Recovery in ventilation plays an important role, as it allows you to increase the efficiency of the system due to design features. There are different designs of recovery units, each of which has its own pros and cons. The choice of supply and exhaust ventilation system depends on what problems are being solved, as well as on the climatic conditions of the area.
Design features, purpose
Recovery in ventilation is quite new technology. Its action is based on the ability to use the removed heat to heat the room. This happens thanks to separate channels, so the air flows do not mix with each other. The design of recuperative units can be different; some types avoid the formation of condensation during the heat transfer process. The performance level of the system as a whole also depends on this.
Ventilation with heat recovery can produce high efficiency during operation, which depends on the type of heat recovery unit, the speed of air flow through the heat exchanger and how large the difference between the temperature outside and inside the room is. The efficiency value in some cases, when the ventilation system is designed taking into account all factors and has high performance, can reach 96%. But even taking into account the presence of errors in the operation of the system, the minimum efficiency limit is 30%.
The goal of the regenerative unit is to maximize efficient use ventilation resources to further ensure sufficient air exchange in the room, as well as energy savings. Taking into account the fact that supply and exhaust ventilation with recovery operates most of the day, and also taking into account that ensuring a sufficient air exchange rate requires considerable equipment power, the use of a ventilation system with a built-in recovery unit will help save up to 30% of energy.
The disadvantage of this technique can be called quite low efficiency when installed over large areas. In this case, electricity consumption will be high, and the performance of the system aimed at heat exchange between air flows may be noticeably lower than the expected limit. This is explained by the fact that air exchange occurs much faster in small areas than in large objects.
Types of recuperative units
There are several types of equipment used in the ventilation system. Each of the options has advantages and disadvantages, which must be taken into account even when forced ventilation with recovery is just being designed. There are:
- Recuperator plate mechanism. It can be made on the basis of metal or plastic plates. Along with fairly high performance (efficiency is 75%), such a device is susceptible to icing due to the formation of condensation. The advantage is the absence of moving structural elements, which increases the service life of the device. There is also a plate type of recuperative unit with moisture-permeable elements, which eliminates the possibility of condensation. A feature of the plate design is that there is no possibility of mixing two air flows.
- Ventilation systems with heat recovery can operate on the basis of a rotor mechanism. In this case, heat exchange between air flows occurs due to the operation of the rotor. The productivity of this design increases to 85%, but there is a possibility of air mixing, which can bring odors back into the room that are removed outside the room. The advantages include the ability to additionally dry air environment, which allows the use of equipment of this type in premises special purpose with an increased level of importance, for example in swimming pools.
- The chamber mechanism of the recuperator is a chamber that is equipped with a movable damper, which allows odors and contaminants to penetrate back into the room. However this type The design is very productive (efficiency reaches 80%).
- Recuperative unit with intermediate coolant. In this case, heat exchange occurs not directly between two air flows, but through a special liquid (water-glycol solution) or plain water. However, a system based on such a node has low performance (efficiency below 50%). A recuperator with an intermediate coolant is almost always used to organize ventilation in production.
- Regenerative unit based on heat pipes. This mechanism works using freon, which tends to cool, which leads to the formation of condensation. The performance of such a system is at an average level, but the advantage is that there is no possibility of odors and contaminants penetrating back into the room. Ventilation in an apartment with recuperation will be very effective due to the fact that it is necessary to maintain relatively small area. To be able to operate such equipment without negative consequences for it, it is necessary to select a model based on a recuperative unit, which eliminates the possibility of condensation. In places with a fairly mild climate, where the air temperature outside does not reach critical levels, the use of almost any type of recuperator is allowed.
It is impossible to imagine comfortable suburban housing without a good ventilation system, since it is this that is the key to a healthy microclimate. However, many are cautious and even wary about implementing such an installation, fearing huge electricity bills. If certain doubts have settled in your head, we recommend taking a look at a recuperator for a private home.
We are talking about a small unit combined with supply and exhaust ventilation and eliminating excessive consumption of electrical energy in winter period when the air requires additional heating. There are several ways to reduce unwanted expenses. The most effective and affordable way is to make an air recuperator yourself.
What kind of device is this and how does it work? This is what we will discuss in today’s article.
Features and principle of operation
So what is heat recovery? – Recovery is a heat exchange process in which cold air from the street it is heated due to the outflow from the apartment. Thanks to this organizational scheme, a heat recovery installation saves heat in the house. In an apartment in a short period of time and with minimal costs electricity creates a comfortable microclimate.
The video below shows the air recovery system.
What is a recuperator? General concept for the average person.
Economic expediency recuperative heat exchanger depends on other factors:
- energy prices;
- unit installation cost;
- costs associated with servicing the device;
- the duration of operation of such a system.
note! An air recuperator for an apartment is an important, but not the only element necessary for effective ventilation in the living space. Ventilation with heat recovery is a complex system that functions exclusively under the condition of a professional “bundle”.
Recuperator for home
As the temperature drops environment the efficiency of the unit decreases. Be that as it may, a recuperator for a home is vital during this period, since a significant temperature difference “loads” the heating system. If it is 0°C outside the window, then an air flow heated to +16°C is supplied to the living space. Household recuperator for an apartment it copes with this task without any problems.
Formula for calculating efficiency
Modern air recuperators differ not only in efficiency, nuances of use, but also in design. Let's look at the most popular solutions and their features.
Main types of structures
Experts emphasize that there are several types of heat:
- lamellar;
- with separate coolants;
- rotary;
- tubular.
Lamellar type – includes a structure based on aluminum sheets. This recuperator installation is considered the most balanced in terms of the cost of materials and thermal conductivity (efficiency varies from 40 to 70%). The unit is distinguished by its simplicity of execution, affordability, and the absence of moving elements. No specialized training is required for installation. Installation can be done at home, with your own hands, without any difficulties.
Plate type
Rotary– solutions that are quite popular among consumers. Their design includes a rotation shaft, powered from the mains, as well as 2 channels for air exchange with countercurrents. How does this mechanism work? – One of the sections of the rotor is heated by air, after which it turns and the heat is redirected to the cold masses concentrated in the adjacent channel.
Rotary type
Despite the high efficiency, the installations also have a number of significant disadvantages:
- impressive weight and size indicators;
- requirement for regular maintenance, repair;
- it is problematic to reproduce the recuperator with your own hands and restore its functionality;
- mixing of air masses;
- dependence on electrical energy.
You can watch the video below about the types of recuperators (starting from 8-30 minutes)
Recuperator: why is it needed, their types and my choice
note! A ventilation installation with tubular devices, as well as separate coolants, is practically impossible to reproduce at home, even if you have all the necessary drawings and diagrams at hand.
DIY air exchange device
The simplest from the point of view of implementation and subsequent equipment is considered to be a plate-type heat recovery system. This model boasts both obvious “pros” and annoying “cons”. If we talk about the advantages of the solution, then even a homemade air recuperator for the home can provide:
- decent efficiency;
- lack of “connection” to the power grid;
- structural reliability and simplicity;
- availability of functional elements and materials;
- duration of operation.
But before you start creating a recuperator with your own hands, you should clarify the disadvantages of this model. The main disadvantage is the formation of glaciations during severe frosts. Outside, the moisture level is lower than in the air in the room. If you do not act on it in any way, it turns into condensate. During frosts high level Humidity promotes the formation of ice.
The photo shows how air exchange occurs
There are several ways to protect the recuperator device from freezing. These are small solutions that differ in efficiency and implementation method:
- thermal effect on the structure due to which ice does not linger inside the system (efficiency drops by an average of 20%);
- mechanical removal of air masses from the plates, due to which forced heating of the ice is carried out;
- addition of a ventilation system with a recuperator with cellulose cassettes absorbing excess moisture. They are redirected to the home, not only eliminating condensation, but also achieving a humidifier effect.
We invite you to watch the video - Do-it-yourself air recuperator for the home.
Recuperator - do it yourself
Recuperator - do it yourself 2
Experts agree that cellulose cassettes today are optimal solution. They operate regardless of the weather outside, and the installations do not consume electricity and do not require sewer outlet, collector for condensate.
Materials and components
What solutions and products should be prepared if it is necessary to assemble a plate-type home unit? Experts strongly recommend paying primary attention to the following materials:
- 1. Aluminum sheets (textolite and cellular polycarbonate). Please note that the thinner this material is, the more efficient the heat transfer will be. Forced ventilation in this case it works better.
- 2. Wooden slats (about 10 mm wide and up to 2 mm thick). Placed between adjacent plates.
- 3. Mineral wool (up to 40 mm thick).
- 4. Metal or plywood for preparing the body of the device.
- 5. Glue.
- 6. Sealant.
- 7. Hardware.
- 8. Corner.
- 9. 4 flanges (according to the pipe cross-section).
- 10. Fan.
note! The diagonal of the recuperative heat exchanger housing corresponds to its width. As for the height, it is adjusted to the number of plates and their thickness in conjunction with the slats.
Device drawings
Metal sheets are used to cut squares, the dimensions of each side can vary from 200 to 300 mm. In this case, it is necessary to select optimal value, taking into account what kind of ventilation system is installed in your home. There should be at least 70 sheets. To make them smoother, we recommend working with 2-3 pieces at a time.
Scheme of a plastic device
In order for energy recovery in the system to be carried out fully, it is necessary to prepare and wooden slats in accordance with the selected square side dimensions (from 200 to 300 mm). Then they must be carefully treated with drying oil. Every wooden element glued to 2 sides of a metal square. One of the squares must be left unpasted.
In order for recovery, and with it air ventilation, to be more efficient, each upper edge of the slats is carefully coated adhesive composition. The individual elements are assembled into a square “sandwich”. Very important! The 2nd, 3rd and all subsequent square products should be rotated 90° relative to the previous one. This method implements alternation of channels, their perpendicular position.
The upper square, on which there are no slats, is fixed with glue. Using the corners, the structure is carefully pulled together and secured. To ensure heat recovery in ventilation systems without air loss, the cracks are filled with sealant. Flange mounts are formed.
Ventilation solutions (manufactured unit) are placed in the housing. It is first necessary to prepare several corner guides on the walls of the device. The heat exchanger is positioned so that its corners rest against the side walls, while the entire structure visually resembles a rhombus.
On the picture homemade version devices
Residual products in the form of condensate remain in its lower part. the main task consists in obtaining 2 exhaust channels, isolated from each other. Inside the structure made of plate elements, air masses are mixed, and only there. A small hole is made at the bottom to drain condensate through a hose. 4 holes are made in the design for flanges.
Formula for calculating power
Example! To heat the air in the room up to 21°C, which requires60 m3 airat one o'clock:Q = 0.335x60x21 = 422 W.
To determine the efficiency of a unit, it is enough to determine the temperatures at 3 key points of its entry into the system:
Calculation of recuperator payback
Now you know , what is a recuperator and how necessary is it for modern ventilation systems. These devices are increasingly being installed in country cottages, social infrastructure facilities. Recuperators for a private home are quite a popular product nowadays. At a certain level of desire, you can assemble a recuperator with your own hands from available materials, as mentioned above in our article.
Creating an energy-efficient administrative building that 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 process of recycling heat from internal exhaust air with temperature t in, emitted into 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, the supply unit is in the basement, and the exhaust unit is 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 heat exchanger plates heats the external supply air. In this case, the air mixing process does not occur.
IN rotary recuperators Heat is transferred from the exhaust air to the supply air through a rotating cylindrical rotor consisting of a package of thin metal plates. In progress rotary recuperator 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.
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 recuperator Russian manufacturer 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 central region, efficiency 80-85%);
- For 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%).
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 a polymer membrane is used instead of aluminum. Since the thermal conductivity of the membrane plate is less than that of aluminum, the required area of the enthalpy recuperator is significantly more area 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 (outside 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 the supply fan and dry 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 | ||
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.
In this article, as an example of an administrative building, we consider a typical five-story building of the Federal State Institution “Research Institute TsEPP” 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 | Extract 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 exhaust from fume hoods, i.e., when any fume hood is turned on, the hood exhaust is automatically reduced by the amount of the hood exhaust. 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 shown 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.
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
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 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 in a period of 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 of cases, 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%.
general information
The service life of ventilation unit equipment manufactured by our company is established subject to compliance with operating rules and timely replacement of filters and parts with a limited resource. The list of such parts and their service life is indicated in the User's Guide for each specific model.
To avoid misunderstandings, we kindly ask you to carefully study the User Manual, pay attention to the conditions for the occurrence of warranty obligations, and check that the warranty card is filled out correctly. The warranty card is valid only if it is correctly and clearly indicated: model, serial number of the product, date of sale, clear seals of the seller company, installer company, and buyer’s signature. The model and serial number of the product must match those indicated in the warranty card.
Warranty Limitations
If these conditions are violated, as well as in the event that the data specified in the warranty card is changed, erased or rewritten, the warranty card is invalid.
In this case, we recommend that you contact the seller to obtain a new warranty card that meets the above conditions. If the date of sale cannot be determined, in accordance with consumer protection legislation, the warranty period is calculated from the date of manufacture of the product.
The warranty on recuperators is 7 years.
A 7-year warranty applies to equipment operated in accordance with all operating rules specified in the “ZENIT Equipment Operation Manual”. The warranty does not apply to equipment operated in rooms with high humidity (swimming pools, saunas, rooms with humidity more than 50% in winter), but the warranty can be maintained if the equipment is equipped with a duct dehumidifier.
Delivery in Moscow and the Moscow region up to 10 km from the Moscow Ring Road
Delivery times are indicated in the card of each product. Delivery costs are paid separately. Delivery is carried out by a transport company.
Delivery to regions
Delivery to the regions is made after 100% payment for the services of the transport company. Delivery costs are not included in the order price.
general information
If you want to know about the terms of delivery and payment, but do not want to read about them, then contact a sales consultant in your city, who will definitely help you.
Prices on the website may differ from retail prices in different regions, this is due to logistics costs. The price for the ordered product is valid for 24 hours from the date of placing the Order.
Payment by credit card on the website
Payment by credit card on the website is made through the payment system. After placing and paying for your order, our sales consultant will contact you to confirm the Order and clarify the delivery time.
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 in enclosed spaces - the presence of oxygen, or more precisely, the percentage of 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 ventilation units with recovery are used. This is especially true for modern business centers, where there is no natural flow of 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 the supply and exhaust ventilation system, clean air is pumped into the room, and 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 at extremely low temperatures
- Use models with an automated recovery process. 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 contains 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, recuperation 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. The optimal use of heat pipes is possible in small rooms in climate 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.
