Types of ventilation, its device. Ventilation installation

Each building should be equipped with an efficient ventilation system, because a constant air exchange is also important, like a good heating system or high-quality water. Scientists have long established a link between the development of a number of negative phenomena in homes and improper ventilation. Thus, a good air exchange of rooms is necessary not only to extend the life of the building, but also to maintain our health.

What is the use of ventilation?

The main purpose of ventilation is the organized supply of fresh air into the room and the subsequent replacement (or removal) of polluted air. Air exchange should be carried out with a certain frequency. In buildings with a poor ventilation system, a lot of dust, microscopic chemicals (regular use of household chemicals) accumulates. High humidity promotes the formation of mold, and in the air there is a high concentration of fungal spores.

A person who works or resides in such a building may complain of burning eyes, headaches, concentration problems and fatigue. Increased humidity in buildings and poor ventilation of the premises leads to condensation and the formation of droplets of moisture on the ceilings and walls.

Such conditions become ideal for the development of fungi that adversely affect human health and lead to the gradual destruction of the building. Also listed factors are very often the cause of most respiratory diseases, and for people prone to allergies pose a serious threat to their health.

Classification of ventilation systems

Ventilation systems are classified in four main ways:

1. By the method of creating an air flow for circulation:

• Artificial ventilation;
• With a natural drive.

2. By appointment:

• Exhaust systems;
• Supply.

3. On the service area:

• General exchange systems;
• Local.

4. According to the design:

• Non-channel systems;
• Channel.

The main types of ventilation

There are the following main types of ventilation systems:

1. Natural.
2. Mechanical.
3. Extractor.
4. Supply air.
5. Supply and exhaust.
6. Local.
7. General exchange.

Natural ventilation

As you might guess, such ventilation is created naturally, without the use of ventilation units, but only through natural air exchange, wind currents and the difference in temperature in the street and in the room, as well as due to fluctuations in atmospheric pressure. Such types of ventilation are relatively inexpensive in cost, and most importantly, they are easy to assemble. However, such systems are directly dependent on climatic conditions, so they can not cope with all the problems.

Mechanical

When forced replacement of the exhaust air by a fresh flow is carried out, this is mechanical ventilation. In this case, special equipment is used that allows you to divert and bring the air flow into the room in the required volume, regardless of changing climatic conditions.

In such systems, air, if necessary, undergoes various types of treatment (humidification, dehumidification, cooling, heating, cleaning, and much more), which is practically impossible to organize in natural ventilation systems.

In practice, very often mixed ventilation is used, which simultaneously combines mechanical and natural systems. For each specific case, the most optimal method of ventilation in sanitary and hygienic conditions is chosen, and also that it is technically and economically rational. The mechanical system can be installed both for the entire room (general exchange) and for a specific workplace (local ventilation).

Supply air

By means of supply systems, a clean air flow is supplied to the ventilated rooms, which replaces the contaminated air. If necessary, the fresh air is subjected to special treatment (humidification, heating, cleaning, etc.).

Extraction

This system is designed to remove contaminated air from the room. In most cases, both exhaust and supply ventilation are provided in the premises. It is important that their performance is balanced, taking into account the possibility of flow of air from adjacent rooms or to adjacent rooms.

Also, only a supply or exhaust system can be installed in the premises. In this case, air enters the room from adjacent rooms or outside through special openings, or flows into adjacent rooms, or is removed from this room outside.

Local ventilation

This is a system in which the air flow is directed to a certain place (local supply system), and the polluted air is removed from places of accumulation of harmful emissions - local exhaust (ventilation).

Local supply system

Air showers (concentrated airflow with increased speed) refer to local supply ventilation systems. Their main task is to supply clean air to permanent workplaces, reduce the air temperature in their zone, blow out workers who are exposed to intense heat radiation.

Air curtains (in furnaces, gates, etc.) also belong to local ventilation systems, they change the direction of the air flow or create air barriers. Such a ventilation system, in contrast to the general exchange, requires less expenditure. In the production premises for the allocation of hazards (heat, moisture, gases, etc.), a mixed ventilation scheme is usually used: local (inflow and local suction) - to service workplaces, and general - to eliminate the entire room of harmful air.

Local exhaust system

When harmfulness (dust, gas, smoke) and heat are allocated locally, for example, from a cooker in the kitchen or a machine in production, a local exhaust ventilation system is used. It catches and removes harmful emissions, preventing their subsequent spread throughout the volume of the room.

These systems include local and on-board suction, exhaust hoods and much more. Also, the local exhaust ventilation refers to air curtains - air barriers that do not allow airflow to penetrate from the street into the room or from one room to another.

General ventilation

Such a system is designed for ventilation of a room as a whole or a large part of it. A common exhaust ventilation scheme provides for the removal of air from the entire service room evenly, and a general exchange supply system delivers the airflow and distributes it throughout the room.

A natural or mechanical system: which one to choose?

For a comfortable existence, a person needs not only warmth, but clean, fresh air. And fresh air to man is necessary constantly and in large quantities. Important is also the space velocity of air flow in the room. With a natural system, the speed is much lower than with mechanical ventilation.

But the air exchange, which is achieved by means of a mechanical system, is much higher than with natural ventilation.

In addition, with a mechanical system, the ventilation ducts are smaller in comparison with natural ventilation. This is due to the normalized speed of airflow in ventilation systems. According to SNiP "Heating, ventilation and air conditioning", for a mechanical system, the speed of air movement should be from 3 to 5 m / s, for natural ventilation - 1 m / s. In other words, to allow the same amount of air to flow through the system, natural ventilation will have 3-5 times the dimensions of the channels.

Very often, when building buildings, there is simply no way to miss such large channels. In addition, under the natural system, the length of the air ducts can not be large, since the pressure created by the difference in the air densities is very small. In this regard, for large areas simply can not do without mechanical ventilation.

Ventilation of premises is the main components

The composition of heating, ventilation and air conditioning includes a mass of units that ensure a high-efficiency circulation of air masses in the room. It is important that the ventilation project, as well as the arrangement of the devices, be carried out in accordance with the current norms and rules (TCH, SNIP).

Ventilation systems can be equipped with channels or do not have them - it all depends on the design features of the room.

It is important to remember that ventilation is a serious and significant element, so both the design and the selection of equipment must be approached competently. It is also worth noting that universal and very diverse units are used to organize regulated air exchange. The most accessible and simple are fans - they can be radial, axial and diametric.

In addition, ventilation installations can be installed in the room, which can be installed in special ducts - air ducts, or on the roof of buildings. Also, the installation of ventilation involves the installation of air valves, dampers, distribution elements and grids, which make it possible to make the movement of airflow in the room as efficient as possible.

Basic parameters of ventilation systems

1. Performance. When calculating this parameter, it is necessary to take into account the number of household appliances, the number of people living in the house, and the area of the premises. It is necessary to calculate what time and what volume the ventilation system will need to remove the polluted air and then fill it clean. For cottages the most optimal value of air exchange is considered from 1000 to 2000 m ³ / h. To calculate the area of the room is multiplied by its height and by 2.
2. Noise level. The higher the speed of operation of the ventilation, the higher the noise level , respectively . Do not need to buy too "fast" systems. If the first item is calculated correctly, you will be able not only to save your budget, but also a quiet sleep. In this case, the ventilation installation will be correct. Also, do not buy air ducts with underestimated indicators, as they will be difficult to install correctly, and they will not be able to withstand the loads during operation. For a cottage, the acceptable average air speed is from 13 to 15 m / s.
3. Another important parameter is power. The temperature of the air entering the room is regulated by the heater. According to SNIP "Heating, ventilation and air conditioning", the temperature should not exceed + 16 ° C. Depending on the intended location of the device, the power of the air heater is calculated. It is important that it can work even in sub-zero temperatures during the winter season. Choosing the power, you should focus on the maximum positive and negative temperature. If the outside temperature is minus -10 ° C, the air heater must be at least 26 ° C warm. For example, for office premises can be used up to 50 kW of power, for an apartment is quite enough and 1-5 kW.

House ventilation, scheme and installation - the main stages

Even at the design stage, it is necessary to determine the fixing points of the ventilation equipment, both main and auxiliary. In this case, there are some limitations - it is not recommended to install the equipment over heat sources (stove, fireplace, etc.). It is important that the ventilation project fully meet the requirements that are imposed on the regulatory and technical documentation.

The design of the ventilation system involves the following main steps:

1. Preparation.

• Marking of the places of the proposed installation of ventilation devices is in progress.
• Given the margin (2-3 centimeters) hollow out holes. A reserve is required for a comfortable installation of the system.
• The edges of the holes are brushed.

2. The device of ventilation.

• The front of the fan is installed in the pipeline section.
• Then the structure is placed in the hole.
• The space between the fan and the wall is filled with foam.

3. Electrical installation.

• Fences under the cable are made in the wall.
• In the resulting holes, the cable to the fan is laid.
• The cable is fixed using brackets.

4. Finishing work.

• A protective box is installed on the fan switch.
• All joints of the ventilation system are greased with a sealant.
• Furrows with wiring, as well as places of abutment of the system to the wall are plastered and shpakkuyutsya.

The system is fully ready for launch. This is a simple ventilation, the price of such a system will depend on the cost of the fan.

Conclusion

Heating, ventilation and air-conditioning systems are an integral part of a modern office, home or any other real estate. These systems consist of the most innovative and modern units, designed depending on the design features of the building, allowing to save a lot on heating.

It is important to remember that a properly designed and installed ventilation system is the key to creating an optimal microclimate in the room.