How and why is fire protection of air ducts done? Types and characteristics of non-combustible thermal insulation Fire-resistant insulation of air ducts
Air ducts are an important component of the climate control system, responsible for supplying and discharging air into the room. Such systems are installed in residential buildings, warehouses and production premises, offices, shopping and entertainment complexes. The main goal The organization of ventilation and air conditioning systems is to create the most comfortable climate conditions in the premises with minimal energy costs. The solution to this problem is high quality insulation air ducts of ventilation systems. To protect air ducts, various types of insulation are used - thermal, fire, sound insulation, insulation that prevents the formation of condensation. For each type of insulation we use various materials, most of which are capable of solving complex problems.
Thermal insulation of air ducts
The use of thermal insulation for air ducts makes it possible to reduce heat loss from the room to the outside through ventilation, thereby reducing heating costs. Thermal insulation is installed on the external elements of ventilation systems to limit and control heat losses.
In various sections of air ducts, the thermal insulation device makes it possible to solve the following problems:
- When moving warm air currents through extended sections of ventilation systems, it is necessary to ensure that their temperature is maintained at a certain level. The type of thermal insulation and its thickness are determined using thermal engineering calculations based on the technical operating conditions of ventilation.
- Thermal insulation is also necessary for air ducts transporting cold air. This measure is necessary to protect cold air flows from heating warm air surrounding ventilation ducts. Without thermal insulation, the efficiency of the air conditioning system is significantly reduced. Properly installed thermal insulation makes it possible to achieve specified temperature conditions and ensures compliance with the operation of the ventilation and air conditioning system without additional settings.
To ensure thermal insulation of air ducts climate systems successfully used following types insulation materials: materials based on basalt fiber, glass wool, foamed rubber, foamed polyethylene, most often coated with aluminum foil, foil-coated mineral wool mats.
Thermal insulation can be both internal and external, but consider the advantages and disadvantages internal insulation makes no sense - in practice, no one insulates air ducts from the inside.
The thickness of the air duct insulation is determined temperature conditions, humidity, aggressiveness and other factors environment. Only qualified specialists should carry out calculations of insulation thickness. The calculation formula is specified in SNIP 2.04.14-88, which can be downloaded from the link below:
SNIP 2.04.14-88*. Thermal insulation equipment and pipelines. .
Air duct insulation device against condensation
A serious problem during the operation of ventilation and air conditioning systems is the formation of condensation on the surface of air ducts transporting air that is colder than the air in the room.
Condensation on air ducts, especially in rooms with high humidity, causes the formation of water droplets that can damage floors, walls and ceilings. Gradually, condensation causes the air duct to fail.
The appearance of condensation can be avoided by installing an insulating layer of sufficient thickness so that the temperature outer surface insulation was not lower than the air temperature in the room. A feature of such insulation is the need for a surface vapor barrier layer, the purpose of which is to protect the insulation from moisture entering it. Most often, foil insulating coatings are used for this purpose. Basalt fiber, foam rubber and polyethylene, and fiberglass can be used as the basis of the insulating layer.
All joints of the foil insulating layer must be carefully taped with foil adhesive tape. For additional fixation of rolled insulation, use wire or steel tape.
Fireproof insulation of air ducts
Due to the fact that ventilation ducts connect different types of premises, they must be protected with a layer of fire-resistant insulating materials. This measure is necessary to prevent destruction of the air duct from external fire in the event of a building fire.
Fire insulation of air ducts can be carried out using mineral wool pierced mats and slabs, cylinders made of basalt fiber.
- Mineral wool boards are used for air ducts square section, during installation they are secured with studs and fixing washers or special screws.
- Stitching mats can be used for both round and round air ducts. rectangular section. The mats are sewn together with wire. The length of the stitching mat for trimming is selected depending on the diameter of the air duct. The use of foil mats increases the functionality of the insulating layer and improves the appearance of the duct.
If vertically located air ducts have a significant length, fire insulation is additionally fixed to the ceiling or other building structures. For fastening, steel wire or special steel plates are used. Methods of fixing fire-retardant insulation to building elements are determined by building and fire codes.
To fix fire insulation of rectangular air ducts to building structures, use various types hairpins.
If the distance between the air duct and the ceiling made of fire-resistant materials is less than that required for placing the insulating layer, then it is permissible to leave the upper surface of the air duct without insulation. If this distance is equal to the thickness of the insulating layer, then the upper surface of the duct can be partially insulated.
IN Lately for increase fire safety air ducts use fire retardants, which appearance similar to paint compositions. They are applied to the surface of the air ducts with a brush, roller, or spray gun. In case of fire under the influence high temperatures protective covering swells to form a fire-resistant barrier.
Air duct sound insulation device
Parts of ventilation systems can become sources of unwanted noise, from which it is necessary to protect the ventilated areas of the building. The main noise generator is the blades of a running fan. In addition to the main ones, there are also additional sources sounds: dampers, valves, other mechanisms with rotating elements. The flow's own turbulence can also create noise and, in addition, provoke resonating vibrations. Such turbulent flows appear in places where the direction and cross-section of air ducts change.
Some noise and vibration can be eliminated due to the properties of the material from which the air duct is made. Flexible hoses perform this function most effectively, partially ventilation ducts from polymer materials. Noise and vibrations travel most strongly through metal air ducts. Therefore, if there are increased requirements for the noise level in the room, a sound insulation device is necessary. In some cases, installing duct silencers is an acceptable solution.
The ideal option for organizing a noise insulation layer, due to its fibrous structure and optimal density, is to use insulation based on basalt or fiberglass.
Reducing noise levels can be achieved using slabs with a special coating made from fiberglass nonwoven fabric or fiberglass. Such plates are installed inside the air duct, the joints are covered with a metal profile.
Brief characteristics of materials used for insulation of air ducts
Based on the results of market analysis building materials and consumer demand, we can highlight a number of popular materials used to construct the insulating layer of air ducts:
- To insulate air ducts of small and medium diameter, materials based on polyethylene foam, consisting of polyethylene foam with a closed-cell structure, are widely used. The most progressive is polyethylene foam, covered with a layer of aluminum foil, which has a reflective effect. This material is chemically resistant, environmentally friendly, effective for sound, heat, steam and waterproofing. Foil-coated PPE may have a layer of moisture-resistant adhesive on one side, allowing the insulation to be attached to metal surfaces and other materials. Common brands of insulating material in this group are “Penofol”, “Izolon”, “Adgilin M”, “Mielterm”.
- Modern insulating material is foamed rubber, which, along with insulation building structures, used to protect air ducts from heat loss. Foamed rubber has a closed porous structure and has a high resistance to water vapor diffusion. To insulate elements of ventilation and air conditioning systems, foam rubber in the form of tubes of the Kaiflex EF and Kaiflex EPDM brands is used. Insulating rubber coating can be produced in the form of rolls and sheets - “Kaiflex Protect”. These materials can be produced with foil, with a self-adhesive layer, or with a combination of foil and adhesive layer.
- For thermal insulation of climate systems, mineral wool is most widely used, which has good heat saving properties and high fire resistance. To protect air ducts large section They use mineral wool mats, which are produced: foil, laminated, laminated, stitched. Most famous brands this type of air duct insulation: “Paroc”, “Nobasil”, “Izover”, “Rockwool”, “TechnoNIKOL”.
All insulating materials for air ducts differ from each other in characteristics and cost. However, it should be remembered that high-quality insulation should, if possible, provide comprehensive protection for the air duct to extend service life the entire climate control system.
PAROC FPS 14 is a non-flammable stone wool board that is used as fire protection steel structures, chimneys, doors, stoves. Slabs based stone wool have fire-retardant characteristics, which directly depend on the density of the material, as well as on the thickness of the insulation. Choosing the right product is determined technical specifications and the regulations of the fire protection system in question. The material is easy to process, install and use.
PAROC FPS 17
PAROC FPS 17 board is a non-combustible stone wool, which is used as fire protection for steel structures, chimneys, doors, stoves. Stone wool-based slabs have fire retardant characteristics that directly depend on the density of the material, as well as the thickness of the insulation. PAROC FPS 17 has ETA (European Technical Approval) approval for use as fire protection for steel structures and a Certificate of Compliance with the fire safety requirements of the Russian Federation. The choice of the right product is determined by the technical specifications and regulations of the fire protection system in question. The material is easy to process, install and use.
PAROC FPS 17t
PAROC FPS 17t board is a non-flammable stone wool, which is used as fire protection for steel structures, chimneys, doors, stoves. Stone wool-based slabs have fire retardant characteristics that directly depend on the density of the material, as well as the thickness of the insulation. PAROC FPS 17t has ETA (European Technical Approval) approval for use as a fire protection for steel structures. The choice of the right product is determined by the technical specifications and regulations of the fire protection system in question. The material is easy to process, install and use. The fireproof board is laminated with fiberglass.
Any building must ensure maximum safety for the people in it. One of the most dangerous situations– occurrence of a fire. The spread of fire between floors most often occurs through the ventilation system, and therefore the problem is one of the most pressing tasks of fire prevention.
We welcome our regular reader and offer him an article about what fire protection for air ducts is, why it is needed and how it is done.
Fire protection for air ducts is a passive means of fire protection and consists of creating a heat-insulating protection (screen) with high heat and fire resistance on the surface of ventilation ducts.
The screen must protect for a specified time:
- near sources of ignition - the air duct from destruction and, if possible, from heating;
- in the rooms above and below, walls, ceilings - flammable structures and materials adjacent to the air duct pipes, from secondary fire.
Fire protection is carried out by applying special compounds or thermal insulation various products from non-combustible materials (mineral wool, asbestos, sometimes ceramic materials– for example, expanded clay concrete, brick).
Why fire protection is needed
In the event of a fire, it is through the through network of ventilation pipelines that smoke and fire spread.
The main task of fire protection of air ducts is to prevent fires and limit the cascading spread of fire through ventilation and industrial air conditioning systems.
What are the dangers of ventilation during a fire?
The ventilation system in case of fire creates two types of danger:
- distribution of smoke-laden air through air ducts. Uninitiated people underestimate the dangers of smoke - and according to statistics, most of Those injured and killed during the fire died from suffocation. But this article will not talk about smoke prevention;
- spread of fire and secondary ignition of combustible structures and materials from contact with the hot walls of the air duct.
In most public, industrial and office buildings it is used natural ventilation(that is, without the use of fans) or mixed (some of the systems are equipped with fans). In private and multi-apartment buildings residential buildings Usually only natural ventilation is used.
The air ducts of any ventilation system are practically not blocked by any valves or dampers (in modern systems special fire dampers are installed, but there is always a possibility that the valves will not operate, and modern systems not installed everywhere).
In large modern buildings there are smoke removal systems - separate exhaust ventilation removes combustion products from places of fire occurrence and from adjacent rooms, forced ventilation pumps air and creates excess pressure in staircases and elevator shafts and prevents them from becoming smoke-filled.
Hot air from the fire zone will rush upward, heat the air ducts, carry away sparks and flames - and cause secondary fires in upper floors, attics, roofing.
Which premises need protection first?
First of all, they need fire protection:
- warehouses for fuels and lubricants;
- production using open fire or molten metals and minerals, welding, plasma cutting, electric furnaces for various purposes;
- places with large crowds of people - shopping centers, shops; entertainment establishments (theatres, cinemas, entertainment complexes, athletic facilities); office buildings, domestic buildings in industrial enterprises, children's and educational establishments; catering enterprises4
- underground structures.
At the domestic level, the first areas that need to be protected (especially those with open fire) are rooms with stoves and fireplaces, bathhouses, kitchens, boiler rooms and the rooms and attics located above them. However, all air vents should be protected - fires also occur for other reasons (cigarettes, pranks, short circuits).
Don’t forget about the quality and proper thermal insulation and sufficient fire resistance of chimneys, especially in places where they pass through walls, ceilings and roofs.
Rules and regulations for the operation of fire protection
Requirements for the implementation and operation of fire protection of ventilation, air conditioning and heating systems are prescribed in the Code of Practice SP7.13130.2013.
Only certified materials may be used. Fire protection must withstand temperatures of 1000°C for at least 150 minutes.
Methods and materials for protection
Fire protection methods:
- insulation using sheet and roll materials from mineral wool;
- application of special intumescent paints;
- application of fire-resistant mastics;
- installation of a fireproof barrier made of heat insulators;
- combined method - the use of paints and roll materials.
For fire protection system forced ventilation(using a fan), vibration-resistant, soundproof materials are required, since ventilation units make noise and create vibration.
The metal thickness for ventilation ducts must be at least 0.8 mm; grilles and diffusers in the system must be installed from metal.
Basalt mats, slabs, canvases
For fire protection, mineral wool mats and sheets, vermiculite boards, foil sheets, self-adhesive basalt fibers, asbestos-cement, and gypsum fiber boards are used. Average in price and affordable for self-installation isolation method. For installation, screws, washers, studs, wire, and clamps are used. They increase the size and weight of the pipes; work cannot be carried out if the pipe is tightly adjacent to the wall or located in a corner. There are a lot of types and varieties of slabs and mats.
Fire retardant paint
Special paints, varnishes and enamels are used that swell under the influence of high temperatures. The resulting layer has high thermal insulation properties.
Easy and quick to apply. Can be applied to hard to reach places, where thicker insulation does not fit - for example, if pipes are laid against the wall and in the corner of the room. The labor intensity of this method is approximately 5 times less than the use of mineral mats or mastics. Disadvantages: Less effective thermal insulation than other methods. Most compounds are quite expensive.
Fire barrier
To create a fireproof barrier, plaster on a mesh, a brick box, or concrete coating is used. These methods are no longer popular. Plaster makes the structure very heavy and requires reinforcement of the fastenings. Brick boxes are sometimes used in private housing construction.
Concreting was previously used in the construction of industrial and residential buildings, but now it is practically not used.
Concrete and brick boxes require installation of a foundation.
Fireproof mastic
All kinds of phosphate-based pastes and mastics are applied to the surface of the air ducts in a thick layer, liquid glass(silicates), mineral or asbestos fiber, nepheline mineral. Coating thickness – from 10 to 50 mm. An effective method of fire protection, also inexpensive and quite lightweight and not too labor intensive.
Application of pastes requires application specialized equipment, available only to organizations. The coating is not resistant to humidity and precipitation - the wet layer cracks due to temperature changes. Significantly increase the weight of structures and require reinforcement of fastenings. You cannot apply the coating to the walls of air ducts adjacent to walls.
Where to buy materials
Your life and the lives of your loved ones depend on the quality of the materials used, so you should not buy fire protection materials in markets and small shops - the quality almost certainly does not meet the standards. You need to buy in large construction supermarkets, with a receipt and certificate. The likelihood of buying a fake in this case will be minimal.
The approximate price of rolled foil mats 50 mm thick is from 200 rubles; 80 mm – from 250 rubles.
Design and installation
Any work on fire protection of public and residential buildings is carried out by specialized organizations with a project in place. However, no one forbids additionally insulating the ventilation duct in your apartment. Fire protection of ventilation systems in private housing construction is practically not controlled by anyone.
Fire protection is advisable in the following cases:
- if the housing has two or more floors, including a usable basement;
- if the ventilation ducts are in one-story house pass close to the chimneys of the heating system. In a small one-story house, fire protection is a matter of your desire.
You can apply intumescent paint yourself or insulate using mineral wool boards. Working with asbestos-cement or gypsum-fiber boards is labor-intensive; the use of asbestos-cement in residential premises is not allowed.
Before carrying out work, you should complete a project or make a drawing, think over the method of fastening, and calculate the quantity of all components.
Most often, basalt mats are used at home.
Installation technology:
- it is necessary to degrease, rinse and degrease the surface of the air ducts (using acetone). Don't forget to open the windows - you can only work if there is enough supply fresh air and as quickly as possible;
- the mats are cut around the perimeter of the air duct, taking into account an overlap of 100 mm;
- special glue for gluing mineral wool sheets is mixed, protruding elements of the air duct (for example, joints, clamps) are coated;
- First of all, protruding parts, brackets, and joints are glued. the foil will be on outside mat; pieces of mat are glued with an overlap of 100 mm;
- the smooth part of the air duct is coated and glued;
- at the joints of mats and protruding parts, mineral wool slabs must overlap; if necessary, the joints are glued aluminum foil;
- It is advisable (but not necessary) to secure the mats on top with wire, clamps, or metal brackets.
Watch the technology in more detail in our video:
Today our plant produces two types of fire protection for ventilation systems:
- (with fire resistance EI 30 - 180) two-component complex system fire protection, consisting of rolled basalt material MBOR and fire-retardant adhesive composition Kleber.
The main advantages of fire protection for air ducts:
Aesthetics (no need for any external elements fastenings, in addition to aluminum tape for sealing joints, the material looks smooth, beautiful) and the possibility of installation in hard-to-reach places, for example, if the air duct is located close to the wall at a distance of 1-2 cm. In such cases, you can apply glue with necessary expense directly onto the material, stretch the resulting piece between the air duct and the wall and secure it to the air duct.
- Heat (with a fire resistance limit of EI 60 - 180) - a heat-and-fire-retardant coating, which is a pierced mat made of super-thin basalt fiber (BSF) without the addition of a binder.
The main difference and advantage of this material- improved thermal insulation properties. Where a big difference ambient temperatures and transported air in the air duct, to prevent overheating/cooling of the transported air and the formation of condensation and metal corrosion, it is better to use this material. For example, if the air duct runs along the street, where in winter the temperature can drop to -30°C, and the temperature in the ventilation system should not be lower than +20°C.
Non-flammable fire protection for ventilation based on basalt fibers solves the following problems:
- increases the stability of structures in case of fire (fire resistance limit)
- the development and spread of fire in buildings and structures is prevented (loss of integrity and load-bearing capacity).
Basalt mats are flexible and, as a result, have a tight fit to the protected object. Installation of fire protection and thermal insulation of air ducts is simple and meets all SNiP and fire safety requirements.
The sizes of basalt mats are 1.2 m wide and 6 - 20 meters long. The mats have an additional lining with foil, metal mesh, glass, basalt or silica fabric. This provides the material with additional protection and, at the same time, an aesthetic appearance.
Used as fastening metal grid, bandage made of steel wire or tape and adhesive compositions, immune to the effects of fire.
The BOS company creates safe solutions that today are trusted by large enterprises throughout Russia. Our products can be purchased in Kazan, Moscow, St. Petersburg, Nizhny Novgorod, Perm, Chelyabinsk, Novosibirsk, Samara, Krasnodar, Rostov-on-Don and other cities of the country. Large production volumes and constant availability of goods in stock allow us to maintain an optimal quality-price ratio.
If you have questions or need advice, contact the BOS manager in your region.
