Installation of exhaust ventilation

If you notice that the windows in the house have become very foggy, dark spots of mold appear in the corners, and the air is musty and "heavy", so it is necessary to immediately install the exhaust ventilation system. In this article we will consider what is threatening poor ventilation at home and how to install a forced-type ventilation system with your own hands.

Why ventilation?

Ventilation of premises is necessary not only so that the occupants of the house can feel comfortable breathing fresh air, however this is a very important factor. If the "exhausted" air has nowhere to go, a person is doomed to feel a constant malaise, drowsiness and can even acquire chronic diseases of the respiratory system. In particular, young children, whose lungs are still undeveloped, are at risk.

But, as we said, troubles do not end there. In the process of life and everyday life, moisture constantly evaporates in the house - from cooking, drying things, showering, through leaves of plants, etc. In a sealed space with "standing" air, the vapor settles on the walls, the ceiling, and furniture, greatly reducing the time of their operation. Due to insufficient or absent ventilation, the walls under the wallpaper or plaster are damped, mold and fungus appear. As a result, not only the lining, but also the supporting structures are destroyed. A house made of concrete or brick without ventilation will stand just a little longer than a wooden one, but the result will be one. And that such an insignificant thing as the evaporation of water does not cause the destruction of housing, you should take care of the installation of supply and exhaust ventilation in advance.

Types of ventilation

There are several types of ventilation systems according to the principle of operation. Before deciding on the installation of one of them, you need to familiarize yourself with all the pros and cons and also the specifics of the installation.

Types of ventilation systems used in private houses and apartments:

1. Natural - air movement occurs due to pressure drops. Such a system can be seen in any apartment of a multi-storey building - ventilation holes in the kitchen and in the bathroom "suck in" the exhaust air with evaporation and are led out through a special pipe.
   
2. Forced ventilation - air movement occurs due to the operation of exhaust fans, which take it out through ventilation ducts from the house.
3. Supply and exhaust - through some ventilation ducts with the help of fans exhaust air is expelled, while other channels "pumped" fresh air from the street into the rooms. This type of system is the most effective and popular for private homes, however the most expensive.
   

The choice of the ventilation system depends primarily on the materials from which the house is built, its squares, and the degree of air purity from the outside( pumping dirty gassed air into the premises is hardly a good idea).If you live in a house made of wood, expanded clay or brick in the country outside the city, where the air is clean and harmless, you can make natural ventilation. In all other cases, the latter two types are preferable. The financial factor is also one of the dominant, but to save on the arrangement of exhaust ventilation at home should be very carefully, so that later not to spend an even larger amount for major repairs.

Exhaust ventilation

In this article we will look at the exhaust and mixed ventilation systems, because they are more efficient than the natural one, and are more suitable for private houses. Ventilation forced type is absolutely necessary in the houses of reinforced concrete, expanded polystyrene concrete, and modern SIP panels( houses built by Canadian technology).The latter need good ventilation most of all, since the specificity of the installation of the panels determines the complete tightness of the internal space( joints without seams and gaps).

Calculation of ventilation

There are certain sanitary standards that dictate the use of any ventilation system. According to them, ventilation works normally if the exhaust air in the room is completely replaced fresh twice an hour or more. Proceeding from this, it is first necessary to calculate the exhaust ventilation, and only then to purchase equipment and make the drawings.

First you need to determine the frequency of air exchange. This parameter indicates how many times in 1 hour the air has changed in the room. The multiplicity depends on the quadrature, the functional purpose of the room, as well as the constant number of people in it. For example, for a house with an area of ​​50 m² and a ceiling height of 3 m, the volume will be 150 cubic meters, and with a double air exchange, the ventilation capacity should be 300 cubic meters per hour. The multiplicity depends on the number of people, which is detailed in the relevant SNiP.For an ordinary house, where a family of 3-4 people live, two-time air exchange will be more than enough, but for an office with the same squared and 30 air exchange workers it is required many times more.

To determine the required capacity of the ventilation system, two calculations should be made: by number of people and by multiplicity.

By the number of people in the room: L = N * L norms( L is the required ventilation capacity, measured in cubic meters per hour, N is the number of people in the room, L is the rate of air consumption by one person).

Here it should be clarified that the norms of air consumption by man have long been calculated, but, nevertheless, are approximate. So, in a state of rest( sleep, rest) a person spends 20 cubic meters of air per hour, while working( working at a computer, with paper, etc.) - 40 cubic meters, and at physical loads - 60 cubic meters per hour.

By multiplicity: L = n * S * H ​​(L is the required ventilation capacity, n is the air exchange rate according to SNiP( 1 for a residential house, 2.5 for a small office), S is the area of ​​a room or the total area of ​​all rooms;H - height from floor to ceiling

When you find both results, choose a higher value - this will be the required capacity of the ventilation system. Based on this indicator, you can already select the appropriate fan( several fans), but remember that the resistanceair network can provokeThis can be avoided if we find the dependency of the system's performance on the pressure on the parameters of the purchased equipment specified in the technical documentation

Principle of operation of the

Let's consider in more detail how the intake and exhaust ventilation system works, in order to understand how it can be constructed with its ownhands and save money at work. The principle of operation is quite simple: two types of airway pipes have been carried out throughout the house: one draws the exhaust air outward, the other sucksie inside the premises fresh air from outside through a special convector. In this convector air is cooled( heated) and disinfected.

Disinfection of outdoor air is carried out by an ultraviolet lamp. Also in the convector can be installed an additional filter of foam or santoninovy ​​(as in cars).Entering the room, fresh air creates a pressure that forces the exhaust air with vapors to exit through special air ducts.

There is also such a thing as heat recovery. But first a little background. When they invented intake and exhaust ventilation, and everyone began to install it in their homes, with the arrival of the first winter, a problem arose unexpectedly: the system pumped cold frosty air inside and "drove out" all the heat outside. Naturally, heating and electricity expenses increased at times, and this situation required an urgent solution. It was the emergence of a recuperation system that allowed the use of heated air from the room to heat fresh air from the street.

Sounds a little confusing and difficult, but in fact the recuperator is a special box, in which several radiators, filters and tapes are installed. It is installed on the "exit" of the exhaust air, as a result of which the heat is reused and allows cutting the heating costs by 50%.In summer the recuperator is closed to make the house cool. The cost of the purchased recuperator is rather low, but if desired, you can do it yourself( more on this later).

Kinds of Motivation

Another important point to be aware of in order to build good ventilation is the types of motivation for air masses. Simply speaking, thanks to what the air starts to move to the exhaust pipes.

There are two types of motivation:

1. Natural - ventilation works due to the pressure difference in the house and on the street. The best solution is to supply the supply air duct from the north side, because it is, as a rule, the most windy one. To increase airflow, you can also use a deflector, which will increase the rate by 2-3 times. Air discharge is best arranged at the farthest end of the house, from where fresh air will flow and spread to all other rooms. A significant disadvantage of this system is that cold air from the street does not warm up, and it is required to install an additional recuperator.
2. Mechanical - the principle of operation is almost the same as with the natural motivation, except that at the inlet of the air ducts there is a cooler or fan. Its task - to forcefully take fresh air and let it into the premises. At the same time, the flow rate increases, which allows to install inside the air duct an ultraviolet disinfection lamp and a recuperator with filters. The speed of exhaust air is also increasing, so it completely changes several times more often than with a natural impulse.

Ventilation by own hands

It is possible to install the supply and exhaust ventilation without professional skills. The main thing is to be able to handle the tool and correctly calculate the capacity of the equipment. Depending on the calculations, the diameter of the air pipes and the performance of the fans should be chosen.

After all calculations, it is necessary to draw a scheme of exhaust ventilation - an air intake( or several) with a cooler is located on the north side of the house, and from the central channel there are bends to all rooms. This channel can be equipped with recuperator and filtration system. Filters should be mounted behind the fans. The outlet of the duct that supplies fresh air from outside should be placed closer to the floor, and the intake - at the ceiling( warm air always tends upwards).

Ventilation installation

When the calculations and scheme are finished and the equipment is purchased, you can proceed with the installation of exhaust ventilation.

Procedure:

1. In the outer wall of the house make an inlet and an outlet for air ducts.
2. Prepare nipples for mounting wall grilles. Pipes should be equipped with non-return valves to prevent small litter, moisture and insects from entering the duct.
3. Install the nozzles in the holes in the wall.
4. Secure the air handling unit to the selected location.
5. Install the ventilation ducts for air intake and supply and connect them to the gasket with metal clips. Air ducts can be used in different ways: flexible aluminum or plastic pipes, ducts with square or rectangular cross-section.
6. Make wiring around the rooms of supply and intake channels, screwing them to walls or ceiling. If necessary, use connectors, tees, etc. It is most convenient to hold channels behind a false ceiling.
7. Install the ventilation grilles in the walls or ceiling, placing the exhaust and supply grilles in different corners of the room.

Recuperator

The installation of exhaust ventilation can save even more if you make a recuperator with your own hands. This is a very useful detail of forced ventilation, so it is better to immediately consider the need for its installation. Its effectiveness and financial benefits depend on the total amount for the annual maintenance of the system, the prices of energy carriers and the approximate operating times of the system.

The most common type of recuperators is plate-type. It can be made from square plates of thick foil, aluminum or copper sheets, thin steel corrugated sheet, textolite or vapor permeable membrane.

The thermal conductivity of the material from which the plates are made has no effect on the heat exchange processes in the recuperator. The number of plates is determined by the number of cassettes to be collected - one is enough for 4 m².To increase the efficiency of the sheet device, you will need 2 times more for the same cassette sizes. It is also possible to make one large cassette, but since it is difficult to remove condensate from it and it requires a lot of free space, this method is almost not used.

Also for work you need a corner for fixing racks and flanges. To re-laminate the plates, use a pro-polished strip or a technical plug.

To make the recuperator body, you will need:

• sheet metal or plywood;
• MDF board 2 cm thick;
• mineral wool, foam rubber or other filtering material( minvata is cheaper than all);
• silicone sealant;
• bar to make the frame;
• hardware.

Procedure:

1. Gently cut the sheet material for the plates into squares with a side of 30 cm. To make them as even as possible and equal, it is better to fold several sheets into a pile and cut them with a power tool. For one cassette you need 70 pieces.
2. On the opposite sides of the squares, glue the silt or the slats or plugs, after cutting them into pieces of 30 cm. Leave the last square uncleaned. If you use a steel thin corrugated sheet, gaskets will not be needed.
3. After the glue dries, glue squares into the cassette, spreading glue on the gaskets. Apply the sheets, unfolding each subsequent one by 90 °.
4. Last glue the plate without laths. Thus, you will get a cassette with multidirectional channels.
   
5. Fill the gaps with sealant.
6. Make flange mounts on the sides of the cassette. Take into account that it should stand on one of the corners of the square as stably and vertically as possible to make an ideal diamond.
7. Condensate will drain into the lower part of the cassette, so there it is necessary to make a drainage hole with a drain pipe.
8. If you want to make more than one cassette in a box, then they must be of identical dimensions, and their corners must fit snugly together without cracks.
9. Insert the cassette into the basket, the length and height of the inner walls of which correspond to the diagonal of the cassette squares, the thickness of the box should be equal to the thickness of the cassette. If there are several, increase the dimensions of the case accordingly.
10. In the walls of the box opposite the points on the cassette, where the fasteners for the flange connections are made, make holes.
11. Install the recuperator in the corner guides, securing them to the walls of the box. Thus, you can remove the cassette for cleaning and repair.

It is recommended to install elementary removable cassette filters to clean air coming from the street. For this it is necessary to attach a layer of mineral wool 3-4 cm thick to the inner surface of the box wall. Also for forced ventilation it is better to install coolers with adjustable speed of rotation.

As you can see, it's not so difficult to make an exhaust ventilation with your own hands if you understand the theory and buy all the necessary materials. At the same time, you can save a significant amount on the installation and will know exactly how the system works in your home, so you can repair and clean it completely independently.