Vents: what it is and how it works hood

Well-designed ventilation system the room - the key to a healthy microclimate. One of the primary conditions of natural air circulation - the presence of thrust. To normalize the pressure is often used vents - the device amplifies the leak of ventkanala due to wind pressure.

Despite the simplicity of construction and affordable prices, this cap greatly increases traction. The only problem - the choice of the optimal variant among the variety of offerings.

We will help you to understand this question. The article provides a detailed overview of the devices and the principles of the various deflectors are given practical recommendations on the selection and installation of hoods.

To help you decide on the model and understand the sequence of installation of the air "driving force", we have prepared a thematic photo and video collection.

The content of the article:

  • The main objectives of "vent cap"
  • Driving apparatus and principle of operation of the deflector
  • Classification of wind nozzles
  • Review of popular models
    • View # 1 - the classic cap Grigorovich
    • View # 2 - universal nozzle TsAGI
    • View # 3 - Staten dynamic cap Astato
    • View # 4 - deflector DS Series
    • View # 5 - rotary or turbine turbodeflektor
    • View # 6 - rotary vane type "hood"
    • View # 7 - Module H-type
  • Nuances of the installation of wind caps motives
  • Conclusions and useful videos on the topic

The main objectives of "vent cap"

Efficiency ventilation systems with natural air impulse is largely determined by atmospheric conditions. Air currents circulate due to the lift, which arose because of the temperature difference between inside and outside.

Job Ventilation "corrects" the wind - it can both enhance and hinder natural ventilation.

natural ventilation

In the summer, when the temperature regime at home and on the street is aligned, the pressure drop and the thrust to zero - natural ventilation fails. The air circulation is reduced and, in some cases, a rollover traction

Partially reduce the impact of weather conditions, direct them to the benefit of the functioning of the ventilation system and to increase air speed It allows the installation of the deflector. Module, shaped like a cap, is mounted at the top of the suction channel.

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Turbine vents on the roof of the enterprise

Deflectors mounted on the exhaust vents of gravity systems, which are based on physical phenomena

Deflector Grigorovich ventshahte

A special fixture design that does not require power, at times increases traction and exhaust air output speed outwardly

Diflektory TsAGI for private houses and shops

Swirls generated inside the uncomplicated construction does not only enhance the removal, but also prevent backflow of air mass

Dynamic embodiment deflector apparatus

The number of independent power supply devices have embodiments with static and dynamic working part - rotating the slightest wind blows. A second embodiment of the first effective

Specific H-shaped design

Strengthen the outflow speed, thus increasing the air circulation can and static deflector. For example, H-shaped, three pipes which vigorously stimulate air circulation

Feathered variety deflector

Vane refer to the category of species to the increased efficiency of the model. They practically do not stop, sensitive to barely noticeable to humans whiff

Deflector in regions with a normal wind load

In regions with normal wind load it does not make sense to use a dynamically rotating deflectors. Using a simple static type

Production deflectors for air ducts

Make a simple cap at a vent pipe creates a vortex of sufficient strength can own hands. As a basis we can take crafts made at the plant deflector

Turbine vents on the roof of the enterprise

Turbine vents on the roof of the enterprise

Deflector Grigorovich ventshahte

Deflector Grigorovich ventshahte

Diflektory TsAGI for private houses and shops

Diflektory TsAGI for private houses and shops

Dynamic embodiment deflector apparatus

Dynamic embodiment deflector apparatus

Specific H-shaped design

Specific H-shaped design

Feathered variety deflector

Feathered variety deflector

Deflector in regions with a normal wind load

Deflector in regions with a normal wind load

Production deflectors for air ducts

Production deflectors for air ducts

Deflector solves two main tasks:

  1. It protects the shaft from clogging debris and hit the birds.
  2. It minimizes the negative impact of rainfall on the ventilation equipment.
  3. It activates and enhances traction, generating and redirecting wind flows - ventilation system efficiency is increased by 15-20%. Deflector reduces the likelihood of reverse thrust.

The umbrella structure used to improve traction and a chimney. Besides, a deflector for the flue additionally acts as a spark arrester.

open baffle

Vent cap loses efficiency when the wind blows from the bottom - the airflow impinges on the visor and prevents the hood. Solving the problem - the installation of the deflector with two cones

Driving apparatus and principle of operation of the deflector

To obtain an accurate picture of what a deflector and how it functions, analyze its typical circuit device.

The main part of the ventilation nozzles:

  1. Diffuser - the base of the truncated cone. The lower part of the cylindrical bulb is placed on top of ventkanala outputted through the roof. It is in the diffuser is slowing down the air flow and pressure rise.
  2. Umbrella - upper protective cap attached to the diffuser struts. An element prevents debris ventkanal.
  3. housing - the ring or shroud. The visible part of the deflector coupled with a diffuser with two or three arms. housing plane bisecting the airflow and creates inside the cylinder area of ​​low pressure.

In some embodiments, it is a net to trap fine dust. Filter insert some weakening cravings.

Driving deflector

The design of the deflector to the inlet 1 - headroom, 2 - diffuser 3 - ring 4 - brackets, tabs, 5 - cap 6 - conical shield, d - diameter

Action ventilation nozzle based on the Bernoulli effect - the relationship between the pressure and flow rate of the air flow in the channel. When accelerating, provoked by the narrowing of the duct, the pressure in the system decreases, vacuum forming in the pipeline.

Principle of operation:

  1. Deflector catches the wind.
  2. Air mass rush into the diffuser, and provoke branch decompression ventkanala above.
  3. The discharged void directs the exhaust air from the room.

With proper selection and installation of the deflector at the end of the suction channel increases the pressure difference, respectively, increases the intensity of ventilation.

Classification of wind nozzles

Despite the same purpose, hoods differ.

Determining the optimal model of the device, it is necessary to evaluate:

  • manufacturing material;
  • principle of operation;
  • design features.

Material. In manufacture of aluminum, stainless steel, galvanized, copper, plastics and ceramics.

The optimal solution in terms of the balance of "price / quality" are considered to be steel and aluminum products. Brass vents are rarely used because of the high cost.

plastic deflector

Plastic models differ from counterparts lower price, variety of colors and shapes. Disadvantages of polymers: sensitivity to high temperatures and limited service

Symbiosis strength and decorativeness - combined caps of metal coated plastic.

Principle of operation. Based on the functional characteristics of the ventilation device is divided into 4 groups.

The types of vents:

  • static nozzle;
  • rotating vents;
  • static installation entraining fan;
  • models with rotating body.

The first group includes the model of the traditional type. Static vents are easy to design and the possibility of self-assembly. The valves are mounted on the exhaust mines of residential and industrial aeration ducts.

The second group (rotary deflectors) are provided with a system of rotating blades. Complex mechanism consists of an active head and a static framework.

The rotary deflector

wind gusts encouraged bladed drum to rotate. During operation in the mouth of the shaft creates a vacuum which prevents the appearance of reverse thrust

Static exhaust deflector ejecting fan - modern technology. At the end cap ventkanala mounted stationary directly underneath inside the shaft is mounted, low-pressure axial fan.

Deflector fan

Apparatus stato-rotational model: 1 - static deflector 2 - fan 3 - pressure sensor, 4 - a thermally insulated flask, 5 - noise absorbing ventkanal, 6 - drainage 7 - falshpotolok

Under normal environmental conditions the system operates as a traditional static deflector. As reducing wind pressure and thermal sensor is triggered - it is switched to the work axial fan thrust and normalized.

An interesting development, noteworthy - the deflector ejection-type rotating body. Rotating cap installed above the mine.

The model consists of horizontal and vertical pipes which are interconnected hinge mechanism. On top of the baffle is a partition - weathervane.

The rotary deflector

Horizontal pipe turns in the direction of the wind. Streams rush into the interior and create a vacuum - in the thrust shaft increases mouth

Design features. The models with the same principle motivations natural ventilation have some differences in the apparatus.

Deflectors are open or closed, circular or square, with one or more conical cap umbrellas. Details of the most popular and effective modifications are described below.

Review of popular models

In practice, well proven following types: Grigorovitch, Volpera, TSAGI, double and H-shaped deflector vane rotary type "skimmer" or "hood".

types of baffles

Selecting the "wind attachment" is based on efficiency, cost deflector and climatic conditions. Some models are available for self-assembly and installation

View # 1 - the classic cap Grigorovich

The most common variant used in the ventilation and smoke extraction systems. Because of the simplicity and accessibility of the deflector Grigorovich holds a leading position among peers.

The apparatus represented by a pair of umbrellas, connected in a "dish."

The cap is mounted on pipes of circular cross section and is mounted through the adapter plate into rectangular or square shaft.

deflector Grigorovich

Basic configuration: 1 - a constricted diffuser cone 2 - protective umbrella, 3 - inverse cap. Fixing strut elements combined nozzle

Due to the design carried double air ejection - in the direction of the extended portion of the diffuser and the reverse side of the hood.

The flow rate below the lower cone is increased by narrowing the channel cross section, as a result, the pressure difference increases.

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Simple deflector vent tube

Simple umbrella-deflector for arranging ventilation pipe is easy to manufacture own hands sheet of tin

The size of the base for fixing the deflector

Base, and along the fastener deflector becomes a regular collar or metal band with curved edges, remove the bolt

The diameter of the metal cap

The diameter of the deflector cap to be improvised 1/3 the diameter of the vent tube

The distance between the clamp and the umbrella

Between the collar, fixing the deflector onto the vent and the hood should be not less than a diameter of the pipe

Simple deflector vent tube

Simple deflector vent tube

The size of the base for fixing the deflector

The size of the base for fixing the deflector

The diameter of the metal cap

The diameter of the metal cap

The distance between the clamp and the umbrella

The distance between the clamp and the umbrella

View # 2 - universal nozzle TsAGI

Ventilation hood, designed Aerohydrodynamic Institute, enhances traction due to wind pressure and the pressure differential at various heights.

Nozzle supplemented cylindrical screen inside which is placed a prototype of a conventional deflector.

deflector TsAGI

The outer shell is to prevent tipping of natural ventilation even in the ducts of large cross section. The allowable diameter of the exhaust shaft - 100-1250 mm. Figure Notes: a - top view, b - side view, D - diameter, H - height of the device

Distinctive features:

  • acceptable bandage, rack and pinion, and the nipple flange connection duct depending on the shape of the shaft of the neck;
  • possibility of air transportation, chemically non-aggressive environment (steel models withstand temperatures up to +800 ° C);
  • winter, frost may form on the inner walls of the cylinder, which is able to block the orifice.

The deflector is susceptible to wind flows - in calm weather creates resistance to traction.

View # 3 - Staten dynamic cap Astato

Articles-mechanical deflector - the development of the French firm Astato. The device amplifies the exhaust stream of the natural ventilation system due to wind thrust and fan.

The nozzle is mounted on any number of storeys of buildings, renovations and new buildings.

deflector Astato

In passive mode, the level of vacuum generated Astato, equals the sum of the gravitational and wind pressure. This value corresponds to the static deflector

After turning on the electric motor aerodynamics ventkanala maintained, the degree of suction - the total value of the fan pressure and pressure.

Features deflector:

  1. installation Methods. Plug-in connection for round air ducts, through the adapter - for a group of ducts and shafts of rectangular section.
  2. control modes. Acceptable manual control and automatic - pressure sensor means, time switch.
  3. Material - aluminum.
  4. The lineup. Astato deflector consists of six positions, the nominal diameter - 16-50 cm.

a series of modifications DYN-Astato equipped with two-speed fan, product costs - 1300-4000 USD Regardless of the size of the deflector.

View # 4 - deflector DS Series

Static nozzle DS open resembles the deflector Astato. But, unlike the French cap, DS series models have no moving parts. three discs conical shape provided in a part of the cap.

Deflector DS Series

Umbrella this type of truncated deflector and located opposite each other, forming a channel of venturi type. The diameter of the central hole of the lower disc corresponds to the pipe section. Brackets hold the net

Maximum speed wind turbulence is observed in a truncated duct cap - over a vent pipe. The pressure difference inside the deflector and remotely from it causes additional vacuum, increases thrust.

Features of the model DS series:

  • deflector is compatible with forced ventilation by means of motivation - fans;
  • wind flow velocity of 5-10 m / s thrust increases by 10-40 Pa - relevant data relative humidity of 50 °, an air temperature of +25 ° C and a deviation of the wind flow 30 ° from the horizontal plane.

Deflectors are produced in 13 sizes. Designation of ventilation hoods: DS - ***where *** - inner diameter in mm. Minimum size is the model DS-100, the maximum - DS-900.

View # 5 - rotary or turbine turbodeflektor

Dynamic deflector consists of a fixed base and a rotating turbine head.

Elements of a spherical cap made of lightweight, thin metal, which allows the drum with blades included in the work with little wind - 0.5 m / s.

active turbodeflektor

The head rotates in one direction of the wind vector. Under the hood there is a "partial vacuum" - ventkanala air atop diluted, the probability of tipping ventilation minimizes the (+)

Benefits turbodeflektora:

  • efficiency operation in 2-4 times higher than static models;
  • space protection Overheating in summer and reducing the cost of air conditioning in hot weather;
  • aesthetic appearance - the head of the deflector is in the form of an elegant spherical cap;
  • preventing the occurrence of condensation inside the roof due to the temperature decreases in hot weather;
  • working efficiency - active deflector operates without power.

Turbodeflektor shaft extends from excess heat, moisture, dust, fumes, and noxious gases from the building and the roof space, thereby increasing the life of the structural elements of the house.

Lack of active deflector - zero performance in calm weather.

Dimensions termodeflektora

The marking of products production Aerotek is represented as TV-160, etc. Digital index denotes the diameter of the cross section of the fixed base cap

Dynamical tips available a wide range of. Demand for goods: Aerotek (Russia), Turbowent (Ukraine), Rotowent (Poland) and Turbomaks (Belarus).

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Turbodeflektory on the roof of the shopping complex

Turbine vents are mainly used on the roofs of large buildings and air ducts, on gyms, production halls, shopping complexes and public

Location of the turbine blades

Turbine blades are arranged so that no matter which side of the wind appear, the device begins to rotate, creating a vacuum inside

Mounting plate turbine device

To the tube deflector turbine attached via clamp to the roof - a mounting plate bolted to the sheathing roof outlet

Fixing of the blades in the top of the deflector

The top blade turbodeflektora connected a circular plate, which are fixed to the studs. The plate prevents penetration of atmospheric water ventkanal

The axis of rotation of the turbine deflector

In the center of the turbine system is axis of rotation with the bearing, providing smooth rotation

Versions models

Deflectors turbine type made from galvanized or stainless steel. In the first case, in preference with polymeric products of decorative and protective coating

Details for the assembly turbodeflektora

Delivered turbine deflectors in the ready-to-install and unassembled

Set to build a turbine vent

To set of parts intended for assembly deflector turbine attached detailed instruction, according to which to connect system components

Turbodeflektory on the roof of the shopping complex

Turbodeflektory on the roof of the shopping complex

Location of the turbine blades

Location of the turbine blades

Mounting plate turbine device

Mounting plate turbine device

Fixing of the blades in the top of the deflector

Fixing of the blades in the top of the deflector

The axis of rotation of the turbine deflector

The axis of rotation of the turbine deflector

Versions models

Versions models

Details for the assembly turbodeflektora

Details for the assembly turbodeflektora

Set to build a turbine vent

Set to build a turbine vent

View # 6 - rotary vane type "hood"

Rotary cap type "hood" or "net" - semicircular rotating airflow catcher mounted on the rod.

Its curved visors attached to the bearing assembly. At the top of the housing is weather vane, allowing construction to follow the wind direction.

Rotary-vane deflector

The circuit device 1 - the working body, 2 - nozzle-deflectors 3 - turning rod 4 - bearing 5 - sealed glass 6 - mounting ring, 7 - a vane

The principle of operation of the ventilating "the hood":

  1. Under the pressure of the wind vane rotates, being located on the air flow line.
  2. air stream passes through the space between the curved visors.
  3. Flows change vector and directed upward.
  4. In this area, according to the tenets of aerodynamics, air displacement velocity increases and the pressure drop - it is formed deep vacuum.
  5. Link from the ventilation shaft is increased by providing an additional exhaust air suction.

Vane-deflector difficult for independent manufacturing than static models. The nozzle is operable to wind load at 0.8 kPa (less than 800 kgf / sq).

View # 7 - Module H-type

Deflector H-shaped advantageously mounted on manufacturing plants. Its purpose - to gain traction in the ventilation and chimney.

H-shaped deflector

The wind hits the vertical bridge module and the exhaust air sucking through the horizontal channels of the deflector, thereby increasing traction in the pipeline

The design does not require the visor, since the tip of the duct is protected by the horizontal member.

The main advantage of the H-shaped hood - operation with strong gusts of wind. To work deflector able to use the force of wind flows, forward upward direction.

Nuances of the installation of wind caps motives

When installing the vent should be guided by the norms SNIP.

The focus is on the height of the vent pipe and cap:

  • 500 mm above the parapet / roof ridge, if the duct is removed from the top of roofs of 1.5 m or less;
  • flush with the ridge or higher, if the distance from ventkanala to the parapet of 1.5-3 m;
  • not lower than line deflection held at an angle of 10 ° down from the ridge, provided the distance tubes longer than 3 meters.

Flat roof vent set at a height of 50 cm and above.

Installing the deflector

When placing the ventilation shaft next to the chimney, it is necessary to keep the same height ducts. If these requirements are ignored, then the furnace smoke may enter the room

Additional settings nuances:

  • invalid installation in the wind shadow of neighboring buildings;
  • a deflector located in the free airflow zone optimally if the hood is the highest part of the roof.

Installation of circular section nozzles per square duct through the transition tube.

Requirements and methods of mounting a deflector on the boiler chimney described in this article.

Conclusions and useful videos on the topic

Comparing characteristics of the rotary turbine and models TSAGI:

The operating principle of the rotary-wind vane deflector:

turbodeflektora installation technology to the flat roof:

Such a simple device such as a baffle, is able to solve common problem of natural ventilation - insufficient exhaust thrust.

In addition to improving the efficiency of air circulation, the cap has a protective role, preventing clogging debris ventkanala.

You have experience in installing and operating the vents? Or have questions on the subject? Please share your opinion and leave comments. Block feedback situated below.

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