Description:
In complex ventilation systems, each change in the position of the damper performed in one of the rooms leads to a difference in flow (pressure) in adjacent rooms. The best way to prevent this problem is to use VAV regulators and pressure regulators when it is necessary to maintain a constant pressure difference in adjacent areas. The use of such systems allows you to reduce energy costs, optimizing the operation of climate systems. In addition, such systems, thanks to modern systems controls can respond to changing loads, such as heat, in individual areas of the house, making them more flexible. Systems built on the basis of VAV regulators have the possibility of subsequent adaptation and modification of existing solutions.
Installation:
To ensure the correct functioning of the installation, when installing regulators, it is recommended to follow the following principles:
Length straight section in front of the 2D controller
Length of straight section behind regulator 1D
The air flow regulator is a multi-leaf valve with counter-rotating plates. It is designed to regulate the air flow of the room, as well as to automatically close the rectangular valve.
Rotary plates of air flow regulators are made from aluminum profile, which makes them strong and durable. In addition, the material makes the regulator corrosion-resistant and lightweight. The body is made of galvanized sheet steel. The position is fixed using a lever with a metal handle and a stopper. Installation is carried out using a flange connection.
Variable Air Volume (VAV) systems can regulate the air supply separately in each room. This way you can turn off the ventilation in any room. Traditional ventilation systems supply air to all rooms, regardless of occupancy. VAV systems are only gaining popularity in Russia, since previously this method of ventilation required sufficient financial costs. Now the situation has changed and such an air flow regulator can be purchased inexpensively.
In the Inplast online store you can buy air regulators at affordable prices. VAV systems available and ventilation equipment Smay. We deliver throughout Russia.
Similar products
The goods are delivered on prepayment
Optima VAV regulators ensure that the required amount of air is supplied to each room, i.e. regulate air flow according to need. Such a regulator is a device that combines a VAV controller, a dynamic differential pressure transducer, an electric drive and the valve itself.
Variable air volume (VAV) controllers are used for supply and exhaust in low pressure ventilation systems. The devices are ideal for single-zone supply and exhaust control in master and slave mode. The VAV ventilation system is the most optimal solution for office and commercial buildings, hotels, hospitals and other buildings public purpose. In air conditioning systems where particularly precise maintenance of the air pressure difference is necessary (operating rooms, workshops, laboratories, etc.), the use of VAV systems will also be optimal.
Main technical characteristics:
High level of accuracy:
The regulator body is made of galvanized steel sheet. The special design of the multi-position differential pressure sensor allows accurate data to be obtained even in complex systems.
Inlet/outlet: ø 80 to ø 630 mm
Optima variable air flow controllers are equipped as standard (BLC1) with a compact Belimo controller with the ability to communicate via MP-Bus (LMV-D3 or NMV-D3), designed to operate in individual mode or in master and slave mode. Also, complete with special compact controllers, Optima regulators can be integrated into a ModBus and LONWork network, and with the help of a gateway you can work using the BACnet protocol. Air flow parameters are adjusted using a special Belimo ZTH-GEN programmer. Compact controllers are calibrated as standard or with custom Vmin and Vmax parameters (specified in the order) at the factory before shipment.
*BLC1 = Belimo LMV-D3 compact controller with MP-Bus communication
BLC4 = Belimo LMV-D3 compact controller without communication
BLC1-MOD = Belimo LMV-D3 compact controller with MODBUS communication
* - standard delivery
Variable Air Volume - variable air flow
SYSTEMAGROUP specialists have implemented more than one project using Systemair VAV ventilation and air conditioning systems, both at the design and installation stage and in the modernization of existing systems.
Advantages of VAV - variable air flow systems over CAV - constant air flow systems:
Let's look at three examples of the objects we have implemented, the layout of VAV systems from advanced to simple.
In all three examples, air handling units with recovery are used. The ventilation system control mode is carried out by maintaining the temperature t of the exhaust air (maintaining room temperature). Controller ventilation system sets the temperature t himself supply air(tmin and tmax).
1. Example
The task set by the Customer is to individually maintain accurate and continuous control of humidity and temperature t in each of the six residential premises: four bedrooms, a living room, a dining room.
In this project, it was necessary to regulate six zones; the operating principle of the system was implemented on VAV variable air flow regulators OPTIMA and an optimizer controller.
The air flow of a given VAV system is independent of the pressure in that system.
2. Example
The task set by the Customer is to maintain accurate and continuous control of CO2 concentration and temperature t in two gyms.
In this project, it was necessary to regulate two zones, the operating principle is implemented according to the scheme - The air flow rate of a given VAV system depends on the static pressure Pa in that system.
Equipment installed at the site:
3. Example
The task set by the Customer was to maintain accurate and continuous temperature control in the office premises.
In this project it was necessary to ensure the temperature of a single office space(call center). The operating principle of the system is implemented according to a scheme controlled directly by the Corrigo ventilation system controller. The Corrigo controller settings allow you to change the air flow m3/h. depending on the temperature deviation t in the room.
Equipment installed at the site:
Variable Air Volume - variable air flow
SYSTEMAGROUP specialists have implemented more than one project using VAV ventilation and air conditioning systems, both at the design and installation stage and in the modernization of existing systems.
Advantages of VAV - variable air flow systems over CAV - constant air flow systems:
Let's look at three examples of the objects we have implemented, the layout of VAV systems from advanced to simple.
In all three examples, air handling units with recovery are used. The ventilation system control mode is carried out by maintaining the temperature t of the exhaust air (maintaining room temperature). The ventilation system controller itself sets the supply air temperature t (tmin and tmax).
1. Example
The task set by the Customer is to individually maintain accurate and continuous control of humidity and temperature t in each of the six residential premises: four bedrooms, a living room, a dining room.
In this project, it was necessary to regulate six zones; the operating principle of the system was implemented on VAV variable air flow regulators OPTIMA and an optimizer controller.
The air flow of a given VAV system is independent of the pressure in that system.
2. Example
The task set by the Customer is to maintain accurate and continuous control of CO2 concentration and temperature t in two gyms.
In this project, it was necessary to regulate two zones, the operating principle was implemented according to the scheme - The air flow in a given VAV system depends on the static pressure Pa in this system.
Equipment installed at the site:
3. Example
The task set by the Customer was to maintain accurate and continuous temperature control in the office premises.
In this project, it was necessary to ensure the temperature of a single office space (call center). The operating principle of the system is implemented according to a scheme controlled directly by the Corrigo ventilation system controller. The Corrigo controller settings allow you to change the air flow m3/h. depending on the temperature deviation t in the room.
Equipment installed at the site:
Imagine that you want to install a ventilation system in your apartment. Calculations show that to heat the supply air in the cold season, a 4.5 kW heater will be required (it will allow heating the air from -26°C to +18°C with a ventilation capacity of 300 m³/h). Electricity is supplied to the apartment through a 32A automatic machine, so it is easy to calculate that the heater power is about 65% of the total power allocated to the apartment. This means that such a ventilation system will not only significantly increase the amount of energy bills, but also overload the electrical grid. Obviously, it is not possible to install a heater of such power and its power will have to be reduced. But how can this be done without reducing the level of comfort of the apartment's inhabitants?
Ventilation unit with recuperator.
It requires a network to work.
supply and exhaust air ducts.
The first thing that usually comes to mind in such cases is the use of a ventilation system with a recuperator. However, such systems are well suited for large cottages, in apartments there is simply not enough space for them: in addition to the supply air network, an exhaust network must be connected to the recuperator, doubling the total length of the air ducts. Another disadvantage of recovery systems is that in order to organize air support for “dirty” rooms, a significant part of the exhaust flow must be directed to the exhaust ducts of the bathroom and kitchen. And the imbalance of the supply and exhaust flows leads to a significant decrease in the efficiency of recovery (it is impossible to refuse air pressure in “dirty” rooms, since in this case unpleasant odors will begin to circulate throughout the apartment). In addition, the cost of a recovery ventilation system can easily exceed twice the cost of a conventional one. supply system. Is there another, inexpensive solution to our problem? Yes, this is a supply VAV system.
Variable air flow system or VAV(Variable Air Volume) system allows you to regulate the air supply in each room independently of each other. With such a system, you can turn off the ventilation in any room in the same way as you are used to turning off the lights. Indeed, we do not leave the lights on where there is no one - this would be an unreasonable waste of electricity and money. Why let a ventilation system with a powerful heater waste energy? However, this is exactly how traditional ventilation systems work: they supply heated air to all rooms where people could be, regardless of whether they are actually there. If we controlled light just like traditional ventilation- it would burn in the whole apartment at once, even at night! Despite obvious advantage VAV systems in Russia, unlike Western Europe, they have not yet become widespread, partly because their creation requires complex automation, which significantly increases the cost of the entire system. However, the rapid reduction in the cost of electronic components, which is occurring in Lately, made it possible to develop inexpensive ready-made solutions for building VAV systems. But before we move on to describing examples of systems with variable air flow, let's figure out how they work.
The illustration shows a VAV system with a maximum capacity of 300 m³/h, serving two areas: living room and bedroom. In the first picture, air is supplied to both zones: 200 m³/h in the living room and 100 m³/h in the bedroom. Let us assume that in winter the power of the heater will not be enough to heat such an air flow to comfortable temperature. If we used a conventional ventilation system, we would have to reduce the overall performance, but then both rooms would become stuffy. However, we have a VAV system installed, so we can only supply air to the living room during the day and only supply air to the bedroom at night (as in the second picture). For this purpose, the valves that regulate the volume of air supplied to the premises are equipped with electric drives, which allow the valve dampers to be opened and closed using conventional switches. Thus, by pressing the switch, the user, before going to bed, turns off the ventilation in the living room, where there is no one at night. At this point, a differential pressure sensor that measures the air pressure at the outlet air handling unit, records an increase in the measured parameter (when the valve is closed, the resistance of the air supply network increases, leading to an increase in air pressure in the air duct). This information is transmitted to the air handling unit, which automatically reduces the fan performance just enough so that the pressure at the measuring point remains unchanged. If the pressure in the air duct remains constant, then the air flow through the valve in the bedroom will not change, and will still be 100 m³/h. The overall performance of the system will decrease and will also be equal to 100 m³/h, that is, the energy consumed by the ventilation system at night will decrease by 3 times without compromising people's comfort! If you turn on the air supply alternately: during the day in the living room, and at night in the bedroom, then the maximum power of the heater can be reduced by a third, and the average energy consumption by half. The most interesting thing is that the cost of such a VAV system exceeds the cost of a conventional ventilation system by only 10-15%, that is, this overpayment will be quickly compensated by reducing the amount of electricity bills.
A short video presentation will help you better understand the operating principle of the VAV system:
Now, having understood the operating principle of a VAV system, let’s see how one can assemble such a system based on equipment available on the market. As a basis, we will take Russian VAV-compatible air handling units Breezart, which allow you to create VAV systems serving from 2 to 20 zones with centralized management from the remote control, by timer or CO 2 sensor.
This VAV system is assembled on the basis of a Breezart 550 Lux air handling unit with a capacity of 550 m³/h, which is sufficient to serve an apartment or small cottage (taking into account that a system with variable air flow may have lower productivity compared to a traditional ventilation system). This model, like all other Breezart ventilation units, can be used to create a VAV system. Additionally we will need a set VAV-DP, which includes a JL201DPR sensor that measures the pressure in the duct near the branch point.
VAV system for two zones with 2-position control
The ventilation system is divided into 2 zones, and the zones can consist of either one room (zone 1) or several (zone 2). This allows the use of such 2-zone systems not only in apartments, but also in cottages or offices. The valves in each zone are controlled independently of each other using conventional switches. Most often, this configuration is used to switch night (air supply only to zone 1) and day (air supply only to zone 2) modes with the ability to supply air to all rooms if, for example, you have guests.
Compared to a conventional system (without VAV control) the increase in the cost of basic equipment is about 15% , and if we take into account the total cost of all elements of the system together with installation work, then the increase in cost will be almost unnoticeable. But even such a simple VAV system allows save about 50% electricity!
In the example given, we used only two controlled zones, but there can be any number of them: the air supply unit simply maintains the specified pressure in the air duct, regardless of the configuration of the air network and the number of controlled VAV valves. This allows, if there is a lack of funds, to first install a simple VAV system in two zones, subsequently increasing their number.
So far we have looked at 2-position control systems, in which the VAV valve is either 100% open or completely closed. However, in practice more often they are used convenient systems with proportional control, allowing you to smoothly regulate the volume of supplied air. We will now consider an example of such a system.
VAV system for three zones with proportional control
This system uses a more productive Breezart 1000 Lux PU at 1000 m³/h, which is used in offices and cottages. The system consists of 3 zones with proportional control. CB-02 modules are used to control proportional valve actuators. Instead of switches, JLC-100 regulators (outwardly similar to dimmers) are used here. This system allows the user to smoothly adjust the air supply in each zone in the range from 0 to 100%.
Composition of the basic equipment of the VAV system (air handling unit and automation)
Note that one VAV system can simultaneously use zones with 2-position and proportional control. In addition, control can be carried out from motion sensors - this will allow air to be supplied to the room only when there is someone in it.
The disadvantage of all the considered VAV system options is that the user has to manually adjust the air supply in each zone. If there are many such zones, then it is better to create a system with centralized control.
Centralized control of the VAV system allows you to activate pre-programmed scenarios, changing the air supply simultaneously in all zones. For example:
VAV system for three zones with centralized control
For centralized control of valve actuators, JL201 modules are used, which are combined into a single system controlled via the ModBus bus. Programming of scenarios and control of all modules is carried out from the standard remote control of the ventilation unit. A concentration sensor can be connected to the JL201 module carbon dioxide or JLC-100 controller for local (manual) control of drives.
Composition of the basic equipment of the VAV system (air handling unit and automation)
The video describes how to control a VAV system with centralized control for 7 zones from the remote control of the Breezart 550 Lux air handling unit:
With these three examples we have shown general principles construction and briefly described the capabilities of modern VAV systems; more detailed information about these systems can be found on the Breezart website.
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