Modern offices, residential buildings, industrial buildings need to ensure normal ventilation in the unit full ventilation. For the construction of an organized system made duct installation. Install them and buildings inside and outside. But a full ventilation system is necessary and at home, you agree with that?
Knowing the principles of the arrangement of the system and the nuances of the connection ducts in a certain sequence, will be able to create a functional ventilation network. But how to do it? Let's deal with - in this material are considered varieties of ducts that are used to create ventilation systems.
Also discussed in detail particularly flexible and rigid mounting channel. Article for clarity supplemented themed photos, diagrams, detailed video instructions for installing and fixing of air.
The content of the article:
- The principle of classification of air ducts
- Aerodynamic calculation of the duct
Duct mounting Features
- General rules of installation
- Types Rigid Air connections
- Methods of fixing of air
- Installation of flexible pipes
- Conclusions and useful videos on the topic
The principle of classification of air ducts
Ducts referred ductwork adapted for movement through it of air flow and arranged in a certain way.
They are used for installation of ventilation systems in houses, form a network of ducts ventilation systems and air conditioning, are connected with their help industrial and cooker hoodsIs used Air heating systems.
Based on the structural design, they are divided into round and rectangular. Ergonomic circular ducts, the air moves him almost silently, a slight vibration at work.
Connect the air duct elements of circular cross section without the use of additional elements.
The ducts are used to form the directional flow of air conveyed to feed or removal from the premises through the channels
Device with air venting systems produced advantageously in industrial halls food and chemical industry, car repair workshops and working with flammable and toxic substances
Using the extractor duct is connected to the ventilation system for discharging exhaust air outside the room
Airway channels air handling systems are equipped with ventilation grilles, through which fresh air is supplied to the room
In a domestic environment ducts are most commonly used in kitchens with apparatus forced system with extraction
In private homes use air ducts in the ventilation systems of surface and underground structures. Basically, they put where you want artificially stimulated ventilation system
If the door and window openings baths, apartments, country houses made with sealed plastic construction, ventilation unit with air just need
Ducts pave the way how to open and concealed, i.e. with placing them in boxes, in building constructions, for false ceilings or partitions of plasterboard
Channel venting system
food industry enterprises Ventilation
Connect the duct to the hood
Bars on the supply air system
Plastic duct in the kitchen
Duct in the basement of a private home
Ducts with hood in a waiting room
Ducting for false ceiling
Rectangular duct cross-section is preferable when the system needs to make invisible, hiding it under the finish.
This and a satisfactory level of capacity due to their choice at the device ventilation systems in residential buildings. In addition, the air ducts are rigid and flexible.
Metal ducts with a rectangular cross-sectional shape are typical sectional dimensions, fluctuating in a range from 10 x 10 to 400 x 320 cm. Direct links have a length of 1 to 2.5 m
In the first section may be either circular or rectangular, and the latter have only a sectional circle. Their use is appropriate in the branching points. produce flexible ducts (corrugated) mostly made of aluminum foil, polyester, although there are items made from silicone, textile, rubber, resistant to aggressive chemicals.
For fans, supply and exhaust diffusers, grilles them is connected directly, but sometimes to tie a duct with the main system, other relevant connective assembly details.
Inside surface of the flexible duct it is not very smooth, so the increased aerodynamic drag creates additional noise.
Flexible ducting may be a carcass, and frameless. The frame forms a wire - a polymer or steel. Formation in the spring wire coated with synthetic material, foil or ribbon polymer. This type of pipes is sometimes equipped with coating - thermal insulation or soundproofing
Structure in multilayer flexible ducts. For greater rigidity between the steel wire layers arranged. Most often air ducts in homes paving of PVC pipe having high sound-absorbing and insulating properties.
Applied corrugation in the places where the air velocity does not exceed 30 m / s, and the pressure is not higher than 5 m. Pa.
Airway channels on the design can be built in the form of ventilation ducts, and outside, padded on walls and ceilings. The first feature inside the walls.
Them to work effectively within their surface should be as smooth as possible, then the air will circulate freely without bumping to any interference. At the bottom of the shaft has a hole that allows you to clean the air duct.
Suspended ladders and boxes used for the device of external ducting. They represent the assembly consisting of pipes and connectors different in size and shape. Based on this feature, as the presence of the insulation, the air ducts are insulated and non-insulated.
Based on the design of premises and design features of the building, stop the choice on any particular a duct.
a-h - horizontal air guide channel; and, to - vertical channels; and, and - attaching to the wall; b, c, d, k - fixing to the columns; d, in - in overlapping; f, h - the forms and purlins. Structural elements: 1 - console; 2 - Rod; 3 - a collar; 4 - duct; 5 - a traverse; 6 - coupling bolt; 7 - lining
Installation of the system must be preceded by a high-quality aerodynamic calculation. You need to determine the system pressure, the volume of air mass passing along the duct, its sectional view, the type of ventilation.
Aerodynamic calculation of the duct
To determine the size of the duct cross-sectional sketch variant need air network. First calculate the cross-sectional area.
For a circular pipe diameter is found from the formula:
D = √4S / π
If a rectangular cross section with an area found by multiplying the length by the width of the part: S = A x B.
Calculating section and using the formula S = L / 3600V, are in volume vozduhozamescheniya mᶾ L / h.
The rate of air flow in the duct to supply air grille recommend taking area in the range from 2 to 2.5 m / s for offices and housing and from 2.5 to 6 m / s in the production.
The trunk duct - from 3.5 to 6 in the first case, from 3.5 to 5, - in the second and from 6 to 11 m / s - in the third. If the speed is higher than these figures will increase the noise level in excess of the standard value. Ratio between coordinates 3600 and a second clock.
Using the tabulated values simplify the calculation process. Sometimes, in order to reduce noise in the system is used with a pipe section, exceeding the size calculated value. From an economic point of view, such a solution impractical. The surround channels are more expensive and steal space
From the table, focusing on the speed of the airflow, you can take and the estimated costs of the air mass.
You may also be useful information about calculating the duct area with the calculation examples in our other article.
Duct mounting Features
Regardless of the type and assigned to the ventilation system features a basic problem, consisting in air transport, is performed therein channels for conveying the air flow. Of all the works on installation of the system the most difficult point is the installation of ducts.
Even with well-executed calculation, breaking technology never will create a system that works without a glitch.
In addition to basic tasks, ventilation and can perform a number of additional functions:
- to monitor the purity of the supplied air in the room;
- to maintain a given percentage of moisture;
- exempt from any air contaminants to be removed from the building.
When the device ventilation It needs only one duct. AT supply and exhaust system require laying of two independent air ducts to one of them walked into the room clean air and left used in another.
Gasket channels for supply, exhaust and combined ventilation is produced in accordance with the general rules. Devices inducing air movement established either at the system inlet or at the outlet from the room
General rules of installation
There are documents that spelled out the requirements for the installation and operation of air ducts. These include JV 60.13330 and SP 73.13330.2012. The first is called "HVAC" and the second - "Internal sanitary systems in buildings."
In addition, manufacturers are producing ducts, making them his instructions.
For requirements subject to strict execution include:
- Full stretch of flexible ducts for the installation.
- Absence of slack in order to avoid pressure loss.
- Required ground because pipe tends to accumulate static electricity.
- Do not schedule the installation of flexible and semi-rigid duct, if the vertical length of the system is a route covering more than 2 floors.
- Set exclusively rigid pipes in the ground floors, basements, in constructions of concrete, in places of contact with the ground.
- During the design phase and during installation of flexible air ducts and other should be considered the point that the system is running the ventilation air path is a spiral.
- Laying the cornering radius equaling at least two pipe diameters.
- Through the wall duct carried out using special sleeve of metal and adapters.
- Damaged during the installation duct, must be replaced.
The most common air ducts attached to the wall, the ceiling, the space between the ceiling trusses. It remains unchanged that the central duct and structural planes should remain parallel to each other.
Regulations and regulated by the minimum distance from the air line to other structures.
The minimum distance can be taken from the table. Please note that when crossing the ducts of constructions all connections must be removed from the points of passage is not less than a meter
When laying duct 2 variants are possible. The first - the combined pipe system constitute a common outlet pipe. The second - each room has individual air duct.
Types Rigid Air connections
When installing the ventilation system is recommended to do as little as possible connections. Combine the ducts by means of a flange and shroud attachment.
In the first case the fittings and the pipe ends complementary flanges are then connected using screws, by means of rivets, arranging them every 200 mm, or by applying welding. As the sealing flange practice the use of rubber gaskets.
Production of flanges - a complex and not very profitable for the producer.
For the formation of the flange connections should not take, with no experience in carrying out similar work. If you come from, do them better on the ground, and then to hang a ready-made design
Wafer bandage or compound is more advantageous both in financial terms and in time costs. It provides for the imposition on the joint bandage, which is a thin metal strip or rail. This type of connection can not be called perfect.
Home - tightness is low, because of which the joints are air leakage sites, and sub-zero temperatures condensate accumulates here.
In forming a compound of nodes both rigid and flexible ducts is important to ensure tightness and to avoid leakage at the points of connection to the equipment
There is a third method of connection with the mounting of rigid ducts - and corner bus. The invention of Metz Engineers from Germany. Now it has successfully recaptures the position of the first two methods. For cutting the tires do not need expensive equipment, and the area is made by stamping.
Methods of fixing of air
There are 4 ways of fastening the duct:
- plus hairpin profile;
- hairpin and yoke;
- plus hairpin clip;
- paper tape.
The first of these techniques love to use professionals. As used has L or Z-shaped shape. The second heavy air ducts are fixed in the main. It reduces the load on the hardware and provides additional support for rigid box area, placed under the bottom corner.
In place of fastening profile enclose seals made of rubber. They need to reduce noise and vibration damping.
The picture shows how the duct mounting with studs and a different profile shape. This method is preferred to all other specialists
When assembling operate heat- and sound-proofed duct where line width is greater than 60 cm, is used a second method of fastening. The load from the duct falls on a traverse, and the horizontal movement insure studs.
For better insulation against noise is needed and laying rubber profile. Placing it between the duct body and crossbeam.
To install the circular ducts - simple or isolated using a third way - the pin and collar. On small duct portions made of flexible tubes can dispense some collars. Easiest and cheapest way - fixation with paper tape.
Punched tape simplifies operation and allows the installation of ducts in a shorter time. It has holes for bolts and rivets
For a circular duct of punched make a loop and for a rectangular - it is connected to the bolts. Used this method to systems with a diameter of not more than 20 cm, because structure does not have sufficient rigidity.
The back side is performed duct fixation directly to the ceiling of the anchoring compound or by using a clamp.
Installation of flexible pipes
Flexible ducts mounted easier than hard.
The technology consists of the following operations:
- Cutting. Duct, to improve the aerodynamic characteristics, stretch, and metered scheduled length. Next, make the cut on the coil.
- connections. Duct wear on the socket with a stop at least 5 cm. In this case, be sure to take into account the direction of air promotion marked by a colored mark on the flexible tube. Proper installation reduces the noise level in the system.
- Sealing. Sealed joint using sealant tape or a special aluminum. Fix the duct using a hose clamp.
In the case of mounting insulated sleeve is used the same technology, but when the duct is cut off or connects portions previously wrapped layer of insulation.
Naked frame dock or cut, sealed connection and only then recycled insulation in place. After that, it is necessary to fix and re-insulated.
Flexible insulated sleeve is used in ventilation systems, air conditioning, and the air supply. A layer of insulation to prevent heat loss and the appearance of condensation
The mounting points must be within 1.5 - 3 m apart. Allowed to sag therebetween not greater than 5 cm to 1 m. If the duct is arranged parallel to and above the ceiling structures, the distance between the axes of the clamps is 100 cm.
When the air duct in a vertical position, the distance between fasteners increase to a maximum of 180 cm. Coverage duct clamp can not be less than ½ of the first diameter.
If you need to rotations needed the largest possible radius. pressure decreases with decreasing this setting. Optimally, when the radius of the bend is 2 times the pipe diameter.
Often the flexible duct bends operate immediately after the pipe connection with the channel. If you make this transition at a slight angle, air ducts made of metal can be covered with cracks. Many such compounds will entail significant pressure loss
Unprotected against weather and ultraviolet flexible duct will last long if it is set outdoors.
Flexible duct made of metallic polyester tape, contacting the heating pipe system, carefully and quickly sag old. We can not allow and interactions of air ducts made of different metals - it also has a negative impact on their useful life.
It is causing considerable damage to the synthetic duct static electricity. With a large cluster and its discharge occurs even explosion may occur. Such situation is possible when in the air, moving with considerable speed, There are a pair of natural solvents.
It helps in this case ground. For this purpose, the ground wire is connected to the wire forming the frame of the duct. If this handling unit is located above the equipment, coiled wire is fed to his body.
Conclusions and useful videos on the topic
Here you can see how experts perform installation ducts:
Ducts made of plastic and their installation:
It is important to initially have a competent duct laying project. After reviewing the types and features of the duct assembly of different types, you can do a simple device system independently.
Cumbersome and difficult in the performance of the design is better to entrust the professionals.
You have not only theoretical knowledge but also practical experience in air ducts installation? You may have noticed the discrepancy information or technical errors in the above material? Write to us, please, about it in the comments below the article.
If you have any questions or would like to clarify one point, the installation of air ducts, ask for advice - try to help you.