Heat recovery ventilation. Supply and exhaust ventilation systems with heat recovery and recirculation
general information
The service life of the equipment for the ventilation unit manufactured by our company is established subject to the observance of the operating rules and the timely replacement of filters and parts with a limited resource. The list of such parts and their resource is indicated in the User's Guide for each specific model.
In order 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 the correctness of filling out the warranty card. The warranty card is valid only if there are correctly and clearly indicated: model, serial number of the product, date of sale, clear seals of the seller, the installer, and the buyer's signature. The model and serial number of the product must correspond to those indicated in the warranty card.
Warranty Limitations
In case of violation of these conditions, as well as in the case when the data specified in the warranty card is changed, erased or rewritten, the warranty card is invalidated.
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 established, in accordance with consumer protection legislation, the warranty period starts from the date of manufacture of the product.
The recuperators have a 7-year warranty.
The 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 a humidity of 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 on the card of each product. Shipping 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. Shipping cost is 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 the sales consultant in your city, who will certainly 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 within 24 hours from the moment of placing the Order.
Payment by credit card on the website
Payment by credit card on the site is made through the payment system. After placing and paying for the order, our sales consultant will contact you to confirm the Order and clarify the delivery time.
Air handling unit is a modern solution for organizing optimal air exchange and rational use of energy resources. The principle of operation consists in the implementation of forced inflow and removal of air outside the room. On the basis of the PVU installation, you can create an individual microclimate system by connecting various filters and devices.
Recovery ventilation system
To save heat energy, some PVU 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 extracted warm air. In this case, the heating of the bulk of the air flow is carried out by a conventional air heater. An air handling unit with heat recovery, although the price is higher than for other devices, due to its energy efficiency, these costs quickly pay off. An important characteristic of the device is its efficiency, which ranges from 30 - 96%, depending on the type of recuperator, the speed of the air flow through the heat exchanger and the temperature difference.
Supply and exhaust ventilation with recuperation fully meets modern requirements for saving thermal energy. And thanks to the function of heating the room, it is considered the most promising development in the field of ventilation.
Main advantages:
- Comfortable air exchange
- Effective energy saving
- Humidity regulation function
- Reliable sound insulation
- High efficiency up to 96%
- Convenient control system
- Air purification from dust and impurities
- Maximum retention of thermal energy
Classification and characteristics of devices.
Depending on the design of the heat exchanger, the PVU with a recuperator can be of several types:
Plate heat exchangers are the most common design. Heat exchange takes place by passing air through a series of plates. Condensate forms during operation, therefore the recuperation system is additionally equipped with a condensate drain. The efficiency is 50-75%.
A rotary heat recuperator is a cylindrical device densely filled with corrugated steel layers. 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 speed of rotation of the rotor. This type of recuperative supply and exhaust system is large and therefore suitable for shopping centers, hospitals, hotels and other large premises. Due to the absence of freezing, the efficiency reaches 75-85%
The less common types are recuperators with an intermediate heating medium (this can be water or water-glycol solution). The efficiency is 40-60%. The air handling 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 is turned over, and the air flows are reversed. The efficiency is up to 90%.
Supply and exhaust ventilation with heat recovery the best price!
In the online store "Yanvent" a wide range of PVU installations for various purposes, performance, configuration and cost is available for ordering.
Thanks to the convenient search form, you can easily find a suitable model and buy an air handling unit with recuperation at the best price!
Building an energy efficient home is the dream of every developer. Many people believe that to achieve this goal, it is enough to insulate the perimeter of the building and provide it with modern windows. But is this issue so easy to solve? It turns out not. It is impossible to ensure comfortable living and full energy saving of the building only by insulating the enclosing structures and installing sealed window blocks. For some reason, many people forget to take into account the need to use ventilation - air handling units (PVU).
To preserve the internal heat of the room it is necessary to equip the supply and exhaust ventilation with a heat exchanger — air recuperator, which will utilize the heat of the air flow coming from the room, giving it to the supply air. Such systems are widely used in Western Europe, providing the construction of buildings with a level of heat loss 5-10 times lower than that of conventional housing. By utilizing the heat from the extract air, they save up to 70% of heating costs and thus pay off in the shortest possible time, usually 3-5 years.
Small-sized supply and exhaust systems with heat recovery AVTU type, which are designed specifically for use in residential and other small premises. They supply the building with fresh, heated, air purified from street dust.
The energy of ventilation emissions in modern buildings reaches 50% of the total level of heat loss, therefore, a building is called energy efficient, in which, in addition to insulating the enclosing structures and installing sealed window groups, energy is used that is returned to the room by utilizing the heat of ventilation emissions.
The heating season in energy efficient buildings can be shortened by more than a month.
The principle of operation of the PVU
This is as follows. The heated air is taken in through the air intakes in the most humid rooms (kitchen, bathroom, toilet, utility room, etc.) and is removed through the air ducts outside the building. However, before leaving the building, it passes through the heat exchanger of the recuperator, where it leaves some of the heat. This heat heats up the cold air taken from the outside (it also passes through the same heat exchanger, but in a different direction) and is supplied inside (living room, bedrooms, offices, etc.). Thus, there is a constant air circulation inside the room.
The principle of operation of the air handling unit with heat recovery
The air handling unit with a recuperator can be of various capacities and sizes - it depends on the volume of ventilated premises and their functional purpose. The simplest installation is a thermally and acoustically insulated set of interconnected elements enclosed in a steel case: a heat exchanger, two fans, filters, sometimes a heating element, a condensate removal system (the automation unit, electrical circuit elements and air ducts are not considered in this context).
Organization of air exchange in the premises of a residential cottage
During the operation of the unit, two air flows pass through the heat exchanger - internal and external, which do not mix at the same time. There are several types of recuperators depending on the design of the heat exchanger.
The most forward-thinking homeowners design two ventilation systems in their buildings at once: gravitational (natural) and mechanical with heat recovery (forced). In this case, the natural ventilation system is emergency and serves in case of malfunctions in the operation of the air handling unit and is used mainly in an unheated period. It should be remembered that during the operation of the mechanical ventilation system, the gravity ventilation ducts must be tightly closed. Otherwise, the effectiveness of the forced ventilation will be lost.
Plate recuperators
Exhaust and supply air flows on both sides of the row of plates. In this case, a certain amount of condensate may form on the plates in plate recuperators. Therefore, they must be equipped with condensate drainage. Condensate traps must have a water seal that prevents the fan from capturing and supplying water to the duct.
The principle of operation of the air handling unit with heat recovery
There is a serious risk of ice formation due to condensation and therefore a defrosting system is required. Heat recovery can be controlled by a bypass valve that controls the air flow through the recuperator. There are no moving parts in the plate heat exchanger. It is characterized by high efficiency (50-90%).
Plate recuperator
Installations of this type from the manufacturer tm. Naveka - Node1. They have an aluminum recuperator, a condensate drainage system and an anti-freeze system for the recuperator. And also the quietest fans in its class, electric or water heater, built-in automation and a remote control with setting modes and operating schedules.
Rotary recuperators
Heat is transferred by the rotor rotating between the removed and supply channels. This is an open system, and therefore there is a high risk that dirt and odors can move from the exhaust air to the supply air, which can be somewhat avoided if the fans are correctly positioned. The heat recovery level can be adjusted by the rotor speed. In a rotary heat exchanger, the risk of freezing is low. Rotary recuperators have moving parts. They are also characterized by high efficiency (75-85%).
Rotary recuperator
This solution has been successfully implemented by the manufacturer tm. Naveka in Node3 series installations. The units have a frost protection system, built-in automation and a remote control. In the Vertical version, the units have thermal and noise insulation made of non-combustible mineral wool 50 mm thick, and the possibility of outdoor (street) installation and operation.
Recuperators with intermediate heat carrier
In this design, the coolant (water or water-glycol solution) circulates between two heat exchangers, one of which is located in the exhaust duct, and the other in the supply duct. The heat carrier is heated by the removed air and then transfers the heat to the supply air. The heating medium circulates in a closed system, and there is no risk of transfer of contaminants from the removed air to the supply air. Heat transfer can be controlled by changing the rate of circulation of the heat carrier. These recuperators do not contain moving parts and have a low efficiency (45-60%).
Recuperator with intermediate heat carrier
Chamber recuperators
In such a recuperator, the chamber is divided into two parts by a damper. The extracted air heats up one part of the chamber, then the damper changes the direction of the air flow in such a way that the supply air heats up from the heated walls of the chamber. In this case, pollution and odors can be transferred from the removed air to the supply air. The only movable part of the recuperator is the damper. The unit is characterized by high efficiency (80-90%).
Chamber recuperator
Heat pipes
This recuperator consists of a closed system of tubes filled with freon, which evaporates when heated by the removed air. As the supply air flows along the tubes, the steam condenses and becomes liquid again. The transmission of contaminants in this design is excluded. The recuperator has no moving parts, but has a relatively low efficiency (50-70%).
Duct-type recuperator based on heat pipes
The most widespread in practice are plate and rotary recuperators. Moreover, there are models of recuperators in which two plate heat exchangers can be installed in series. They are highly efficient.
Two-stage recuperation with two rotors
The amount of heat taken away by a heat exchanger depends on a number of factors, in particular, the temperature of the indoor and outdoor air, its humidity, and the speed of the air flow. The greater the difference between the temperatures inside and outside the premises, the higher the humidity, the greater the effect of the recuperator operation. By the way, most of the installations can be installed for the summer period. instead of the usual heat exchanger of the so-called summer cassette, which allows you to provide air flow without the recuperation process. In addition, in some cases it is possible to change the direction of the air flows inside the unit, so that they bypass the heat exchanger.
The main characteristics and features of the types of heat exchangers
Fans
Air movement is provided by fans - supply and exhaust, although you can find systems with an integrated supply and exhaust fan, which is powered by a single engine. In simple models, the fans have three levels of speed: normal, reduced (used for working at night or in the absence of residents, if it is a house or apartment) and maximum (used when the highest level of air exchange is needed). Some modern fan models have much higher speed levels, which makes it possible to better meet the needs of the users of the system in different degrees of ventilation intensity.
The fans can be controlled automatically. Control panels, as a rule, are installed indoors in places convenient for their use. Time programmers provide the setting of the fan speed mode during the day or week. In addition, some advanced models can be integrated into the smart home system and controlled by a central computer. The operation of the recuperator may also depend on the level of humidity in the premises (this requires the installation of appropriate sensors) and even the level of carbon dioxide.
Since the ventilation system must operate around the clock, high quality fans are an extremely important feature of the air handling unit.
Filters
The air taken from outside must be supplied to the room only after passing through the filter. Typically, recuperators are equipped with filters that trap particles up to 0.5 microns in size. This filter complies with EU7 according to DIN or F7 according to European standards. Thus, the filter retains dust, fungal spores, pollen, and soot.
This feature of the air handling unit should be appreciated by allergy sufferers. At the same time, a filter is also installed in the exhaust system in front of the heat exchanger. True, its class is somewhat lower - EU3 (G3). It protects the heat exchanger from impurities that are removed from the premises together with the air. Filters are made of synthetic materials, they can be both disposable and reusable. The material of the latter should be easy to clean. These filters can be shaken out and washed. Some models of recuperation units have filters for filter clogging, which at a certain moment signal the need to replace or clean the filter.
Heating elements
Of course, a situation where the supply air is heated by the heat removed would be ideal. But in some cases this cannot be achieved. For example, if it is -25 ° C outside the window, then the temperature of the exhaust air, whatever the efficiency of the heat exchanger, will not be enough to warm the supply air to a comfortable temperature. In this regard, recuperators are equipped with an electric system for additional heating of the air supplied to the premises. As practice shows, heating of the supply air is needed even if the outside temperature is less than -10 ° C.
The heating element is also automatically controlled and switches on depending on the program if the extracted heat is not enough to heat the supply air in accordance with the set parameters. It is usually mounted together with a heat exchanger. The power and dimensions of the heating elements depend on the power of the entire installation.
It happens that with high air humidity and severe frost, condensation forms on the heat exchanger, which can freeze. To avoid this phenomenon, there are several technical solutions.
For example, the supply fan can work intermittently (it turns on every half hour for five minutes), and then the exhaust fan works, and warm air passing through the heat exchanger protects it from ice formation.
The second, rather common solution, is to direct part of the cold air flow past the heat exchanger. There are a number of other methods, including the use of an electric heater, which partially heats the air entering from the outside in front of the heat exchanger. The resulting condensate should not be collected inside the unit, but discharged through the pipeline system either directly into the sewer, or to another place provided for by the project.
During the construction of individual houses, it is possible to use a structural diagram of the device of a forced ventilation system with air intake at a certain distance from the house and its delivery to the air handling unit through air ducts located in the ground below the level of soil freezing. During the passage through such a channel, the air temperature will increase, which reduces the risk of condensation and ice formation on the heat exchanger and, in general, increases the efficiency of the recuperator.
Air ducts
As we have already noted, the installation of supply and exhaust ventilation is much easier to perform in a building under construction than in an existing one. Consequently, its design should be an element of the entire construction project. Typically, the unit is located in unused attics (it is easier to ensure the intake of cleaner air), in basements, boiler rooms, utility and utility rooms. It is important that it is a dry room with positive temperatures. Air ducts to an unheated room must be thermally insulated. Indoors, they are usually mounted behind false ceilings.
Aluminum or plastic flexible air ducts
In practice, various types of air ducts are used. The most convenient to install - aluminum or plastic flexible ducts in the form of a pipe reinforced with steel wire. The pipes can also be insulated with mineral wool. Air ducts of rectangular or square cross-section are also used. Ventilation grilles are usually installed in walls or ceilings. Experts recommend using variable-flow diffusers for air supply as the most convenient option, although conventional grilles are most often used for these purposes. The supply air must be drawn in places where it is least prone to contamination.
In conclusion, a few videos on the use of air handling units with heat recovery:
The device and principle of operation of the plate air recuperator.
Using an air recuperator as the main means to combat the formation of mold and mildew in the living space.