panels, room temperature controllers and other smart devices can not only reduce utility bills, but also maintain a comfortable room temperature. Of course, a recuperator for a private home cannot be called an innovation, however, the savings in money and heat energy are obvious.

This device is a design similar to a house ventilation system. Their difference lies in the fact that conventional ventilation removes stale air from the room and fills it with fresh air. The recuperator performs similar actions, only it brings heated warm or cooled air into the house. An air conditioner performs similar functions, however, it requires electricity and a refrigerant - freon; the heat recovery unit does without it. Heating or cooling of the inflow occurs due to the heat exchange of the primary and secondary coolant through the wall separating the air masses.

The main link of the air handling unit with a recuperator is the heat exchanger. The device is equipped with a thermal electric heater or fan, check valves to prevent air movement in the opposite direction, and much more.

The use of such a system makes it possible to recover part of the thermal energy that is usually lost when passing through ventilation ducts. Warm air masses circulate freely in the heat exchanger, come into contact with the cold flow through the dividing wall and transfer their thermal energy to the latter.

A surface-type recuperator is a heat exchanger with double walls. One channel is occupied by the outgoing primary, the other by the secondary, cooler one. The walls have high thermal conductivity and are installed to prevent mixing of air flows of different temperatures. The outgoing air element passes along the box, the incoming air element crosses. As a result of heat transfer to cold air, heated air masses enter the house.

The temperature of the incoming air depends on the temperature of the outgoing air. The warmer the outgoing stream is, the higher the supply temperature.

Operating principle

The principle of operation of the recuperator is that it accumulates heat from the removed flow and communicates it with high efficiency to the air supply masses. This allows you to save money and supply a fresh heated air element into the house.

The operating principle of the system is determined by two principles:

Waste or stale air masses are removed from the room, pass through the ceramic recovery chamber and heat it. In this case, almost 97% of the thermal energy is released. When the recovery chamber heats up, the heat exchanger automatically switches to the fresh jet inflow mode.
The air passes through the ceramic recovery chamber, is heated by the heat accumulated in it and is supplied to the house. Cooling of the regenerator serves as a signal to turn on the fan in exhaust mode.

Such a recuperator ventilation system allows you to reduce the consumption of gaseous, solid or liquid fuel, which may be necessary for the operation of other devices, and create comfortable living conditions.

Note! Installing a supply and exhaust air recuperator for your home will save up to 80% of the heat in the room.

Advantages of a thermal power device

A thermal power device of this type has been gaining great popularity recently. There is no need to ventilate the home in summer and winter, thereby releasing precious heat outside. On a dusty summer day, the device will supply the room with clean atmospheric air, which will first pass through an air purification filter.

There is also no need to use the mentioned system manually - the automation will do it for you. Cold masses in winter will be heated due to the outgoing warm flow, and hot summer days will cool down when heat is transferred to a cooler flow.

In addition, the system is characterized by the following number of advantages:

saving money on heating;
savings on separate exhaust fans;
removal of unpleasant heavy odors;
removal of dust particles;
ease of operation and installation;
low cost of use;

process automation;
long service life of the system.

Even periodic use of a heating installation will allow you to saturate your home with clean atmospheric air masses without losing heat or, conversely, increasing the temperature.

High-quality ventilation

Installing a recuperator will keep the house clean along with the flow of fresh outside air. Tobacco, fireplace or smoke of other origins, carbon dioxide or other unhealthy emissions, harmful or unpleasant odors - a rotary heat exchanger can handle everything. The operation of the system has a beneficial effect on the human body, drying air with high humidity, which is especially important for hypertensive patients, as well as people with atherosclerosis or cardiovascular diseases. In addition, high humidity threatens other ailments.

Economical heating

By installing a heat exchanger, you will ensure stable savings not only in money, but also in the heat in the house. The outgoing warm flow will warm the cold supply air to a comfortable temperature, which will significantly avoid unnecessary operation of heating equipment. The heating system carefully handles the heat entering its box, practically preventing it from escaping into the atmosphere. There is also no need to monitor the temperature of the incoming air masses; this will be done by the heat exchanger, supplying them with only a small temperature difference compared to the outgoing flow.

Important! According to experts, savings in electricity or any type of fuel for heating devices range from 40 to 50%. Of course, you should not neglect the high-quality thermal insulation of the room.

No additional ventilation

Gas stoves, fireplaces, water heaters and weeping metal-plastic windows require additional ventilation or periodic ventilation. Frosty and hot periods of the year significantly complicate this process: the first threatens to cool the room, the second threatens with dust and hot dry winds with low humidity. If you decide to buy an air recuperator, you will ensure high-quality ventilation of the entire house, avoiding unnecessary financial expenses and installation of equipment for additional ventilation.

Silent and high-quality air purification

Atmospheric supply air in any case brings with it dust particles, dirt elements, diluted exhaust gases from cars, chimneys and industrial enterprises. The air filter installed in the heat-energy device will rid the house of unwanted odors and dust particles. After undergoing high-quality cleaning, the atmospheric stream will fill the room with not only fresh, but also clean air. True, the latter will be determined by the necessary regular maintenance of the air filter and other elements of the system.

Note! A filter clogged with dust or uncleaned is a breeding ground for pathogenic bacteria. Its regular cleaning and periodic replacement will allow the home owner to avoid infectious respiratory diseases.

Recyclers for an apartment or house have high operating efficiency and low noise levels, which range from 25-35 dB. This is equivalent to the sound made by an air conditioner.

Recuperator for a private home: types and characteristics

Supply and exhaust recuperators can have various design features. A sales consultant in any specialized store of heating devices will help you choose the appropriate option.

The following types of equipment exist:

lamellar;
rotary;
roof;
recirculating water.

All of them are designed to create a favorable indoor climate, be it an apartment, a large mansion or a country house.

Related article:

Types and features of devices, additional functions. Power calculation based on room parameters. Care tips.

Lamellar

It is the most common type due to its good performance, ease of operation and low price. This type of recuperator consists of fixed metal plates with a high specific heat capacity and relatively low weight. The plates are collected in a kind of cassette, which slightly resembles a beehive. Atmospheric air passes through the apparatus box with cassettes and is then heated or cooled, depending on the winter or summer season. The condensate formed during operation is discharged through a specially available drainage outlet or channel.

Along with the listed advantages, the system has a certain disadvantage: the formation of ice in the box, which is especially evident in the autumn-winter period.

Rotary

A recuperator of this type carries out the inflow and outflow of the air stream due to the blades. The thermal energy system has from one to two drive rotors, depending on the model. Externally, the installation looks like a cylindrical barrel with a drum. As air is pumped out of the room and the cylindrical box is heated, atmospheric mass is taken in.

Advantages of this device:

improved efficiency;
increased efficiency;
absence of condensate, and, consequently, drainage gutters;
absence of ice;

does not dry out the air, which does not require additional humidification;
adjusting the amount of air supply and intake due to the speed of rotation of the blades.

However, there are also disadvantages:

increased electricity consumption;
rotating elements wear out faster than stationary ones;
the need for additional exhaust to prevent possible mixing of incoming and outgoing air masses.

Note! Before purchasing a rotary heat exchanger, you need to take into account its increased power, which can lead to an increase in the cross-section of the electrical wiring of the room.

Roof

This recuperator processes large masses of air. The expediency of its use can be explained by a large mansion, other residential or non-residential premises. The principle of operation is in many ways similar to the plate unit, however, the latter differs from the roof unit in its smaller size. The ease of installation of the device, low cost of maintenance and operation have made it indispensable in ventilation devices of shops, repair shops, and production areas. Installing such a recuperator on the roof generally eliminates the penetration of any sounds or noise into the room.

Glycol recuperator

The glycol (or recirculation) regenerative apparatus combines the qualities of plate and rotary thermal devices. Its main difference from the previous ones is the use of an intermediate coolant. The last is a water-glycol solution consisting of propylene glycol or ethylene diluted with distilled water. The mixture has a high heat capacity, which allows it to utilize a large amount of heat, and retains its working qualities at sub-zero temperatures. In severe low-temperature conditions, it is possible to replace the specified coolant with antifreeze. The equipment allows you to work simultaneously with several ventilation ducts, hoses or hoods.

Recuperator for an apartment: calculation and review of manufacturers

An apartment heat and power device will be the best purchase, especially if the home is located in a big city or the center of a metropolis. Automotive and industrial gases, street noise, heat or cold will forever remain outside the room. The device will not only add a lot of clean air to the apartment, but will also allow you to save on heating, ventilation and cleaning the incoming atmospheric flow. This is achieved by simple heat exchange between the supply and exhaust flows passing through a heat-insulating box with a cleaning filter.

Recuperator calculation

You can calculate the required heat and power device yourself, without resorting to the services of specialized companies. Calculation of the efficiency and efficiency of the device is determined by knowledge of the energy costs for the supply or exhaust masses. The calculation formula is:

Q = 0.335 x L x (t 1 – t 2),

where L is the flow of air masses, t 1 is the temperature of the inflow, t 2 is the temperature of the outgoing masses, 0.335 is the regional coefficient.

The efficiency is calculated using the following formula:

E = Q x n,

where: Q – energy or electrical costs for heating or cooling the jet, n – device efficiency.

Helpful advice! Before buying a recuperator for a private house or city apartment, you need to familiarize yourself with their types, technical characteristics and operating principles. It may be necessary to carry out preparatory installation work and draw up a project.

Recuperator PRANA

This manufacturer of heat power and ventilation equipment has been on the market for more than 15 years. Its equipment has a long service life, high efficiency and reasonable prices.

Operating characteristics of the device:

type – lamellar;
electricity consumption – 5-90 V/hour, depending on the model;
noise level – 25-140 dB;
unit length – 500 mm;
incoming jet – 115-650 m³/h;
outgoing jet – 105-610 m³/h;
Efficiency – 79-80%, depending on the model.

The entire model range is equipped with a remote control and operates at ambient temperatures from -15 to 45°C. The relatively low price of the air recuperator, significant retention of the set temperature during heating or heating, and small dimensions make this device one of the most popular, which is confirmed by numerous positive reviews. The Prana recuperator can be built into the wall of a room or installed outdoors. Installation of the device is quite easy and is carried out within 2-3 hours.

You can notice such a decentralized system only by the presence of a ventilation grill on the wall. Not the least positive quality is heat exchangers made of copper, which has an antimicrobial effect. The average price of an air recuperator for a home of this brand is about 25,000 rubles. The cost of devices with increased productivity ranges from 50 to 110 thousand rubles.

Recuperators MARLEY

The compact German heat exchanger is equipped with a ceramic heat exchange element, which allows the device to be operated even at a temperature of -30ºC. Washing it and cleaning the air filters is a simple operation that can be carried out by the average user. The duration of continuous operation is about 6 months, after this period the indicator light will light up. Operating the device near highways or in the central part of the city will require more frequent cleaning. This operation does not take much time and lasts 15-20 minutes.

You can buy an air recuperator for your home, the price of which is 24,000 rubles, in a specialized store. At a fairly moderate cost, the device has the following performance characteristics:

three power phases – 15, 25 and 40 m³/h;
electrical power consumption – from 3.5 to 8 W;
The electric motor rotor is brushless;
noise level – 22, 29 and 35 dB;
heat recovery – 80-85%;
service area – from 60 m²;
external dimensions – 285-500 mm. The small dimensions of the unit allow it to be installed in the wall.

A new line from the manufacturer Marley is the menv 180 recuperator, which differs from previous analogues in its low power consumption - only 3 W. Nice functional additions are:

temperature, carbon dioxide and humidity controllers;
improved aerodynamics;
low noise level;
waterproofing coating for work in damp residential or non-residential premises;
high category of supply jet cleaning.

By installing such a recuperator, the price of which is around 27,500 rubles, you will forget about street soot and exhaust gases, dust, fog and emissions from industrial enterprises.

DIY recuperator

Any craftsman can make an air recuperator for the home with his own hands. For this you will need:

two sheets of galvanized steel;
wood-laminated box for the shell of the apparatus;
cork gaskets;
silicone neutral sealant;
pressure controller;
metal corners;
thermal insulating mineral wool.

An electric jigsaw, metal fasteners and connecting flanges will also be useful for the work.

Steel sheets must be cut into rectangular plates measuring 200x300 mm. To do this you will need about 3–4 m² of steel. Cutting must be done very carefully so that the sections do not have burrs or nicks. For this purpose, it is recommended to use a special tool - a grinder or a hacksaw.

Then the plates are stacked on top of each other with a gap of at least 4 mm. This distance is ensured by gluing along the perimeter of each element of thermal insulation material (cork, wood or textolite). After laying the plates, the joints are treated with a special neutral sealant.

The housing is then fabricated and sized to fit inside its plate structure. Holes are cut in the walls of the housing into which pre-prepared plastic flanges are inserted, which must correspond to the diameter of the air ducts. All joints are also carefully sealed.

When the sealant has dried, the plate structure is placed inside the housing. External walls must be lined with thermal insulation material, for example, polystyrene foam or glass wool. The finished structure, in order to enhance the aesthetic component, can be placed in a wooden box.

Note! Visually noticeable crevices and slits in the box of a self-assembled recuperator for a private home must be filled with silicone neutral hermetic mass.

Previously, recuperators and ventilation systems were installed only in industrial production, coal and mining mines. Today, heating devices for exhaust gas recovery are increasingly located in houses and apartments.

An industrial device or a self-assembled air recuperator becomes our indispensable assistant. It supplies clean cooled or heated atmospheric air, cleans the house of dust and unpleasant odors and saves some money on heating the room.

Supply and exhaust unit is a modern solution for organizing optimal air exchange and rational use of energy resources. The principle of operation is to force the influx and removal of air outside the room. Based on the installation's PVC, you can create an individual microclimate system by connecting various filters and devices.

Recuperation ventilation system

To save thermal energy, some PES installations are equipped with recuperators. The recuperator is a metal heat exchanger that is integrated into the ventilation system and partially heats the outside air due to the removed warm air. In this case, the bulk of the air flow is heated by a conventional air heater. Although the price of a supply and exhaust unit with heat recovery is higher than for other devices, due to energy efficiency these costs quickly pay off. An important characteristic of the device is its efficiency factor, which ranges from 30 to 96% depending on the type of recuperator, the speed of air flow through the heat exchanger and the temperature difference.

Supply and exhaust ventilation with recovery fully meets modern requirements for saving thermal energy. And thanks to the room heating function, it is considered the most promising development in the field of ventilation.

Main advantages:

Comfortable air exchange
Efficient energy saving
Humidity control function
Reliable sound insulation
High efficiency up to 96%
Convenient control system
Air purification from dust and impurities
Maximum thermal energy conservation

Classification and characteristics of devices.

Depending on the design of the heat exchanger, a heat exchanger with a recuperator can be of several types:

Plate recuperators are the most common design. Heat exchange occurs by passing air through a series of plates. During operation, condensate forms, so the recovery system is additionally equipped with a condensate drain. Efficiency is 50-75%.

A rotary-type heat recuperator is a cylindrical device densely filled with layers of corrugated steel. Heat exchange is carried out by a rotating rotor, which sequentially passes first warm and then cold air. In this case, the intensity depends on the rotor rotation speed. The supply and exhaust system with recovery of this type is large in size, so it is suitable for shopping centers, hospitals, hotels and other large premises. Due to the absence of freezing, efficiency reaches 75-85%

Less common types include recuperators with an intermediate coolant (this can be water or a water-glycol solution). Efficiency is 40-60%. A supply and exhaust unit with a recuperator can be made in the form of heat pipes filled with freon. The efficiency of such a device is 50-70%. In addition, a chamber recuperator is used. Cold and warm air pass through one chamber, which is separated by a special damper. Periodically, the damper turns over and the air flows change places. Efficiency is up to 90%.

Supply and exhaust ventilation with heat recovery best price!

A wide range of PVC installations for various purposes, performance, configuration and cost are available for order in the Yanvent online store.

Thanks to a convenient search form, you can easily find a suitable model and buy an air handling unit with recovery at the best price!

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 cost of purchasing and installing the system quickly pays 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. An important characteristic of the equipment is the level of efficiency of the recuperator. This value for different types of 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:

carry out constant change of 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 a common air conditioning system is especially relevant. 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 a separate room in the basement, basement or attic. If installation in the attic is necessary, it will need to be additionally soundproofed to prevent heat loss and condensation in the 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 a better comparison, we present the types of recuperators in a separate table.

type of instalation	Short description	Advantages	Flaws
Lamellar with plastic and metal plates	The outgoing and incoming flow passes on both sides of the plates. The average efficiency level is 50-75%.	The streams do not touch directly. There are no moving parts in the circuit, so this design is reliable and durable.	Not identified
Lamellar, with ribs made of water-conducting materials.	The efficiency of the devices is 50-75%, air flows on both sides.	There are no moving parts. Air mass flows do not contact each other. There is no condensation in the system.	There is no possibility of dehumidifying the air in the serviced room.
Rotary	High level of efficiency 75-85%. The flows pass through separate foil-coated channels.	Significantly saves energy and can reduce air humidity in serviced areas.	Possible mixing of air masses and penetration of an unpleasant odor. Requires maintenance and repair of a complex structure with rotating parts.
Air recuperator with exposure to intermediate coolant	A solution of water and glycol is used as a coolant or filled with purified water. In this scheme, the exiting gas gives off heat to the water, which heats the incoming flow. Designed for servicing industrial premises.	There is no contact between the flows, so their mixing and the flow of exhaust gases are excluded.	Low level of efficiency
Chamber recuperators	A damper is installed in the chamber of the device, capable of increasing the magnitude of the passing flow and changing the vector of its direction.	Due to its design features, this type of equipment has a high level of efficiency, 70-80%.	The flows are in contact, so the incoming air may become contaminated.
Heat pipe	The device is equipped with a system of freon-filled tubes.	There are no moving mechanisms, the service life is increased. The air comes in clean, there is no contact between the flows.	Low level of efficiency, it is 50-70%.

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:

Possibility of condensation formation. When flows of air masses with a high heating temperature pass through and come into contact with cold atmospheric air, water droplets fall out on the walls of the chamber in a closed 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.
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 of various types of equipment 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.

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 over a 10-year 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, supply and exhaust units with a built-in heat recuperator can be protected from 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;
The most reliable method that eliminates the possibility of freezing of the recuperator fins is to equip the device with an electronic control system for defrosting, the activation of which takes into account several parameters. To do this, it may be necessary to set the date for switching on the electric heaters of the 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 the supply ventilation is turned on, 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:

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.
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.
Based on the building standards of 08/2/01-89, standards for the frequency of air replacement in a room of a certain area per hour have been 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 of the supply and exhaust system with a heat recuperator is to create 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.

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