Exhaust ventilation by one's own hands

Contents

Device and principle of operation

It is not so difficult to do exhaust ventilation by own hands if you know the principles of its operation and use suitable materials. Homemade ventilation systems are relevant for small apartments and private houses. Even if special double-glazed windows with supply valves are installed on the windows, this is not enough - it is necessary to ensure not only the flow of fresh air, but also the removal of waste vapors outside. If, on the contrary, only an outlet is made for the exhaust air, then where do fresh ones come from? Thus, it becomes clear that full ventilation is only possible in combination with the supply and exhaust ports.

The principle of the supply and exhaust ventilation is as follows:

1. Fresh air from the street penetrates into the house through the supply valve. This can be done both naturally and compulsorily. In the first case, air enters the supply pipe due to the difference in temperatures outside and inside the house, and also because of gusts of wind. This is not the most reliable way, because it does not allow you to control the volume of clean air masses. To make this possible, organize a forced system, working at the expense of special fans. They suck air from the street and push it into the room in the required volume.
2. When entering the inlet, fresh air passes the filtration system, if filters are installed, it heats up if there is heating equipment. Heating takes place in the recuperator, the benefits of installing which we will talk about later.
3. Then the cleaned and heated stream goes through the duct and enters the room.
4. At the same time, the exhaust air is heated and, according to the laws of physics, rises up to the exhaust port. A natural or mechanical( forced) operating principle can also be used here. In the latter case, the air is sucked by the fan, passes through the air duct and is pushed out.
   

Arrangement of forced supply and exhaust ventilation can "fly in a lot of money, but a one-time investment will pay off fairly quickly, and then save on electricity and heating. The advantages of using such systems can also be attributed convenience of operation, absolute safety and efficiency. When the air circulates continuously in the house, the residents get sick much less often and generally feel more cheerful, the service life of the walls and ceilings becomes longer, the laundry dries out faster, and so on. Thus, by establishing ventilation, you contribute to your own health and the longevity of your housing.

The degree of complexity of the ventilation system depends directly on the volume of the room, which needs to be ventilated. In the case of a private house, this is the total volume( not to be confused with the area) of all rooms on all floors.

Exhaust ventilation:

1. Supply air valve - equipped with a grill valve, which serves to change the capacity of the element. Through the supply valve clean air gets from the street into the air duct. The part can have primary cleaning filters. It is placed on the side of the house where the strongest wind blows( this is usually the north side).
2. Supply fan - pressure equipment, which creates a vacuum zone in the valve socket, thereby driving air into the air duct.
3. Supply pipe - pipes, through which clean air moves inside the house.
4. A mixer is a chamber that is interfaced with external supply air ducts and ducts, which discharge supply air from the rooms. Channels are installed only in recycling systems, which take air not only from the street, but also from the inside.
5. The recuperator is a special unit in which cold air from the street is heated to a comfortable temperature. The device operates in such a way that the supply air does not mix with the exhaust - they pass through separate channels inside the recuperator, as can be seen in the diagram below. The fresh air is warmed up by the heated exhausted air flowing out. As a result, you save a significant amount of electricity for heating the room.
   
6. The air conditioner is a device that cools the hot supply air in the hot season.
7. The calorifer is a special device for heating the supply air. Allows to unload the main heating system in the winter season. An alternative to a recuperator, but unlike it, the air heater does not take heat from the exhaust air, but consumes electricity to heat cold streams from the street.
8. The collector is a distribution compartment in which the supply air is distributed over ducts that lead to different rooms.
9. Exhaust diffusers are grids built into the ceiling or the top of the walls. They take the exhaust air from the rooms.
10. Exhaust fans - they are integrated in the exhaust ducts to create a vacuum and pressure.
11. Air ducts leading from the diffusers to the recuperator, where heat is collected from the exhaust air and transferred to the cold flow from the street.
12. Central ventilation pipeline - a pipe that is brought to one level with the roof ridge. It passes the waste stream and is discharged outside.

As you have already managed to understand, the installation of such a complex system with the presence of all the nodes requires professional knowledge and skills, so the installation is better entrusted to specialists. With your hands, you can make a simpler exhaust ventilation system, but with a similar operating principle.

Recuperator

Above we have already several times hinted at the advantages of using a recuperator for the arrangement of ventilation in the house. We propose to consider this point in more detail. During the mixing of supply and exhaust ventilation, there are large losses of efficiency. Recuperation allows to increase the efficiency by 10-15% and to expend energy as economically as possible.

The principle of the recuperator is very simple: the exhausted air masses leave the room and enter a special heat exchanger where they give their heat to the fresh air moving along the adjacent duct. The most popular companies offering such energy-saving systems are Daikin and Mitsubishi electric, but the cost of their products will scare any economical master. Therefore, an alternative is brewing by itself - why not make a recuperator with your own hands?

The simplest is a plate structure. With its manufacture can handle even the beginner. This self-made recuperator consists of plates that can be made of thick foil, sheet copper, aluminum, textolite, etc. The device consists of several cassettes, each of which has an equal number of plates. Thus, the number of plates depends on the number of cassettes( about 4 m2 of plates per cassette).If you want to immediately make a recuperator with high efficiency, put a double number of plates in one cassette.

Tools and materials needed for the manufacture of a recuperator for the exhaust ventilation of the house with their own hands:

• steel angles for fixing flanges to racks;
• impregnated with linseed lath for the transfer of plates( can be replaced by a technical plug);
• plywood or sheet steel 3-4 mm thick;
• MDF panel 20 mm;
• mineral wool or foam for filter;
• wooden blocks 30x30;
• hardware;
• silicone-based sealant;
• scissors for metal.

How to make exhaust ventilation with recuperator:

1. Using scissors for metal, cut plates for cassettes in the form of squares 30x30 cm. One cassette includes 70 plates.
2. On the parallel sides of each square on one side, glue impregnated with linseed oil polish. It will provide the necessary ventilation clearance between the elements. The length of the slats should correspond to the length of the edge of the square - 30 cm. Do not paste the last piece. If you chose a corrugated sheet of minimum thickness for the manufacture of plates, you do not need to glue the slats to it - the wavy structure will leave the required clearances.
3. Next, glue together the details with each other in a special way: each subsequent sheet is spread with glue and turn 90 ° relative to the previous one. So you will get an equal number of ventilation gaps on each side and they will not intersect with each other. One will flow cold air, the other - a warm spent.
4. The last plate without the lath will close the cassette.
5. In the intervals fill the silicone sealant.
6. Attach flange mounts to the sides of the resulting cassette.
7. It is very important to install the cassette at an angle( in the form of a diamond) and fix it in this position. During the heat exchange, condensation will appear. Since there is nowhere for him to go, he will settle on the inner walls of the plates and roll down - into the lower corner of the diamond. To give moisture out, it is necessary to make a hole and insert a drainage pipe there. From time to time, check the drainage and remove any liquid that has escaped.
8. If the recuperator consists of two or more cassettes, they should all be the same size and be arranged so that the corners fit as tightly and tightly as possible.
9. When the cassette is ready, insert it into a box, the frame of which is made of wooden beams, and the casing is made of MDF or sheet steel. Cassettes should not dangle inside the box, but sit as tightly as possible, so try to immediately make it of the appropriate size. To the inner wall of the box, attach a layer of filtering material( foam rubber or mineral wool), so that clean air from the street passes through the primary cleaning.
10. In the sides of the box at the points opposite the flange connections on the cassettes, drill the holes.
11. Install the heat recovery unit in the guides from the steel corner, screwing them to the walls. This will at any time remove the cassette for maintenance or repair.

Ventilation installation

Before proceeding with the installation of exhaust ventilation, it is necessary to calculate the required amount of clean air that is needed for all premises in the house. There are certain rates of air exchange for living quarters and they depend on the specifics of the use of a particular room. For example, in the kitchen and in the bathroom, the air exchange should be more intense than in the living room or bedroom, because the humidity and air pollution rate there are higher.

The table below shows the air exchange rate according to the purpose of the room:

In a residential house, each person should have a minimum of 60 cubic meters of fresh air every hour. In the office this parameter is reduced to 20 cubic meters. Air exchange of industrial premises depends on the features of the working process. For example, if an employee simply sits at a computer, he spends less air than someone who works intensively physically. Calculation of air exchange is also in accordance with the area of ​​the room: per 1 m² should account for 3 m³ of fresh air per hour. If you learn the total amount of supply air mass per hour, you can purchase a compressor of the appropriate capacity and performance. Depending on the speed of the air flow induced by the compressor, it is possible to easily calculate the cross section of the duct and the number of ducts for drawing.

The table below shows the air duct cross-section against room air exchange:

Since the calculation of ventilation is quite complicated, many prefer to entrust this work to specialists, and the installation of equipment is done by themselves.

Specificity of the

installation The installation of exhaust ventilation should not cause difficulties if you have correctly calculated and prepared all the necessary components. Each part must be simply attached using brackets or standard hangers, and then assemble the ducts of the desired geometry as a designer. The only difficulty is not in the assembly, but in the creation of the draft ventilation, because at this stage it is necessary to make all calculations.

Sequence of the assembly of the ventilation system:

• supply valve;
• recirculation unit;
• exhaust and supply manifolds;
• recuperator / air heater / air conditioning / filters;
• wiring of exhaust and supply air ducts in the manifold;
• grilles for intake and exhaust diffusers.

Helpful Hint: In some areas it is more convenient to use non-plastic pipes for air ducts, but corrugation, which can be bent at any angle and avoids additional connections. For fixing the pipe, use standard self-tapping screws for gypsum board, screwing them in "butt" after sealing with a sealant.

Remember that the success of the result mostly depends on a well-designed exhaust ventilation scheme. If you are unsure of your abilities or are confused when trying to deal with this yourself, it is better to entrust the design to specialists.