Without food, a person can live for several weeks, without water for several days, without air for a few minutes. We very rarely think about how we breathe air. But our health, quality of rest and working mood depend on air quality.

Table of contents

1. Air characteristic
2. Types of ventilation systems video
3. The choice of ventilation system of a country house video
4. Types and material of ducts
5. Calculation of the ventilation system
6. Installation of a ventilation system

Air characteristic

We all know the feeling of stale air after a long stay in the room. What causes this? In the process of human life, heat is released from his body and household appliances, air humidity changes. For a comfortable stay, this heat must be removed, humidity should be regulated. Also, when breathing, carbon dioxide is released and the level of oxygen in the room decreases. All of these factors lead to air deterioration. To restore its quality parameters, ventilation systems are used. Air quality, both in production and in domestic conditions, is regulated by GOST 12.1.005-88, according to which the normal temperature should be about 23 ° C, relative humidity 60%. These conditions are considered optimal.

Types of ventilation systems

Let's find out what ventilation systems exist.

Natural ventilation is carried out due to the difference in temperature of the room air and the environment. Great influence on natural ventilation is determined by the wind. Such a ventilation system may be organized and not organized.

With an unorganized ventilation system, air seeps into the slots of windows, doors, walls. With the advent of modern building materials and windows with sealed double-glazed windows, the possible air intake has greatly decreased.

An organized system of natural ventilation, in other words aeration of the air. These are specially provided technological holes in the walls of houses or other premises for air intake. To improve the operation of such a system, special exhaust pipes with deflectors are installed. The height of the pipe should be 1.5-2m above the roof ridge in the area of \u200b\u200bactive wind exposure. A big plus of such a ventilation system is that it does not use ducts and fans, it is very easy to operate, does not require maintenance costs. The downside is the poor organization of ventilation in calm weather.

Mechanical ventilation is carried out due to the movement of air under the influence of fans or ejectors. The ventilation system with mechanical induction of air allows you to adjust all the parameters of the inlet air: pollution, temperature, humidity, to supply the house with fully prepared and processed air. Also, with the help of the ventilation system, it is possible to carry out air heating of the house in the winter season and air conditioning in the hot.

The choice of ventilation system of a country house

We single out the main types of action of ventilation systems.

General ventilation provides an influx of fresh purified air into the house and the removal of dirty air from the house from all rooms.

Local ventilation has several point exhaust fans and provides exhaust from specific places, mainly, it is: kitchen, bathroom, bathroom. In this case, the influx of fresh air will pass, in most cases, by aeration. It is very rare to install supply fans with an air purification system.

If your house is under construction, then you should think about the organization of general ventilation. Then you will always be provided with fresh and clean air.

Types and material of ducts

Almost all ventilation system designs use air ducts. A duct is a pipe of a certain section, designed to transport air in the right direction and to the right room or to the street.

To install a general ventilation system for a country house, we need ducts.

Air duct classification:

-shaped: rectangular, round, flexible, semi-flexible, rigid;

-on applied materials: metal (galvanized steel, stainless steel, copper), metal-plastic, non-metal.

-by the method of connection: flange, wafer, welded;

-to a specialized purpose: sound-absorbing, heat-insulated.

- by the constructive method of manufacturing the duct: roller or welded, straight-seam or spiral.

For the installation of industrial ventilation systems use rectangular and circular ducts.

Variation in the shapes and sizes of such a duct allows them to be used in various places. Using the shaped element of the adapters, the cross-sectional area of \u200b\u200bthe duct is regulated. They have a sufficiently high rigidity and do not contribute to the loss of pressure in the system.

Ducts made of stainless and galvanized steel can safely work in aggressive environments.

Flexible air ducts are made up to 400 mm inclusive of aluminum foil, textile, and other materials. Used for small ventilation systems or in the peripheral sections of large systems. Due to their physical properties, air ducts are easy to install. To reduce aerodynamic drag, it is recommended that manufacturers when installing such an air duct stretch it completely, and also prevent sagging of the air duct more than 5 cm per one linear meter of the route.

Calculation of the ventilation system

According to sanitary standards, the air exchange rate for residential premises should be 1-2 times, or 60m3 / hour per person.

We will calculate the ventilation system based on the given parameters and the conditional house.

For example, take a family of four: two adults and two children, live in a small country house: living room 25 m2, bedroom 15 m2, children 20 m2, kitchen 18 m2. The height of the ceilings is 2.6 m.

For three rooms, we take the air exchange ratio as 1, for the kitchen we choose a large ratio, for example 3. For the living room, we need 65m3 / hour, for the bedroom 39m3 / hour, for the children 52m3 / hour, for the kitchen 140m3 / hour. Total 300m3 / hour.

We have a volume of air for ventilation, as a result we can choose the installation. There are many companies in the market of manufacturers of air handling units and fans: DIMMAX, Vents, Salda, soler & palau, Systemair, Dospel and others. Such systems are equipped with filters for air purification, heat recuperators, heating the input stream using a water or electric heating element. The price, depending on the manufacturer, will be 120-300 thousand rubles.

For many owners of suburban homes, the purchase of a supply and exhaust system is an expensive acquisition. Therefore, they are looking for an opportunity to assemble a ventilation system on their own.

The main element of the fan system.

Important! Each manufacturer in the technical specifications of the fan indicates the maximum amount of air m3 / hour at zero pressure.

When calculating the ventilation system, it is necessary to pay attention to the fact that the fan must create pressure in the system to move air. Each element of the system has some resistance:

• 1 mp air duct 1-5Pa;
• turn 45 3-7 Pa;
• turn 90 5-10 Pa:
• input grille 15-20Pa;
• filter 25-75 Pa (depending on the filter cloth and contamination);
• water heating element 20-30Pa;
• silencer 5-10Pa;
• ventilation grilles and diffusers 5-7Pa.

In our conventional ventilation system, the maximum length of the ducts is about 20-25m, the cross-sectional area is 264cm2. This is a rectangular duct 320x100, or round with a diameter of 200mm. The speed of air movement, according to sanitary standards, should not exceed 4.5 m / s, with its increase, noise increases. In our case, 4m / s. The pressure that the fan will create in the system should be 120-150Pa. For these purposes, fans of the well-known Swedish manufacturer Systemair K / KV150M or K / KV160M are suitable, the power consumption of which is 60 watts. These fans can be installed in both supply and exhaust ventilation systems.

With independent design of the ventilation system, the most expensive element will be a heat recuperator. You can not install it, but make the so-called air mixture. For this, an additional air duct is installed between the exhaust duct and the intake. Then part of the air from the exhaust duct is redirected to the supply air to heat the incoming air from the street. The valve or damper in the channel can be adjusted manually by choosing the amount of air to be mixed.

Installation of a ventilation system

Installation of the ventilation system begins with the installation of the system fans. They should be mounted on rubber pads to reduce vibration. Also, so that vibration is not transmitted through the duct system, flexible inserts are attached to the fans on both sides. To reduce noise in ventilation systems, silencers are installed, in which mineral wool is used as fillers.

When installing external grilles on the supply and exhaust channels, the distance between them should be maximum, but not less than 2 meters. It is also not recommended to install the intake grille of the supply duct above the exhaust duct. The size of the air intake must be selected so that the air velocity on the grate is 1.5-2 m / s, at a higher speed the grate will make noise. In order to prevent small birds from entering the ventilation channel, a net with a small eyelid must be installed on the inside.

The fastening of rectangular ducts is carried out using a flange.

Round flexible ducts are connected using self-adhesive aluminum tape. A seal is used to seal the flange joint. The arrangement of supply and exhaust diffusers and gratings should be done in opposite sections of the ceiling or wall.

By installing a ventilation system, you will always have fresh air and a good mood in your house.

Author: Sergey and Svetlana Khuentsov

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