How to arrange ventilation ducts in a private house: design rules and construction guide

Cleaning of ventilation ducts

Over time, the ventilation system must be cleaned of dirt and dust. If the ventilation ducts are not long, then this work can be done independently with a vacuum cleaner. With a long channel, it is better to use the services of specialized organizations.

This has certain advantages:

• Cleaning will be carried out by competent, trained specialists.
• The quality of such cleaning will be much higher.
• Firms that are engaged in this activity have special equipment.
• In addition to cleaning, disinfection and disinfection of ventilation can be carried out.

The device of this design in a private house is not a luxury, but a necessity.The presence of this design should be laid down at the design stage of the house. When using a natural system, you can mount it yourself.

If more complex forced or combined options are planned, using special equipment for air heating, then you should contact the specialists.

Such complex systems are first calculated in special programs, after which a separate project is drawn up for them. For the device of these structures, installers with special technical knowledge will be required.

Peculiarities

Ventilation designers deal with seemingly "weightless", but with a very capricious substance - air. If for the development of the project of electrical wiring, plumbing and other communications, an increase in the volume of the building only increases the quantitative complexity of the work, then with ventilation it is not so. On an area of ​​1000 sq. qualitatively new problems arise. In addition, it is necessary to analyze from the very beginning where it is possible to use the natural course of air, and where it is necessary to help it. In some cases, fans are indispensable.

Another caveat: you need to consider the location of the ventilation. If the building has one floor - this is one situation, but in multi-tiered buildings the situation is different. The preparation of projects for such buildings as:

• residential buildings;
• industrial premises (with a breakdown by industry);
• medical institutions;
• educational organizations;
• hotels and so on.

Pro Tips

Some owners of private houses make mistakes when designing networks and then buy expensive equipment to eliminate the negative points.

There are some of the most common mistakes:

• Installing an air conditioner will solve the problem. No. The equipment does not create a circulation of flows, it only provides cooling and drying of the environment in the room without the influx of fresh oxygen.
• An exhaust fan will suffice for ventilation. No. Without supply ventilation, a few minutes after the operation of the exhaust device, the pressure level will drop so much that it will no longer supply air to the fan blades.
• To ensure ventilation, regular ventilation or setting the window sash to micro-ventilation mode is enough. No. Under the condition of high humidity in the room or the accumulation of a large number of people, these measures do not solve a permanent problem and can only save a short time.

The arrangement of the ventilation system is a necessary measure to maintain a comfortable microclimate in a private house. When choosing equipment, the user is advised to take into account the power of the devices, the indicators of the intensity of air exchange and the noiselessness during operation.

State standards

All rules are summarized in state standards - GOST, sanitary rules and norms - SanPiN, sets of rules - SP.

In these regulations, calculations of the air flow into various types of premises are given, which depend on various factors. They regulate the necessary parameters of air exchange and a healthy microclimate, as well as establish standards for the installation of ventilation equipment and its operation. For example, according to GOSTs, on average, one square meter of an enclosed space should account for up to three cubic meters of fresh air. In addition, up to 30 cubic meters per hour is provided for one adult tenant.They also indicate that for gasified kitchens the norm is higher than for kitchens with electric stoves - 90 cubic meters per hour versus 60 cubic meters. At the same time, 25 cubic meters are enough for bathrooms. m/h, and bathrooms - up to 50.

In addition to domestic standards, there are regulatory documents of the foreign community of Ashare engineers. If you plan to use American-made ventilation systems to equip your own cottage, then you should familiarize yourself with them. In particular, Ashare 62.1 defines the minimum allowable coefficients and parameters for ventilation, and Ashare 55 provides the necessary conditions for the microclimate and thermal comfort of buildings.

The initial stage of designing ventilation communications is to develop a technical assignment, which must specify the requirements for the exchange of air flows in each room of the building. Drawing up such a document requires certain knowledge, so if there is no confidence in self-development, it is better to invite specialists.

Basic development steps.

• Determination of standards for the amount of air supplied to each room. This parameter is necessary for calculating the dimensions and cross-sections of air ducts, as well as for working out the scheme of their branches. In the future, using the calculated data of the first stage, the optimal solution for the location of the ventilation ducts is selected.
• Choice of air flow method. After analyzing the technical conditions of the premises, safety requirements and the wishes of the customer, the most rational option is chosen. It can be natural, forced or mixed.
• Calculation of flow distribution inside the ventilation complex.At this stage, the required fan power, the volume of air that must pass through a certain section, and the losses of each unit are calculated.
• Calculation of noise characteristics and calculation of the sound pressure that air flows exert when moving through ducts. According to SNiP, noise should not exceed 70 dB.
• The final stage is the preparation of drawings with full details and specifics of each node of the system.

Based on the developed task, the scheme of the ventilation system is selected. It is necessary to coordinate and approve it before the internal finishing works of the building, since its implementation will require additional installation work for drilling various holes and channels. It should be remembered that some technical rooms require the installation of a separate ventilation cycle. For example, a boiler room and a boiler room - according to fire safety requirements, a garage - according to technical requirements. Solution methods may be different, but they must comply with the terms of reference, ensure ease of installation and further operation, that is, adhere to the following criteria.

• The number of nodes in the system should tend to a minimum, since the fewer parts, the less often they break.
• Service maintenance should be organized in such a way that it becomes available to ordinary users - residents.
• If air exchange adjustment and microclimate adjustment are understandable to non-specialists, then this significantly increases the rating of the equipment in the eyes of the buyer, as it reduces the cost of its maintenance.
• The ventilation system must have redundant units that will replace the main ones in case of their breakdown and during maintenance.
• Not the last factor is ergonomics: the complex must be correctly entered into the interior of the house.

Forced ventilation

Forced ventilation is installed when it is not possible to make natural ventilation. This option allows you to mechanically regulate the inflow and outflow of air. Fans are used for forced ventilation. Most often, channel devices are mounted. They are selected depending on the diameter of the duct section.

Forced exhaust ventilation - a safer option in the boiler room

If the boiler room is equipped with a floor gas boiler, mechanical devices are selected with a margin of 30% of their maximum load. The performance of the equipment depends on the length of the ventilation ducts and their bends, as well as the diameter of the pipe section. To do this more accurately, you must at least use the formula for calculating air exchange:

L = V x K

L - the maximum productivity of the equipment is expressed in m3 / 1 hour

V is the volume of the ventilated room. It can be found by multiplying the area by the height (V = S x h).

K is a value that indicates the rate of air exchange individually for each room. Knowing all these indicators, you can easily choose a fan with the required power. There is also a simpler option for performing calculations - a calculator on our website.

The supply air can be heated or cooled as desired. There are options for arranging boiler rooms with an air conditioning system. It is better to mount fans in metal cases in air ducts.

The forced ventilation system can be equipped with automation. For example, when the boiler is turned on, the fans will turn on at the same time.

It is important to remember that according to the norms of SNiP, a complete renewal of the air in the boiler room should be carried out 3 times in 1 hour. Based on these requirements, you need to take care of how to make a ventilation duct in a private house for a gas boiler correctly

Priority air exchange volume

Regulatory documents are intended to determine the parameters of natural air circulation. For a dwelling with an area of ​​30 m2, air exchange should be 4.5 m3 of air per 1 m2. With a larger room volume, each person needs 30 m3 of fresh air per hour.

According to the laws of gravity, warm air, saturated with the vapor of our breath and other household vapors, moves up. This property is taken into account when designing the system. The supply components are located below the exhaust

In the kitchen and bathroom, the indicator should be in the range of 110-140 m3 / h. For forced ventilation, the indicators will be higher.

Plastic pipes with a diameter of 160 mm are excellent for arranging ventilation in your home. This parameter provides air flow of about 30 cubic meters per 1 hour with a duct height of 3 meters. With other indicators, the efficiency will be less.

If you need to increase the throughput, you can increase the cross section of the duct and its length. To ensure maximum draft in each room, the same length of duct must be on the same floor.

The role of air distribution in the efficiency of the ventilation system

In the design of supply and exhaust ventilation, the process of proper distribution of air flows plays an important role.If these data are not taken into account in the calculations, then the ventilation system, even with high air exchange rates, may turn out to be inefficient in the process of removing polluted air from an apartment or cottage. One of the main tasks in the design of ventilation is the correct location of supply and exhaust distribution devices to achieve maximum effect.

• Grilles, adjustable and non-adjustable, of various geometric shapes and with air direction both in one direction and in all directions. Such air distributors can be used for supply, exhaust and overflow ventilation systems and be located on the ceiling, walls or on the floor.
• perforated panels. These devices are panels with perforation, located both in one and in several rows. They remove air currents from the top of the room.
• Diffusers or shades. Such devices are used for supply and exhaust ventilation, they can be with an air flow regulator.
• Nozzle and slotted. They are both supply and exhaust and can create a large jet of air at high speed, up to 30-40m/s.

It is their correct location that allows you to effectively distribute the supply and exhaust air throughout the room.

A scheme for the correct distribution of air masses in a building is ordered separately from the project, to companies that specialize in this, and you can independently make calculations using reference books or various computer programs. One such program is called Swegon.

Use of Check Valves

The technology for installing outlet ducts described above allows you to equip a fairly effective ventilation system in the house. However, under certain conditions in such shafts of private residential buildings, unfortunately, due to their low height, back draft can occur. In this case, the smells from the utility rooms begin, of course, to enter the rooms.

To prevent this from happening, special devices called check valves are often installed on the exhaust pipes. The design of such elements may be different. In some cases, they are mounted at the entrance to the ventilation duct, and in some - at the exit.

It is believed that when installing a natural ventilation system with your own hands, it is best to simply purchase decorative grilles for outlets of exhaust arms, already equipped with check valves. In this case, the installation of the device will be carried out approximately as follows:

• the opening of the exhaust channel in the room expands according to the size of the purchased grate with a valve;
• the edges of the grille are coated with silicone glue;
• the grate is inserted into the hole so that the valve body is in the shaft, and is pressed tightly against the wall.

Basement ventilation

To prevent dampness, each basement must be ventilated. Usually, for this purpose, vents or windows are arranged around the perimeter of the basement, which are periodically opened for ventilation. But the best solution is ventilation through special channels arranged in smoke ventilation units and extending beyond the attic floor or roof. The exhaust pipe starts under the basement ceiling and exits along with the rest of the pipes above the roof of the house.To improve traction, it is advisable to lay it next to the smoke channel of the furnace or heating boiler. The larger the cross section of the exhaust channel, the better; in any case, it must not be less than 140 x 140 mm. In summer, natural draft may not be enough, and a fan will have to be installed in the chimney.

The inflow of air is usually provided due to non-densities in the building envelope. You can also arrange special channels with air intake either from the street or from enclosed spaces (tambour, veranda). It is best to start the supply pipe in the attic. The supply and exhaust channels are located on opposite sides of the basement, with the first of them near the floor and the second near the ceiling.

Cross section and dimensions

The choice of section dimensions should be based on the normative value of the flow velocity. So for residential buildings, this figure in the branches is 4 m/s, for public buildings - 5 m/s, for industrial purposes - 9 m/s. At other speeds, the hum in the system will disturb people.

Standard sizes according to VSN 353-86 and SNiP 41-01-2003 are:

• for round ducts: 100, 125, 160, 200, 250, 315, 355, 400, 450, 500, 560, 630, 710, 800, 900, 1000, 1120, 1250, 1400, 1600, 1800 and 2000 mm;
• for rectangular and square air ducts, the wall lengths in cross section vary from 100 mm to 3200 mm.

Which is better, round or rectangular?

The choice of using round or rectangular air ducts for the construction of a ventilation system is based on such parameters as the area of ​​the building, the location of the channels and their configuration, and the requirements for the noise level in the room.

When designing, the temperature and humidity conditions and the decisions made on interior design are also taken into account. In rectangular ventilation systems, air leakage is possible due to the use of two flanges during installation, sections of round air ducts are connected using one fitting, so they are more tight.

However, they are more difficult to hide behind indoor decor elements.

Connectors and fittings

To connect sections of air ducts, to connect ventilation equipment, various types of hardware parts and fittings are used. The list of such elements consists of:

1. nipple - a part designed to ensure the sealing of air duct connections. Usually nipples have left and right threads at the same time, which allows you to fix the two ends of the pipes at the same time;
2. couplings - a connecting element of air ducts with a circular cross section;
3. bends 30º, 45º, 60º, 90º - used to change the direction of air movement at a certain angle when bypassing obstacles during installation of the system;
4. round transition - used for articulating pipes of different diameters, connecting shaped elements with a round section;
5. tee - details for connecting two branches of pipelines with a main line;
6. round or rectangular tie-ins - replace the tee and allow you to connect the elements to the finished structure;
7. plugs - regulate the air flow, protect the ventilation system from foreign objects and debris;
8. ducks (outlet S - shaped) - contributes to a change in the level of air ducts;
9. round umbrella - protect the outer part of the duct from precipitation;
10. crosses - parts for connecting at a right angle three branches into one common duct;
11. transition from a rectangular section to a round one - used to connect parts of a ventilation system of different sizes.

Where what section is used

Models with a rectangular section are not the most ideal option for an air duct, this is due to unsatisfactory aerodynamics and more complex installation. However, with their help, you can save space, since the walls of the pipe are as close as possible to the surfaces without additional fasteners. This advantage puts rectangular ducts in the first place for arranging ventilation in residential premises and offices of a small area.

They have less air resistance, and have a high level of rigidity and tightness. In addition, round exhaust pipes are less material-intensive, therefore, with the same throughput, they are cheaper, and it is much more profitable to use them at large facilities.

Features of project documentation

The project documentation can be divided into three parts:

• explanatory note;
• set of drawings;
• additional information.

The explanatory note contains a brief description of ventilation, technical specifications for the arrangement of ventilation ducts, power and heat consumption, the value of air exchange in the context of the premises.

In residential premises, as a rule, a supply and exhaust system is installed. The so-called branch with ventilation units includes individual fans, ventilation units, automatic heater control, check valves

The set of drawings includes a distribution diagram of ventilation equipment with details of nodes and a structural diagram, drawings of nodes, layout plans for routes, air ducts. This part of the project also includes the rules for maintaining communications and additional information for installing a ventilation system.

A complete package of project documentation is impossible without additional information - certificates, licenses, integration tables, axonometric diagrams and equipment specifications.

Installation of supply valves step by step

Structurally, natural ventilation inlet valves consist of the following elements:

• plastic short air duct;
• cylindrical body;
• filter;
• protective cover.

The holes for the valves are made as follows:

• on the wall, markings are made under the opening for the device;
• small holes are drilled along the marking contour with a step of about 10 mm;
• the remaining material is knocked out with a hammer and chisel.

The valve itself is mounted like this:

• the air duct is wrapped with a heat insulator;
• drive it into the hole so that it protrudes slightly from the side of the room;
• the remaining free space in the hole is foamed;
• inserted into the air duct using silicone inside the valve.

The installation of the supply air device is completed by attaching the filter washer to the inner wall.

The principle of operation of ventilation systems

The installation of ventilation ducts in a private house or cottage allows you to timely eliminate unpleasant odors from the premises. If you save on the arrangement of ventilation systems, then periodically accumulating stale air can adversely affect the health of the residents of the house.It is necessary to correctly select, design and assemble a ventilation system in order to ensure decent operation of private housing. Existing types of ventilation systems are based on the following principles of air flow circulation:

• natural;
• mechanical;
• mixed.

The use of the natural circulation method is not associated with the installation of mechanisms that allow the air flow to be pumped. Plastic and metal wooden valves are used, which are replaced by windows with micro-ventilation. To remove exhaust air from the premises of the house, ventilation shafts are laid in the walls. The forced system of ventilation ducts is provided by installing a fan in the shaft. The device of mechanical type systems involves the installation of supply equipment, which is responsible for the supply of clean air flow in the required volume to each room of the house.

The system must provide the output of the exhaust air flow to the outside. This method of installing ventilation ducts is more complicated than installing a ventilation system with natural air circulation. The method of installing mixed ventilation is associated with the use of a mechanical and natural ventilation system. The exhaust air masses are removed from the premises of the house during the installation of mechanical equipment.

How to make natural ventilation in the cottage

If, according to all indicators, it is natural ventilation that suits you best, and it was not originally provided for in some way, then we do it ourselves.

• Initially, we make an air flow. To do this, stepping back 15-20 cm from the window frame, punch a hole for installing supply valves. They are recommended to be made in every room of the cottage.If you don’t have a desire to hammer a wall, then contact the manufacturer of your wonderful metal-plastic windows. Inlet valves can be mounted directly into the windows.
• We do air flow. To do this, drill several small holes in the bottom of each interior door for free circulation of air masses. Openings can be closed with a metal mesh for better sound insulation.
• We do an extraction. In the kitchen, toilet and bathroom, you need to break through the ceiling and roof. It is necessary to insert air ducts into the prepared holes, i.e. segments of a plastic or sandwich pipe with insulation in the attic area, and with umbrellas installed to protect against precipitation.
• Fasten the air ducts to the wall with clamps, and seal the gaps with mounting foam.