IRIS VALVE WITH SERVO MOTOR

Thanks to the unique design of butterfly valves, air flow can be measured and adjusted within a single device and process, delivering a balanced amount of air to the room. The result is a constant comfortable microclimate.
IRIS butterfly valves allow you to quickly and accurately regulate air flow. They cope everywhere where individual comfort control and precision air control are required.
Measuring and adjusting flow for maximum comfort
Balancing the air flow is usually a time-consuming and expensive step when starting up a ventilation system. The linear restriction of air flow found in lens throttle valves simplifies this operation.
Throttle valve design
IRIS butterfly valves can function in both supply and exhaust installations, eliminating the risk associated with incorrect installation errors. IRIS lens butterfly valves consist of a galvanized steel body, lens planes that regulate air flow, and a lever for smoothly changing the diameter of the hole. In addition, they are equipped with two tips for connecting a device that measures the force of air flow.
The butterfly valves are equipped with EPDM rubber seals for a tight connection with the ventilation ducts.
Thanks to the engine mount it is possible automatic control stream without the need to manually change settings. A special plane is provided for stable mounting of the servomotor, protecting it from movement and damage.
What makes lens butterfly valves different from standard butterfly valves?
Conventional throttle valves increase the speed of air flow along the walls of the ducts, generating a lot of noise. Thanks to the lens closure of IRIS throttle valves, suppression does not cause turbulence or noise in the passages. This allows higher flows or pressures than standard butterfly valves without making installation noise. This is a great simplification and saving, because... there is no need to use additional soundproofing elements. Adequate noise suppression is possible through proper installation of throttle valves in the ventilation system.
To accurately measure and control air flow, throttle valves should be placed on straight sections, no closer than:
1. 4 x diameter of the air duct in front of the throttle valve,
2. 1 x diameter of the air duct behind the throttle valve.
The use of lens dampers is very important to ensure the hygiene of the ventilation installation. Thanks to the possibility of full opening, cleaning robots can successfully enter channels connected to this kind of butterfly valves.
Advantages of IRIS throttle valves:
1. low level noise in channels
2. easy installation
3. excellent balancing of the air flow, thanks to the measuring and control unit
4. simple and quick flow adjustment without the need for additional devices - use of a handle or servomotor
5. precise measurement flow
6. stepless adjustment - manually using a lever or automatically thanks to the use of a version with a servo motor
7. Design allowing easy access for cleaning robots.

The main purposes of this system are: reducing operating costs and compensating for filter contamination.

Using a differential pressure sensor, which is installed on the controller board, the automation recognizes the pressure in the channel and automatically equalizes it by increasing or decreasing the fan speed. Supply and exhaust fan at the same time they work synchronously.

Compensation for filter contamination

When operating a ventilation system, the filters inevitably become dirty, the resistance of the ventilation network increases and the volume of air supplied to the premises decreases. The VAV system will allow you to maintain a constant air flow throughout the entire life of the filters.

• The VAV system is most relevant in systems with high level air purification, where filter contamination leads to a noticeable decrease in the volume of supplied air.

Reduced operating costs

The VAV system can significantly reduce operating costs, this is especially noticeable in supply ventilation systems, which have high energy consumption. Savings are achieved by completely or partially turning off the ventilation of individual rooms.

• Example: you can turn off the living room at night.

At calculation of the ventilation system are guided by different standards of air consumption per person.

Typically, in an apartment or house, all rooms are ventilated simultaneously; the air flow for each room is calculated based on the area and purpose.
What to do if this moment is there anyone in the room?
You can install valves and close them, but then the entire volume of air will be distributed throughout the remaining rooms, but this will lead to increased noise and waste of air, the precious kilowatts were spent heating it.
You can reduce the power ventilation unit, but this will also reduce the volume of air supplied to all rooms, and where users are present there will be “not enough air”.
The best decision, is to supply air only to those rooms where there are users. And the power of the ventilation unit must be regulated itself, according to the required air flow.
This is exactly what a VAV ventilation system allows you to do.

VAV systems pay for themselves quite quickly, especially in air handling units, but most importantly, they can significantly reduce operating costs.

• Example: Apartment 100m2 with and without VAV system.

The volume of air supplied to the room is controlled by electric valves.

An important condition for constructing a VAV system is the organization of the minimum supplied air volume. The reason for this condition lies in the inability to control air flow below a certain minimum level.

This can be solved in three ways:

1. in a separate room, ventilation is organized without the possibility of regulation and with an air exchange volume equal to or greater than the required minimum consumption air in the VAV system.
2. A minimum amount of air is supplied to all rooms with the valves turned off or closed. The total of this amount must be equal to or greater than the required minimum air flow in the VAV system.
3. The first and second options together.

Control from a household switch:

To do this, you will need a household switch and a valve with a return spring. Switching on will lead to the full opening of the valve, and the room will be ventilated in full. When switched off, the return spring closes the valve.

Damper switch/switch.

• Equipment: For each serviced room you will need one valve and one switch.
• Exploitation: If necessary, the user turns the room ventilation on and off using a household switch.
• pros: The simplest and a budget option VAV systems. Household switches always fits the design.
• Minuses: User participation in regulation. Low efficiency due to on-off regulation.
• Advice: It is recommended to install the switch at the entrance to the serviced room, at +900mm, next to or in the light switch block.

The minimum required volume of air is always supplied to room No. 1; it cannot be turned off; room No. 2 can be turned on and off.

The minimum required volume of air is distributed to all rooms, since the valves are not completely closed and a minimum amount of air passes through them. The entire room can be turned on and off.

Control from a rotary regulator:

This will require a rotary regulator and a proportional valve. This valve can open, regulating the volume of supplied air in the range from 0 to 100%, the required degree of opening is set by the regulator.

Circular regulator 0-10V

• Equipment: for each room served, one valve with 0...10V control and one 0...10V regulator will be required.
• Exploitation: If necessary, the user selects the required level of room ventilation on the regulator.
• pros: More precise regulation of the amount of air supplied.
• Minuses: User participation in regulation. Appearance regulators do not always fit the design.
• Advice: It is recommended to install the regulator at the entrance to the serviced room, at +1500mm, above the light switch block.

The minimum required volume of air is always supplied to room No. 1; it cannot be turned off; room No. 2 can be turned on and off. In room No. 2 you can smoothly regulate the volume of supplied air.

Small opening (valve 25% open) Medium opening (valve 65% open)

The minimum required volume of air is distributed to all rooms, since the valves are not completely closed and a minimum amount of air passes through them. The entire room can be turned on and off. In each room you can smoothly regulate the volume of supplied air.

Presence sensor control:

This will require a presence sensor and a valve with a return spring. When registering in the user’s room, the presence sensor opens the valve and the room is ventilated in full. When there is no user, the return spring closes the valve.

Motion Sensor

• Equipment: For each serviced room you will need one valve and one presence sensor.
• Exploitation: The user enters the room - ventilation of the room begins.
• pros: The user does not participate in the regulation of ventilation zones. It is impossible to forget to turn the room ventilation on or off. Many occupancy sensor options.
• Minuses: Low efficiency due to on-off regulation. The appearance of presence sensors does not always suit the design.
• Advice: Use high-quality presence sensors with a built-in time relay for the correct operation of the VAV system.

The minimum required volume of air is always supplied to room No. 1; it cannot be turned off. When the user registers, ventilation of room No. 2 begins

The minimum required volume of air is distributed to all rooms, since the valves are not completely closed and a minimum amount of air passes through them. When a user registers in any of the rooms, ventilation of this room begins.

CO2 sensor control:

This requires a CO2 sensor with a 0...10V signal and a proportional valve with 0...10V control.
When the CO2 level in the room is detected, the sensor begins to open the valve in accordance with the recorded CO2 level.
When the CO2 level decreases, the sensor begins to close the valve, and the valve can close either completely or to a position at which the required minimum flow will be maintained.

Wall or duct CO2 sensor

• Example: For each room served, one proportional valve with 0...10V control and one CO2 sensor with a 0...10V signal will be required.
• Exploitation: The user enters the room, and if the CO2 level is exceeded, ventilation of the room begins.
• pros: The most energy efficient option. The user does not participate in the regulation of ventilation zones. It is impossible to forget to turn the room ventilation on or off. The system starts ventilation of the room only when it is really needed. The system most accurately regulates the volume of air supplied to the room.
• Minuses: The appearance of CO2 sensors does not always match the design.
• Advice: Use high-quality CO2 sensors for correct operation. A duct CO2 sensor can be used in supply and exhaust ventilation systems if there is both supply and exhaust in the serviced room.

The main reason why room ventilation is required is if the CO2 level is too high.

In the process of life, a person exhales a significant amount of air with a high level of CO2 and being in an unventilated room, the level of CO2 in the air inevitably increases, this is what determines when they say that there is “little air”.
It is best to supply air into the room when the CO2 level exceeds 600-800 ppm.
Based on this air quality parameter, you can create the most energy efficient system ventilation.

The minimum required volume of air is distributed to all rooms, since the valves are not completely closed and a minimum amount of air passes through them. When an increase in CO2 content is detected in any room, ventilation of that room begins. The degree of opening and the volume of air supplied depends on the level of excess CO2 content.

Management of the Smart Home system:

This will require a system Smart House"and any type of valves. Any type of sensors can be connected to the Smart Home system.
Air distribution can be controlled either through sensors using a control program, or by the user from a central control panel or a phone application.

Smart home panel

• Example: The system operates using a CO2 sensor and periodically ventilates the premises, even in the absence of users. The user can forcefully turn on ventilation in any room, as well as set the amount of air supplied.
• Exploitation: Any control options supported.
• pros: The most energy efficient option. Possibility of precise programming of the weekly timer.
• Minuses: Price.
• Advice: Install and configure by qualified specialists.

Imagine that you want to install a ventilation system in your apartment. Calculations show that for heating supply air in the cold season, a heater with a power of 4.5 kW 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 total power allocated for 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?

How to reduce energy consumption?

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 an imbalance of the supply and exhaust flows leads to a significant decrease in the efficiency of recovery (it is impossible to refuse air support for “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 don’t 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. We will take as a basis the Russian VAV-compatible air handling units Breezart, which allow you to create VAV systems serving from 2 to 20 zones with centralized control from a remote control, by a timer or a CO 2 sensor.

VAV system with 2-position control

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 traditional system ventilation). 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 conventional system(without VAV control) increase in cost of basic equipment is approx. 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 with proportional control

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.

VAV 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:

• Night mode. Air is supplied only to the bedrooms. In all other rooms, the valves are open at a minimum level to prevent air from stagnating.
• Day mode. All rooms except bedrooms are supplied with full air. In bedrooms, valves are closed or open at a minimum level.
• Guests. The air flow in the living room is increased.
• Cyclic ventilation(used when people are absent for a long time). A small amount of air is supplied to each room in turn - this avoids the occurrence of unpleasant odors and stuffiness that can create discomfort when people return.

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. The JL201 module can be connected to a carbon dioxide concentration sensor or a JLC-100 controller for local (manual) control of actuators.

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:

Conclusion

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.